JP2015037385A - Cultivation method of sweet potato - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cultivation method of a sweet potato which can utilize bacterial acting usefully during growth to secure a stable crop yield while a risk of infection with harmful bacteria can be reduced.SOLUTION: In a cultivation method of a sweet potato, a scion B1 collected from a seedling B for the scion and a rootstock A1 collected from a seedling A for the rootstock which is raised in an approximately aseptic condition compared with the seedling B for the scion are grafted. The grafted seedling C consisting of the rootstock A1 and the scion B1 is raised. When the rootstock A1 is collected from the seedling A for the root stock, the collection is performed so that a leaf 5 raised from a vine 6 to be cut or a vine 7 branched off from the vine 6 is left on the rootstock A1 side. The rootstock A1 is collected from the aseptic seedling raised in the aseptic condition.

Description

  The present invention relates to a method for cultivating sweet potatoes.

  In general, cut seedlings (cutting heads) that have been bred and cut from sweet potato seedlings are planted in the field and cultivated sweet potatoes, but the cut seedlings are violated by harmful bacteria or viruses (fungi etc.) , Yield decreases. In order to prevent this, a sweet potato cultivation method for raising seedlings in an environment close to sterility is known (for example, see Patent Document 1).

JP-A-9-294495

In the sweet potato cultivation method of the above-mentioned document, seedlings in a state in which fungi and the like are not included or are hardly included (hereinafter referred to as “sterile state”) are planted.
On the other hand, there are a plurality of types of fungi that are useful in the growth process, but as described above, since the seedlings are in a sterile state, it is necessary to supply most of these useful fungi from the soil. The degree depends greatly on the soil condition.
However, since it is very difficult to set the type and amount of bacteria and the like contained in the soil to a desired state, the yield varies greatly depending on the soil condition, and it is difficult to stabilize the yield of sweet potato.

  It is an object of the present invention to provide a method for cultivating sweet potatoes that can reduce the risk of being violated by harmful fungi and the like, and can secure a stable yield by using fungi that act usefully during growth. To do.

  In order to solve the above-mentioned problem, the younger brother 1 is from the saplings B1 collected from the seedlings B for hogi and the seedlings A for rootstocks that have been bred in a condition closer to the sterility than the seedlings B for hogi. The grafted rootstock A1 is grafted, and a grafted body C composed of the grafted rootstock A1 and hogi B1 is grown.

  When the rootstock A1 is collected from the seedling A for rootstock, the younger brother 2 leaves the leaves 5 generated from the vine 6 to be cut or the vine 7 branched from the vine 6 on the rootstock A1 side. Then, the cutting is performed.

  The younger brother 3 is characterized in that the rootstock A1 is collected from aseptic seedlings grown in aseptic conditions.

  The younger brother 4 is characterized in that the rootstock A1 is collected from a Mericlon seedling which is a kind of aseptic seedling and grown in a sterile medium.

  The younger brother 5 is characterized in that the seedling B for hogi and the seedling A for rootstock are different varieties.

  The younger brother 6 grows the graft body C, collects the vine extending from the graft body C as a spike B1, and grafts the spike B1 to the rootstock A1 to form a new graft body C. Features.

  According to the present invention, it is possible to supply useful fungi or the like to a rootstock in which the amount of fungi contained is small or aseptic, via a saf grafted to the rootstock. In addition to reducing the risk of being violated by harmful bacteria, it is possible to secure a stable yield by utilizing bacteria that act usefully during growth.

It is explanatory drawing of the cultivation method of the sweet potato which applied this invention. It is a flowchart which shows the process of the cultivation method of this sweet potato. It is the total dry weight of the graft body 71 days after transplantation in hydroponics. It is a graph which shows the nitrogen content of the graft body on the 71st after transplanting in hydroponics. It is a specific graph which shows the fungus density and fungus name of the vine tip stem and leaves of the graft body and the seedling body which were hydroponically cultivated. It is a graph which shows the result of a passage test. It is the total dry weight of grafted body 108 days after transplanting in soil cultivation.

