中国小麦农家品种‘老白麦’抗条锈性遗传分析

Genetic analysis of the resistance of Chinese wheat landrace‘Laobaimai'to stripe rust

小麦条锈病是小麦生产上重要的气传叶部病害。不断发掘和利用新抗源是持续控制条锈病流行危害的重要基础研究工作。‘老白麦’是我国小麦农家品种,对我国当前主要流行小种和致病类型均表现为高抗水平。本研究采用常规杂交分析方法,对‘老白麦’及其与感病品种‘Taichung 29’的杂交后代在成株期和苗期分别接种CYR32号小种和CYR33号小种,进行抗条锈性鉴定和统计分析。结果表明,‘老白麦’对CYR33号小种在苗期和成株期均表现近免疫,其全生育期抗条锈性由1对显性基因控制;对CYR32号小种在成株期表现近免疫,苗期表现高感,成株抗条锈性由1对显性基因控制,属细胞核遗传。研究结果表明‘老白麦’至少含有2对显性抗病基因,分别控制‘老白麦’对CYR33号小种的全生育期抗性和对CYR32号小种的成株抗性。基因推导分析认为‘老白麦’对CYR33的全生育期抗性基因可能为未知新基因。建议在抗病育种中加以有效合理利用,促进小麦品种中抗病基因多样化布局。

Stripe rust is one of the most destructive airborne leaf diseases of wheat.It is important to continuously develop and utilize new resources resistant to stripe rust,and often regarded as the critical basis for durably controlling the epidemic disease.Chinese wheat landrace‘Laobaimai'is highly resistant to most presently predominant races and pathotypes of Puccinia striiformis f.sp.tritici.In this study,by using crossing and genetic analysis,resistant parent‘Laobaimai',susceptible‘Taichung 29'and their progeny populations derived from the crosses of these two cultivars were all inoculated with the two races CYR32 and CYR33 at seedling and adult stages respectively to identify their disease resistance levels,and statistical analysis was carried out.Based on the results,‘Laobaimai'was nearly immune to race CYR33 at both seedling and adult stages,containing a single dominant over-all resistant gene.On the other hand,‘Laobaimai'was highly susceptible to race CYR32 at seedling stage,while nearly immune to it at adult stage,indicating that its adult resistance was controlled by a single nuclear-genetic-type dominant gene.Accordingly,‘Laobaimai'contained at least two dominant resistance genes,over-all resistant gene for race CYR33 and adult resistance for race CYR32,respectively.Through gene postulation analysis,it was suggested that‘Laobaimai'possibly contained an unknown over-all resistance gene to race CYR33.We propose that the stripe rust resistance germplasm ‘Laobaimai'could be reasonably used in wheat resistance breeding practice for promoting the diverse distribution of the resistance genes in wheat cultivars.