A method for breeding high-oil, low-phenol cotton

Abstract

This invention provides a method for breeding high-oil, low-phenol cotton, belonging to the field of cotton breeding technology. The breeding method of this invention includes (1) using early-maturing, high-quality, and high-oil germplasm resources with excellent comprehensive traits as the female parent and a glandless, low-phenol cotton variety as the male parent to obtain F1; (2) screening F1 glandless plants and backcrossing them with the female parent for 3 generations to obtain BC3F1; (3) separating the BC3F2-BC3F6 generations, continuously conducting single-plant selection, disease nursery identification, and quality testing to breed a kanamycin-resistant, glandless line BC3F7 with excellent traits; (4) conducting plant row identification, line comparison, and variety comparison tests on BC3F7 to obtain a purified population BC3F8, and screening out a new high-oil, low-phenol cotton variety. The 'Simu 180' cotton variety bred in this invention is an early-maturing, high-quality, multi-resistant, high-oil, low-phenol cotton line with a full growth period of 103 days, a single boll weight of 5.5g, a lint percentage of 40.3%, an average upper fiber length of 30.2mm, a specific strength of 30.5cN / tex, a micronaire value of 4.5, a kernel oil content of 42.5%, and a phenol content of 0.0126%.

Description

Technical Field

[0001] This invention belongs to the field of cotton breeding technology, and in particular relates to a method for breeding high-oil, low-phenol cotton. Background Technology

[0002] Cotton, as one of the five major oilseed crops, is an important vegetable oil resource. 55%-60% of cottonseed by weight is the kernel, and after hulling, the kernel contains 30%-40% fat and 40%-50% protein. Refined cottonseed oil has high nutritional value, containing a large amount of essential fatty acids, with linoleic acid being the most abundant, reaching over 50%, the highest among all edible oils. With the improvement of people's living standards and the adjustment of dietary structure, the consumption of edible vegetable oils has been increasing year by year, and the proportion of dependence on imports is also growing.

[0003] However, the toxic substance gossypol in cotton greatly limits the comprehensive utilization of cotton kernels, resulting in a serious waste of cottonseed oil resources. Gossypol is a yellow polyphenolic hydroxybis(naphthyl) aldehyde compound, mainly found in the roots, stems, leaves, and seeds of cotton, with the highest content in the kernels. The difference between low-phenol cotton and ordinary cotton lies in the lower content of free gossypol in its various tissues and organs. Free gossypol is a phenolic derivative that is toxic to humans, animals, and other organisms. A content above 0.1% is considered toxic to humans, animals, and other organisms. Its safe range for use is a content below the national food safety standard (0.02%) and the World Health Organization standard (0.02%-0.04%). The gossypol content in the kernels of ordinary cotton varieties is 0.5%-2.5%, requiring dephenolization treatment before utilization. However, dephenolization treatment destroys the nutritional components of cottonseed meal, and the dephenolization process is complex, costly, and prone to pollution.

[0004] For a long time, breeders have focused their cotton breeding efforts primarily on improving cotton yield, quality, and resistance, while cottonseed has been treated merely as a byproduct of cotton production and has not received sufficient attention. Therefore, in-depth research on high-oil, low-phenol cotton varieties and the full development and exploration of the utilization value of cottonseed are of great significance for ensuring my country's food security and the effective supply of cotton and other major agricultural products. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method for breeding high-oil, low-phenol cotton, which produces new cotton varieties with good early maturity, excellent quality, and high yield, especially with high oil content and low phenol content in the cotton kernels.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for breeding high-oil, low-phenol cotton includes the following steps:

[0008] (1) Using early-maturing, high-quality, and high-oil germplasm resources with excellent comprehensive traits as the female parent and a glandless, low-phenol cotton variety as the male parent, F1 was obtained by hybridization;

[0009] (2) Select F1 plants without glands and backcross them with the female parent for 3 generations to obtain BC3F1;

[0010] (3) Separate generations from BC3F2 to BC3F6, continuously select individual plants, identify disease nurseries, and determine quality to breed the excellent kanamycin-resistant, glandless line BC3F7.

[0011] (4) BC3F7 was subjected to plant identification, strain comparison and variety comparison tests to obtain the purified population BC3F8, and a new high-oil and low-phenol cotton strain was screened out.

