JP6607633B2 - Cultivation method for hybrid rice seeding - Google Patents

Description

  The present invention relates to a new cultivation method that provides efficient harvesting of hybrid (F1) rice seeds. That is, the present invention relates to an efficient cultivation method for hybrid rice seeding (collection of hybrid rice seeds). More specifically, the present invention relates to a cultivation method including mixed planting of hybrid rice having parental lines with different heading seasons.

  Hybrid rice is a rice cultivar group that is cultivated for the purpose of realizing high yield by the hybrid stress phenomenon. In general, self-breeding varieties obtain seeds by pollinating their own pistil with their own pistil, but hybrid rice is a line that has been cultivated so that it cannot form pollen with its own fertilizing ability (seed parent line). The seeds are obtained by artificially applying the pollen of a line (pollen parent line) having a factor that brings about recovery of fertility in a hybrid progeny with a sterile line.

  When this is done in the field, the parent lines are cultivated simultaneously in one paddy field.

  However, since only the seeds obtained from the seed parent line become hybrid rice seeds, in order to maintain high seed purity, measures must be taken so that the seeds of pollen parent lines growing in the same paddy field are not mixed as much as possible. It is necessary to take these separately.

  For this reason, in the field seeding of the conventional hybrid rice, the following additional work was needed compared with the seeding of the self-breeding variety.

  (1) At the sowing / nurturing stage, it is necessary to handle two types of parent lines separately. For this reason, it is necessary to take preventive measures such as using seedling boxes of different colors or raising seedlings by separating seedling spaces in order to prevent mistakes.

  (2) At the transplantation / cultivation stage, it is necessary to clearly distinguish the place where the parental line is transplanted. On the other hand, in order to facilitate the exchange of pollen, it is necessary to lay out in the field in such a manner that they are adjacent to each other. For this reason, in consideration of the convenience of the specifications of the rice transplanter and the combine, the cultivation area is often arranged in blocks like the pollen parent line 4 -the seed parent line 8.

  (3) With regard to paddy field management, it is necessary to eliminate different strains multiple times during the cultivation period so that the seedling parent line does not mix the pollen parent line with the flow seedlings.

  (4) In the harvesting / adjustment stage, harvesting work must be carried out separately so that the seeds of the parent parent line are not mixed with the seeds of the parent pollen line. In addition, for the equipment used, thorough cleaning work is necessary to avoid contamination with pollen parent line seeds.

  Thus, in conventional field rice seedling of hybrid rice, a complicated additional work is required as compared with seeding of self-breeding varieties.

  Such a conventional series of hybrid rice seeding systems not only makes it difficult to secure workers in Japan's rice field, which is less time consuming and time consuming, but also yields compared to self-breeding varieties. As a result, it led to lowering. These were also a major cause of soaring seed prices for hybrid rice.

  For this reason, a new method to realize hybrid rice seeding with high purity has been developed so far by cultivating in a mixed manner in paddy fields without distinguishing parental lines and sandwiching the process of selecting each seed after harvesting. Has been studied. If such a method can be realized, the pollen released from the pollen parent line can be removed from the parent seed line by reducing the physical distance between the parent line individuals due to mixed planting in addition to being freed from the complicated workability described above. It is easy to reach the pistil, and it can be expected to improve the fruiting rate.

  Such seeding method is called “mixed planting method”. Such mixed planting methods are also being studied for the seeding of F1 varieties of other crops, and there is a demand for practical application in rice.

  For example, according to the report of Maruyama, as a test example, by carrying out mixed planting of two seed parent lines and one pollen parent line, the seeding yield becomes 121 kg / 10a, and the seed parent line 2: pollen Results have been reported that the seed yield (73 kg / 10a) of the normal seeding conducted in the parent line 1 was greatly exceeded (Kiyoaki Maruyama, “Breeding Study of Primary Hybrid Rice Cultivars” (1993), non-patent literature 1).

  However, when the mixed planting method is applied to rice, there are still many issues to be solved regarding the development of seed pods and seedlings in the field.

  In particular, since the seeding of hybrid rice needs to disperse the pollen of the pollen parent line during the flowering period of the seed parent line, the parent line must be headed simultaneously, that is, the heading period must be synchronized.

  However, in the case of hybrid rice that is generally grown in a combination of distantly related lines, the maturity period between the parent lines is often different. It was difficult to synchronize.

  The above-mentioned report by Maruyama was conducted on a trial basis using selectively the parental lines of the same mature period. However, in reality, there were more cases where the maturity between the parental lines differed, and this method could not be adopted as it was at the seeding site of hybrid rice.

  For this reason, the concrete cultivation method which satisfy | fills these requirements required in the seed | planting field of a hybrid rice is not known so far.

  As a general rice cultivation method, for example, JP-A-6-78638 (“rice cultivation method”, patent document 1), JP2010-4835 (“paddy rice cultivation method”), Patent Document 2) and JP 2010-142126 A (“paddy rice cultivation method”, Patent Document 3) have been reported. However, all of these are intended to increase the yield in cultivation of self-breeding varieties, and are not related to the above-described problems and solutions for hybrid rice cultivation.

JP-A-6-78638 JP 2010-4835 A JP 2010-142126 A

Maruyama Kiyoaki, “Breeding Studies on Primary Hybrid Rice Cultivars”, published 14 February 1993, PhD thesis (Agriculture), University of Tokyo Akira Yoshimura, “Business Development of Hybrid Rice“ Mitsuhikari ””, Techno Innovation, Vol. 20, No. 20 (Vol. No. 76) (2010), pp. 20-29

  Since the heading time of rice can be controlled mainly by changing the sowing date and transplanting date, transplanting work should be performed multiple times at each line or desired heading time at the seeding site of hybrid rice. Was done. However, the conventional seeding method is not mixed planting, but the transplanting is done by dividing the cultivation area of the parental line into individual blocks, like pollen parent line: seed parent line = 4: 8. The practice was similar to traditional rice farming. For example, seed harvesting of a variety “Mitsuhikari” that has been put to practical use as hybrid rice shows that cultivation is carried out by dividing the cultivation area of the parent line in this way (Akira Yoshimura, “Hybrid Rice” “Mitsuhikari Business Development”, Techno Innovation, Vol. 20, No. 20 (Vol. 76, No. 76) (2010) Photo 3, Non-Patent Document 2)

  However, if the same thing is done by the mixed planting seeding method, the cultivation area is not divided for each line, so that inconvenience occurs in multiple transplants and sowings.

  That is, when a rice planting machine is run in the same direction in the same paddy field a plurality of times, there is a concern that a plant planted up to the previous time may be stepped on by a wheel or an attached float part at the time of the second and subsequent transplanting operations. If the plant body is partially damaged by trampling, the delay in growth will cause a delay in heading, and as a result, the heading time that was initially planned cannot be realized. In addition, if the strain is damaged by being trampled, such as being completely buried in the soil, the number of individuals deployed on the field will be greatly reduced.

  Thus, conventionally, from the viewpoint of efficiently pollinating between the pollen parent line and the seed parent line when hybrid rice is seeded, hybrid planting is desirable, while hybrid rice grown in a combination of distantly related lines is desirable. In many cases, the maturity of the parent lines is different, and this also means that the time of seedling transplantation is different. For this reason, as described above, due to the difficulty of transplanting seedlings at different times so as to be mixed planting, conventionally, the parent lines had to be cultivated by arranging them in blocks.

