CN113475331A - Planting method for corn DH line combining ability identification - Google Patents

Abstract

The invention provides a planting method for identifying the combining ability of a corn DH system, which comprises the steps of firstly dividing the corn DH system to be identified into three types of early maturity, middle maturity and late maturity according to the number of leaves of the DH system, and then dividing each type of corn DH system to be identified into an NSS group and an SS group according to a heterosis group. After classification, the maize DH line to be identified is planted in a planting area corresponding to the mature period and the blood margin. The number of planting holes of each corn DH line planting field is 5-8, pollination is carried out according to the direction of the section during pollination, the same pollen can be conferred to female ears of different DH lines, the operation is simple, the pollen is not easy to be polluted and make mistakes easily, the requirement on pollinators is low, and the working efficiency is high; harvesting according to the row direction during harvesting can realize that the same DH system is harvested into a group in different combinations, the group is clear when the subsequent combining ability is identified, and the manual grouping classification is not needed, so that a large amount of manual labor is saved. The identification method is simple and rapid to operate, saves identification time and saves breeding cost.

Description

Planting method for corn DH line combining ability identification

Technical Field

The invention relates to the field of agricultural breeding, in particular to a planting method and a zoning tool for identifying the combining ability of a corn DH line.

Background

Corn is an annual herbaceous plant of the genus zea of the family poaceae. It is an important food crop and feed crop and is the crop with the highest total yield all over the world, and the planting area and the total yield are next to rice and wheat. Corn has been praised as a long-life food all the time, contains rich protein, fat, vitamins, trace elements, cellulose and the like, and has great potential for developing high-nutrition and high-biological function foods. But the propagation is more complex, the variety is rich, and the conventional breeding process has the defect of overlong period. Haploid breeding is adopted to solve the problems, a large number of corn DH lines are obtained, however, the related characters and properties of the new DH lines cannot be determined, the biological characteristics, the stress resistance and the genetic characteristics of the new DH lines need to be identified, particularly, the identification of combining ability is important, the existing planting method is large in workload during pollination and harvest classification, time and labor are wasted, and breeding cost is greatly increased.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a planting method for identifying the combining ability of a DH line of corn.

The technical scheme adopted by the invention is as follows: a planting method for the identification of the combining ability of a corn DH line is characterized in that the corn DH line to be identified is divided into three types of early maturity, middle maturity and late maturity according to the maturity stage according to the number of leaves of the DH line; dividing each type of corn DH line to be identified into an NSS group and an SS group according to the heterosis group; after classification, planting the maize DH line to be identified in a planting area corresponding to the mature period and the blood margin; the number of planting holes of each corn DH line planting field is 5-8, pollination is carried out according to the direction of the section during pollination, and the same pollen is conferred to the female ears of different DH lines; harvesting according to the row direction during harvesting, and harvesting the same DH line into a group in different combinations, which comprises the following steps:

s1, type division: dividing the maize DH to be identified into three types of early maturity, middle maturity and late maturity according to the maturity stage according to the number of leaves of the DH, and dividing each type of maize DH to be identified into an NSS group and an SS group according to a heterosis group;

s2, numbering: the DH lines were numbered according to partition type and number, the first DH line of the early-maturing NSS-like population: the precocity is compiled into E, and the NSS group is compiled into N, E-N-0001;

s3, selecting test seeds: selecting 20-30 corresponding test seeds for each group according to the heterosis mode;

s4, sowing: dividing corresponding planting areas according to the maturity and the heterosis group before sowing, dividing each DH line to be tested into a row, dividing the DH line to be tested into sections with corresponding number according to the number of the tested seeds, wherein the section interval is 50-80cm, each section is 4-8 holes, and the planting distance is 18-25 cm; planting different DH lines in wide and narrow rows, wherein the wide rows are 70-80cm, the narrow rows are 40-50cm, corresponding test seeds are planted at two ends of each planting area, and the number of the test planting rows is 1/8-1/10 corresponding to the number of the DH lines;

