甘蓝型油菜开花期和光周期敏感性的遗传分析

以对光周期分别表现稳定弱敏感和强敏感的春性甘蓝型油菜品种DH401（P₁）与Q2（P₂）配制F₁代并经小孢子培养获得的DH群体来研究开花期和光周期敏感性的遗传规律。将P₁、P₂和DH群体连续2年分别种植在长日照的甘肃省和政县和短日照的广东省肇庆市、湖北省武汉市3地并调查开花期，以从和政和肇庆获得的开花期来计算光周期敏感指数（PSI），采用主基因-多基因混合遗传模型对该DH群体的开花期及光周期敏感指数进行遗传分析。结果表明，在和政、武汉和肇庆，开花期分别由3对加性-上位性主基因+多基因、2对加性-上位性主基因+多基因和2对累加作用主基因+多基因的控制；主基因遗传率分别为91.13%、63.05%和62.02%；多基因遗传率分别为4.43%、1.58%和22.71%。光周期敏感指数由2对隐性上位主基因及多基因控制，主基因和多基因遗传率分别为50%和37.5%。同时也估算了该DH群体的其他遗传参数。因此，开花期和光周期敏感性主要由2对或2对以上主基因及多基因控制，不同光周期条件下开花期基因之间的互作模式有所不同。同时也讨论了本研究结果在育种中的意义。

Genetic Analysis of Flowering Time and Photoperiod Sensitivity in Rapeseed ( Brassica napus L.)

One doubled haploid(DH) population derived from F1 plants of the cross between DH401(P1) and Q2(P2) was used to study the inheritance of flowering time and photoperiod sensitivity of spring Brassica napus in this study.Two parents had exhibited a low and high sensitivity to photoperiod,respectively.Days to flower(DTF) were investigated in the P1,P2 and DH population at Hezheng(Gansu Province) with a long day in summer and at both Zhaoqing(Guangdong Province) and Wuhan(Hubei Province) with a short day in winter for consecutive two years.Photoperiod sensitivity index(PSI) was calculated according to DTF obtained from Hezheng and Zhaoqing.The means of DTF and PSI were analyzed by applying a mixed major gene and polygene inheritance model.The results showed that DTF at Hezheng,Wuhan and Zhaoqing was controlled by 3,2,and 2 pairs of major genes with additive and epistatic effect plus polygenes,duplicate effect plus polygene,respectively.Heritability values of the major genes at the three locations were 91.13%,63.05% and 62.02%,and those of polygenes were 4.43%,1.58%,and 22.71%,respectively.The PSI was conditioned by 2 pairs of major genes with epistatic recessiveness effect and some polygenes.The heritability values of the major genes and polygenes were 50% and 37.5%,respectively.Other genetic parameters were also estimated.Therefore,it is speculated that both flowering time and photoperiod sensitivity in this DH population were controlled by 2 or over 2 pairs of major genes and polygenes,and the plants might have some different interaction models among flowering genes under different photoperiods.Meanwhile,how to use the results for Brassica napus breeding was discussed.