  For this reason, it can be said that the method which can implement | achieve the efficient seeding of the hybrid rice seed by mixed planting, controlling the seed | inoculation time of the seed to the paddy field of a pollen parent line and a seed parent line, or the transplanting of a seedling is still desired.

In such a situation, the present inventors have now conducted seeding of seeds of each parent line or transplanting of seedlings (development to a field) in paddy fields when hybrid rice having different parental lines is mixed. By adjusting the interval, we succeeded in controlling the heading time of the parent lines at the same time. This enabled efficient pollination between parental lines. Here, when performing the development of the parental line to the field, the first transplantation uses the late seedling of the parental line, and the second transplantation uses the early growing seedling of the parental line, In addition, by performing the second transplantation in a substantially orthogonal direction with respect to the seedling planting row by the first transplantation, the stepping of the seedling at the time of the second transplantation, which has been a problem in the past, has been a problem. And succeeded in greatly reducing damage caused by burial of stocks. Furthermore, even if the first or second transplantation is changed to direct sowing by the row seeding or spot sowing method, or by changing to direct sowing of the seeding method, the transplanted seedlings or strains that have been problematic can be damaged. I found that it can be greatly reduced. By combining these, the present inventors actually succeeded in significantly improving the seed yield of hybrid rice seeds compared to the conventional seeding method.
The present invention is based on these findings.

  Since early growth lines have a shorter period from seeding or seedling transplanting to heading time compared to late growth lines, this difference can be used to transplant or sow late growth lines in the field earlier than early growth lines. The inventors thought that the heading time of the line could be synchronized. However, depending on the varieties and conditions to be used, there may be a case where the fast-growing line may be developed in the field earlier than the late-growing line. On the other hand, when the seedlings are deployed in the field, the heading period is usually earlier than when seeds are directly sown. Depending on which of the early-stage and late-stage lines is used as the development method to the field, it may affect the heading time of both lines. Furthermore, whether either the pollen parent line or the seed parent line is an early-growth line or a late-grow line can affect the synchronization of heading time of both lines. Although these combinations are enormous in theory, in practice, only some combinations can synchronize the heading periods of both lines.

  The present inventors synchronize the heading time of both lines, the development order of the early and late lines, the development method to the field for each, either the pollen parent line and the seed parent line, Based on the results of actual cultivation of the above, it is possible to examine what combinations are effective for the late-generation line, etc., and to find effective and specific combinations for field development. did it.

  Therefore, an object of the present invention is to provide a method for controlling the seed sowing or transplanting time of seedlings in the paddy field of the pollen parent line and the seed parent line, and realizing efficient seeding of hybrid rice seeds by mixed planting. To do.

  That is, according to the present invention, the following inventions are provided.

<1> Seeding time of seeds of seeds obtained from seeding seeds of late-flowering rice varieties or seeds and seedlings obtained from seeds and seedlings obtained from seeding or seeding seeds of early-growing rice varieties Or it is a cultivation method for hybrid (F1) rice seeding which shifts seedling transplanting time and cultivates mixed planting,
The period between when seeds of late rice cultivars are directly sown in paddy fields or when the seedlings are transplanted to paddy fields, and when seeds of early rice cultivars are sown directly on paddy fields or when the seedlings are transplanted into paddy fields The cultivation method characterized by controlling by adjusting so that the heading time of the late-flowering rice varieties and the heading time of the early-growing rice varieties may become simultaneous.

<2> In the cultivation method according to <1>, among the above-described cultivars of both lines, a seed row or a directly sown seed row of one of the cultivars previously seeded with seeds or transplanted with seedlings. Alternatively, the seedlings of the other cultivar may be transplanted or directly sown in a direction that is not parallel to the state or not overlapping.

<3> In the cultivation method according to <1> or <2>, the period between the seeding or transplanting time of the late rice cultivar and the seeding or transplanting time of the early rice cultivar is determined for the parental line. It is good to determine by regression analysis of the cultivation data for the past several years in the same area as the area to perform.

<4> In the cultivation method according to any one of <1> to <3> above, seeds of late-grown rice varieties are directly sown in paddy fields, or seedlings thereof are transplanted into paddy fields, and then seeds of early-grown rice varieties are transplanted into paddy fields. By adjusting the period between direct sowing or transplanting the seedlings to paddy fields, the heading time of late rice varieties and the heading time of early rice varieties are controlled to be the same time. Is good.

<5> In the cultivation method according to any one of <1> to <3>, a period from directly seeding seeds of an early rice cultivar to a paddy field until transplanting seedlings of a late rice cultivar to the paddy field By adjusting, it is preferable to control so that the heading time of late-growing rice varieties and the heading time of early-growing rice varieties are coincident.
<6> In the cultivation method according to any one of <1> to <3>,
(A) After seedlings of late-grown rice varieties were planted in rice fields and transplanted in a straight line,
(1) From there, transplant the seedlings of early-growing rice varieties in a straight line in a direction that is not parallel to the row of seedlings of late-growing rice varieties,
(2) From there, directly seed the seeds of early-growing rice varieties in a direction not parallel to the row of seedlings of late-growing rice varieties, either by row seeding or spot seeding, or
(3) From that, seeds of early rice varieties can be directly sown in paddy fields by the sowing method,
(B) After seeding seeds of late-grown rice varieties directly on the paddy field by row seeding or spot seeding,
(i) From there, transplant the seedlings of the early rice cultivar linearly in a direction that is not parallel to the row of seeds sown directly of the late rice cultivar,
(ii) From there, seed the seeds of early-growing rice varieties directly by sowing or spotting in a direction not parallel to the row of seeds directly sown by late-growing rice varieties, or
(iii) From that, seeds of early rice cultivars are sown directly in paddy fields by the sowing method,
(C) After seeding the rice varieties of late-stage rice varieties directly in the paddy field,
(I) From that, transplant the seedlings of early rice cultivars in a straight line,
(II) From that, seeds of early rice cultivars are directly sown by row seeding or spot seeding, or
(III) From that, seeds of early-growing rice varieties are directly sown in paddy fields by the sowing method.
(D) After seeding seeds of the early-growing rice cultivar directly on the paddy field by seeding or spotting, the late-growing rice cultivar is oriented in a direction not parallel to the row of seeds directly seeded of the early-growing rice cultivar. Or (E) either directly seeding rice seeds of early rice cultivars in paddy fields in a seeding method and then transplanting seedlings of late-growing rice varieties from there It is preferable to include a process.

<7> In the cultivation method according to any one of <1> to <6>, among the above-described cultivars of both lines, a seeding line of seedlings of one of the cultivars in which seeds are first sown or seedlings are transplanted or It is preferable to transplant the seedlings of the other cultivar at an angle of 45 ° to 90 ° with respect to the directly sown row of seeds, or to directly sown the seeds by the sown or spot sowing method.

<8> In the cultivation method according to any one of <1> to <6>, among the above-described cultivars of both lines, a seeding line of seedlings of one of the cultivars in which seeds are first sown or seedlings are transplanted or The seedlings of the other cultivar are transplanted in the orthogonal direction or almost orthogonal direction (direction of 85 to 90 degrees) with respect to the row of seeds that have been directly sown, or the seeds are directly sown by the sowing or spotting method. It is good.

<9> In the cultivation method according to any one of <1> to <8>,
It is recommended to use the pollen parent line as the late-growing line and the seed parent line as the early-growing line.