s5, bagging: bagging the female spike of DH line and the male spike of test seed before spinning and powdering;

s6, pollination: collecting pollen of the test seeds at two ends of each row of DH line planting areas, pollinating the pollen to the DH line filaments in the corresponding row, and bagging;

s7, listing: hanging cards: the label writing format is as follows: DH line number is before, test kind number is after, the middle one separates two numbers with "x", hang the label written according to the above-mentioned form on pollinating plant after pollinating;

s8, harvesting: harvesting according to the direction of the DH line, harvesting the same section in a harvesting bag, and harvesting the labels hung during pollination in the harvesting bag together, wherein the ears in the same row are grouped into a group;

s9, threshing and storing: after harvesting, the DH is an independent unit in the same bag, and can not be mixed with other fruit ears in the subsequent selection, threshing and storage processes;

s10, combining ability identification: and (4) performing classified sowing according to the harvest groups during the identification of the combining ability in the next year, and classifying and arranging different testing combinations of the same DH line.

The invention has the beneficial effects that:

1. the invention reduces the time for identifying the combining ability of the DH line, is convenient for cross pollination, reduces the occupied area for planting and saves the breeding cost.

2. According to the invention, the sowing is carried out according to the harvest groups in the next year of combining ability identification, so that different combinations of the same DH system can be conveniently and rapidly classified and arranged, and the following working property and combining ability can be conveniently measured.

3. The number of planting holes of each corn DH line planting field is 5-8, pollination is carried out according to the direction of the section during pollination, the same pollen can be conferred to female ears of different DH lines, the operation is simple, the pollen is not easy to pollute and make mistakes easily, the requirement on pollinators is low, and the working efficiency is high; harvesting according to the row direction during harvesting can realize that the same DH system is harvested into a group in different combinations, the group is clear when the subsequent combining ability is identified, and the manual grouping classification is not needed, so that a large amount of manual labor is saved. The identification method is simple and rapid to operate, saves identification time and saves breeding cost.

Drawings

FIG. 1 is a schematic view of the planting method of the present invention;

FIG. 2 is a schematic illustration of the invention.

Detailed Description

The invention will be further explained and illustrated with reference to specific examples;

example 1

A planting method for identifying the combining ability of a corn DH line specifically comprises the following steps:

s1, type division: dividing the maize DH to be identified into three types of early maturity, middle maturity and late maturity according to the maturity stage according to the number of leaves of the DH, and then dividing each type of maize DH to be identified into an NSS group and an SS group according to a heterosis group;

s2, numbering: the DH lines are numbered according to the division type and number, for example, the DH lines of the first early-maturing NSS group can be coded as follows: precocity is coded as E, NSS group is coded as N, E-N-0001

S3, selecting test seeds: selecting 20-30 corresponding test seeds for each group according to the heterosis mode;

s4, sowing: dividing corresponding planting areas according to the maturity and the heterosis group before sowing, dividing each tested DH line into one line, dividing the test seeds into sections with corresponding number according to the number of the test seeds, wherein the section interval is 50-80cm, each section has 4-8 holes, the plant distance is 18-25cm, planting different DH lines by adopting wide and narrow lines, the wide lines are 70-80cm, and the narrow lines are 40-50cm, so that the pollination operation is facilitated, planting corresponding test seeds at two ends of each planting area, and testing the planting line number to be 1/8-1/10 corresponding to the line number of the DH line;

s5, bagging: bagging female ears of DH lines and male ears of test seeds before spinning and pollen scattering to prevent foreign flowers from mixing;

s6, pollination: collecting pollen of the test seeds at two ends of each row of DH line planting areas, pollinating the pollen of the test seeds to the DH line filaments in the corresponding row, and bagging;

s7, hanging the card: the label writing format is as follows: DH line number is before, test kind number is after, the middle one separates two numbers with "x", hang the label written according to the above-mentioned form on pollinating plant after pollinating;

s8, harvesting: harvesting according to the direction of the DH line, harvesting the same section in a harvesting bag, and harvesting the labels hung during pollination in the harvesting bag together, wherein the ears in the same row are grouped into a group;

s9, threshing and storing: after harvesting, the DH is an independent unit in the same bag, and can not be mixed with other fruit ears in the subsequent selection, threshing and storage processes;

s10, combining ability identification: the seeding is classified according to the harvest groups when the combining ability is identified in the next year, different testing combinations of the same DH system can be conveniently classified and arranged, and the follow-up working property investigation and the combining ability determination are facilitated.

