授粉时期和套袋方式对烟草母本起源单倍体鉴定效率的影响

Effects of pollination time and bagging means on identification of tobacco maternal haploids

以普通烟草(Nicotiana tabacum)为母本,非洲烟草(N.africana)为父本进行远缘杂交,在子代中孤雌应激可获得母本起源的单倍体。为解决实际应用中存在的单倍体诱导频率偏低、鉴别困难等问题,采用流式细胞术(Flow cytometry,FCM),鉴别了不同授粉时期、套袋方法条件下杂交子代中的单倍体。结果表明,FCM能够在苗期准确、快速鉴别母本起源的单倍体,排除二倍体、混倍体对试验的干扰。采用纸管法套袋,非单倍体的烟苗存活率为0.24%,而常规纸袋法套袋的非单倍体烟苗存活率为1.56%,纸管法非单倍体的烟苗存活率明显低于常规纸袋法,说明纸管法套袋可提高单倍体的鉴定效率。当母本花冠长度与萼片长度差(SCD)为2.5 cm时,是进行非洲烟草杂交、预防混杂的适宜时期。因此,在SCD为2.5 cm时进行授粉,用纸管法套袋,利用FCM分析后代倍性,是获取母本起源单倍体的最佳方法。

Maternal haploid （MH） was obtained by the interspecific hybridization method. In this system, Nicotiana tabacum was hybridized as a female with Nicotiana africana due to parthenogenesis. In order to overcome the problems such as low induction rate of maternal haploid and difficult identification of maternal haploid from aneuploid interspecific hybrids in breeding practice, flow cytometry （FCM） was adopted to identify the maternal haploids of hybrid progenies produced by different bagging means at different pollination time. The results showed that maternal haploids were accurately and quickly identified by FCM at seedling stage and eliminated the disturbances from diploids and aneuploid interspecific hybrids. The survival rates of non-haploid seedlings bagged with paper tube and common paper bag were 0.24% and 1.56%, respectively. The identification efficiency of paper tube bagging means for haploid was higher. The suitable time for hybridization was identified as when the difference between sepal length and corolla length （SCD） was 2.5 cm, which was beneficial to the induction of maternal pollination at SCD of 2.5 cm, adopting haploids. Therefore, the better way for obtaining maternal haploid was paper tube bagging means and analyzing progeny ploidy with FCM.