<10> In the cultivation method according to any one of <1> to <8>,
It is recommended to use the seed parent line as the late-growing line and the pollen parent line as the early-growing line.

<11> From the seeds obtained by cultivating and harvesting by any one of the methods <1> to <10> above, by separating the seeds of the seed parent line, and selecting and obtaining hybrid rice, Hybrid (F1) rice seeding method.

<12> In the method of <11>, separating seeds of seed parent lines from seeds obtained by harvesting is performed based on a difference in reactivity of coloring reaction by phenols between the parent lines. Or by seed selection based on the morphological differences of the seeds.

  According to the present invention, even when parental lines having different heading characteristics are used, the heading season can be synchronized with high probability and mixed planting can be performed. At this time, it is possible to prevent the growth of the plant body (seed and seedling) developed at the first time due to trampling or damage of the strain at the time of development such as transplanting of seedling or seed sowing at the second time. Therefore, stable seeding yield and significant yield improvement can be expected compared to conventional methods. Furthermore, according to the present invention, the seeding cost of the hybrid rice can be reduced, and the working efficiency in seeding can be greatly increased.

It is a conceptual diagram of the expansion method (transplantation-transplantation method) to the field performed in Example 1. FIG. It is a conceptual diagram of the expansion method (direct seeding-transplantation method) to the field performed in Example 2. FIG. It is a conceptual diagram of the expansion method (conventional type block division transplanting method) performed in Comparative Example 1. It is a conceptual diagram of the transplant-direct seeding (spot seeding) method among the expansion | deployment methods to a farm field (Example 3 (reference example)). It is a conceptual diagram of direct seeding (spot seeding) -transplantation method among the development methods to a farm field (Example 4 (reference example)). It is a conceptual diagram of the direct sowing (sowing) -direct sowing (sowing) method among the expansion methods to a farm field (Example 5 (reference example)).

  Hereinafter, embodiments of the present invention will be described.

As described above, the cultivation method for hybrid rice seeding is as follows.
Seed seeding time or seedling transplantation of seeds obtained by sowing and seeding seeds of late-grown rice varieties or seeds and seedlings obtained by sowing and seeding seeds of early-grown rice varieties or seeds It is a cultivation method for hybrid (F1) rice seeding, which is mixed planting at different times,
The period between when seeds of late rice cultivars are directly sown in paddy fields or when the seedlings are transplanted to paddy fields, and when seeds of early rice cultivars are sown directly on paddy fields or when the seedlings are transplanted into paddy fields It is related with the cultivation method characterized by controlling so that the heading time of a late-flowering rice varieties and the heading time of an early-growing rice varieties may become simultaneous by adjusting.

  That is, the present invention relates to a cultivation method for collecting (seeding) hybrid rice seeds having parental lines with different maturity.

  As described above, in the present invention, for efficient collection (seeding) of hybrid rice seeds, among the parent lines of hybrid rice, the pollen parent line and seed parent line varieties are sown and seedling transplanted. At the same time, mixed planting cultivation is performed at different times. This is to synchronize the heading time so that pollination between two lines with different maturity is possible, so that seeding (seeds) is seeded for each parent line so that the heading time is the same. Adjust the timing for transplanting seedlings, shift them to each other, and plant them together.

  In the present invention, varieties with different ripening periods are used as the parent lines, so the early and late life in the present invention can be said to be relative.

  That is, in the present invention, the late rice cultivar is not particularly limited as long as it is a rice cultivar having a late vegetative tendency from the viewpoint of lateness relative to the other parent rice cultivar used in the present invention. However, normally, rice varieties that correspond to late life when classified into early growth (seize), middle life (Nakate), late life (delay) in the early and late nature of the cultivation period until the harvest season. Say.

  Further, in the present invention, the early-growing rice cultivar is not particularly limited as long as it is a rice cultivar showing a relatively early tendency in terms of early / late nature relative to the other parent rice cultivar used in the present invention. Usually, rice varieties corresponding to early growth when classified into early growth, middle growth, and late growth in the early and late characteristics of the cultivation period until the harvest season.

Therefore, in the present invention, one of the late-growing rice varieties and the early-growing rice cultivar is the pollen parent line, and the other is the seed parent line.
Therefore, according to one preferable aspect of the present invention, a pollen parent line is used as a late-flowering line, and a seed parent line is used as an early-growing line.
Alternatively, according to another preferred embodiment of the present invention, a seed parent line is used as the late-flowering line, and a pollen parent line is used as the early-growing line.

  In addition, mixed planting here is not mixed planting of parental lines, but planting and cultivating parental lines mixed in a paddy field without distinguishing the parental lines by dividing them into blocks. Say.

  In the present invention, the seed parent line is a line (male sterile line) grown so that pollen capable of fertilizing itself cannot be formed. Specifically, for example, backcrossing is performed with a parent strain having a male sterile cytoplasm as a parent, a parent once, and a target strain that has been confirmed to have no fertility recovery factor as a recurrent parent. By replacing the cytoplasm of the target line with a male sterile cytoplasm, male sterility can be imparted, thereby obtaining a seed parent line.

  Further, in the present invention, the pollen parent line is a line having a factor that causes recovery of fertility in a hybrid progeny with a sterile line, for example, a line having a fertility recovery factor such as a long grain type in at least one parent By improving the varieties using, a pollen parent line can be obtained with an establishment of 1/2 or more.

  When performing mixed planting, it is cultivated so that the number of seed parent lines in which the F1 seeds actually stand is relatively larger than the number of pollen parent lines responsible for flying pollen in the field. It is desirable to make it.

In the present invention, “seed obtained by seeding seeds of late-flowering rice varieties or seeds thereof and raising seedlings, and seedlings obtained by seeding seeds of early-growing rice varieties or seeds thereof and raising seedlings, Mixed planting with different sowing time or seedling transplanting time.
That is, in the present invention, the time of sowing is shifted between the time of seeding of the late line rice cultivar and the time of seeding the seed of the early line rice cultivar,
Shift the timing between the time of seeding of the seeds of the late line rice cultivar and the time of transplanting the seedlings obtained by sowing and raising the seeds of the early line rice cultivar,
The timing of seedling transplantation between the time of transplanting seedlings obtained by sowing and raising seeds of late-grown rice cultivars and the time of transplanting seedlings obtained by seeding and raising seeds of early-grown rice varieties Or shift the time between the time of transplanting seedlings obtained by sowing and raising seeds of late-grown rice varieties and the time of sowing seeds of early-grown rice varieties. In this way, mixed planting of both lines (late and early lines) is performed.

  In the present invention, “shifting” the seed sowing time or seedling transplanting time means that the respective times between the two lines do not coincide (not at the same time).

  Here, the seeds of rice varieties mean seeds of the varieties used in the cultivation method of the present invention (preferably seed pods), which are appropriately obtained from the seed maintenance and storage destination, the organization or organization of the cultivation destination, etc. Can do.

  The rice cultivar “seed obtained by sowing seeds and raising seeds” means that seeds are separately sown in nursery areas when transplanted to paddy fields (fields) for mixed planting. It means raising seedlings and getting seedlings.

  In the present invention, the seeds of late-grown rice varieties are directly sown in paddy fields or the seedlings are transplanted to paddy fields, and the seeds of early-grown rice varieties are directly sown in paddy fields or the seedlings are transplanted into paddy fields. By adjusting the period between the seasons, the heading period of the late rice cultivar and the heading period of the early rice cultivar are controlled at the same time.

