CN110024686B

CN110024686B - Method for screening corn varieties with grains quickly dehydrated in later period

Info

Publication number: CN110024686B
Application number: CN201910462185.0A
Authority: CN
Inventors: 曹钟洋; 陈志辉; 郭欢乐; 汤彬; 陈松林
Original assignee: HUNAN INSTITUTE OF CROPS
Current assignee: HUNAN INSTITUTE OF CROPS
Priority date: 2019-05-30
Filing date: 2019-05-30
Publication date: 2021-03-23
Anticipated expiration: 2039-05-30
Also published as: CN110024686A

Abstract

The invention provides a method for screening corn varieties with quickly dehydrated grains in the later stage, which comprises the steps of sampling the corn grains entering or about to enter the later stage of quick dehydration, measuring the water content, calculating the dehydration rate of the grains according to the change of the dehydration rate of the grains in a period of time, taking the starting point of quick rising of the later stage dehydration rate of the grains as a separation point, counting and comparing the water content of the grains at the starting point and the average dehydration rate in N days after entering the later stage of quick dehydration, and determining the screening standard of the needed corn varieties: the initial point of the seed after-stage rapid dehydration is between 35% and 40%, the water content of the seed after-stage rapid dehydration is higher than or similar to that of the first jade 335, and the average dehydration rate of the seed in N days of the later-stage rapid dehydration is higher than or similar to that of the first jade 335. The method quantifies the evaluation indexes, selects the most suitable entry point for comparing the rapid dehydration condition of the corn in the later period, and has simple operation and visual and accurate result.

Description

Method for screening corn varieties with grains quickly dehydrated in later period

Technical Field

The invention relates to the technical field of corn breeding, in particular to a method for identifying the late dehydration speed of corn kernels.

Background

The moisture content of corn kernels in the harvesting period is one of the main factors influencing the quality of the corn and is also a key factor influencing the mechanized harvesting quality of the corn, because the higher moisture content of the kernels brings a lot of difficulties to the harvesting, threshing, storing, transporting and reprocessing processes of the corn. For example, the moisture content of corn kernels in the harvesting period is too high, which not only causes high kernel breakage rate, large loss and low production efficiency during mechanical harvesting, but also easily causes the harvested kernels to mildew during stacking and airing, thereby seriously restricting the popularization of the mechanical harvesting technology and influencing the improvement of the quality of the corn kernels.

According to research, the moisture content of the grains during harvesting is directly influenced by the dehydration rate of the later-stage grains, and main cultivars selected in the main production area of corn in China at present have the characteristics that the moisture content of the grains is generally higher (namely the moisture content of the grains is more than 30%) when the grains are physiologically mature and the later-stage dehydration of the grains is slow. Therefore, planting corn varieties with high seed dehydration rate in the later stage of physiological maturity and low seed water content during harvesting in production is a fundamental way for solving the problem of corn quality, and has important significance for promoting mechanical corn harvesting and improving social and economic benefits. In order to achieve the above purpose, a set of method for efficiently identifying the corn varieties with high late dehydration rate of seeds needs to be researched, the optimal identification period is mastered, and then the corn varieties with high late dehydration rate of seeds are quickly and accurately screened out.

The method for identifying the dehydration speed of the corn ears, which is commonly adopted at present, is mainly an indirect method, the method relates to a plurality of indexes related to plant characters in practical application, and corn varieties with high kernel dehydration speed have the following characteristics: 1. the plant height of the variety is low, the number of green leaves is small in the grouting period, the distance between leaves on the spikes is large, the leaves are narrow, and the length is reasonable; 2. the fruit ears are long but not thick, the diameter of the shaft is small, the length and the width of the seeds are moderate, and the seed skin is thin; 3. thin, moderate in length, less in number and loose in bract; 4. proper early ripening occurs in the growth period. Researchers think that the more corn varieties meeting the above conditions have lower moisture content of grains during harvesting, and the easier the corn is to be harvested by a corn field thresher. However, the method has the advantages that the index quantity is large, the working intensity is high, the index cannot be quantized, the judgment standard cannot be quantized, an exact result cannot be intuitively shown, and the accuracy is not high particularly when a plurality of corn varieties with similar external expressions are identified; in addition, the character performance of the plants is influenced by the external environment besides being controlled by genetic materials, so that the maize varieties with high seed later dehydration rate are bred by an indirect method, and the reliability of the obtained results is low. For example, the rapid dehydration of premature varieties is generally considered inaccurate, and the reason that the moisture content of grains is low when some premature varieties are harvested in production is that the premature varieties are matured earlier than other varieties, the net dehydration time is long, and the moisture content of the grains is naturally lower than that of other varieties when the seeds are harvested together with other varieties.

