烟草黑胫病抗性遗传分析

选用中烟90(高抗),革新3号(高抗)、L8(中抗)、Burley21(中抗)、KBM20(高感)、KY14(高感)等6个烟草品种作为杂交亲本,按Griffing双列杂交的第1种方法设计36个杂交组合.用DPS数据处理系统对烟草黑胫病病情指数的配合力和遗传力进行了分析,结果表明,不同品种、不同组合问抗病性存在极显著差异,不同亲本抗病性能稳定表现出来.6个品种间黑胫病的一般配合力和特殊配合力存在极显著差异,一般配合力效应分析,中烟90为第一负效应,KBM20为第一正效应,说明中烟90在黑胫病抗性育种中有较好的潜力,KBM20不利于黑胫病抗性育种,6个品种年度间一般配合力表现有一定的差异,主要是在亲本Burley21上,中烟90、革新3号一般配合力表现比较稳定,为黑胫病抗性高值亲本,较适宜作为黑胫病抗性亲本来源,Ky14、KBM20一般配合力表现为低值亲本,不适宜作为抗黑胫病抗性来源的亲本;杂交组合Burley21和KBM20特殊配合力较高,抗性上有进一步研究利用价值.烟草黑胫病遗传以显性效应为主,加性效应也较大,抗性表达还受环境影响.黑胫病抗性遗传规律稳定,亲本抗性对后代影响较大,但在早世代进行抗性改良效果不好.

Genetic Analysis on Tobacco Resistance to Black Shank Disease

36 hybrid combinations were obtained based on six tobacco cultivars Zhongyan90 (high resistance), Gexin3 (high resistance), L8 (middle resistance), Burley21 (middle resistance), KBM20 (high susceptibility) and Ky14 (high susceptibility) by the first method of C=P*P of Griffing diallel analysis. The combining ability of resistance to tobacco black shank were analyzed by DPS software. Results showed that there was great significant resistance difference among combinations. The resistance of different parents could be exhibited stably. General combining ability (GCA) and special combining ability (SCA) of resistance to black shank of six cultivars differed significantly. Zhongyan90 and KBM20 respectively showed the fh-st negative and positive effect which indicated that Zhongyan90 could be better than KBM20 in resistance breeding. There was some difference of GCA among six parents. Zhongyan90 and Gexin3 used as high resistance parents could exhibit steady GCA when combined with Burley21. However,Ky14 and KBM20 had low GCAs and were not appropriate parents resistant to black shank. The combination of Burley21 and KBM20 with a high SCA should be further studied. Furthermore, dominant effect was the main part in the heritance of black shank resistance also with large additive effect. Meanwhile, environmental factors will affect resistance expression to some extent. The resistance of parents had one great influence on combinations though there was a stably heritance. As a result, it is not suitable to select objective lines in the early generation.