Breeding method of early-maturing high-resistance corn male parent

Abstract

The invention relates to a breeding method of an early-maturing high-resistance corn male parent. Comprising the following steps: (1) by taking an European early-maturing stable-yield corn population or hybrid as a basic material, performing high-density planting in a coastal region of a warm-temperature zone, and performing selfing breeding of at least three generations to obtain a first character stable line; (2) conventionally planting the first character stable line in a coastal region of a warm zone, and carrying out selfing breeding of at least three generations to obtain a second character stable line; and (3) planting the second character stable line in a third accumulated temperature zone of Heilongjiang, and screening an excellent line as a male parent KPB001 of the early-maturing corn variety. The early-maturing corn male parent cultivated by the method is bred in multiple generations under the environmental stress of high temperature, high humidity, high density, strong wind and the like in northern China coastal areas; the pollen scattering period is 3-5 days later than that of the male parent of the corn variety mainly pushed in the third accumulated temperature zone of Heilongjiang, normal pollen scattering, fruiting and maturing can be achieved, and light and temperature reaction is not sensitive; the method can be used for cultivating early-maturing corn hybrids with wide adaptability, high resistance and stable yield.

Description

Technical Field

[0001] The invention relates to the technical field of corn breeding, and in particular to a method for breeding an early-maturing and highly resistant corn male parent. Background Art

[0002] Heilongjiang Province is the main corn-growing area in my country, and its total corn output, per capita possession and commercialization rate are among the highest in the country. As an important food, feed and industrial raw material crop, corn occupies a pivotal position in agricultural production in Heilongjiang Province. In recent years, the planting area of ​​early-maturing corn varieties represented by Demeya 1, 2 and 3 bred by the German KWS company has gradually expanded in Heilongjiang Province, and the market share is relatively high. The Demeya series of corn varieties have the characteristics of early maturity, high resistance, stable yield, fast grain dehydration in the late stage, and suitability for mechanized harvesting. It has now become the main corn variety in the 3rd and 4th temperate zones in Heilongjiang Province.

[0003] Breeding early-maturing corn germplasm materials is the basic condition for breeding early-maturing corn hybrids. In the early-maturing spring corn areas in northern my country, there are few self-bred excellent early-maturing corn varieties with high resistance and stable yield, and the varieties are not widely adaptable. The main reasons are: the corn varieties in this region are weakly resistant to high temperature heat damage and southern rust, and are poorly adaptable to the high temperature and high humidity synchronous environment in coastal areas in summer; the corn growth period in this region is short, and the migration of northern varieties to the south often results in lower corn yields than the local main varieties, and more serious ear rot. Therefore, it is of great significance to create excellent early-maturing male germplasm materials in the coastal areas of North China and introduce them to the third accumulated temperature zone of Heilongjiang for identification and combination, which will further improve the adaptability of corn hybrids.

[0004] In view of this, the present invention provides a method for breeding early-maturing and highly resistant corn male parents. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a method for breeding early-maturing and highly resistant maize male parents, with the purpose of breeding maize varieties with good early maturity, wide adaptability and stable yield by adopting early-maturing maize male parents.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] In a first aspect, a method for breeding an early-maturing and highly resistant maize male parent comprises the following steps:

[0008] (1) Using European early-maturing stable-yield corn populations or hybrids as the basic material, planting them at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, and conducting self-pollination breeding for at least three generations to obtain a first trait stable line; the first trait stable line has the characteristics of male-female coordination, good lodging resistance, strong disease resistance, large pollen quantity, and more male spike branches;

[0009] (2) Continue to routinely plant the first trait stable line at 60,000 to 100,000 plants per hectare in warm temperate coastal areas, conduct self-pollination and selection for at least three generations, and obtain the second trait stable line;

[0010] The second trait stable line has the characteristics of good early maturity, strong disease resistance, good lodging resistance, moderate plant height and good fruit setting;

[0011] (3) The stable line of the second trait was planted in the third accumulated temperature zone of Heilongjiang Province, and the excellent strains were selected as the male parent of the early-maturing corn variety KPB001.

[0012] Based on the above technical solution, the present invention can also be improved as follows.