  As a result of the sharp examination, the present inventors grafted a safoli collected from seedlings holding useful fungi to rootstocks collected from aseptic seedlings, and useful fungi on the rootstock side through the saplings And the like are found to promote the growth of graft bodies composed of rootstocks and spikelets grafted to each other, and this is utilized in the present invention.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  FIG. 1 is an explanatory diagram of a sweet potato cultivation method to which the present invention is applied, and FIG. 2 is a flowchart showing the steps of the sweet potato cultivation method. The cultivation method of the sweet potato shown in the figure is to grow a seedling for rootstock (seedling for rootstock) A and a seedling process for growing a seedling for hogi (seedling for hogi) B, and a seedling for seedling A for rootstock. The tree A1 is collected, the harvesting process for harvesting the saplings B1 from the saplings B for saplings, the grafting process for grafting the rootstock A1 and the saplings B1, and the rootstocks grafted to each other by the grafting process; And a growth process for growing a graft body C made of hogi.

  Incidentally, the grown graft body C may be used as a cut seedling by cutting a part of the extended vine, or may be grown as it is to harvest sweet potatoes.

  In the seedling-raising step, seedlings grown in an environment closer to aseptic conditions than the saplings for hogi B are used as rootstock seedlings A. Specifically, a Meliclone seedling, which is a kind of virus-free aseptic seedling (hereinafter simply referred to as “sterile seedling”), is used as the rootstock seedling A. Incidentally, the Meliclone seedling is a sterile seedling grown in a sterile medium. As this sterile medium, a liquid medium using a culture solution or a solid medium such as agar is assumed.

  More specifically, the rootstock seedling A will be described. First, the Melklon seedling planted in the pot is obtained at hand, and after raising for a while, it is planted again in another pot 1 immediately. At this time, vermiculite or perlite, which is a baked aseptic soil 2, is used as the soil in the new pot 1, and the aseptic state is maintained even during the raising of the seedlings.

  On the other hand, as the seedling B for hogi, a normal seedling grown in a normal state (non-sterile state) is used. Since normal seedlings are nurtured in a state where bacteria are present, a plurality of types of useful bacteria and the like are abundant. However, normal seedlings are healthy seedlings that retain many fungi but are not infected with pathogenic bacteria or harmful viruses.

  More specifically, the seedling B for hogi will be described. First, a normal seedling planted in a pot is obtained at hand, and after raising for a while, or immediately, it is planted again in another pot 3. At this time, vermiculite or perlite, which is a baked aseptic soil, is used as the soil 4 to be put into the new pot 3, and unintended fungi and the like are prevented from being mixed into the seedlings.

  In collecting the rootstock A1 from the seedling A for rootstock in the above-described collecting step, the thickest main vine (main vine) 6 is selected as a cutting target, and the main vine 6 is selected from the root side to two to three sections or three Cut vertically at a section of about 4 nodes (5 cm in length), and use the root side portion including the pot 1 as the rootstock A1. This rootstock A1 is directly generated from one or more vines (branches) 7 or main vines 6 that are branched from the above-mentioned nodes of the main vines 6 and have leaves 5 (the number of nodes is the same as the number of nodes in the illustrated example). Either one or both of the leaves 5 are included.

  Then, a cut groove 6a is cut and formed in the cut end portion of the main vine 6 of the rootstock A1 so that the cross section is divided symmetrically about the axis side.

  On the other hand, in the harvesting process, the thickest main vine (main vine) 8 is selected as a target for cutting, and 2 to 4 nodes (length) from the tip side of the main vine 8 are collected. A portion of about 10 cm) is cut into a V shape when viewed from the side, and this tip side portion is used as the hogi B1. By the cut shape, a wedge-shaped piercing portion 8a is formed at the base end portion of the main vine 8 of the hogi B1.

  This hogi B1 was also directly generated from one or a plurality of vines (branches) 9 or main vines 8 that were branched from the above-mentioned nodes of main vines 8 and grew leaves 10 (the number of nodes in the illustrated example is the same as the number of nodes). Either one or both of the leaves 10 are included. Normally, the amount of leaves (the total number of leaves 5 and 10 or the total surface area of the leaves 5 and 10) is higher for the hogi B1 than for the rootstock A1, but this is set in reverse. The amount of leaves of the rootstock A1 can be set larger than that of the tree B1.

