Construction And Extention Of The Recurrent Selection Population Of The New Type Brassica Napus

The genetic difference between species are often large, and the hybridization between different species can offen produce a strong heterosis. But as a result of reproductive isolation between different species, it’s not easy to be fertile hybrid off-spring. The laboratory is committed to a new Brassica napus cultivation, respectively, using cabbage A genome and Brassica carinata C genome segment substitution in Brassica napus A, C genome, to generate a high cabbage A gene composition and high Brassica carinata C genome composition of new rapeseed. After10years of screening and nurturing work, it is suggested that new Brassica napus has been similar to regular cabbage type rape in terms of fertility, which the content of exogenous cabbage A genome and Brassica carinata C genome has been close to90%, presenting a very strong potential for heterosis. For the purpose of Polymerizing eximious alleles, the dominant nuclear sterile line was introduced into the new Brassica napus, and then built the group of recurrent selection. Consequently, the proportion of eximious genes in Brassica napus L.gene pool was enhanced through the selection and improvement in the groups every year.In this study, the characters of the inbred lines in the improvement cycle to are turned to the improvement dominant genic male sterile lines, which has great improve for the recurrent cultivate work of the selection cycle groups.Simultaneity, three groups coded as spring rape, semi-winter and winter rap were isolated form the group based on the blossom period, the lines in possession of better morphological characteristics and quality traits were selected to compose drought resistance preselected groups for the sake of investigating drought resistance of the new Brassica napus, which also have further expansion for the Brassica napus L. germplasm resources.2441copies of new Brassica napus seeds harvested in May2010were measured by the NIR. The quality data shows that in1504inbred lines there are965lines, which glucosinolate content is lower than30μmol/g, erucic acid content are less than2%. While in138dominant genic male sterile lines there are52lines, which glucosinolate content are less than35μmol/g, and50lines, which erucic acid content are less than2%, but only29lines there, which glucosinolate lower than35μmol/gand erucic acid less than2%. Therefore, the quality improvement work recurrent of inbred lines in cycle selection groups has achieved great results, however, the improvement of dominant nuclear sterile line needs to be improved. Similarly,2030lines of the next generation of cycle selection groups were harvested in May2011. Quality data measured using NIR reveal that in618inbred lines there are449lines close to double lower, coded as glucosinolate content are less than30umol and erucic acid content are less than2%.While in334dominant genic male sterile line, there are97lines with glucosinolate content lower than35μmol/g and erucic acid content less than2%. The two years data displays that the quality traits of dominant genic male sterile line have been improved through the improvement.When contrast some agronomic traits of two-year harvest lines such as seed size, pod length, seed color, It is found that in2441lines harvested in2010, the large seed lines were accounted for2.3%of the harvest strains, accounting the siliquesstrain for6.3%, yellow-seeded lines for0.04%; whereas among2030lines harvested in2011, the large seed lines were accounted for8.4%of the harvest strains, accounting the siliquesstrain for22%, yellow-seeded lines for1.5%. Obviously, the results show that the proportion of the good agronomic traits has expanded via the improvement.The recurrent selection groups of new Brassica napus have been gradually improved after the improvement. The research is turning into another main stage, namely the expansion of new Brassica napus L. germplasm pool. According to the blossom period from the resource library, some early lines were screened out gradually, and then sowed in May in Gansu, afterward harvested in September. In this way, spring rape groups are successful cultivated. On the other hand, the late-blossom strains were grow in Gansu in September and did not get seeds for the sake of the cold; therefore winter rape ecological groups are in the pipeline. Lastly, the lines with the blossom period between the both lines were sowed in October in Wuhan, and so set up the semi-winter rapeseed ecological groups successful.At present, screening for drought resistance lines among the Brassica napus group is in the pilot phase. The laboratory is committed to screening its resistance to disease and high temperature as well.It is challenging, meanwhile, enormously significant to improve the new Brassica napus groups and cultivate the ecological groups. Since it can not only cultivate high yield oilseeds, and also has better adaptability of different ecological groups for convenient popularization.