Here, the timing of direct seeding of late-field rice varieties to paddy fields or transplanting the seedlings to paddy fields and the timing of direct seeding of early-grown rice varieties to paddy fields or transplanting the seedlings to paddy fields The period between
The period between the period of direct sowing of late-type rice varieties seeds in paddy fields and the period of direct seeding of early-grown rice varieties seeds in paddy fields,
Period between the time of direct seeding of seeds of late-grown rice varieties in paddy fields and the time of transplanting seedlings of early-grown rice varieties to paddy fields Timing of transplanting seedlings of late-grown rice varieties to paddy fields and seeds of early-grown rice varieties It means either the period between direct seeding of rice in paddy fields, or the period between transplanting seedlings of late rice varieties to rice fields and transplanting seedlings of early rice varieties to paddy fields.

  In the present invention, seed sowing is performed by direct sowing (direct sowing) when used in a field except for use in raising seedlings.

  Here, “direct sowing” when seeds are directly sown in paddy fields may be either dry paddy direct sowing or flooded direct sowing, but in the present invention, direct sowing is preferred. Here, flooded direct sowing is further divided into three types: row sowing, spot sowing, and sowing. Therefore, direct sowing in the present invention is divided into sowing, row sowing, and spot sowing.

  Here, the sowing refers to sowing seed pods in the form of streaks at regular intervals. In the present invention, the seed is typically sown in a straight stripe shape. In the case of adopting the row sowing method as the direct sowing method, for example, it can be carried out by using a seed sowing machine dedicated to row sowing or an improved machine of a side row fertilizer planting machine. According to the row sowing method, it is easy to keep the seeding depth constant, so that seedling establishment and growth are uniform, and rice that is more resistant to lodging than the sowing method can be grown.

  Here, spot sowing refers to sowing a plurality of seed pods at regular intervals. In the present invention, the places to be seeded together are typically arranged in a straight line. In the case of adopting the spot sowing method as the direct sowing method, for example, it can be performed using a seed sowing machine dedicated to spot sowing. According to the spot sowing method, it is easy to secure the seeding depth, so that the seedling establishment and growth are uniform, and the most resistant to lodging can be cultivated by forming a strain.

  Further, here, sowing refers to a sowing method in which seed pods are dispersed. Generally, sowing has high work efficiency and is suitable for large-compartment fields, and is low in cost. However, there is a tendency for seeds to vary so that they become prone to overgrowth. When adopting a sowing method as the direct sowing method, for example, a power spreader, a radio control helicopter or the like can be used. According to the seeding method, seeding can be performed on the entire surface regardless of the condition of transplantation.

  In the case of direct sowing, seeds (seeds) may be coated in order to stabilize budding and seedling establishment. Examples of the coating include calper coating and iron coating, which can be performed by a conventional method.

  In the present invention, seedling transplantation is preferably performed by normal planting. Normal planting refers to arranging rows of seedlings and planting plants at a constant interval.

  In the case of transplanting seedlings in the present invention, it is desirable to use seedlings as seedlings that have been sown in a seedling box in advance and cultivated in a nursery house for about 20 to 30 days.

  In the present invention, as described above, the period (ie, the interval) between the timing of direct sowing or seedling transplantation of late-growing rice cultivars and the timing of direct sowing or seedling transplanting of early-growing rice cultivars is adjusted. The heading period of the late-growing rice cultivar and the heading period of the early-growing rice cultivar are controlled at the same time.

  Here, “control the heading time of late-growing rice varieties and heading time of early-growing rice varieties at the same time” means that the heading time of both lines is the same time. Since the transfer of pollen from the seed line to the seed parent line can be performed efficiently, the heading time of the parent line is adjusted by adjusting the transplanting time etc. of each line, and the heading date is It means controlling so that it becomes the same time. Therefore, as long as such pollination is possible, the “simultaneous period” may have a time span of several days, but as the time shift increases, the pollination efficiency, that is, the seeding efficiency decreases. It is desirable to be as close as possible.

  Here, the period between the time of direct sowing or seedling transplanting of late-growing rice varieties and the time of direct sowing or seedling transplanting of early-growing rice varieties is for each of the late-growing rice varieties and early-growing rice varieties used It can be determined based on known cultivation data or past cultivation data. Regarding past cultivation data, it is desirable to consider the region, climate, etc. that are actually cultivated.

  Here, “cultivation data” preferably means cultivation day data. The cultivation date data refers to date and number of days such as transplanting date, heading date, harvest date, and their interval (period).

  Furthermore, the cultivation data is obtained by acquiring past cultivation data of the field where the cultivation is actually performed, and the past multiple years (e.g., It is desirable to collect data for 2 to 5 years and perform regression analysis based on these data to improve data leveling and systems. It is desirable to acquire cultivation data in advance for each parental line. From the obtained data, a desired heading date can be set, and an interval between transplant dates and a desired transplant date can be predicted.

  More specifically, in the field where the cultivation is actually carried out, the cultivation data on the transplanting date and heading date for the past several years (for example, the past three years) is collected for the parent line used, and these regression analyzes are performed. From the result, the transplanting date (transplanting interval) of each line is predicted and calculated so that the heading period of the parental line becomes the same period at the desired heading date, so that it can be transplanted on the transplanting day Moreover, the seedlings of each line can be cultivated. In addition, when predicting the transplant date and transplant interval, if necessary, the weather conditions at the time of cultivation data acquisition (may include other conditions such as lack of sunlight and irregular weather), and experience in cultivation of the varieties used For example, additional adjustment may be performed.

  In addition, when seeding instead of seedling transplantation at the time of transplantation, it is desirable that the cultivation data collected in advance is also the data when seeding seed directly into a paddy field. Or in such a case, it can also estimate from the cultivation data in the case of a seedling transplant in consideration of the period which grows from a direct seeding to a seedling in a paddy field.

  Therefore, according to one preferred embodiment of the present invention, the period between the sowing or transplanting time of the late rice cultivar and the sowing or transplanting time of the early rice cultivar is the same as the area where cultivation is performed for the parental line. It is good to determine by regression analysis of cultivation data for the past several years in the region. At this time, it is preferable to determine the period in consideration of the desired heading date in the regression analysis.

  Here, the interval between days for transplantation can vary depending on the varieties of the parental strains used and the combinations thereof, so the specific time is not particularly limited, but is, for example, up to about 28 days, preferably 18 Up to about a day, more preferably 2 to 10 days.

  When acquiring past cultivation data, there is no limitation on the cultivation area and the required number of years, as long as data that can be used as reference for cultivation of the current fiscal year can be obtained, but as a preferable example, the area is about 30a. It is recommended to acquire about 3 years of cultivation data.

  According to a preferred aspect of the present invention, in the cultivation method of the present invention, among the above-mentioned cultivars of both lines, seedlings of one cultivar previously seeded or seeded were transplanted or directly sown. The seedlings of the other variety should be transplanted or seeded directly in a non-parallel or non-overlapping direction with respect to the seed row or state.

