小麦成株期抗条锈病基因YrCH7056的定位及其抗源分析

摘要

Stripe rust resistance and genetic model from Thinopyrum ponticum(2n=10x=70)were studied to better utilize the resource and expand the selection range of resistance source for breeding in wheat. Recombinant inbred lines (RILs) were constructed by using CH7056,the introgression line of Th. ponticum,and wheat cultivars SY95-71. The F7 and F8populations from RILs were identified for their adult plant resistance using mixed Pst types CYR32+CYR33+v26. The results showed that the proportion of resistant and susceptible individual plants in the genetic groups were both close to 1:1 in 2013 and 2014,suggesting that CH7056 carried one dominant stripe rust resistance gene,temporarily des-ignated YrCH7056.Exogenous signals had not been detected using genomic in situ hybridization.YrCH7056 was located on wheat chromosome 1B by scaning DArT chip to the bulks of resistance and suspection of RILs.Then 129 pairs of the pub-lic SSR markers and 72 pairs of developed Thinopyrum ponticum-specific SSR markers on chromosome 1B were screened to construct the genetic map of YrCH7056.The flanking markers were 1BL-3848555 and barc240 with genetic distance of 1.1,2.5 cM,respectively.The stripe rust resistance gene differs from the resistance gene that had been mapped on chro-mosome 1BL by comparing the period of resistance,the source of gene,and the close linkage distance of the marker.It was deduced that YrCH7056 was a new gene of stripe rust resistance.In the meantime,the amplified bands of 1BL-3848555 among Thinopyrum ponticum,Thinopyrum ponticum-wheat octoploid Xiaoyan 7430 and CH7056 were the same, which showed that YrCH7056 might derive from Thinopyrum ponticum.%为了更好地利用彭提卡偃麦草资源,拓宽小麦抗源育种选择范围,对其抗条锈性和遗传模式进行探究.利用彭提卡偃麦草渗入系CH7056和小麦品种SY95-71构建重组自交系,以条锈混合菌种CYR32+CYR33+v26对重组自交系的F7和F8家系进行成株期抗性鉴定.结果表明:遗传群体家系中抗感单株比例在2013年和2014年间均接近1:1,由此推断CH7056中携带有1个显性抗条锈病基因,暂命名为YrCH7056.利用细胞学技术(基因组原位杂交)已检测不到外源信号.通过对群体抗感池扫描DArT芯片,将YrCH7056初步定位在小麦1B染色体;之后利用1B染色体上的129对公共SSR标记以及72对新开发的偃麦草特异标记构建了YrCH7056的遗传图谱,侧翼标记为1BL-3848555-1.1cM-YrCH7056-2.5cM-barc240.通过比较抗性表现的时期、基因来源以及紧密连锁标记的遗传距离得出,这个抗条锈病基因不同于已定位于染色体1BL上的抗性基因,推断YrCH7056是一个抗条锈病新基因;同时,1BL-3848555在CH7056中的扩增条带与在彭提卡偃麦草和小偃7430中的条带一致,推断YrCH7056可能来自于彭提卡偃麦草.