Example 2

A planting method for identifying the combining ability of a corn DH line specifically comprises the following steps:

s1, type division: the maize DH line to be identified is divided into early maturing class, middle maturing class and late maturing class according to the number of leaves of the DH line, wherein the number of the parent leaves of the early maturing class is below 15, the number of the parent leaves of the middle maturing class is 15-18, and the number of the parent leaves of the middle maturing class is above 18.

After the maize DH lines to be identified are divided into early-maturing types, middle-maturing types and late-maturing types, differential sowing can be correspondingly tested according to different maturing periods, the fact that different DH in different maturing periods can meet flower periods of corresponding test seeds is guaranteed, hybrid pollination can be conducted, pollination concentration and pollination rate are improved, and pollination operation workload is reduced.

Dividing the DH lines with the divided mature periods into two groups of SS and NSS according to blood margins, wherein the blood margin division can be determined according to parent blood margins or can be determined by a DNA molecular marking method; the blood relationship division can ensure that the heterosis type is utilized to select the corresponding test seeds, thereby ensuring the accuracy and the practicability of the combining ability identification.

Because the number of the selected maize DH lines to be planted is large, the selected maize DH lines to be planted only depend on mental memory, confusion is easily caused, the sowing arrangement of the maize DH lines to be planted subsequently is influenced, and further the cross pollination and the harvesting are influenced. In order to solve the problem, the planting seeds of the maize DH line which is classified to be planted are numbered, so that the planted DH line can be ensured not to be mixed up when planning and implementing subsequent planting planning, cross pollination, harvesting and threshing, and the accuracy of cross pollination and harvesting is ensured.

S2, numbering: the specific numbering method is as follows: e is woven for early maturity, M is woven for middle maturity and L is woven for late maturity; the SS group is numbered as S, the NSS group is numbered as N, then DH lines are numbered according to the sequence of maturity, blood relationship and serial number, for example, the first DH line with blood relationship of the precocious group as SS group is numbered as E-S-001.

S3, selecting test seeds: the selection of the test species refers to the standard test species of the domestic inbred line and the heterosis utilization mode for selection.

TABLE 1 maize inbred line heterosis group

TABLE 2 maize inbred line heterosis model

The method comprises the steps of classifying the numbered planting seeds of the DH line of the corn to be planted according to the seeding amount of 2-3 seeds in each hole, filling the classified planting seeds into seed bags, numbering the seed bags, wherein the used seed bags are the existing cowhide seed bags, and the size of the seed bags is determined according to the quantity of the seeds. The seeds are planted in 2-3 grains per hole, so that the problem of non-emergence caused by low seed germination rate can be effectively prevented.

The seed bag number may be the same as the number of the DH line, or a new number may be used.

S4, sowing:

and (3) seeding the corn DH line planting seeds to be identified: the seed sowing is carried out on 20-25 m multiplied by 30-50 m block lands with 4500-6000 plants/mu, the planting density is determined according to irrigation water and land fertility conditions, and the waste of land space caused by the influence on the planting effect or the overlow planting density due to overhigh planting density is avoided; the thickness of a soil layer of a block land selected for planting corn is more than 60 cm, and the thickness of mellow soil of a plough layer is more than 20 cm; the deep soil layer is beneficial to forming a strong root system and improving the water and fertilizer absorption capacity of the root system, the soil of the block land is sandy soil or light loam, and the basic fertility of the soil is good.