In addition, researchers have also thought that: the seed grains with low water content at a certain time point after the corn pollination are measured are an effective way for judging the low water content of the seed grains when the variety is harvested. However, the method also considers the influence of meteorological factors while selecting low kernel water content, and in addition, corn varieties with different maturity stages naturally have different water content even at the same time point after spinning. Therefore, it is not ideal nor spectrum-dependent to select directly the corn variety with low kernel water content at a certain time point after pollination to realize the screening of the corn variety with fast dehydration in the later period.

At present, the dehydration rate of the seeds at the later stage is directly calculated by a method, namely, the corn varieties with high dehydration speed are identified and screened by calculating and comparing the average dehydration rate of the seeds in a certain same time period after spinning. However, this method is mechanical in the selection of the calculation time period, so that the results calculated for different varieties in different development time periods may be completely different, because the varieties in different maturity stages may be in different development stages at the same time point after spinning. For example: when the early-maturing corn variety enters the later-stage rapid dehydration stage, the late-maturing corn variety may be in the slow dehydration stage before the rapid dehydration is started, and does not enter the later-stage rapid dehydration stage, if the dehydration rate of the early-maturing corn variety in the rapid dehydration stage is compared with the dehydration rate of the late-maturing corn variety in the slow dehydration stage, the obtained result is naturally that the dehydration rate of the early-maturing corn variety is higher, and the identification and screening result is poor in effect.

Disclosure of Invention

The invention aims to provide a simple and practical method for efficiently comparing corn varieties with high seed later dehydration rate so as to solve the problems in the background art.

In order to achieve the purpose, the invention provides a method for screening a corn variety with grains quickly dehydrated in the later stage, which comprises the following steps of firstly sampling the corn grains entering or about to enter the quick dehydration stage in the later stage, measuring the water content, and calculating the dehydration rate of the grains according to the change of the water content of the grains between two adjacent sampling and the number of days between the two sampling, wherein the calculation formula is as follows:

then according to the change situation of the dehydration rate of the seeds in a period of time, taking the starting point of the rapid increase of the late dehydration rate of the seeds as a separation point, enabling the corn seeds to enter a late rapid dehydration stage, and counting and comparing the water content of the seeds of different varieties at the starting point and the average dehydration rate within N days after the seeds enter the late rapid dehydration stage;

finally, screening out corn varieties with quickly dehydrated grains in the later stage, wherein the requirements are as follows: the initial point of the later-stage quick dehydration of the seeds is between 35% and 40%, the water content of the seeds is higher than that of a control variety or similar to that of the control variety (the difference value of the seeds compared with the control variety is not more than 1.0%) when the later-stage quick dehydration is started, and the average dehydration rate of the seeds in N days after the later-stage quick dehydration is higher than that of the control variety or similar to that of the control variety (the difference value of the seeds compared with the control variety is not more than 0.1%/day).

The method of the invention is characterized in that: the selection of the time period of the change of the moisture content of the seeds takes the starting point of the rapid rise of the dehydration rate of the seeds in the later period as a separation point. According to the latest research results of the applicant, the dehydration rate of the corn kernels shows a change trend of firstly rising and then falling, and then falling to a low point and then rapidly rising, and when the dehydration rate rapidly rises again in the later period, the water content of the corn kernels is between 30 and 40 percent. The starting point of the rapid increase of the late dehydration rate of the seeds is taken as a separation point, the dehydration rate of the early seeds is in extremely obvious positive correlation (r is 0.845) with the grouting rate, and the dehydration rate of the early seeds is not in obvious correlation with each meteorological factor, so that the physiological dehydration characteristic influenced by development is shown; the dehydration rate of the later-stage seeds is obviously positively correlated with the meteorological factor and the average sunshine hours correlated with the temperature, and is obviously negatively correlated with the rainfall, so that the net dehydration characteristic is shown. The dehydration rate difference affecting the water content of the seeds in the harvest period among different varieties is mainly reflected in a post-stage rapid dehydration stage, the water content of the seeds and the post-stage dehydration rate are used as evaluation scales, when the initial point of the post-stage rapid dehydration of the seeds is between 35% and 40%, the water content of the seeds is higher than or similar to that of a reference variety when the seeds are rapidly dehydrated in the post-start stage, and the average dehydration rate of the seeds entering the post-stage rapid dehydration stage within N days (N is more than or equal to 4) is higher than or similar to that of the reference variety, so that the corn variety has the characteristic of rapid dehydration of the. Thus, the applicant believes that: the corn varieties with high dehydration rate at the later stage are quickly dehydrated at the beginning of higher moisture content of the seeds, and the seeds have lower moisture content when being harvested.

Preferably, when the corn kernels are sampled, representative plants which are consistent in spinning period and healthy and free of plant diseases and insect pests are selected from all varieties, the early-maturing variety or the variety with later spring sowing are sampled from the 35 th day after spinning, and the middle-late-maturing variety or the variety with earlier spring sowing are sampled from the 42 th day after spinning.

