绵麦37特异位点在其衍生品种中的遗传贡献率分析

Frequency and contribution of specific genetic loci transferred from wheat cultivar Mianmai 37 to its derivatives

优良亲本的创制和利用能有效提高育种效率。文章对绵麦37及其衍生品种产量构成因子和抗病性进行比较鉴定,并利用SSR标记检测高产品种绵麦367遗传背景中绵麦37的遗传贡献。结果表明:衍生品种丰产性显著提高,穗粒数的增加是衍生品种增产的主要因素;绵麦37及其衍生品种高抗当前国内条锈菌主要流行小种,特别是高抗对Yr24/Yr26具有强毒性的条锈病新菌株V26;绵麦37优良的抗病性很好地传递给了后代品种;在绵麦367等后代品种的遗传背景中,绵麦37的遗传贡献率达78.9%,其中A、B、D基因组中的遗传率分别为75.0%、83.6%和74.2%,远高于理论值50.0%;衍生品种绵麦367与绵麦37相同染色体区段主要为2B的Xgwm374-Xbarc167-Xbarc128-Xgwm129-Xgwm388-Xbarc101,3B的Xwmc446-Xwmc366-Xwmc533-Xbarc164-Xwmc418等区段,这些区段包含了许多重要性状位点如穗粒数、千粒重和抗病性等。这可能是由于人工定向选择的结果,使那些与目标性状紧密连锁的位点被高频率保留下来。

The development and utilization of outstanding germplasm in breeding programs can expedite breeding process. The high yielding variety Mianmai 37, grown widely in southwestern China, has been used widely in breeding programs.Comparisons between Mianmai 37 and its derivatives for yield and yield components were conducted. Simple sequence repeat （SSR） markers were used to test the frequency of specific alleles transferred from Mianmai 37 to its derivative culti var Mianmai 367. The results indicated that the yield of the derivative cultivars was significantly higher than Mianmai 37, due to an increased grain number per spike. Favorable traits from Mianmai 37 such as resistance to stripe rust, were trans ferred to its derivatives. At molecular level, 78.9% loci in Mianmai 367 were derived from Mianmai 37 with 75.0, 83.6 and 74.2% from A, B and D genomes, respectively. Mianmai 367 shared common loci with its parent Mianmai 37, such as re gions Xgwm374-Xbarc167-Xbarc128-Xgwm129-Xgwm388-Xbarc101 on chromosome 2B and Xwmc446-Xwmc366- Xwmc533-Xbarc164-Xwmc418 on chromosome 3B, these regions were associated with grain number, 1000-kernel weight and resistance. The preferred transmission of alleles from Mianmai 37 to its derivatives probably can be explained by the strong selection pressures because of its favorable agronomic traits and the disease resistance.