Planting seeds of the maize DH line to be identified: and calculating the identification land according to the number of DH lines and the number of test plots, and dividing the planting plots into 6 areas, namely an early maturing group SS area, an early maturing group NSS area, a middle maturing group SS area, a middle maturing group NSS area, a late maturing group SS area group and a late maturing group NSS area, according to the calculation results. The early maturing group SS area is correspondingly planted with a plurality of corn DH systems to be planted of an early maturing type SS group, the early maturing group NSS area is correspondingly planted with a plurality of corn DH systems to be planted of an early maturing type NSS group, the middle maturing group SS area is correspondingly planted with a plurality of corn DH systems to be planted of a middle maturing type SS group, the middle maturing group NSS area is correspondingly planted with a plurality of corn DH systems to be planted of a middle maturing type NSS group, the late maturing group SS area is correspondingly planted with a plurality of corn DH systems to be planted of an late maturing type SS group, and the late maturing group NSS area is correspondingly planted with a plurality of corn DH systems to be planted of a late maturing type NSS group.

Zoning: the interval between the sections is 50-80cm, the length of each section is 72-200cm, the width row is 70-80cm, and the narrow row is 40-50 cm; after the zoning tools are adjusted, the zoning tools are assembled according to the number of the DH lines of the premature maize to be planted in the planting land of the SS area of the premature group, the number of the assembled zoning tools is ensured to be consistent with the number of DH coefficients of the planting area, the number of the segments is consistent with the number of tests of the planting area, and the zoning tools are assembled in other planting areas according to the method.

The planting according to the classification method aims to plant the same DH line into a row and perform segmentation, the planting method is not easy to be confused during planting, cross pollination and harvesting, the working efficiency is improved, and the working intensity is reduced.

The number of planting holes of each section of the corn DH line planting field is 4-8, 4-8 seedling holes grow 4-8 corn seedlings, and 3-5 corn seedlings can be normally hybridized and pollinated according to the flowering phase condition in the subsequent hybridization and pollination process. If the number of hybrid strains is less than this range, the amount of seeds harvested subsequently becomes too small to perform the combination measurement. If the number of hybrid pollination plants is higher than the range, the land, workload, time and the like are greatly increased, and the breeding cost is increased. The specific planting mode is to adopt a dibbling gun to dibble seeds.

The invention plants corresponding test seeds in two areas of each DH line planting area respectively, the test planting amount is 1/10 corresponding to DH lines, the test seeds are sowed in three stages, the sowing time in one stage is 3-4 days before sowing of DH lines, the sowing time in the second stage is sowed with DH lines in the same period, the sowing time in the third stage is 3-4 days after sowing of DH lines, and the purpose of wrong stage is to ensure that the flowering period of the test seeds is long enough to pollinate all corresponding DH lines.

S5, bagging: and (3) timely sheathing the female ears of the DH line with a parchment bag after the female ears grow out to prevent the female ears from pollinating with foreign pollen after the female ears grow out of the filaments, and observing and bagging the female ears in the field 5-6 days before the DH line silks and every day when the silks are silked.

S6, pollination: after the DH line silks, collecting test seed pollen planted before the corresponding section, and pollinating, wherein the pollination time is preferably 9:30-11: 30.A, and the pollen amount is large and the activity is good. And (3) preventing external pollination from being polluted during pollination, and continuously covering the female ears with a sheepskin paper bag and fixing the female ears with pins after pollination. The pollination can also be that pollen of a test species before each section is collected firstly, then, the DH line of each row in the section is checked along a walkway, and the pollination is performed by crossing and pollinating the silks which are already spun, so that the workload can be greatly reduced, and the pollination of each section by using the same pollen is not easy to be confused, and the operation is simple and convenient.

