Genetic Diversity Analyses, Collection And Conservation Of Non-heading Chinese Cabbages

The vegetables of Brassica L., belonging to Cruciferae family and having a wide-range of distribution and plentiful germplasm resources, are a group of the most important and popular resourse of vitamines and feeding fibres. Non-heading Chinese cabbages in Brassica genus have been planted as begetables for more than one thousand years. These plants play an important role in table supplement of vegetables, and occupy 30%-40% of vegetable planting areas in Southern China, and the planting area is expanding gradually in Northern China recently. Brassica vegetable is becoming a kind of world-wide vegetables growing extensively in Europe, America and Japan.In the present paper. 61 cultivated vegetables of Brassica L., kept in Shanghai Agrobiological Gene Center, were used as the materials to study the genetic diversity of Brassica varieties in Shanghai. Further more, 112 Non-heading Chinese cabbages were used as the materials in order to understand the relationships of different types and their genetic diversity, which will benefit the effective collection and utilization of the germplasm and further improvement of the breeding work. Morphologic traits and SSR, SRAP markers as major technical methods can be used in analyzing of genetic diversity and genetic relationship in Brassica campestris ssp. Chinensis germplasm resources. Here are the main results and conclutions of the research:1. 112 Non-heading Chinese cabbages in Brassica L. were collected by investigation.2. Genetic diversity of 61 samples was estimated by SSR markers and agronomic traits. The UPGMA results showed that 61 samples were divided into 2 groups, Brassica oleracea L and Brassica campestris L. Further analysis of UPGMA results indicated that genetic variation of Brassica oleracea was more abundant than Brassica campestris's, so it is necessary to protect the existing germplasm of Brassica campestris, and to overcome genetic erosion.3. 21 agronomic traits of 112 non-heading Chinese cabbage were observed. The UPGMA results showed that 112 samples were divided into 7 groups. The similarity was in the range of 0.63-1.00. It shows the similarity of J78-09 and kangre605 is 100%. 5 savoys except cultivar Heiyeyoutacai were divided in the same group. It showed that Brassicaca mpestris L. ssp. Chinensis (L) Makino var. rosularis Tsenet Lee was less variant.4. SSR and SRAP techniques have been used to explore the genetic diversity and taxonomy of 112 Brassica campestris ssp. Chinensis. The UPGMA results showed the similarity was in the range of 0.67-0.96. The 112 samples were divided into 9 groups as the similiarity was 0.75. Sounindaqingcai from Fujian, xiacunchiyebaicai from Guangdong, wujinbai from Hunan, baiyeqingdatou from Zhejiang were respectively divided into its own group, and the similarity among these cultivars and the others was low.5. There were strongly variable in Brassica campestris ssp. Chinensis from the dendrogram results of morphologic traits and molecular markers, however, the genetic diversity of 7 varieties from Japan was low, and they had high similiarity with other varieties originated in China in the aspect of genetic background.