Preferably, the corn planting area and the seeding stage with enough high temperature and enough light at the later stage are selected to ensure that the starting point of the rapid increase of the dehydration rate at the later stage is obvious.

Preferably, when the corn kernels are sampled, the corn kernels are sampled once every 3-7 days, the continuous sampling time exceeds 15 days, and the whole sampling process covers a dehydration process in which the moisture content of the corn kernels is reduced from 40% to 30%.

Preferably, when the corn kernels are sampled, more than three ears are taken for each variety at a time, 100 intact kernels are taken from the middle part of each ear, the fresh weight of each ear is rapidly measured, then the seeds are de-enzymed for 30min at a high temperature of 105 ℃, finally the seeds are dried at 80 ℃ until the fresh weight is constant, and the dry weight of each seed is weighed, wherein the calculation formula is as follows:

or directly measuring the water content of the corn kernels by using an infrared moisture meter.

Preferably, N is more than or equal to 4 when the number of days for the corn kernels to enter the later rapid dehydration stage is counted.

Preferably, the control variety is Xiuyu 335.

The corn 335 is a corn variety which is widely popularized and applied in China and has a wide planting area, and the corn variety has the advantages of high seed later-stage dehydration speed and suitability for mechanical harvesting. Therefore, when the moisture content of the seeds in the later-stage rapid dehydration starting stage and the later-stage dehydration rate of the seeds are compared, the first jade 335 is selected as a comparison variety, and the early and late starting of the later-stage rapid dehydration stage and the later-stage dehydration rate of the seeds are measured by the first jade 335, so that a good benchmarking effect can be achieved.

The technical scheme provided by the invention at least has the following beneficial effects:

1. the method provided by the invention is suitable for the screening and breeding process of the corn varieties with quickly dehydrated grains in the later stage, other observation indexes are not needed, the operation is simple, the popularization and the application are convenient, the screening result can be more accurately and visually indicated by quantifying the evaluation indexes, and the reliability of the obtained result is high.

2. The method provided by the invention introduces the starting point (the water content is between 30% and 40%) of the rapid increase of the late dehydration rate of the seeds as the separation point so as to define the optimal time period for comparing the late dehydration rate of the seeds, and selects the condition of rapid dehydration at the beginning and later stage of the water content of more than 35% as the judgment standard according to research and analysis, thereby greatly improving the screening effect of the varieties.

3. The method provided by the invention can eliminate the influence of different varieties in mature period and meteorological factors on the selection result, and also improves the evaluation effect on the dehydration speed by introducing the jade 335 as a reference variety.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, it is obvious that the drawings described below are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

FIG. 1 is a schematic flow diagram of a method of screening a maize variety with post-emergence rapid dehydration of kernels according to the present invention;

FIG. 2 is a graph of the trend of the late-stage dehydration rates of kernels of three corn varieties at S1 sowing time in example 1 of the present invention;

FIG. 3 is a graph of the trend of the late-stage dehydration rates of kernels of three corn varieties at S2 sowing time in example 1 of the present invention;

fig. 4 is a graph of the trend of the late grain dehydration rates of the three corn varieties of example 1 of the present invention at S3 seedtime.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the process of this example is shown in fig. 1, and the specific scheme is as follows:

the test varieties are as follows: zheng 958, deng hai 605.

Selecting a control: and selecting jade 335 as a control variety for evaluating the later dehydration rate of the seeds.

And (3) experimental design: adopts the design of a fission zone, takes the sowing period as the main treatment, takes the test variety and the contrast variety as the auxiliary treatment, arranges the test zone in a random complete block mode in the field, and the area of the test zone is 19.2m²The line spacing is 60cm, and the density is 60000 strains/hm²And repeating the three-time sowing test, wherein the field management is slightly higher than the management level of the common field.

Determining the moisture content and the dehydration rate of the seeds: selecting representative plants with consistent spinning periods and healthy and free from diseases and insect pests for marking during spinning, wherein in the S1 sowing period, sampling is started from 42 th day after spinning due to early spring sowing, in the S2 and S3 sowing periods, sampling is started from 35 th day after spinning due to late spring sowing, the water content of grains is about 40% at the moment, the grains can reach or are about to reach the starting point of the later rapid dehydration stage of the grains, sampling is carried out once every 7 days, continuous sampling is carried out for 4 times, 6 fruit ears are taken for each variety, 100 grains with complete grains are taken from the middle part of each fruit ear, the fresh weight of the grains is rapidly measured, then the seeds are subjected to enzyme deactivation for 30min at a high temperature of 105 ℃, and finally dried at 80 ℃ until the constant weight is obtained, and the dry weight of the grains is weighed. And calculating the water content and the average dehydration rate of the grains according to the following formulas, and obtaining data as shown in figures 2-4 and tables 1-2.