S7, hanging the card: after pollination, the tag is hung immediately, and the writing format of the tag is as follows: DH line is numbered first, test species is numbered later, two numbers are separated by X, if L-N-001 is hybridized with test species Zheng 58, the tag is written as L-N-001 × Zheng 58. The tag is hung on the middle upper part of the pollinating plant, and the tag is hung on the middle upper part of the pollinating plant, so that the pollinated plant can be clearly known, and different hybrid combination seeds can be distinguished after later harvest, so that the hybrid is avoided.

S8, harvesting: in the mature period, each worker stands one row to harvest according to the row direction, the same section is harvested in one harvesting bag, labels hung during pollination are harvested in the harvesting bag together, and the ears in the same row are grouped into one group. The harvest according to the method can conveniently classify different hybridization combinations of the same female parent (DH line) so as to facilitate the sowing, recording and production testing work in the subsequent combining ability identification.

S9, threshing and storing: after the moisture of the seeds is reduced to below 14 percent, the seeds are manually threshed, the harvested seeds and the bags of DH are an independent unit, and the seeds cannot be mixed with other ears during threshing and storage.

S10, combining ability identification: the seeding is classified according to the harvest groups when the combining ability is identified in the next year, different testing combinations of the same DH system can be conveniently classified and arranged, and the follow-up working property investigation and the combining ability determination are facilitated.

Claims (2)

1. A planting method for identifying the combining ability of a corn DH line is characterized by comprising the following steps: dividing the maize DH line to be identified into three types of early maturity, middle maturity and late maturity according to the maturity stage according to the number of leaves of the DH line; dividing each type of corn DH line to be identified into an NSS group and an SS group according to the heterosis group; after classification, planting the maize DH line to be identified in a planting area corresponding to the mature period and the blood margin; the number of planting holes of each corn DH line planting field is 5-8, pollination is carried out according to the direction of the section during pollination, and the same pollen is conferred to the female ears of different DH lines; harvesting is carried out in the row direction, and the same DH line is harvested into a group in different combinations.

2. The planting method for maize DH line zygosity identification according to claim 1, wherein: the method specifically comprises the following steps:

s1, type division: dividing the maize DH to be identified into three types of early maturity, middle maturity and late maturity according to the maturity stage according to the number of leaves of the DH, and dividing each type of maize DH to be identified into an NSS group and an SS group according to a heterosis group;

s2, numbering: the DH lines were numbered according to partition type and number, the first DH line of the early-maturing NSS-like population: the precocity is compiled into E, and the NSS group is compiled into N, E-N-0001;

s3, selecting test seeds: selecting 20-30 corresponding test seeds for each group according to the heterosis mode;

s4, sowing: dividing corresponding planting areas according to the maturity and the heterosis group before sowing, dividing each DH line to be tested into a row, dividing the DH line to be tested into sections with corresponding number according to the number of the tested seeds, wherein the section interval is 50-80cm, each section is 4-8 holes, and the planting distance is 18-25 cm; planting different DH lines in wide and narrow rows, wherein the wide rows are 70-80cm, the narrow rows are 40-50cm, corresponding test seeds are planted at two ends of each planting area, and the number of the test planting rows is 1/8-1/10 corresponding to the number of the DH lines;

s5, bagging: bagging the female spike of DH line and the male spike of test seed before spinning and powdering;

s6, pollination: collecting pollen of the test seeds at two ends of each row of DH line planting areas, pollinating the pollen to the DH line filaments in the corresponding row, and bagging;

s7, listing: the label writing format is as follows: DH line number is before, test kind number is after, the middle one separates two numbers with "x", hang the label written according to the above-mentioned form on pollinating plant after pollinating;

s8, harvesting: harvesting according to the direction of the DH line, harvesting the same section in a harvesting bag, and harvesting the labels hung during pollination in the harvesting bag together, wherein the ears in the same row are grouped into a group;

s9, threshing and storing: after harvesting, the DH is an independent unit in the same bag, and can not be mixed with other fruit ears in the subsequent selection, threshing and storage processes;

s10, combining ability identification: and (4) performing classified sowing according to the harvest groups during the identification of the combining ability in the next year, and classifying and arranging different testing combinations of the same DH line.

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