Method for efficiently screening high linolenic acid germplasm of brassica napus

Abstract

The invention discloses a method for efficiently screening high linolenic acid germplasm of brassica napus. The method comprises the following steps of (1) expanding phenotypic variation of linolenicacid by utilizing a plurality of different ecological environments in winter and spring; (2) establishing different screening indexes according to different screening environments and generations; (3)performing comprehensive screening on the linolenic acid yield and the fatty acid composition to quickly obtain the high linolenic acid germplasm; (4) screening agronomic and quality characters whilescreening linolenic acid by utilizing a method of combining selfing and plant selection, so as to improve the comprehensive characters of the high linolenic acid germplasm; and (5) performing geneticstability analysis and quantitative evaluation on the many-year and multi-point results, so as to obtain the genetically stable high linolenic acid germplasm of brassica napus. The method disclosed by the invention has the characteristics of quantifiability and mechanical repeatability, can meet the screening requirements of the high linolenic acid germplasm of brassica napus, and can also enrichand complete the brassica napus breeding method; and meanwhile, beneficial reference can be provided for the development of fatty acid improvement work of other crops.

Description

technical field [0001] The invention belongs to the technical field of crop genetic breeding and agricultural application, and in particular relates to a method for efficiently screening high linolenic acid germplasm of Brassica napus. Background technique [0002] Rapeseed is one of the most important oil crops in China, with an annual planting area of ​​120 million mu, which can provide about 4 million tons of edible oil per year (accounting for 50% of China's total self-produced vegetable oil), and plays a very important role in the national economy. The quality of rapeseed oil has an important effect on the healthy consumption of oils and fats in China (Yin Yan, et al., 2010). Rapeseed (oil) mainly contains palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3) and Erucic acid (C22:1) and other fatty acids. With the improvement of awareness and the needs of human nutrition and health, consumers have higher require...

AI Technical Summary

Problems solved by technology

[0004] The disadvantages of reducing the content of linolenic acid in rapeseed are becoming more and more obvious: based on the fact that linolenic acid is easy to oxidize and cause oil rancidity, the shelf life of rapeseed (oil) can be extended after the reduction, and the generation of soot during high-temperature cooking can be reduced. Breeders in Canada and other countries have proposed "high-oil Acid and low linolenic acid"—the content of oleic acid (C18:1) increased from 60%-65% to more than 85%, and the content of linolenic acid (C18:3) decreased from 8%-9% to less than 3%, but practice shows that the reduction Linolenic acid did not achieve the desired effect: 1) Low linolenic acid leads to a decrease in polyunsaturated fatty acid content in rapeseed (oil), and a decrease in nutritional value

2) Low linolenic acid and high oleic acid have a significant impact on the growth potential and agronomic traits of rapeseed: high oleic acid and extra high oleic acid rapeseed (oleic acid content is 86% and 89% respectively) mutant plants will have some nutrients such as Slow body growth, flower bud death, low seed setting rate, low cold tolerance (Kinney A, 1994; Miquel, 1993); seed germination and hypocotyl elongation (Wang, et al., 2010; Becker, et al., 2011), reduced yield (Becker, et al. 2011) and other unfavorable performance

[0010] 4. Effectively alleviate the shortage of linolenic acid resources. In recent years, the concept of health has greatly increased the demand for linolenic acid in public consumption, but the content of linolenic acid in daily food is generally very small; linolenic acid mainly exists in plants and aquatic organisms in alpine regions. Its biological resources are relatively scarce. At present, it is mainly obtained by killing a large number of fish in the Arctic Ocean and the high-latitude seas of Antarctica; the yield and quality are unstable due to the influence of seasons and climates. At the same time, the number of marine fish caused by overfishing has decreased sharply. Resource output is increasingly limited (Ni Yu, 2003; Li Xianhui et al., 2016)

[0016] 3. Affected by many factors, the linolenic acid content of rapeseed is difficult to be stable in actual production. The continuous inheritance of fatty acid synthesis in vegetable oils is an overall system approach. The synthesis process of linolenic acid, oleic acid, linoleic acid and erucic acid is closely related.

[0017] 4. Long growth period The high linolenic acid germplasm with stable inheritance has a long growth period: winter rape is a multi-year crop with a growth period of more than 200 days, which can only be "2 years and 1 ripe" in the field; the growth period of spring rape 90-140 days, in the field, it can only be "one ripening per year"; the stability of rapeseed linolenic acid traits and the homozygosity of genes require 5-6 generations of breeding. Therefore, under normal conditions, it takes 5-6 years. It takes even longer for selective breeding to obtain genetically stable rapeseed high linolenic acid germplasm

Rapeseed with high linolenic acid breeding is a new type of breeding based on high-yield and high-oil breeding. It involves many factors and involves a wide range of areas. It is still in the exploratory stage. standard

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