[0013] Further, step (1) includes the following specific steps:

[0014] (1-1) Using European early-maturing and stable-yield maize populations or hybrids as the basic material, plant them at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S1 generation;

[0015] (1-2) Continue to plant the S1 generation at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S2 generation;

[0016] (1-3) Continue to plant the S2 generation at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S3 generation, which is the stable line of the first trait.

[0017] Further, step (2) includes the following specific steps:

[0018] (2-1) In warm temperate coastal areas, the S3 generation is conventionally planted at 60,000 to 100,000 plants / hectare, and excellent individual plants are selected for self-pollination to obtain the S4 generation;

[0019] (2-2) Continue to conventionally plant the S4 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S5 generation;

[0020] (2-3) Continue to conventionally plant the S5 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S6 generation line, which is the stable line for the second trait.

[0021] Furthermore, the superior strain in step (3) is a corn inbred line that sheds pollen 3-5 days later than the local main corn variety male parent A, can shed pollen, set fruit, and mature normally, and is insensitive to light and temperature. The insensitivity to light and temperature is mainly manifested in that the same corn variety can tassel, shed pollen, set fruit, and mature normally when planted in different latitudes, and the corn plants show strong environmental adaptability.

[0022] Furthermore, the male parent A of the local main corn variety is the male parent HA131 of Keyu 19.

[0023] Furthermore, the warm temperate coastal area includes any one of Hebei Province, Tianjin City, and Shandong Province; the third accumulated temperature zone of Heilongjiang includes areas with active accumulated temperature between 2300℃ and 2500℃, mainly referring to areas with active accumulated temperature between 2300℃ and 2500℃ in Heilongjiang.

[0024] Furthermore, the basic material includes the European early-maturing and stable-yield corn hybrid Demeya 3.

[0025] Furthermore, among the traits of the first trait stable line, the male-female coordination is that the silking period is 0-3 days earlier than the pollen shedding period, the good lodging resistance is that the sum of the corn lodging rate and the lodging rate is less than 5%, the strong disease resistance is high resistance to large leaf spot, small leaf spot, Curvularia leaf spot, brown spot, rust, and stem rot, the large pollen amount is that the continuous pollen shedding time is more than 6 days, and the large number of male spike branches is that the number of male spike branches is greater than 5.

[0026] Furthermore, among the traits of the second trait stable line, the good early maturity means that the growth period is more than 10 days shorter than that of the local main corn variety father B, the strong disease resistance means high resistance to large leaf spot, small leaf spot, Curvularia leaf spot, brown spot, rust, and stem rot, the good lodging resistance means that the sum of the corn lodging rate and the lodging rate is less than 5%, the moderate plant height means that the height difference with the local main corn variety father B is ±10 cm, and the good firmness means that the grains are closely arranged without gaps, and the bald tip is less than 0.5 cm.

[0027] Furthermore, the male parent B of the local main corn variety is the male parent PH4CV of Xianyu 335.

[0028] The invention uses European early-maturing, highly resistant and stable-yield corn hybrids or populations as basic materials, introduces the varieties or populations to the coastal areas of North China for planting; obtains relatively stable second trait stable lines through self-pollination and breeding in the warm temperate coastal areas; selects the second trait stable lines for planting and identification in the early-maturing spring corn type areas in the north; uses the male parent of the local main corn variety as a control, and screens out the inbred lines with a pollen shedding period that is basically consistent with the control, strong disease resistance, good lodging resistance, relatively tall plants, a large number of male spike branches, and insensitive light and temperature reactions as the male parent materials.

[0029] The beneficial effects of the present invention are as follows: the early-maturing corn male parent cultivated by the present invention is based on European early-maturing and stable-yield corn groups or hybrids, and is bred through multiple generations under environmental stresses such as high temperature, high humidity, and strong winds in the coastal areas of North China; the pollen shedding period is 3-5 days later than that of the male parent of the local main corn variety promoted in the early-maturing area, and the corn can shed pollen, set grains, and mature normally, and is insensitive to light and temperature reactions; and the corn can be used to cultivate early-maturing corn hybrids that are widely adaptable, highly resistant, and have stable yields. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is the breeding pedigree diagram of KPB001 of the present invention. DETAILED DESCRIPTION

[0031] The principles and features of the present invention are described below, and the examples are only used to explain the present invention and are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in this field or the product instructions are used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased through regular channels.