That is, among the varieties of both lines described above,
Transplant the seedling of the other variety in a non-parallel direction with respect to the seeding row of the seedling of one of the varieties previously seeded or seeded or transplanted;
Directly sowing (row-seeding or spot-seeding) the seed of the other variety in a non-parallel direction with respect to the seeding row of the seedling of one variety previously seeded or seeded.
Directly sowing seeds of the other cultivar in a non-overlapping state for the seeding row of the seedlings of one cultivar previously sown or transplanted with seedlings,
Transplant seedlings of the other cultivar in a non-parallel direction with respect to the row of seeds directly sown of one cultivar previously seeded with seeds or transplanted seedlings,
Direct seeding (row seeding or spot seeding) of the seeds of the other cultivar in a direction that is not parallel to the row of seeds directly seeded of one cultivar previously seeded with seeds or transplanted seedlings,
Seed seeds of one cultivar previously seeded or transplanted with seedlings, sow seeds of the other cultivar directly, or seed seeds or transplant seedlings in a non-overlapping condition with respect to the row of seeds directly seeded of one cultivar It is preferable that the seeds of the other cultivar are directly sown in a non-overlapping state with respect to the state of the directly sown seed of one cultivar.

  Here, the “non-parallel direction” means that a seedling line (planting line) that has already been planted or a seed line that has been directly sown is transplanted with the other seedling or seeds of the other variety. It means that direct seeding is performed in the direction other than the parallel direction by the used row seeding or spot seeding method. By minimizing the overlap between the row of seedlings already planted, the row of seedlings to be transplanted, and the row of seeds as much as possible, the adverse effects on the previously planted seedlings are reduced. By partially planting new seedlings in the planting part such as transplanted seedlings, it can be expected that the distance between the seedlings of the parental line by mixed planting will be as close as possible.

  Preferably, a seedling of the other cultivar is transplanted or a seed of the other cultivar is transplanted to a row of seedlings of one cultivar previously seeded with seeds or transplanted with seedlings or a row of seeds directly seeded The angle with the direction of direct sowing in the row seeding or spot seeding method is a direction of 45 to 90 degrees, more preferably 60 to 90 degrees, still more preferably 75 to 90 degrees, even more preferably 80 to 90 degrees, Particularly preferred is an orthogonal direction or a substantially orthogonal direction (direction of 85 to 90 degrees), most preferably an orthogonal direction.

  According to another preferred embodiment of the present invention, in the cultivation method of the present invention, seeds of late-grown rice varieties are directly sown in paddy fields, or seedlings thereof are transplanted into paddy fields, and then seeds of early-grown rice varieties are transferred to paddy fields. The period between direct sowing or transplanting of the seedlings into paddy fields is adjusted so that the heading time of the late rice cultivar and the heading time of the early rice cultivar are controlled at the same time. This aspect includes cases (A) to (C) described later.

Here, “From the time when seeds of late-growing rice varieties are directly sown to paddy fields or transplanting the seedlings to paddy fields until the seeds of early-grown rice varieties are directly sown to paddy fields or the seedlings are transplanted to paddy fields. Is the period of
The period between direct seeding of late-grown rice varieties in rice fields and direct seeding of early-grown rice varieties in rice fields,
The period between direct seeding of late-grown rice varieties in rice fields and transplanting seedlings of early-growing rice varieties to paddy fields. It means either the period until direct seeding of rice in paddy fields, or the period from transplanting seedlings of late rice varieties to paddy fields until transplanting seedlings of early rice varieties to paddy fields.

  According to still another preferred embodiment of the present invention, in the cultivation method of the present invention, the period between direct seeding of the early rice cultivar and the seedling of the late rice cultivar is transplanted to the paddy field. By adjusting, the heading period of the late-growing rice cultivar and the heading period of the early-growing rice cultivar are controlled at the same time. This aspect includes the cases (D) and (E) described later.

  As described above, the early line has a shorter period from the sowing or seedling transplanting to the heading time than the late line. It can be said that it is desirable to synchronize the heading time of both lines, but when the heading time of both lines is close, as a field expansion method, the early-growing line is directly seeded and the late-growing line is seedling transplanted Thus, it becomes possible to develop the early-stage line before the late-stage line.

Development Method to Field A method of seed seeding and seedling transplantation to a paddy field (field) in the cultivation method of the present invention (development method), that is, a step of field development will be further described.
Here, the method of deployment to the field can be roughly divided into transplantation for transplanting seedlings and direct sowing for direct seeding. Direct sowing can be further divided into strip sowing, spot sowing, and sowing.

  As described above, in the present invention, when the parent lines having different heading seasons are developed in the field, mixed planting is performed by shifting the timing of developing each of the parent lines.

For this reason, the process of expanding each of the parental lines from the above-described expansion method can be classified as follows.
a) Transplantation-transplantation method b) Deployment method combining transplantation and direct sowing c) Direct sowing-direct sowing method

These are described more specifically as follows.
That is, as described above, the cultivation method of the present invention is
(A) After seedlings of late-grown rice varieties were planted in rice fields and transplanted in a straight line,
(1) From there, transplant the seedlings of early-growing rice varieties in a straight line in a direction that is not parallel to the row of seedlings of late-growing rice varieties,
(2) From there, directly seed the seeds of early-growing rice varieties in a direction not parallel to the row of seedlings of late-growing rice varieties, either by row seeding or spot seeding, or
(3) From that, seeds of early rice varieties can be directly sown in paddy fields by the sowing method,
(B) After seeding seeds of late-grown rice varieties directly on the paddy field by row seeding or spot seeding,
(i) From there, transplant the seedlings of the early rice cultivar linearly in a direction that is not parallel to the row of seeds sown directly of the late rice cultivar,
(ii) From there, seed the seeds of early-growing rice varieties directly by sowing or spotting in a direction not parallel to the row of seeds directly sown by late-growing rice varieties, or
(iii) From that, seeds of early rice varieties can be directly sown in the paddy field by the sowing method,
(C) After seeding the rice varieties of late-stage rice varieties directly in the paddy field,
(I) From that, transplant the seedlings of early rice cultivars in a straight line,
(II) From that, seeds of early rice cultivars are directly sown by row seeding or spot seeding, or
(III) From that, seeds of early-growing rice varieties are directly sown in paddy fields by the sowing method.
(D) After seeding seeds of the early-growing rice cultivar directly on the paddy field by seeding or spotting, the late-growing rice cultivar is oriented in a direction not parallel to the row of seeds directly seeded of the early-growing rice cultivar. Or (E) either directly seeding rice seed varieties of early-stage rice varieties in paddy fields in the paddy field and then transplanting seedlings of late-line rice varieties from there It is preferable to include a process (field development method).

  Hereinafter, these methods will be described in more detail.

a) Transplantation-transplantation This transplantation-transplantation method is a case in which any of the development of parental strains in a field is performed by seedling transplantation.

This corresponds to the expansion method (A) (1) described above.
That is, in one preferred embodiment of the present invention, the cultivation method of the present invention comprises (A) (1) a seedling of a late-grown rice cultivar, planted in a paddy field and transplanted in a straight line, from above, This includes transplanting seedlings of early-growing rice varieties in a straight line in a direction that is not parallel to the seedling row of seedlings of late-growing rice varieties.

  That is, in the first transplantation, the late-lined seedlings of the parental line are used for regular planting in paddy fields, and the seedlings are transplanted in a straight line. Next, in the second transplantation, a seedling of an early growth line among the parent lines is used, and the seedling is planted in a direction that is not parallel to the first line (a direction that is not parallel). Thereby, the possibility of damaging the seedlings transplanted by the first transplantation by stepping on the second transplantation can be reduced as much as possible. From the viewpoint of suppressing the damage of the first seedling as much as possible, it can be said that it is desirable to be as close as possible to the direction orthogonal to the first transplanting line.

