Application Study Of Vegetable Resource Of Brassica Campestris In Rapeseed Breeding

This paper firstly reported the agronomic and quality character of vegetable germplasm resources of Brassica campestris, such as Chinese-cabbage , No-heading Chinese-cabbage and purple Tsai-tai from the point of views of domestic rapeseed breeding. The following main results were obtained: 1 Analysis and study in agronomic character 1.1 There are some special characters according with the aim of rapeseed breeding in vegetable germplasm resource of Brassica campestris, such as very earliness , cold resistance, white flower, yellow-coat seeds, dwarf stem, more branches, more pods, big grain and special sterile type, etc.. 1.2 The core germplasm resources were set up, and 40 materials were screened out from 120 materials(10 materials per type) which were clustered into12 types through 15 agronomic characters. Purple Tsai-tai and Brassica campestris are one type respectively, whereas the clustering results of No-heading chinese-cabbage and Chinese-cabbage were quitely complex, and there were more types among them. So the conclusion that the blood relationship between Brassica campestris and Brassica campestris is farther, and the genetic difference is also bigger. This was proved by crossing between them, and the conclusion had been approved in practice application. 1.3 The accepting pollen capability of sterile line of vegetable in Brassica campestris and Brassica napus was compared, too, and the result showed that cross-rate of the sterile line of vegetable in Brassica campestris is very high. The character provides science base for heterosis application. 2 Analysis and sdudy in quality character 2.1 The analysis result of oil content showed that average oil content of No-heading chinese-cabbage is highest, 40.94%, that of Chinese-cabbage is 39.34% and purple Tsai-tai is 38.93%. Moreover,Chinese-cabbage and No-heading Chinese-cabbage have more germplasm resources with over 45% oil content, so some lines with more oil content may be selected through single directional selection. 2.2 The analysis result of fatty acid components indicated that oleic acid content of vegetable of Brassica campestris is higher than Brassica napus, and saturated fatty acid content of Chinese-cabbage and No-heading chinese-cabbage is lower than Brassica napus. There are not low erucic acid materials, but there are high erucic acid materials, which erucic acid content is over 55%. This will provide different germplasm gene for quality breeding of rapeseed and special rapeseed breeding with high erucic acid used in industry. 2.3 From the analysis result of glucosinolates content, it was discovered that there were low glucosinolate resources in vegetable of Brassica campestris, and they came mostly from Chinese-cabbage. From glucosinolate components , glucosinolate of vegetable of Brassica campestris is Gluconapin mainly, and it is over 70% of total glucosinolates. Other glucosinolate components were less. It is different from Brassica napus, which glucosinolate is mainly Progoitrin. So lower glucosinolate varieties may be selected by crossing between the vegetable of Brassica campestris and Brassica napus. Besides, high-glucosinolate in No-heading Chinese-cabbage has medical value. 2.4 5 materials with protein content over27% were selected through protein content analysis. 2.5 According to principle component analysis of 8 quality characters, 9 materials were screened out for their better integrated quality character. They will become good materials in rapeseed breeding. 3 Application study The vegetable resources of Brassica campestris were first directly applied in domestic rapeseed breeding. Cross was done between male sterile line Bai1A with 46.65% high oil content of Chinese-cabbage and restorer CH334 of Brassica campestris, and cross combination Baizayou No.2 was obtained, which oil content is 45.5% and yield is 2303.85kg/hm2. At present, the variety has been in the region test in dry land near the North of River Wei in Shaanxi province and the region test of Jiangxi province. It will prove that vegetable of Brassica campestris germplasm genes have important application value for selecting fine rapeseed variety.