Different genetic components control coat-imposed and embryo-imposed dormancy in wheat
Different genetic components control coat-imposed and embryo-imposed dormancy in wheat
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DOI：
10.1017/s0960258500000052
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发表时间：
2000-03-01
影响因子：
2.1
通讯作者：
Flintham, JE
中科院分区：
文献类型：
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作者：
Flintham, JE
小麦籽粒休眠性是一个多基因性状，受红色种皮色素基因和其它基因共同控制，其中至少有一个基因在胚中起主要作用。在六倍体小麦中，增强的籽粒休眠性和红色种皮是由三个显性R等位基因的多效性效应遗传的。然而，R基因的多态性不能解释不同的红粒品种之间观察到的休眠性的广泛变化。各种不同的显性R等位基因都有相同的影响，休眠渗入到白粒小麦，虽然后者在休眠的情况下，并在显性R等位基因的存在下。因此，某些红粒基因型可以表现出中间休眠性，类似于一些具有不同遗传背景的白粒基因型。一个新的主基因（Phs）被确定为控制两个红粒品种之间的差异，广泛不同的休眠。Phs基因似乎发挥其作用，在胚胎的粮食，在母体种皮组织中的R基因表达。因此，离散的遗传功能的基础上，生理上不同的机制，外套强加的休眠和胚强加的休眠小麦。
Wheat grain dormancy is a multigenic trait controlled both by R genes conferring red testa pigmentation and by other genes, at least one of which has a major effect in the embryo. Enhanced grain dormancy and red testa colour are inherited as pleiotropic effects of dominant R alleles at triplicate loci in hexaploid wheat. However, polymorphism for R genes cannot account for the wide variation in dormancy observed among different red-grained varieties. A variety of different dominant R alleles all have equivalent effects on dormancy when introgressed into white-grained wheats, although the latter vary in dormancy both in the absence and in the presence of dominant R alleles. As a result, certain red-grained genotypes can exhibit intermediate dormancy, similar to that of some white-grained genotypes with different genetic backgrounds. A new major gene (Phs) was identified as controlling the difference between two red-grained cultivars with widely different dormancies. The Phs gene appeared to exert its effect in the embryo of the grain, in contrast to R gene expression in maternal testa tissue. Discrete genetic functions thus underlie physiologically distinct mechanisms of coat-imposed dormancy and embryo-imposed dormancy in wheat.