  In this transplantation-transplantation method, direct seeding work is not required, so even a producer who does not have advanced direct seeding techniques can perform mixed planting seeding. In order to achieve a high seeding yield, it is usually desirable to increase the number of seed parent lines to which seeds are actually attached as compared to the number of pollen parent lines, but the pollen parent line is developed at the first transplantation. In this case, when the seed parent line is transplanted, the pollen parent line is stepped on at the portion where the stripes intersect, so that the number of father lines can be appropriately reduced.

b) Deployment method combining transplantation and direct sowing (transplantation-direct sowing method or direct sowing-transplantation method)
The development method combining this transplantation and direct sowing is a case where the development of the parental line in the field is performed by direct seeding on one side and by seedling transplantation on the other side. That is, in this expansion method, either transplantation or direct seeding may be performed first.

This corresponds to the expansion methods (A) (2), (A) (3), (B) (i), (C) (I), (D) and (E) described above.
That is, in one preferable embodiment of the present invention, the cultivation method of the present invention comprises:
(A) (2) After planting seedlings of late rice cultivars in rice paddies and transplanting them in a straight line, from there, in a direction not parallel to the row of seedlings of late rice cultivars , Sowing seeds of early rice cultivars directly by sowing or spot sowing,
(A) (3) After seedling seedlings of late-grown rice varieties were planted in a row and transplanted in a straight line, seeds of early-grown rice varieties were directly sown on the entire surface of the paddy field by the sowing method,
(B) (i) After seeding seeds of late-grown rice varieties directly in paddy fields by row seeding or spot-seeding method, early seeding in a direction not parallel to the row of seeds directly seeded by late-line rice varieties Transplant seedlings of line rice varieties in a straight line,
(C) (I) After seeding seeds of late rice varieties directly into paddy fields by seeding method, transplant seedlings of early rice cultivars in a straight line from above.
(D) After seeding seeds of the early-growing rice cultivar directly on the paddy field by seeding or spotting, the late-growing rice cultivar is oriented in a direction not parallel to the row of seeds directly seeded of the early-growing rice cultivar. Transplant the seedlings in a straight line, or
(E) After directly seeding rice seed varieties of early-stage rice varieties in paddy fields in a seeding manner, transplanting seedlings of late-line rice varieties from above.

  Usually, when seeds are directly sown, a longer period is required from field development to heading compared to transplanting seedlings. In this development method that combines transplantation and direct sowing, by combining seedling transplantation and seed direct seeding, it is possible to use the difference in period that occurs between direct seeding and seedling transplanting.

  Moreover, in this unfolding method combining transplantation and direct sowing, it is possible to reduce the amount of work required for field deployment by incorporating direct sowing work.

Moreover, in the development method combining this transplantation and direct sowing, it is also possible to develop the early growth line among the parental lines as the direct sowing method and the late growth line as the transplantation method.
In this case, since the early-growth line can be deployed to the field earlier, the deployment operation can be completed in a shorter period of time than the above-described “transplant-transplant method”. Thereby, stable mixed planting can be performed even on land where planting by the “transplanting-transplanting method” becomes difficult due to the soil solidifying quickly after plowing.
For this reason, this unfolding method can be expanded even in a place where the soil becomes hard, and can be expected as a means for compensating for the unfolding by the transplant-transplant method.

The expansion method combining the above transplantation and direct sowing is
・ Development of late-growing rice varieties first, and development of early-growing rice varieties later ((A) (2), (A) (3), (B) (i) and (C) ( I)) and
-It can be broadly divided into those that develop the early-growing rice varieties first and those that later develop the late-growing rice varieties ((D) and (E)).

Among these, as a method of combining "transplanting" and "strip seeding (spot seeding)"
(A) (2) is a “transplanting-striping (spot-seeding) method” in which a seedling is transplanted from a late-strain and seeded (or seeded) with an early-strain.
The (B) (i) is a “row seeding (sown) -transplantation method” in which a late line is seeded (or spot-seeded) and an early-stage line is transplanted as a seedling.
In addition, (D) is a “row seeding (sown) -transplantation method” in which an early line is seeded (or spotted) and a late seedling is transplanted as a seedling.

  In any case, the second development is performed in a non-parallel direction (a non-parallel direction) with respect to the seedling or the strip seeding (spot seeding) by the first development. Thereby, it is possible to reduce the possibility of damaging the seedlings by the first deployment by stepping on the second deployment as much as possible. From the viewpoint of suppressing the damage of the first seedling as much as possible, it can be said that it is desirable to be as close as possible to the direction orthogonal to the first transplanting line.

In addition, as a method of combining "transplantation" and "dispersion"
(A) (3) is a “transplanting-spreading method” in which a seedling is transplanted from a late-growth line and the early-growth line is spread.
(C) (I) is a “spraying-transplanting method” in which a late-line strain is scattered and seedlings are transplanted.
The (E) is a “spreading-transplanting method” in which an early-flowering line is scattered and a late-lined line is transplanted as a seedling.

c) Direct seeding-direct seeding method This transplant-transplantation method is a case where any of the development of the parental line in the field is performed by direct seeding. Here, direct sowing includes row sowing, spot sowing, and sowing.

This corresponds to the development method of (B) (ii), (B) (iii), (C) (II) and (C) (III) described above.
That is, in one preferable embodiment of the present invention, the cultivation method of the present invention comprises:
(B) (ii) After seeding the seeds of late-grown rice varieties directly in a paddy field by row seeding or spot seeding, the seeds grow early in a direction that is not parallel to the row of seeds directly seeded by late-line rice varieties. The seeds of the line rice varieties are directly sown by the row sowing or spot sowing method, or (B) (iii) the seeds of the late-growing rice varieties are directly sown in the paddy field by the sowing or spot sowing method, and then the early-growing rice cultivar Sowing seeds directly on the whole surface of the paddy field, or
(C) After seeding the rice varieties of late-stage rice varieties directly in the paddy field,
(II) From that, seeds of early rice cultivars are directly sown by row seeding or spot seeding, or
(III) From this, it includes directly sowing seeds of early-growing rice cultivars in paddy fields by the sowing method.

  In the direct sowing-direct sowing method, transplanting work is not required, and therefore the work amount required for field development can be greatly reduced. Furthermore, since the physical distance between the parent lines becomes very short, an improvement in pollination efficiency can be expected.

That is, the above-mentioned development method is to perform development of late-growing rice varieties first, and to develop early-breeding varieties later,
As (B) (ii), a late line is seeded (or spotted), and an early seeded line is seeded (or spotted), the “striped (sown) -sown (sown) method”,
As (B) (iii), the late line is seeded (or seeded), and the early seeding line is sowed, “row seeding (sowing) -sowing method”,
As (C) (II), a late-breaking strain is seeded, and an early-flowering strain is seeded (or seeded), and the seedling-striped (sown) method is further referred to as (C) (III). And “spreading-spreading method”, in which an early seeding line is spread.

Of these field deployment methods, the method (C) is beneficial from the viewpoint of reducing work labor.
Moreover, among the above, the “spreading-spreading method” is useful in the sense that it is possible to overwhelmingly improve efficiency of sowing. In this sense, (C) (III) can be said to be a preferred embodiment in the direct sowing-direct sowing method.

  In the present invention, preferable field deployment methods are the “a) transplantation-transplantation method” and the “b) deployment method combining transplantation and direct seeding”, and more preferably the “a) transplantation-transplantation method”. .

