春化、光周期和矮秆基因在不同国家小麦品种中的分布及其效应

摘要

To efficiently use exotic resources in Chinese wheat breeding programs, we investigated the heading date, maturity date,rnand plant height of 100 representative cultivars collected from 14 countries at eight locations in China, and detected the allelic variations of vernalization loci VRN-1 and VRN-B3, photoperiod gene Ppd-Dla, and dwarfing genes Rht-Bib and Rht-Dib by means of molecular markers. The frequencies of vernalization loci were 8.0% for Vrn-Ala, 21.0% for Vrn-BI, 21.0% for Vrn-DI and 64.0% for vrn-AI+vm-BI+ vrn-Dl, except for the absence of dominant allele Vrn-B3 in all tested materials. Dominant vernalization alleles Vrn-Ala, Vm-BI, and Vm-DI were mainly observed in cultivars from Chinese spring wheat region, Italy, India, Canada, Mexico, and Australia; whereas, cultivars carrying all recessive alleles at the four vernalization loci and vm-AI+ vrn-DI+Vm-BI+vm-B3 genotype were mostly found in cultivars from Chinese winter wheat region, United States (US) winter wheat region, Russia winter wheat region, United Kingdom (UK), France, Germany, Romania, Turkey, and Hungary. All cultivars headed normally when sown in autumn. Cultivars with dominant alleles showed earlier heading date than those with recessive alleles, and genotypes with two or more dominant alleles showed additive effects. Some European and US cultivars with recessive genes at the four vernalization loci could not mature in Yangling and Chengdu. Under spring-sown condition, the cultivars with dominant vernalization alleles showed high heading frequency; in contrast, most cultivars with recessive alleles failed to head. Gene Ppd-Dla was distributed mainly in cultivars from China, France, Romania, Russia, Mexico, Australia, and India with the total frequency of 68%. Most cultivars with Ppd-Dlb were from high latitude regions, such as UK, Germany, Hungary, and Canada. The Ppd-Dla genotypes appeared to head earlier than the Ppd-Dlb genotypes. Daylight condition had no effect on maturity of most Ppd-Dla genotypes, but short daylight condition resulted in failing mature in most Ppd-Dlb genotypes. The frequencies of dwarfing genes Rht-Blb and Rht-Dlb were 43.0% and 35.0% in the cultivars tested, respectively. Rht-Blb was mainly observed in cultivars from US, Romania, Turkey, Italy, Mexico, and Australia, while Rht-Dlb had high frequency in varieties from China, Germany, UK, Italy, and India. Generally, cultivars from one country contain either Rht-Blb or Rht-Dlb, and the frequencies of Rht-Blb and Rht-Dlb were very low in cultivars from high latitude regions. The effect of Rht-Blb, Rht-Dlb and Ppd-Dla on reducing plant height was significant, of which Rht-Blb and Rht-Dlb exhibited an additive effect.%为促进国外种质资源在我国的有效利用,将14个国家的100份代表性小麦品种在国内的8个代表性地点种植,调查抽穗期、成熟期和株高,并以4个春化基因(Vrn-A1、Vrn -B1、Vrn-D1和Vrn -B3)、1个光周期基因(Ppd-D1a)及2个矮秆基因(Rht-B1b和Rht-D1b)的分子标记检测所有品种的基因型.春化基因Vrn-A1a、Vrn-B1、Vrn -D1和vrn-A1+vrn-B1+ vrn-D1的分布频率分别为8.0％、21.0％、21.0％和64.0％；显性等位变异Vrn-A1a、Vrn-B1和Vrn-D1主要存在于来自中国春麦区及意大利、印度、加拿大、墨西哥和澳大利亚的品种中,这些品种一般为春性类型；春化位点均为隐性等位变异或vrn-A1+vrn D1+Vrn-B1的品种主要分布在中国冬麦区、美国冬麦区、俄罗斯冬麦区,以及英国、法国、德国、罗马尼亚、土耳其和匈牙利,这些地区的小麦均为冬性类型.秋播时,供试品种均能正常抽穗,且携带春化显性变异的材料较隐性类型抽穗早,显性等位变异表现加性效应,4个春化位点均为隐性变异的一些欧美材料因抽穗太晚在杨凌和成都不能正常成熟；而春播时,显性等位变异基因型抽穗的频率高,隐性等位变异基因型基本不能抽穗.光周期不敏感基因Ppd-D1a的分布频率为68.0％,主要分布在中国、法国、罗马尼亚、俄罗斯、墨西哥、澳大利亚和印度,而光周期敏感等位变异Ppd-D1b主要分布在英国、德国、匈牙利和加拿大等中高纬度地区；携带Ppd-D1a的品种较携带Ppd-D1b的品种抽穗早,大多数Ppd-D1a品种在长日照和短日照条件下均能成熟,大部分Ppd-D16品种在短日照条件下不能成熟.Rht-B1b和Rht-D1b基因的分布频率分别为43.0％和35.0％,其中,Rht-B1b主要分布于美国、罗马尼亚、土耳其、意大利、墨西哥和澳大利亚,Rht-D1b主要分布于中国、德国、英国、意大利和印度.一般来说,一个国家的品种携带Rht-B1b或Rht-D1b之一,而这2个基因在高纬度地区分布频率较低.Rht-B1b、Rht-D1b和Ppd-D1a的降秆作用均达显著水平,Rht-B1b和Rht-D1b的加性效应突出.