[0032] Example

[0033] This embodiment relates to a method for breeding early-maturing and highly resistant maize male parents, comprising the following steps:

[0034] (1) Using European early-maturing stable-yield corn populations or hybrids as the basic material, planting them at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, and conducting self-pollination breeding for at least three generations to obtain a first trait stable line; the first trait stable line has the characteristics of male-female coordination, good lodging resistance, strong disease resistance, large pollen quantity, and more male spike branches;

[0035] (2) Continue to routinely plant the first trait stable line at 60,000 to 100,000 plants per hectare in warm temperate coastal areas, conduct self-pollination and selection for at least three generations, and obtain the second trait stable line;

[0036] The second trait stable line has the characteristics of good early maturity, strong disease resistance, good lodging resistance, moderate plant height and good fruit setting;

[0037] (3) The stable line of the second trait was planted in the third accumulated temperature zone of Heilongjiang Province, and the excellent strains were selected as the male parent of the early-maturing corn variety KPB001.

[0038] In this embodiment, step (1) preferably includes the following specific steps:

[0039] (1-1) Using European early-maturing stable-yield corn populations or hybrids as the basic material, planting them at a high density of 100,000 to 140,000 plants / hectare in warm temperate coastal areas, such as 100,000 plants / hectare, 120,000 plants / hectare, or 140,000 plants / hectare, selecting excellent individual plants for self-pollination to obtain the S1 generation;

[0040] (1-2) Continue to plant the S1 generation in warm temperate coastal areas at a high density of 100,000 to 140,000 plants / hectare, such as 100,000 plants / hectare, 120,000 plants / hectare, or 140,000 plants / hectare, and select excellent individual plants for self-pollination to obtain the S2 generation;

[0041] (1-3) Continue to plant the S2 generation in warm temperate coastal areas at a high density of 100,000 to 140,000 plants / hectare, for example, 100,000 plants / hectare, 120,000 plants / hectare, and 140,000 plants / hectare, select excellent individual plants for self-pollination, and obtain the S3 generation, which is the stable line of the first trait.

[0042] In this embodiment, step (2) preferably includes the following specific steps:

[0043] (2-1) In warm temperate coastal areas, the S3 generation is conventionally planted at 60,000 to 100,000 plants / hectare, such as 60,000 plants / hectare, 80,000 plants / hectare, or 100,000 plants / hectare, and superior individual plants are selected for self-pollination to obtain the S4 generation;

[0044] (2-2) Continue to conventionally plant the S4 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, such as 60,000 plants / hectare, 80,000 plants / hectare, or 100,000 plants / hectare, and select superior individual plants for self-pollination to obtain the S5 generation;

[0045] (2-3) Continue to conventionally plant the S5 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, such as 60,000 plants / hectare, 80,000 plants / hectare, and 100,000 plants / hectare, and select excellent individual plants for self-pollination to obtain the S6 generation line, which is the stable line for the second trait.

[0046] In this embodiment, the superior strain in step (3) is a corn inbred line that sheds pollen 3-5 days later than the local main corn variety male parent A, can shed pollen, set fruit, and mature normally, and is insensitive to light and temperature. The insensitivity to light and temperature is mainly manifested in that the same corn variety can tassel, shed pollen, set fruit, and mature normally when planted in different latitudes, and the corn plants show strong environmental adaptability. The local main corn variety male parent A is the male parent HA131 of Keyu 19.

[0047] Preferably, in this embodiment, the warm temperate coastal area includes any one of Hebei Province, Tianjin City, and Shandong Province.

[0048] In this embodiment, the third accumulated temperature zone preferably includes areas with active accumulated temperature between 2300°C and 2500°C, mainly referring to areas with active accumulated temperature between 2300°C and 2500°C in Heilongjiang.

[0049] Among them, among the traits of the first stable character, the male-female coordination is that the silking period is 0-3 days earlier than the pollen shedding period, the good lodging resistance is that the sum of the lodging rate and the inversion rate of corn is less than 5%, the strong disease resistance is high resistance to large spot disease, small spot disease, Curvularia leaf spot disease, brown spot disease, rust disease, and stem rot disease, the large amount of pollen is that the continuous pollen shedding time is more than 6 days, and the more male spike branches are that the number of male spike branches is more than 5. Among the traits of the second stable character, the good early maturity is that the growth period is more than 10 days shorter than that of the local main corn variety male parent B, the strong disease resistance is high resistance to large spot disease, small spot disease, Curvularia leaf spot disease, brown spot disease, rust disease, and stem rot disease, the good lodging resistance is that the sum of the lodging rate and the inversion rate of corn is less than 5%, the moderate plant height is ±10cm different from the height of the local main corn variety male parent B, and the good solidity is that the grains are closely arranged without gaps, and the bald tip is less than 0.5cm. The male parent B of the local main corn variety is the male parent PH4CV of Xianyu 335.

