Studies On CMS Selective Breeding And Its Utilization And Seed Picking Technology In Chinese Cabbage

Chinese cabbage(bratssica campestris L.ssp.pekinensis(Lour)01sson) origins China, it is a vegetable crop that distributed widest, cultivated most extensively and liked by most of people in China. For obvious heterosis in Chinese cabbage, the utilization of F₁ hybrid became the primary measure in its resistance to diseases and with good quality and stable yield breeding in the world. Two main methods self-incompatibility line and selection of male-sterile line of heterosis utilization at the present were employed. High cost and difficulty to get 100% hybrid seed is the major problem in using self-incompatibility line. To employ male-sterile line to produce Fihybird seeds could solve all those defects easily in breeding and seeds production, especially CMS that is very stable to environment and ontogenesis could produce 100% purity and high quality F₁ hybrid seeds. Therefore, using CMS to formulate F₁hybird is always the target for cabbage breeders.1.Using Brassica napus CMS.RC97-1 which is introduced presently as sterile material source, conduct interspecific cross to transfer the RC97-1 sterility to Chinese cabbage through continuing backcross breeding and strictly economic characters selection gained Chinese RC₇ that has stable sterility with 100% sterile plant ratio and sterile degree, leaf color and normal nectary perfect pistil function and strong bearing ability. The sterile line RC7 was similar to transfer breeding male parent in economic characters, has high combing ability and could attract insects to pollination that showed as a valuable line.2.Through cross between sterile line RC₇ and other kinds of parents, two Chinese cabbage F₁hybird which have prominence superiority Jinqiu70 and Jinqiu90 had gained. Through more spots verity comparative test and adaptive test, the results were as follow:Jinqiu70: Belongs to mid-early Fihybird, growing period about 70 days, Plant showed strong growth vigor, high pile and upright tubule form, and it outer leaf is dark green, nap form leaf light green, white leafstalk, leaf head height 46cm, leaf head diameter 16cm, leaf-head index 2.9, single orb weight 3.5～4kg, clean vegetable ratio 80%, yield 7500kg per 667m², resists virus, downy mildew and soft rot. In addition, it has little fibro, good quality, tight wrapping spear and stands saving and storage.Jinqiu90: Belongs to late-maturing Fi hybrid, growing period is 90 days. Uniformity and accord, few outer leaves, green leaf, white leafstalk, high pile and upright tubule form, symembrace, leaf head height 56cm, leaf head diameter 17cm, leaf head index 3.3,single orb weight 4.5⁵.5kg,clean vegetable ratio 80%,yield 8500kg per 667m2 and it resists virus, downy mildew and soft rot, good quality and stands saving and storage.3.Yield form factors and correlation on Chinese cabbage RC7 and remainder B7 were studied through application of linear regression and correlated analysis ways. Results of correlated analysis showed: the pod number of single plant of sterile tine RC7(r=0.96583**), second branch number(r=0.96419**), seed number per pod(r=0.75701**), pod number on main inflorescence(r=0.49024*), main inflorescence(r=0.40623*) and single yield exists quite remarkable or remarkable positive correlation.4.Then multivariate linear regression equations about form factors of single plant seed yield between remainder B7 and Chinese cabbage sterile line were set up.Sterile RC7: Y=-31.9097+0.0559X5-0.6744X7+0.3624X8+1.165X10 Multivariate B7: Y=59.0137+0.0881X5+0.8142X6-0.5156X8+1.0978Xi0 Multivariate linear regression showed: the multivariate linear regression equations about form facts of single plant seed yield had high similarity between remainder B7 and sterile line RC7 in pod number of single plant, second branch number and pod number on main inflorescence, these three characters become main form factors of single plant seed yield. All studies showed: pod number on main inflorescence is determined by mainly pod number and second branch number of single plant. Increase branch number especially second branch number is the major method to get high yield in seed production.5.Twelve characters in four categories were investigated and determined: yield character (including leaf head, clean vegetable ratio and yield of unit area), agronomic character (life period, number of outer leaves, plant height), qualitative character (commercial character, ratio of soft leaf and flavoring character) and disease resistance (disease index of virus, downy mildew and soft rot). A series of multilateral dimension all-round judgment method about gray related degree of new Chinese cabbage cultivars. This method make the selective breeding of new well quality cultivars from large quantity Chinese cabbage Combination or cultivars, efficiently develop the exactitude and select efficiency of breed new cultivars.