杂种优势的数量遗传学理论及其在玉米育种中的应用

Quantitative Genetics Theory of Heterosis and Related Application in Maize Breeding

杂种优势现象已经被广泛应用在商业化育种实践中,不同群体(系)之间杂交第一代往往表现出杂种优势,这是生物界的一种普遍现象。杂种优势形成的遗传基础仍然停留在假说阶段,主要包括显性假说、超显性假说以及上位性、杂种优势基因、等位基因特异性表达等理论解释。在综述不同杂种优势假说的基础上,结合多年的玉米自交系和杂交种选育实践,阐述HF1=Σdy^2的实用性,讨论并探讨杂种优势形成的双亲基因频率差异互补理论,提出玉米自交系、杂交种选育的群间选系组配观点。此外,还讨论了一些改良和创新杂种优势类群的玉米育种实践。

Heterosis is a common phenomenon in biology,which has been widely used in commercial breeding practice.It often shows the difference of heterosis among individuals derived from the first generation of a cross be⁃tween pair-populations(lines).However,the genetic basis of heterosis’formation is still in the stage of hypothesis,mainly including dominant hypothesis over-dominant hypothesis,epistasis heterosis gene,allele specific expression and other theoretical explanations.In this paper,different reviews of heterosis hypotheses were summarized,and the utilization of the practicability of HF1=Σdy^2 was clarified,when combined reported heterosis hypotheses with cur⁃rent maize inbred line and hybrid breeding practice.Based on this,the complementary theory of parental gene fre⁃quency difference in the formation of heterosis was discussed.One viewpoint about inbred selection and hybrids crossed between groups was proposed.In addition,some breeding practices of maize improving and innovating for heterosis groups were also discussed.