[0012] Preferably, in step (1), the parent plant is selected from excellent cotton germplasm resources with good comprehensive traits and an oil content of ≥40% in the kernel.

[0013] Preferably, in step (1), the maternal parent is the early-maturing, high-quality, and high-oil germplasm resource "Simu 20-17", which is bred from Simu 4 as the maternal parent and the high-oil breeding resource SGK9708 as the paternal parent.

[0014] Preferably, the parent variety in step (1) is "Jinongda Cotton No. 25".

[0015] Preferably, the screening of glandless plants in steps (2) and (3) is carried out at the three-leaf stage of cotton.

[0016] Preferably, in step (3), individual plants and strains with a height of 80-90cm, a single boll weight of 5.5-6.0g, and a lint content of >40% are selected; at the six-leaf stage, kanamycin solution is applied to the surface of the tender true leaves to select and retain kanamycin-resistant strains.

[0017] Preferably, in step (4), the selected plants and lines have a full growth period of 100-110 days, a plant height of 80-90cm, an average fiber upper half length of 30.0-31.0mm, a specific strength of 30.0-31.0cN / tex, a micronaire value of 4.0-4.5, and a cotton kernel oil content of >40% and a gossypol content of <0.02%.

[0018] Preferably, the breeding method adopts the form of southern breeding and shuttle breeding, with each generation being sown and bred in the middle and lower reaches of the Yangtze River in May during the summer, and bred in Hainan in October during the winter.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention provides a method for breeding high-oil, low-phenol cotton. It utilizes self-bred early-maturing, high-quality, insect-resistant, and high-oil superior breeding resources to crossbreed with low-phenol cotton varieties to obtain F1 hybrids. After the hybrids are separated, they are backcrossed for several generations. The backcross progeny are then subjected to multi-ecological and multi-adversity shuttle breeding and multi-generation purification, combined with various auxiliary detection methods, to obtain a new early-maturing, superior, insect-resistant, high-oil, and low-phenol cotton line with stable genetics.

[0021] The creation and breeding of high-oil, low-phenol cotton germplasm resources can fully develop and explore the comprehensive utilization value of cotton kernels, which is of great significance for ensuring my country's food security and the effective supply of major agricultural products such as cotton. The bred variety 'SiMian 180' has a full growth period of 103 days, a plant height of 86.2 cm, 12.3 bolls, a single boll weight of 5.5 g, a lint percentage of 40.3%, an average upper fiber length of 30.2 mm, a specific strength of 30.5 cN / tex, a micronaire value of 4.5, and a kernel oil content of 42.5% and a phenol content of 0.0126%. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the breeding process of a new high-oil, low-phenol cotton variety for summer direct seeding according to the present invention.

[0023] The biological materials involved in this invention include the maternal parent "Simu 20-17", which was bred by using Simu 4 as the maternal parent and the high-oil breeding resource SGK9708 as the paternal parent. It is published on the official website of the Suqian Agricultural Research Institute of Jiangsu Academy of Agricultural Sciences, with the link http: / / sq.jaas.ac.cn / xww / tzgg / art / 202-4 / art_18a970ec17ba4ba68aad293610300779.html; and the paternal parent "Jinongda Cotton 25", which was bred by the College of Agriculture of Hebei Agricultural University and approved by Hebei Province, with the approval number Ji Shen Mian 20189003. Detailed Implementation

[0024] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0025] Example 1

[0026] The early-maturing, high-quality, insect-resistant, and high-oil cotton germplasm resource “Si Mian 20-17” was bred and crossed with the low-phenol cotton “Jinong Damian 25” as the male parent.

[0027] (1) In October 2017, the female parent “Simu 20-17” and the male parent “Jinong Damian 25” were planted in Hainan for hybridization and F1 generation seeds were harvested.

[0028] (2) In May 2018, the harvested hybrid and the female parent “Simian 20-17” were planted in Siyang, Jiangsu. At the three-leaf stage, plants with glands were removed, and F1 plants without glands were backcrossed with the female parent “Simian 20-17” to obtain BC1F1.