[0050] The following is a further explanation with a specific breeding case.

[0051] The present embodiment specifically provides a method for breeding an early-maturing and highly resistant maize male parent, comprising the following specific steps:

[0052] (1) This inbred line is based on the European early-maturing and stable-yield corn hybrid Demeya 3. It was planted in Tangshan, Hebei Province from 2015 to 2017, with a planting density of 120,000 plants / hectare. Under high density, individual plants with coordinated male and female sexes, good lodging resistance, strong disease resistance, large pollen count, and a large number of male spike branches were selected for self-pollination and harvest.

[0053] (2) From 2018 to 2020, the S4 to S6 generations were planted in Tangshan, Hebei Province, with a planting density of 90,000 plants / hectare. The selection targets were early maturity, moderate plant height, and good fruit set. Individual plants were self-pollinated and harvested. By the end of 2020, a stable corn inbred line KPB001 was bred.

[0054] (3) In 2022, KPB001 will be planted and identified in Keshan County and Linkou County of Qiqihar City, with a planting density of 90,000 plants / hectare and a planting area of ​​60m2 per test site. 2 The male parent HA131 of the main variety Keyu 19 was used as the control. The comparison results are shown in Table 1 below.

[0055] Table 1 Survey table of KPB001 plant and yield characteristics

[0056]

[0057] As shown in Table 1, the growth period of KPB001 in spring sowing in Tangshan is about 115 days, and the growth period in Qiqihar, Heilongjiang is about 130 days. The seedlings of this inbred line are strong, with green leaf sheaths and dark green leaves. The plant height is about 181cm in Tangshan and about 174cm in Qiqihar. The plant type of this inbred line is semi-compact, with 8-10 primary male spike branches, green anthers, and light purple filaments. The fruit spike is conical, the spike axis is pink, the spike length is 15 cm, the number of spike rows is 12-16, and the bald tip is 0.3 cm. The grains are yellow, hard, with a thousand-grain weight of 341 grams and a seed rate of 88%. Compared with the male parent of the main variety in the third accumulated temperature zone of Heilongjiang: the plant height is 6-9cm higher, the tasseling period is 3-4 days later, the number of male spike branches is two more, and the single spike yield is 11-17g higher.

[0058] The lodging resistance, disease resistance and light and temperature sensitivity of KPB001 are shown in Table 2 below. Among them, the lodging rate is the percentage of corn plants with an inclination greater than 45 degrees to the total number of corn plants in the area, and the survey is conducted immediately after the corn lodging; the breaking rate is the percentage of plants with broken parts below the cob to the total number of plants in the area, and the survey is conducted before harvest. The evaluation method of corn disease resistance refers to the National Corn Comprehensive Resistance Field Survey and Identification Standard (DB52 / T 1501.12-2020). The light and temperature sensitive plant rate is the percentage of corn plants that cannot bloom, bear fruit, and mature normally to the total number of plants in the area.

[0059] Table 2 KPB001 resistance survey table

[0060]

[0061]

[0062] As shown in Table 2, the KPB001 inbred line is highly resistant to corn leaf blight, leaf spot, Curvularia leaf spot, brown spot, rust, and stem rot. Compared with the HA131 inbred line, KPB001 has stronger resistance to leaf spot, lodging and bending resistance, and is slightly more sensitive to light and temperature than HA131.

[0063] In summary, the early-maturing corn male parent cultivated by the present invention is based on the European early-maturing and stable-yield corn population or hybrid, and is bred through multiple generations under environmental stresses such as high temperature, high humidity, and strong winds in the coastal areas of North China. The pollen shedding period is 3-5 days later than that of the male parent of the local main corn variety in the early-maturing area, and the corn can shed pollen, set fruit, and mature normally, and is insensitive to light and temperature. The corn can be used to cultivate early-maturing corn hybrids with wide adaptability, high resistance, and stable yield.