  In the grafting step, the piercing portion 8a is inserted into the cut groove 6a in an engaged state, and the grafting tape 11 is wound around and fixed to the outer periphery of the engaging portion. By sandwiching the outer periphery of the grafting tape 11 (the outer peripheral side of the tip of the rootstock), the insertion portion 8a is sandwiched and held in the cut groove 6a, thereby completing the above grafting operation. .

  In the growth process, the graft body C is grown by hydroponics or soil cultivation. In the case of hydroponics, the pot 1 of the rootstock A1 can be used as it is. The soil 2 made of vermiculite or pearlite is used, and a predetermined amount of the culture solution is periodically supplied for hydroponics. Do. In the case of soil cultivation, it is necessary to transplant the graft C planted in the pot 1 to a field or another pot. In this case, a cut seedling collected from the grown graft C It may be planted in a field or another pot. In the process of growing the graft body C, effective bacteria and the like move from the hogi B1 side to the rootstock A1 side, and the growth is promoted.

  In addition, as shown by the phantom line arrow in FIG. 2, the spike B1 is collected from the grown graft C by the same means as described above, and the spike B1 and the rootstock A1 are grafted and newly obtained. A good graft C may be used. Further, this procedure may be repeated to inherit the generations one after another. Hereinafter, this generation of inheritance is referred to as “passage”.

  Moreover, since Hogi B1 is in the state of cutting ears, a piercing portion 8a may be formed at the proximal end portion of the cutting ear obtained at hand and used as it is as Hogi B1. In this case, it is possible to omit all of the seedling raising process of Hogi B1 and a part of the collecting process.

  The same applies to the rootstock A1. A sterile pot seedling may be obtained, the tip end side of the pot seedling may be cut, and the root side including the pot may be used as the rootstock A1 as it is. In this case, all the seedling raising processes of the rootstock A1 are omitted.

  According to the sweet potato cultivation method configured as described above, the above-mentioned useful fungi of Hogi B1 can also move to rootstock A1 and promote efficient growth.

  Moreover, since rootstock A1 and panicle B1 are collected from sweet potato seedlings of different varieties, sweet potato seedlings of different qualities are used as rootstock seedling A and panicle seedling B. It becomes possible to harvest a lot of expensive sweet potatoes. For example, a combination of grafting rootstock A1 collected from a sweet potato seedling of a variety having a high sugar content but a small yield and a panicle B1 collected from a sweet potato seedling of a variety having a high yield is conceivable. In addition, you may extract rootstock A1 and hogi B1 from the sweet potato seedling of the same kind.

  By the way, the mechanism of this growth promoting effect is explained. First, nitrogen exists as an important substance indispensable for growth. And when this nitrogen is fixed, the growth is promoted, but there is a nitrogen-fixing endobacterium as a fungus that effectively acts on this nitrogen fixation. Explaining the fixation of nitrogen, nitrogen-fixing endophytic bacteria coexist with plants, constantly take in nitrogen from the air, and change the taken-in nitrogen into a form of nitrogen that can be used by the plant. Here, this series of phenomena is called nitrogen fixation.

  These nitrogen-fixing endophytic bacteria are abundantly contained in normal seedlings, but many of them alone do not sufficiently function to retain nitrogen, and in an environment where they coexist with other bacteria (symbiotic environment) Since the nitrogen retention function is exhibited for the first time, it is often impossible to achieve such a high effect even if an isolated and cultured nitrogen-fixing endobacterium is used.

  That is, in order to activate the nitrogen-fixing endobacterium, it is necessary to reproduce the same symbiotic environment as the body of the seedling from which the nitrogen-fixing endobacterium was collected. We found that this symbiotic environment can be reproduced by grafted Hogi.

  Specifically, since the symbiotic environment is constructed in the body of a healthy hogi B1 that is surely containing nitrogen-fixing endophytic bacteria, the hogi B1 is a sterile rootstock. By grafting on A1, it is possible to move the nitrogen-fixing endophytic fungus whose function of fixing nitrogen in the symbiotic environment is activated to the rootstock A1 side as it is, and this promotes growth. The

  Next, an experiment in hydroponics was conducted for the purpose of confirming the superiority of the cultivation method of the sweet potato, and the contents and results of the experiment will be described.

  First, aseptic seedlings and normal seedlings shown in the following table were prepared.

