4个茶树不孕品种的细胞学及遗传背景

Study on the Cytology and Genetic Background of 4 Sterile Tea Clones

对福鼎大毫茶等4个无性系不孕品种的减数分裂行为进行了观察,结果表明,这些品种的染色体行为有高度的不规则性,在终变期出现的各种价体中,Ⅲ价体的出现率最高,各品种平均每个细胞分别为:福鼎大毫茶6.91,福安大白茶5.59,岭路大白茶5.33,毛蟹6.39;后Ⅰ,后Ⅱ有50%以上的分裂相落后染色体1—9条,后Ⅰ到达极区的染色体数为19—24条的占72.4%—83.3%,因此,认为这4个品种都是自然三倍体茶树。文中还根据品种间染色体行为的差异,对其起源及利用问题进行了讨论。

Study on the cytological mechanismof the sterility of Fuding Dahao Chaand other 3 tea clones was carried out through the observation of their meio-sis.Results showed that the chromosome behaviors in the meiotic processwere all highly irregular in all clones.In the diakinesis,the frequencies ofthe trivalents were always the highest among all forms of the valents,andthe average number of trivalents were 6.91 in Fuding Dahao Cha,5.59 inFu＇an Dabai Cha,5.33 in Linlu Dabai Cha and 6.39 in Maoxie.In the anaphasesⅠ and Ⅱ the number of lagging chromosomes in more than 50% meioticPMCS ranged from 1 to 9,and in 72.6%—83.3% PMCS,the number of thechromosomes reaching each polar area in anaphase I varied from 19 to 24,indicating that all the clones observed were natural triploid clones.Theorigins and the further utilization of the clones were discussed based on thedifferences of chromosome behaviors in the meiotic process among the clones.