几个芒果品种的胚性及多胚苗遗传分析

通过目测,筛选出芒果多胚种子,观察其多胚形态;将多胚种子培育成多胚苗,观察其生长发育状况;取多胚苗和母树叶片进行体细胞染色体数目鉴定及同工酶的分析.结果表明,多胚类群的品种中有单胚现象出现,土芒、吕宋、象牙单胚出现的频率分别为1.04%、3.85%和5.44%;土芒和象牙胚数出现的范围分别为2-6和2-8.多胚种子子叶形态和胚轴的着生位置各异.种子多胚的萌发率、成活率及多胚苗的生长状况均与多胚种子的胚数、子叶发育大小等因素相关.多胚苗体细胞染色体数目是2n=40,未发现染色体的数目变异.POD同工酶分析表明,同一种子的多胚苗间酶谱上存在着差异.

Polyembryony in Mango (Mangifera indica L.) and Genetic Analysis

Monoembryony was observed in polyembryonic mango cultivars Tu-mang, Carabao and Aroemanis, the frequencies of monoemhryony being 1.04%, 3.85% and 5.44%, respectively. Two- to 6-embryonic cultivars appeared in Tu-mang, and 2- to 8-embryonic cultivars in Aroemanis. The morphology of cotyledons and the location of radicles in polyembryonic seeds varied with the cultivars. Germination rate and seedling survival rate of polyembryonic cultivars were negatively related with the increase of the number of embryos. Somatic chromosome number ofpolyembryonic seedlings was 2n=40, and no change in chromosome number was observed. Peroxidase analysis showed that variation existed among polyembryonic seedlings from the same seed.