  Then, while using high type 14 aseptic seedlings as rootstock seedling A, high type 14, assorted aseptic seeds of red, red and far, and high type 14, red and red, far far 3 A total of six types of normal seedlings were used as the seedlings B for the hogi, and each type of the seedling B for the hogi was grafted to the rootstock seedling A prepared individually.

  Each rootstock seedling A and each sapling seedling B were cut out leaving 10 fully expanded leaves, and the leaves leaving 5 leaves were cut out and put into a spiked state, and vinyl pots 1, 3 filled with vermiculite Inseed into. Then, seedlings were grown for about 20 to 24 days in the season of May to June, and then grafting work was performed with the seedling A for rootstock and the seedling B for hogi.

  The graft C planted in the pot 1 was grown in a vinyl tunnel that was shaded for about one month in the season from June to July. At this time, in order to prevent drying, automatic irrigation for 5 minutes was performed twice a day at 6:00 am and 0:00 pm.

  Subsequently, each pot seedling made of each grafted body C grown was trimmed from a root-bottomed root and transplanted to a monkey packed with vermiculite. The colander is a net housed in a plastic box, the colander is raised about 7 cm, and a supply filter is provided on the bottom side.

  And hydroponics were performed with the semi-garden trial formulation (Otsuka B) hydroponic solution (culture solution) shown in the following table.

  The concentration of the culture solution was changed as shown in the table below according to the growth.

  And the hydroponics period after transplanting was set to about 70 days (in this example, 71 days), and various measurements were performed on each grown graft body C.

  FIG. 3 shows the total dry weight of the graft body 71 days after transplantation in hydroponics. The leaves 5,10, vines 6,7,8,9, roots and tuberous roots of the graft body C were dried in an air dryer at 80 ° C. for 48 hours or more to obtain dry matter, and the total weight of the dry matter in each graft body C was measured. . The results are as shown in the figure, and three types of rootstock A1 collected from sterile seedlings and grafted with spikelet B1 collected from ordinary seedlings are spiked into rootstock A1 from sterile seedlings. It was significantly heavier than the three types grafted with the tree B1, and showed the superiority of the present invention. Incidentally, in the figure of FIG. 3, “Haruka” is an abbreviation for far, and “High system” is an abbreviation for High system No. 14.

  FIG. 4 is a graph showing the nitrogen content of the grafted body 71 days after transplantation in hydroponics. First, the dry matter is finely pulverized, and the nitrogen content is measured by a nitrogen analyzer, and vermiculite in the monkey is collected and dried in a ventilation dryer at 105 ° C. for 48 hours or more. The content was measured.

  Subsequently, nitrate nitrogen in the given culture solution and the remaining culture solution is monitored with an ion electrode, and ammonia nitrogen and total nitrogen are each measured by a nitrogen analyzer to determine the nitrogen balance, and the plant's 15N The nitrogen utilization rate derived from air was calculated by the natural abundance ratio method using heavy nitrogen.

  The results are as shown in FIG. 4. Three types of rootstocks A1 collected from sterile seedlings and grafted with spikelets B1 collected from ordinary seedlings are spiked into rootstocks A1 from sterile seedlings. Compared to three types of grafted tree B1, the nitrogen utilization rate derived from air and the total nitrogen content are high, and nitrogen-fixing endophytic bacteria that have moved from Hogi B1 to rootstock A1 are useful. The state is confirmed. In particular, a significant difference was found in the nitrogen utilization rate derived from air. Incidentally, in the figure of FIG. 4, “Haruka” is an abbreviation for far, and “High system” is an abbreviation for High system No. 14.

  FIG. 5 is a specific graph showing the fungus density and the fungus name of the vine tip stems and leaves of hydroponic-cultivated grafts and seedlings. About 6 types of grafted body C which was hydroponically cultivated for 71 days as described above, and 3 types of normal seedlings from which panicle B1 was collected, the fungus was separated from the vine tip and leaves, and the fungus name and fungus The density was examined.

  The result is as shown in the figure, and the one from which the fungus has been separated is grafted body C grafted with red and red cuttings of normal seedlings and ears B1 collected from normal seedlings of the same varieties. Met. Moreover, in the passage test mentioned later, it is in agreement with the result in which the favorable result was shown about the red sweet potato variety. Incidentally, in FIG. 5, “Haruka” is an abbreviation for far and “High” is an abbreviation for High 14.