TABLE 1 moisture content of kernels of three maize varieties at different sowing times at the beginning of rapid dehydration at later stage

TABLE 2 average dehydration rates of kernels for three corn varieties at different stages of sowing within 7 days of the late stage rapid dehydration stage

Screening varieties: the initial point of the later-stage quick dehydration of the seeds is 35 to 40 percent of the water content, the water content of the seeds is higher than that of the first jade 335 or is similar to that of the first jade 335 when the later-stage quick dehydration is started, and the average dehydration rate of the seeds in N days after the later-stage quick dehydration is started is higher than that of the first jade 335 or is similar to that of the first jade 335. In this embodiment, N takes a value of 7.

And (4) evaluating the results: from the comparison of the data in FIGS. 2-4 and tables 1-2, it can be seen that: the moisture content of the seeds in the quick dehydration at the later stage of the start of the Shanghai 605 is slightly higher than that of the first jade 335, and the average dehydration rate within 7 days after the quick dehydration is started is also higher than that of the first jade 335, so the Shanghai 605 is a corn variety which is required by people and is quickly dehydrated at the later stage of the seeds; the moisture content of the seeds in the quick dehydration at the later stage of the Zhengdan 958 starting is greatly lower than that of the Xiuyu 335, and the average dehydration rate within 7 days after the quick dehydration is started is obviously lower than that of the Xiuyu 335, so the Zhengdan 958 is a corn variety with slower dehydration rate at the later stage of the seeds.

The fact proves that in the harvest period, the Shanghai 605 shows that the moisture content of corn grains is low in production, the corn grains are suitable for direct harvesting of mechanical grains, the grain damage rate is low, the Zheng 958 shows poor performance in production, the moisture content of the corn grains is high, and a large number of grains are damaged in the process of utilizing machinery to directly harvest the grains, so the Zheng 958 is not suitable for the mode of mechanical grain harvesting.

The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention, and various modifications and changes may be made by those skilled in the art. Any improvement or equivalent replacement directly or indirectly applied to other related technical fields within the spirit and principle of the invention and the contents of the specification and the drawings of the invention shall be included in the protection scope of the invention.

Claims

1. The method for screening the corn varieties with the seeds quickly dehydrated in the later stage is characterized in that the corn seeds entering or about to enter the quick dehydration stage in the later stage are sampled and the moisture content is measured, the seed dehydration rate is calculated according to the moisture content change of the seeds between two adjacent samplings and the number of days between the two samplings, and the calculation formula is as follows:

finally, screening out corn varieties with quickly dehydrated grains in the later stage, wherein the requirements are as follows: the initial point of the later-stage quick dehydration of the seeds is between 35 and 40 percent of the water content, the water content of the seeds is higher than that of a control variety or similar to that of the control variety when the later-stage quick dehydration is started, and the average dehydration rate of the seeds in N days after the later-stage quick dehydration is started is higher than that of the control variety or similar to that of the control variety;

when the corn kernels are sampled, representative plants which are consistent in silking period and healthy and free of plant diseases and insect pests in each variety are selected, the early-maturing variety or the variety with later spring sowing are sampled from the 35 th day after silking, and the middle-late variety or the variety with earlier spring sowing are sampled from the 42 th day after silking.

2. The method of screening maize varieties with kernels that are rapidly dehydrated in a later stage of claim 1, wherein the maize growing area and the seeding stage with sufficient temperature and sufficient light in the later stage are selected to ensure that the starting point of rapid increase of the dehydration rate in the later stage is obvious.

3. The method for screening corn varieties with kernels rapidly dehydrated at the later stage according to claim 2, wherein the corn kernels are sampled once every 3-7 days for more than 15 days, and the whole sampling process covers a dehydration process in which the moisture content of the corn kernels is reduced from 40% to 30%.

4. The method of claim 3, wherein when the corn kernels are sampled, more than three ears are taken for each variety, 100 good-phase kernels are taken from the middle of each ear, the fresh weight of each ear is rapidly measured, then the ears are de-enzymed for 30min at a high temperature of 105 ℃, finally the ears are dried at a temperature of 80 ℃ until the weight of each ear is constant, and the dry weight of each ear is weighed, wherein the calculation formula is as follows:

5. The method for screening the corn varieties with kernels rapidly dehydrated in the later stage according to any one of claims 1 to 4, wherein N is more than or equal to 4 when the number of days for the corn kernels to enter the rapid dehydration stage in the later stage is counted.

6. The method for screening the corn variety with post-kernel rapid dehydration according to claim 5 characterized in that said control variety is Yu Xian 335.