[0029] (3) In October 2018 and May 2019, the backcross generation and the maternal parent “Simu 20-17” were planted in Hainan and Siyang respectively. They were screened and treated according to the standards in step (2) to obtain backcross progeny BC2F1 and BC3F1 respectively. During the backcrossing stage, the focus was on the condition of the plant glands. Hybrid plants with glands were removed to facilitate the effective aggregation of genes for early maturity, high quality, multiple resistance, high oil content and low phenol content.

[0030] (4) In October 2019, the backcross population BC3F1 was planted in Hainan. During the seedling stage, plants without glands were screened. At the six-leaf stage, 2000ppm kanamycin solution was applied to the surface of the tender true leaves with a brush. After one week, the leaves were observed to see if yellow-white spots appeared. Plants that showed chlorotic spots and were susceptible to kanamycin were eliminated, while plants that showed normal green color and were resistant to kanamycin were retained. Plants with a height of 80-90cm, a single boll weight of 5.5-6.0g, and a lint content of >40% were selected to obtain BC3F2.

[0031] (5) In May 2020, October 2020, May 2021, October 2021, and May 2022, the segregation generations BC3F2, BC3F3, BC3F4, BC3F5, and BC3F6 were planted in Siyang, Hainan, Siyang, Hainan, and Siyang respectively. The offspring BC3F3, BC3F4, BC3F5, BC3F6, and BC3F7 were obtained according to the criteria in step (4).

[0032] (6) In October 2022, the basically stable strain BC3F7 was planted in Hainan. The strains were identified and compared. Through shuttle breeding in multiple ecological environments and multiple stress environments, strains with a full growth period of 100-110 days, plant height of 80-90cm, average upper fiber length of 30.0-31.0mm, specific strength of 30.0-31.0cN / tex, micronaire value of 4.0-4.5, cotton kernel oil content of >40%, and gossypol content of <0.02% were selected to obtain the purified population BC3F8.

[0033] (7) In May 2023, the purified population BC3F8 was planted in Siyang. According to the standard in step (6), a new cotton variety “Simian 180” was obtained. It has a planting density of 5000 plants / mu, a full growth period of 103 days, a plant height of 86.2cm, 12.3 bolls, a single boll weight of 5.5g, a lint percentage of 40.3%, an average upper fiber length of 30.2mm, a specific strength of 30.5cN / tex, a micronaire value of 4.5, a cotton kernel oil content of 42.5%, and a phenol content of 0.0126%. It is an early-maturing, high-quality, multi-resistant, high-oil and low-phenol cotton variety.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for breeding high-oil, low-phenol cotton, characterized in that, Includes the following steps: (1) Using early-maturing, high-quality, and high-oil germplasm resources with excellent comprehensive traits as the female parent and a glandless, low-phenol cotton variety as the male parent, F1 was obtained by hybridization; the female parent was the early-maturing, high-quality, and high-oil germplasm resource "Si Mian 20-17", which was bred from Si Mian 4 as the female parent and the high-oil breeding resource SGK9708 as the male parent; the male parent was "Jinong Damian 25". (2) Select F1 plants without glands and backcross them with the female parent for 3 generations to obtain BC3F1; (3) Separate generations BC3F2-BC3F6, continuously select individual plants, identify disease nurseries, and determine quality, and select the BC3F7 line with excellent kanamycin resistance and no glands; screen individual plants and lines with a plant height of 80-90cm, a single boll weight of 5.5-6.0g, and a lint percentage of >40%; apply kanamycin solution to the surface of young true leaves at the six-leaf stage, and screen for and retain kanamycin resistant lines; (4) BC3F7 was subjected to plant identification, line comparison and variety comparison tests to obtain the purified population BC3F8, and new high oil and low phenol cotton lines were screened out; single plants and lines with a full growth period of 100-110 days, plant height of 80-90cm, average upper fiber length of 30.0-31.0mm, specific strength of 30.0-31.0cN / tex, micronaire value of 4.0-4.5, cotton kernel oil content >40% and gossypol content <0.02% were screened out.

2. The method for breeding high-oil, low-phenol cotton according to claim 1, characterized in that, The screening of glandless plants in steps (2) and (3) is carried out at the three-leaf stage of cotton.

3. The method for breeding high-oil, low-phenol cotton according to claim 1, characterized in that, The breeding method adopts the form of southern breeding and shuttle breeding. Each generation is sown and bred in the middle and lower reaches of the Yangtze River in May, and bred in Hainan in October.

Images