白菜稳定新种质的创制与遗传分析

Creation of a new germplasm of Chinese cabbage and its genetics

为了创制白菜新种质和探索白菜杂种后代的遗传特征,采用人工杂交获得矮抗青与黄芽白杂种,再经过连续自交形成植株高大、营养生长旺盛的稳定新种质。通过形态学和细胞学观察研究杂种遗传学特征。结果表明,所获得的新种质营养生长旺盛,叶片肥大,营养器官单株质量大,具有较大生产潜力。通过菌核病抗性鉴定,筛选出具有较好菌核病抗性的植株。分析同源染色体联会规律和染色体分离规律,在第一次减数分裂(MI)终变期,大部分染色体同源配对形成二价体,二价体构型有环状和棒状两种,另外还有四价体等其他构型多价体出现。MI后期,80%以上的花粉母细胞发生10∶10染色体均等分离。两种不同类型的白菜杂交并经多代自交获得减数分裂较正常、育性良好、具有较强菌核病抗性的白菜育种新材料。

The hybrids were obtained by artificial hybridization and a new germplasm of Chinese cabbage with stable characters,tall plants and vigorous vegetative growth were formed by selfing.One of hybrids showed resistance to Sclerotinia sclerotiorum via identification.Chromosome behavior of pollen mother cells(PMCs)in different stages of Meiosis of hybrids was observed.At diakinesis,most chromosomes paired to bivalents as ring and rod configurations.Other chromosomes also formed tetravalents and other multivalents.At anaphase of the first Meiosis,chromosomes segregated as equipartition with 10∶10 in more than 80%of PMCs,and there were 11∶9 or 12∶8 chromosome equipartition in other PMCs.Chromosomes lagged behind or form anaphase bridges during anaphase separation in a few of PMCs.A new Chinese cabbage breeding material with normal Meiosis,good fertility and strong resistance to Sclerotinia sclerotiorum was obtained by crossing between two different types of B.rapa。