  In addition, about the thing from which a microbe is not isolate | separated, it is not that the microbe does not exist but it is estimated that the number is small or the microbe which is not isolate | separated exists in the normal seedling and the graft body C. These bacteria are nitrogen-fixing endophytic bacteria or bacteria related thereto.

  FIG. 6 is a graph showing the results of the passage test. Each type of graft body C was subcultured, and a new graft body C was grown by the same method as described above, and the increased weight of dry matter was measured 44 days after transplantation.

  The result is as shown in the figure, and the panicle B1 collected from three types of grafts C1 obtained by grafting the spikelet B1 collected from the normal seedling to the rootstock A1 collected from the sterile seedling is further aseptic. A new graft body C obtained by grafting a rootstock A1 collected from a seedling is obtained from three types of graft bodies C obtained by grafting a rootstock B1 collected from a sterile seedling to a rootstock A1 collected from a sterile seedling. The collected hogi B1 is further grafted to a rootstock A1 collected from aseptic seedlings to obtain a new graft C. The increase in dry matter is significantly heavier, and the usefulness of nitrogen-fixing endophytic bacteria Was confirmed to be retained even after passage. Incidentally, in the drawing of FIG. 6, “Haruka” is an abbreviation for far, and “High system” is an abbreviation for High system No. 14.

  Next, an experiment in soil cultivation was performed for the purpose of confirming the superiority of the cultivation method of the sweet potato, and the contents and results of the experiment will be described.

  First, aseptic seedlings and normal seedlings shown in the following table were prepared.

  And using the normal seedling of the high system No. 14 as the seedling A for rootstock A, the graft body C was made by the method similar to the above, and this graft body C was cultivated in soil.

  It is the total dry weight of grafted body 108 days after transplanting in soil cultivation. As shown in the figure, the total weight of the dry matter of each type of grafted body was not significantly different between the spike B1 collected from the sterile seedling and the spike B B collected from the normal seedling. By the way, “High” in the figure is an abbreviation for High System No. 14, “Yellow” is an abbreviation for Golden Senju, “Ha” is a much more abbreviation, and “East” is an abbreviation for Azuma. "Red" is an abbreviation for red and red. The results shown in the figure indicate that aseptic seedlings are more desirable than ordinary seedlings as seedlings for collecting rootstock A1.

5 Leaves 6 Main vine
7 Branch vine
10 Leaf A Rootstock Seedling (Rootstock Seedling)
A1 Rootstock B Hogi Seedling (Hogi Seedling)
B1 Hogi C graft body

The present invention found, as a result of acute meaning study, the rootstock taken from a sterile seedling, grafted a scion taken from seedlings to retain useful bacteria, useful in the stock side through the該穂tree It has been found that the growth of graft bodies composed of rootstocks and spikelets grafted with each other is promoted by moving the fungus and the like, and this is utilized in the present invention.

Claims (6)

  Haruki (B1) collected from the seedling for hogi (B) and the seedling for rootstock (A) grown in a condition closer to asepticity than the seedling for hogi (B) A sweet potato cultivation method for grafting a rootstock (A1) and growing a graft body (C) composed of the grafted rootstock (A1) and hogi (B1).   When the rootstock (A1) is collected from the rootstock seedling (A), the leaves (5) generated from the vine (6) to be cut or the vine (7) branched from the vine (6) The cultivation method of the sweet potato of Claim 1 which performs the said cutting | disconnection so that it may remain on the rootstock (A1) side.   The cultivation method of the sweet potato in any one of Claim 1 or 2 which extract | collects the said rootstock (A1) from the aseptic seedling grown in aseptic condition.   The cultivation method of the sweet potato of Claim 3 which extract | collects the said rootstock (A1) from the meliclon seedling which was 1 type of aseptic seedlings, and was grown on the aseptic culture medium.   The method for cultivating sweet potatoes according to any one of claims 1 to 4, wherein the seedlings for hogi (B) and the seedlings for rootstock (A) are different varieties.   The graft body (C) is grown, the vines extending from the graft body (C) are collected as spikelets (B1), and the graft (B1) is grafted to the rootstock (A1) to form a new graft The cultivation method of the sweet potato according to any one of claims 1 to 5, wherein the body (C) is used.

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