Construction Of Reciprocal Introgression Lines And Evaluation In Brassica Napus L.

Based on TN DH population with 202 lines, which is constructed by a winter and a semi-winter type of B. napus. In order to construct reciprocal introgression lines, Tapidor is used as the male parent to get the introgression lines called N-BC4 population. At the same time, a preliminary evaluation is made with the traits of flowering time. Meanwhile, using T-BC4 population is a good way to study the trait of glucosolinate in B. napus. Results stated as below:The work of construction of reciprocal introgression lines is successfully accomplished and the seeds of N-BC1, N-BC2, N-BC3, and N-BC4 populations are harvested. Four-thousand self-pollinated and hybrided seeds had been harvested from the N-BC4 populations. The seeds number of N-BC2F1, N-BC2F2,N-BC3F1, N-BC3F2 is 239,360,501 and 418.The seeds gained from the T-BC4 population is divided into two parts:self pollinated seeds of BC4F2 inherited from 133 DH liens and hybrided seeds of BC5F1 from 133 DH lines.In order to evaluate the introgression lines, markers from QTL region on C6 and A10 has been used to detect the trait of flowering time. In hypothesis, if the segements of QTL region within C6 is introgressed, the flowering time would be earlier than Ningyou7. On the contrary if the segements of A10 QTL region is introgressed, the flowerting time would be later than Ningyou7 in the T-BC4 populations. However, in the N-BC2 populations, there is a different situation. The introgression segments of A10 QTL region will flower earlier than Tapidor, vice verse. The results goes as what we wished.Confirm target QTL and construct NIL. Two in sixty-four mQTL, q.mcG-A9b and q.mcG-A9c, were two major QTL that controlled the content of total glucosinolate, each explaining more than 20% of phenotypic variation and controlled different glucosinolates in seeds, so the two mQTL, qmcG-A9b and q.mcG-A9c were the target QTL. Some polymorphic markers responding to BACs and Scaffold of B. rapa were mapped in the confidence intervals of the two target QTL, and the candidate genes for q.mcG-A9b were achieved through comparing A9 genomics between B. rapa and B. napus. By the tool of comaparative genomics analysis, the QTL region of A9 has been denstified with BAC-based and BAC end -based SSR markers. Three of fifty seven markers were mappped to the QTL region the QTL region was narrowed 2 cM. The materials of backcross populations derived from lines of TN DH population, and in BC4F2 population,11 NILs with the number of 2000, and in BC4F3 population,7 NILs with the number of 810 included target chromosome segments of varying length is developed through the foreground selection for target QTL.