Resynthesis Of Rapeseed (B. Napus L.) From Yellow-seeded B. Oleracea Var.aceaphala And B.campestris

Oil and protein content in seeds of yellow rapeseed (Brassica napus L.) are higher than that of black rapeseed from the same genetic background. It is much easier for yellow rapeseed to go into the market. The breeding of yellow rapeseed has become one of the main objectives in rapeseed breeding. It is hard for breeders to select effective yellow rapeseed lines due to the scarcity of yellow-seeded gene resources. It is very important to explore new genetic resources of yellow rapeseed. Yellow seed plant was excitably found in natural population of B. oleracea var. aceaphala, which is a variety of Cruciferae Brassica oleracea, in summer of 1994 by researcher of Oilcrop Lab of SWAU. After consecutive artificial selection for many years, some lines with good performance were obtained. They are valuable genetic materials for the study of the breeding of yellow rapeseed(5. napus).The agronomic traits and qualitative traits of B. oleracea var. aceaphala were analyzed in present paper. The results demonstrated that performance of agronomic traits in B. oleracea var. aceaphala is almost the same as that in B. napus. Qualitative analysis indicated that not only seed oil and embryo protein content of B. oleracea var. aceaphala were higher than that of Zhongyou 821,but also the other qualitative traits were better.To investigate the relationship between yellow-seeded gene(s) on genome C and genome A , to explore the feasibility of transfer of yellow-seeded gene(s) to B. napus, the studies were conducted on artificial synthesis of B. napus by using culture of ovary originated from interspecific hybridization and protoplast fusion betweenyellow-seeded B. campestris and yellow-seeded D. oleracea var. aceaphala. The results indicated that the culture of ovary taken 10 days after pollination on MS+2.0mg/L6-BA-K).2mg/LNAA+7%Sucrose+300mg/LCH+0.8%Agar medium had most efficient for seed production in the cross of B. campestris X B. oleracea var. aceaphala. Altogether 19 seeds were produced in the experiment, 8 of them germinated on medium and 4 regenerated lines were obtained at last in vitro. Protoplast fusion between B. campestris and B. oleracea var. aceaphala failed to give expected results. Cell cluster was observed in this study, but no regenerated plantlets were obtained. Regeneration lines from ovary culture in vitro were identified with morphological, cytological and biochemical methods. The results showed that two lines (2-3 and 5-1) were true hybrids from B. campestris Xfi. oleracea var. aceaphala cross. The two lines will be important materials for yellow rapeseed breeding.