Improvement Of Pol CMS Restore Line In Brassica Napus By Marker-assisted Selection

Rapeseed(Brassica napus L.) is one of the four major oilseed crops in China, which plays an important role in the national economy. With the development of social economy, the gradual improvement of living standards, the demand for high quality vegetable oil is improving. At the same time, rapeseed plays vital roles in the fine feed, biodiesel, eco-tourism and chemical industry and so on. Therefore, to improve the yield and rapeseed oil content in Brassica napus, improving the resistance ability and the oil quality is an important direction of rapeseed research. Heterosis of rapeseed is significant, heterosis utilization is one of the most important ways for the direction. Cytoplasmic male sterility has been used for heterosis utilization, and polima cytoplasmic male sterility,one of cytoplasmic male sterility materials was used for rapeseed breeding.In this study,we transferd a restoring gene from ―Huaza No.9‖(pol CMS restore line) to four excellent materials(lodging resistance material Z116, yellow seed material P17, prematurity and high oil content material HY01 and Zhejiang oil 50) by using the marker-assisted backcross technique.We expect that the new restore lines with the genetic background of four materials can be used for heterosis utilization.The main results were as follows:1) Foreground selection of BC3F2 generation in four populations.Two molecular markers associated with restoring gene(ssr48 and Rt5) were used for the foreground selection of BC3F2 generation population. 67,118,152 and 77 restore lines were obtained from Z116, P17, HY01, and Zhejiang oil 50.2) Background selection of BC3F2 generation in Z116 population. 40 pairs of AFLP random primers and 60 polymorphic bands were used for analyzing the background of the restorer individuals in BC3F2 generation.The cluster analysis showed that 20 restorer line individuals and recurrent parent were in same group.The average proportion of recurrent parent genome(PRPG) was 81.8% and the highest was up to 89.2%.3) Background selection of BC3F2 generation in P17 population. 30 pairs of AFLP random primers and 70 polymorphic bands were used for analyzing the background of the restorer individuals in BC3F2 generation.The cluster analysis showed that 59 restorer line individuals and recurrent parent were in the same group. The average proporation of recurrent parent genome(PRPG) was 90.83% and the highest was up to 96.43%.4) Background selection of BC3F2 generation in HY01 population. 40 pairs of AFLP random primers and 61 polymorphic bands were used for analyzing the background of the restorer individuals in BC3F2 generation.The cluster analysis showed that 59 restorer line individuals and recurrent parent were in same group.The average proporation of recurrent parent genome(PRPG) was 87.33% and the highest was up to 96.72%.5) Background selection of BC3F2 generation in Zhejiang oil 50 population. 30 pairs of AFLP random primers and 24 polymorphic bands were used for analyzing the background of the restorer individuals in BC3F2 generation.The cluster analysis showed that 27 restorer line individuals and recurrent parent were in the same group.The average proporation of recurrent parent genome(PRPG) was 90.85% and the highest was up to 97.92%.6) Observation on the taris of BC3F2. The average plant height and the average effective pod number per plant of BC3F2 lines from Z116 were bigger than recurrent parent, reaching extremely significant differernce and significant difference respectively. The average plant height and the average length of main infloscence of BC3F2 lines from P17 were bigger than recurrent parent, reaching extremely significant difference. The average plant height and the average first effective branch number of BC3F2 from HY01 were lower than recurrent parent, reaching extremely significance difference; The average plant height and the average length of main inflorescence of BC3F2 lines from Zhejiang oil 50 were bigger than recurrent parent, reaching extremely significance.