In the present invention, a more specific preferred field development method is the method (A) or (B) described above, and more preferably the method (A). The method (A) can be said to be desirable from the viewpoint of seedling establishment and yield stability as a result. As a more preferable field development method, the method (A) (1) can be mentioned.

Hybrid rice seeding method A series of operations from subsequent cultivation to seed preparation can be performed in the same manner as in the case of normal seed production.
The seeds of the target seed parent line are separated from the harvested and collected seeds. This makes it possible to selectively seed the intended hybrid rice.

  Therefore, according to another preferred embodiment of the present invention, the method includes separating and obtaining hybrid rice by separating seeds of a parent seed line from seeds obtained by cultivation and harvesting by the cultivation method described above. A hybrid (F1) rice seeding method is provided.

  Here, the separation of the seed of the target seed parent line from the harvested seed is not particularly limited as long as the target selection / separation is possible. For example, a seed selection method as reported by Maruyama, for example. It may also be performed by selecting seeds based on the difference in reactivity of the coloring reaction by phenols between parental lines, or by morphological differences of seeds (eg, particle size, seed shape, etc. ) Based on seed selection.

  For example, as a screening method using phenols, when the pollen parent is grown using a long grain seed or the like as a base, only the wrinkles of the pollen parent line can be dyed black with phenols. Can be selected from the target seed parent pods (hybrid rice seeds) (Maruyama literature mentioned above ("Breeding studies of primary hybrid rice varieties" (Kiyoaki Maruyama, published February 14, 1993)) (Non-Patent Document 1)).

  Similarly, as a method for selecting seeds based on the morphological differences of seeds, for example, the seed traits (grain width) of seeds of varieties and strains related to selection are investigated in advance, and the soil quality is determined based on the results. By using a test stage sieve and sieving it on a sieve shaker, the target straw can be selected (as described in the above-mentioned Maruyama literature ("Breeding studies of primary hybrid rice varieties"). (Kiyoaki Maruyama, issued February 14, 1993) (Non-Patent Document 1)).

  Therefore, according to another preferred embodiment of the present invention, in the seeding method of the present invention, the separation of the seed of the seed parent line from the seed obtained by harvesting is carried out by reacting the coloring reaction by phenols between the parent lines. It is preferable to perform the seed selection based on the difference of the seeds or to select the seed based on the morphological difference of the seeds.

  In the following, the present invention will be described in detail by the following examples, but the present invention is not limited thereto.

Example 1: Transplantation-transplantation method Rice cultivar "JMS-023" (patent microorganism deposit number: BP-FERM11463), which is the seed parent line of rice cultivar "Hybrid Togo 3" (variety registration No. 23694), and Using the rice cultivar “JFR-004” (cultivated and maintained by the Rice Research Institute for Rice Production), a pollen parent line, in a rice field of 6a in Aichi Prefecture in 2013 It was.

  The schedule from sowing to harvesting is shown in Table 1.

  In the case of the cultivar of Example 1, since the pollen parent line is more late than the seed parent line, the former was developed at an earlier stage, changing the transplanting period, and being developed in the field.

  As an expansion method to a farm field, first, four pollen parent lines were installed in every other row on an 8-row rice transplanter, and seedlings were transplanted.

Next, seedlings of the seed parent line were transplanted as a second transplant. Seed parent lines were transplanted on all 8 lines 8 days later than the above-mentioned pollen parent lines. At this time, the second transplantation was performed in a form orthogonal to the first transplantation.
The seedlings were transplanted on the 25th with both parental lines.

  Here, the interval from the transplantation of the pollen parent line seedling to the transplantation of the seed parent line seedling was determined as follows. That is, regression analysis is performed on the cultivation data related to the transplanting date and heading date of the parental line in the same region for the past 4 years, and based on the result, the interval between the transplanting date and the desired transplanting date are predicted from the desired heading date. And calculated. As a result, in this example, the transplant day interval according to the parental line used was calculated as 8 days. In addition, the transplanting date of the pollen parent line seedlings was set as shown in Table 1 above.

  The relationship between the first expansion method and the second expansion method is as shown in FIG.

  The state of the seedlings in the field after the second transplantation was visually observed, and the pollen parent line strain (seedling) transplanted the first time was buried in the soil in some places, and the seed parent line transplanted later It was confirmed that the strain (seedling) of the plant filled the space.

Then, when cultivation was performed according to a customary cultivation method, the heading time of each line was as shown in Table 1.
As shown in the results of the table, the heading of the seed parent line could be synchronized with the heading of the pollen parent line.

Next, pollination promotion treatment was carried out for 7 days after the heading of the seed parent line.
Continued cultivation and harvesting at the same time during the harvest period, seeds collected from pollen parent lines and hybrid rice seeds collected from seed parent lines can be selected based on the difference in seed particle size and shape Using a special sorter set up as above, seed sorting was performed.

As a final result, the estimated seeding yield as hybrid rice seed was 204.2 kg / 10a. Here, “estimated seeding yield” means the seeding yield estimated and calculated from the weight ratio of the pollen parent line to the seed parent line in the harvested sperm.
The estimated seeding yield of hybrid rice seeds was 2.62 times higher than the seeding yield of 77.8 kg / 10a of the conventional seeding method (Comparative Example 1) under the same conditions.

Comparative Example 1: Conventional seeding method (line planting seeding method)
As shown in FIG. 3, the method for expanding seedlings in the field was cultivated and harvested in the same manner as in Example 1 except that the parent lines were divided into blocks and planted in rows, and selection of hybrid rice seeds was performed. Went. In addition, the cultivated area was 320a (Earl).
The estimated seeding yield as hybrid rice seeds was 77.8 kg / 10a.

Example 2: Direct sowing and transplanting method Rice cultivar “Hybrid Togo No. 4” (variety registration No. 23695), a rice cultivar “JMS-024” (patent microorganism deposit number: BP-FERM11464), and A rice cultivar “JFR-004”, which is a pollen parent line, was used and tested in a rice paddy field 5a in Niigata Prefecture in FY2013.

  The schedule from sowing to harvesting was as shown in Table 2.

  In the case of this example as well as Example 1, since the pollen parent line is more late than the seed parent line, the former was developed in the field earlier.

As an expansion method to a farm field, first, four pollen parent lines were installed in every other row on an 8-row rice transplanter, and seedlings were transplanted.
As a pollen parent line seedling, seedlings were transplanted on the 27th.

  Seeds for direct seeding of paddy rice seeding (revised in December 2012) (http://www.maff.go.jp/j/seisan/ryutu/zikamaki/z_kenkyu_kai/pdf/ According to the method described in 24chokuha.pdf), Calper coating was performed.

  As the second transplant, seeds of the seed parent line coated with calper were directly sown in the same paddy field using a power sprayer 8 days after transplanting the seedling of the pollen parent line.

  Here, the interval from transplanting the seedlings of the pollen parent line to direct seeding of the seeds of the seed parent line was determined as follows. That is, a regression analysis was performed on the cultivation data regarding the transplantation date, direct sowing date, and heading date of the parental line in the same region for the past three years, and based on the results, the desired heading date and the interval between transplanting and direct sowing And the desired transplantation date was predicted and calculated. As a result, in this example, the interval between transplantation and direct seeding in the used parental line was calculated as 8 days. In addition, the transplanting date of the pollen parent line seedling was set as shown in Table 2 above.

  The relationship between the first expansion method and the second expansion method is as shown in FIG.

