Studies On Selection And Application Of Nucleus Male-Sterile N97AB Line Of Brassica Napus L.

Rape is one of the important economic crops. Annual cultivated acreage of rape in Enshi municipal state is greater than 40,000 hectares in normal season. A majority of employed varieties were local routine lines and introduced hybrids including Zhongyouza No. 2 and Huayouza No.3. There were some practical problems such as poor quality, low output of local routine varieties, and poor climate adaptability of introduced hybrids. Considering the specific ecological condition in Enshi, we have conducted a series of studies on breeding novel varieties with low mustard acid and low sulfur glucoside (double low). The main results in this thesis are summarized as follows:A nucleus male-sterile N97AB of Brassica Napus L was produced from a cross of Guiza101×Mianyouza96-97, the phenotypic ratio of 1:1 between siber sisters was stable, and this line has inherited the advantage from both parents.Hybridization and rounds of backcross were applied to a pair of double low local routine varieties, and 80 self-pollination lines were selected from the compound offspring population of this cross. These 80 lines were prefered as tester lines, N97A was set as a driver line, and clock-like hybridizations between the driver line and each of tester lines were performed simultaneously. The results exhibited that about 81.3% tester lines could restore the sterility of the driver line at 100% level. A two-line hybrid Enyou 02-7 which belongs to nucleus male-sterile Brasica Napus L. was selected from the offspring of these cross lines successful. The quality of this hybrid has met the case of double low, and it also has some outstanding characteristics including high and steady output, strong lodge-resistance and special climate adaptability and so on.The Enyou 02-7 line has some wonderful performances, such as 2.58% of mustard acid, 21.66 μmol/g of sulfur glucoside, and 41.3% of oil content. Among the experiments including varieties comparation and region constrast in Enshi municipal state, the average yield was 2479.95kg/hm~2 and significant higher than that of the control Zhongyouza No. 2, it could be ranked the No.1 among all entrants.Based-on these facts, investigations on seed producing, asexual cuttage and...