[0064] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for breeding early-maturing and highly resistant maize male parents, characterized in that: The steps include: (1) Using European early-maturing stable-yield maize populations or hybrids as the basic material, planting them at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, and conducting self-pollination breeding for at least three generations to obtain a stable line of the first trait; The first trait stable line has the characteristics of male-female coordination, good lodging resistance, strong disease resistance, large pollen quantity, and more male spike branches; (2) Continue to routinely plant the first trait stable line at 60,000 to 100,000 plants per hectare in warm temperate coastal areas, conduct self-pollination and selection for at least three generations, and obtain the second trait stable line; The second trait stable line has the characteristics of good early maturity, strong disease resistance, good lodging resistance, moderate plant height and good fruit setting; (3) The stable line of the second trait was planted in the third accumulated temperature zone of Heilongjiang Province, and the excellent strains were selected as the male parent of the early-maturing corn variety KPB001.

2. The method for breeding an early-maturing and highly resistant maize male parent according to claim 1, characterized in that: Step (1) includes the following specific steps: (1-1) Using European early-maturing and stable-yield maize populations or hybrids as the basic material, plant them at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S1 generation; (1-2) Continue to plant the S1 generation at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S2 generation; (1-3) Continue to plant the S2 generation at a high density of 100,000 to 140,000 plants per hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S3 generation, which is the stable line of the first trait.

3. The method for breeding an early-maturing and highly resistant maize male parent according to claim 1, characterized in that: Step (2) includes the following specific steps: (2-1) In warm temperate coastal areas, the S3 generation is conventionally planted at 60,000 to 100,000 plants / hectare, and excellent individual plants are selected for self-pollination to obtain the S4 generation; (2-2) Continue to conventionally plant the S4 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S5 generation; (2-3) Continue to conventionally plant the S5 generation at 60,000 to 100,000 plants / hectare in warm temperate coastal areas, select excellent individual plants for self-pollination, and obtain the S6 generation line, which is the stable line for the second trait.

4. The method for breeding an early-maturing and highly resistant maize male parent according to claim 1, characterized in that: The superior strain in step (3) is a corn inbred line that sheds pollen 3-5 days later than the local main corn variety male parent A, can shed pollen, set fruit, and mature normally, and is insensitive to light and temperature.

5. The method for breeding early-maturing and highly resistant maize male parent according to claim 1, characterized in that: The main local corn variety, male parent A, is the male parent HA131 of Keyu 19.

6. The method for breeding early-maturing and highly resistant maize male parent according to any one of claims 1 to 5, characterized in that: The warm temperate coastal area includes any one of Hebei Province, Tianjin City, and Shandong Province; the third accumulated temperature zone of Heilongjiang includes areas with active accumulated temperature between 2300°C and 2500°C.

7. The method for breeding early-maturing and highly resistant maize male parent according to any one of claims 1 to 5, characterized in that: The basic material includes the European early-maturing and stable-yield corn hybrid Demeya 3.

8. The method for breeding early-maturing and highly resistant maize male parent according to claim 1, characterized in that: Among the traits of the first trait stable line, the male-female coordination means that the silking stage is 0-3 days earlier than the pollen shedding stage, the good lodging resistance means that the sum of the corn lodging rate and the lodging rate is less than 5%, the strong disease resistance means high resistance to large leaf spot, small leaf spot, Curvularia leaf spot, brown spot, rust and stem rot, the large pollen amount means that the continuous pollen shedding time is more than 6 days, and the large number of male spike branches means that the number of male spike branches is more than 5.

9. The method for breeding early-maturing and highly resistant maize male parent according to claim 1, characterized in that: Among the traits of the second trait stable line, the good early maturity means that the growth period is more than 10 days shorter than that of the local main corn variety father B, the strong disease resistance means high resistance to large leaf spot, small leaf spot, Curvularia leaf spot, brown spot, rust, and stem rot, the good lodging resistance means that the sum of the corn lodging rate and the lodging rate is less than 5%, the moderate plant height means that the height difference with the local main corn variety father B is ±10 cm, and the good firmness means that the grains are closely arranged without gaps, and the bald tip is less than 0.5 cm.

10. The method for breeding early-maturing and highly resistant maize male parent according to claim 9, characterized in that: The male parent B of the local main corn variety is the male parent PH4CV of Xianyu 335.

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