  The state of the seedlings in the field after the second transplant (direct seed sowing) was visually observed, and the space between the pollen parent line strain transplanted the first time and the missing part was sown later. It was observed that the seed parent line was buried.

  Then, when cultivation was carried out according to the customary cultivation method, as shown in Table 2, the heading time of each line was mid-August, and the heading of the seed parent line was synchronized with the heading of the pollen parent line. I was able to.

Next, pollination promotion treatment was carried out for 7 days after the heading of the seed parent line.
In the same manner as in Example 1, the cultivation was further continued and harvested all at once during the harvest period, and the seeds collected from the pollen parent line and the hybrid rice seeds collected from the seed parent line were divided into the grain size and shape of the seeds. The seeds were sorted using a special sorter that was set so that sorting could be performed based on the difference between the two.

    The final result was an estimated seeding yield of 123 kg / 10a as hybrid rice seeds. This was clearly higher than 83.9 kg / 10a, which is the average value of the seeding yield at three locations in the same line in the same year.

Example 3 (reference): Transplantation-direct sowing (spot seeding) method The pollen parent line is developed as an early line, the seed parent line is developed as an early line later on the field, and the seedling development method on the field is As shown in FIG. 4, cultivation is performed in the same manner as in Examples 1 and 2 except that seedling transplantation is used for the first development and spot seeding is used for the second development, harvesting is performed, and hybrid rice seeds are selected.

  Here, spot sowing is carried out in the form of sowing Calper-coated seeds in a flooded paddy field using a dedicated sowing period, and by transferring the pollen parent every single line, the pollen parent line is transferred. Reduce the number of strains to about half the number of strains that will become seed parents, and improve seeding efficiency.

Example 4 (reference): Direct sowing (spot sowing) -transplantation method The seed parent line was developed as a late growth line at an earlier stage , the pollen parent line was developed as an early growth line and later on the field, and the seedling development method on the field was As shown in FIG. 5, cultivation is performed in the same manner as in Examples 1 and 2 except that the first development is spot seeding and the second development is seedling transplanting, and harvesting is performed, and hybrid rice seeds are selected.

  Here, spot sowing is carried out in the form of sowing Calper-coated seeds in a flooded paddy field using a dedicated sowing period, and the number of transferred pollen parents can be determined by transplanting pollen parent every single row. Reduce seeding efficiency to about half the number of strains that will become seed parents.

Example 5 (reference): Direct sowing (spreading) -direct sowing (spreading) method The pollen parent line is used as a late growth line at an earlier time, the seed parent line is used as an early growth line, and is later developed in the field. The method is cultivated and harvested in the same manner as in Examples 1 and 2 except that both the first and second developments are spread as shown in FIG. 6, and hybrid rice seeds are selected. .

Here, seeding is carried out by using a radio control helicopter to sow iron-coated seeds in a flooded paddy field, and the seeding amount of the pollen parent line is about half that of the seed parent line. By sowing, the seeding efficiency is improved.

Claims (11)

Seed seeding time or seedling transplantation of seeds obtained by sowing and seeding seeds of late-grown rice varieties or seeds and seedlings obtained by sowing and seeding seeds of early-grown rice varieties or seeds It is a cultivation method for hybrid (F1) rice seeding, which is mixed planting at different times,
The period between when seeds of late rice cultivars are directly sown in paddy fields or when the seedlings are transplanted to paddy fields, and when seeds of early rice cultivars are sown directly on paddy fields or when the seedlings are transplanted into paddy fields By adjusting, the heading period of late-growing rice varieties and the heading period of early-growing rice varieties are controlled to be the same period ,
Among varieties of both strains mentioned above, with respect to ridges or condition of previous planting ridges seedlings of one cultivar were transplanted seeding or seedling seeds or direct seeding seeds, in the direction not parallel, or transplanting seedlings of the other varieties linearly, or you direct sowing the seeds linearly cultivation培方method. Regression analysis of the cultivation data for the past several years in the same area as the area where the parent line is cultivated, the period between the sowing or transplanting period of the late rice cultivar and the sowing or transplanting period of the early rice cultivar The cultivation method according to claim 1, wherein the cultivation method is determined. Controls the period between seeding of late-grown rice varieties directly into paddy fields or transplanting their seedlings into paddy fields and then seeding seeds of early-grown rice varieties directly into paddy fields or transplanting the seedlings into paddy fields The cultivation method according to claim 1 or 2 , wherein the heading period of the late-growing rice cultivar and the heading stage of the early-growing rice cultivar are controlled to be the same period. By adjusting the period between direct seeding of early-growing rice varieties to rice fields and transplanting seedlings of late-growing rice varieties to paddy fields, the heading time of late-growing rice varieties and the The cultivation method according to claim 1 or 2 , wherein the heading period is controlled so as to coincide with the heading period. (A) After seedlings of late-grown rice varieties were planted in rice fields and transplanted in a straight line,
(1) From there, transplant the seedlings of early-growing rice varieties in a straight line in a direction that is not parallel to the row of seedlings of late-growing rice varieties,
(2) From that point, seeds of early-grown rice varieties may be directly sown by row seeding or spot seeding in a direction that is not parallel to the seedling row of seedlings of late-line rice varieties,
(B) After seeding seeds of late-grown rice varieties directly on the paddy field by row seeding or spot seeding,
(i) From there, transplant the seedlings of the early rice cultivar linearly in a direction that is not parallel to the row of seeds sown directly of the late rice cultivar,
(ii) From there, directly seed the seeds of the early line rice cultivar in a row sowing or spot sowing method in a direction that is not parallel to the row of seeds directly seeded of the late line rice cultivar, or (D) the early line After direct seeding of rice varieties in paddy fields by row seeding or spot seeding, seedlings of late-line rice varieties are straightened from above in a direction that is not parallel to the row of seeds directly seeded for early-grown rice varieties. cultivation method according to to that <br/> include any steps that, according to claim 1 or 2 implanted into. Among the varieties of both of the above-mentioned lines, the angle is 45 degrees to 90 degrees with respect to the seeding line of one of the cultivars or the seed line directly seeded sowing seeds or transplanting seedlings first. The cultivation method according to any one of claims 1 to 5 , wherein a seedling of the other cultivar is transplanted in the direction, or the seed is directly sown by row seeding or spot seeding. Among the varieties of both lines described above, an orthogonal direction or a substantially orthogonal direction (85) with respect to the seeding row of seedlings of one of the varieties to which seeds were previously sown or seedlings were transplanted or directly sown seed rows (85 The cultivation method according to any one of claims 1 to 6 , wherein a seedling of the other cultivar is transplanted or the seed is directly sown in a row sowing or spot sowing method. The cultivation method according to any one of claims 1 to 7 , wherein a pollen parent line is used as the late line, and a seed parent line is used as the early line. The cultivation method according to any one of claims 1 to 7 , wherein a seed parent line is used as the late-breaking line and a pollen parent line is used as the early-growing line. A hybrid comprising selecting hybrid rice by separating seeds of a parent seed line from seeds obtained by cultivation and harvesting by the method according to any one of claims 1 to 9. F1) Rice seeding method. Separation of seeds of seed parent lines from seeds obtained by harvesting is performed by seed selection based on the difference in reactivity of coloring reaction by phenols between the parent lines, or morphological differences of seeds The seeding method according to claim 10 , wherein the seeding method is performed by selecting seeds based on the seeds.

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