A-3中抗条锈新基因YrTp1和YrTp2的分子标记定位分析

【目的】半个多世纪的中国小麦育种史基本是育种家与条锈病的赛跑史。因此，筛选、鉴定、储备和利用新抗源是我国育种和资源研究中的一个长远战略性课题。【方法】利用小麦条锈菌条中31、32号生理小种，对来自小麦与十倍体长穗偃麦草［Thinopyrum ponticum (Host) Liu & Wang］的杂交后代材料A-3进行抗性遗传分析。用荧光SSR分子标记技术，鉴定所携带抗条锈病基因是否为新基因，并对其进行染色体定位研究。【结果】遗传分析表明，A-3对条中31号和32号的抗性由一显一隐2对基因控制。经过对196对微卫星引物的筛选，发现2B染色体短臂上的WMC477-167bp与显性基因紧密连锁，遗传距离为0.4 cM,将该显性基因定位于2BS上；7B染色体短臂上的WMC364-208bp与隐性基因连锁，遗传距离为5.8 cM。图位比较、系谱分析和抗谱分析表明，A-3所含抗条锈基因不同于已知抗条锈基因，暂定名为YrTp1和YrTp2。【结论】可利用A-3中与条锈病抗性紧密连锁的分子标记YrTp1和YrTp2将抗性基因转移到主栽品种中，在小麦育种和生产上发挥作用。

Molecular Mapping of Two Novel Stripe Rust Resistance Genes YrTp 1 and YrTp2 in A-3 Drived from Triticum aestivum × Thinopyrum ponticum

【Objective】Loss of varietal resistance to stripe rust (Puccinia striiformis Westend f. sp. tritici) is an important factor causing massive periodical epidemic of rust in China′s wheat producing areas. Creation and development of new races of rust pathogen have led widely cultivated varieties into serious crisis of resistance loss. So searching new resistance genes is a long-term strategic task. 【Method】 and 【Result】A-3 line with high resistance (immunity) to current epidemic yellow rust races (CY29, 31, 32) was screened out in offspring of Triticum aestivum × Thinopyrum ponticum. Segregation in F2 and BC1 populations indicated that the resistance was controlled by two independent genes, a dominant gene and one recessive gene, respectively. SSR markers were employed to map the two resistance genes in the F2 and BC1 population. A marker WMC477-167bp locating on 2BS was linked to the dominant gene with genetic distance of 0.4 cM. Another marker WMC364-208bp locating on 7BS was linked to the recessive resistance gene with genetic distance of 5.8 cM. The two genes identified in this paper might be two novel stripe rust resistance genes, which were temporarily designated as YrTp1 and YrTp2, respectively. 【Conclusion】Good resistance to CY31 and CY32, availability of the tightly linking SSR markers can assist rapid transfer of the resistance genes into new varieties to control the epidemic of the two races in wheat production.