摘要
以抗白粉病的波斯小麦-小伞山羊草双二倍体Am9为母本,与高感白粉病的普通小麦品种陕160杂交,并用陕160回交一次,从其后代中选育的普通小麦种质N9628-2对陕西省关中地区白粉病流行小种关中4号表现免疫。为了明确N9628-2所携带抗性基因的遗传方式及与抗性基因连锁的分子标记,对该种质的抗白粉病基因进行了遗传分析和SSR标记分析。用高感白粉病品种陕160、陕优225与N9628-2杂交,F1代对白粉病均表现高抗,F2代抗感分离比例均符合3∶1,表明N9628-2的白粉病抗性由1对显性基因控制。通过208对SSR引物对陕160×N9628-2F2代抗感分离群体的142个单株的检测,发现位于6A上的SSR位点Xwmc553和Xwmc684在双亲和抗、感池间有特异性,并与抗性基因连锁,遗传距离分别是10.99和7.43cM,表明抗病基因可能位于6A染色体上。用中国春部分第6同源群的缺体-四体系和双端体系进行验证,进一步将抗性基因定位在6AS。用连锁的SSR标记和相关亲本分析表明,该抗病基因可能来源于小伞山羊草Y39,它不同于已有抗白粉病基因,可能是一个新基因。
Powdery mildew, caused by Blumeria graminis D C f. sp. tritici （former Erysiphe graminis f. sp. tritici）, is one of the devastating diseases of wheat （Triticum aestivum L.）. So far, a total of 34 resistance genes have been formally named. However, very few of them are used in wheat production due to resistance lose and close linkage to ill agronomic traits. The new resistant germplasm N9628-2, which was derived from the backcross of Am9 （F1 progeny of the cross between tetraploid wheat-Aegilops amphidiploid and a sensitive wheat cultivar “Shaan 160”） and Shaan 160, showed highly resistant to Guanzhong 4, the prevailing Blumeria graminis f. sp. tritici race in Shaanxi province. In the present study, we aimed to identify the resistance gene in N9628-2, and locate it on wheat chromosome. The F1 （308 plants） and F2 （275 plants） populations derived from crosses of N9628-2 and highly susceptible eultivars Shaan 160 and Shaanyou 225 were inoculated with powdery mildew race Guanzhong 4 at the seedling stage for resistance identification. The parents and F2 individuals were used for gene location with 208 pairs of SSR markers including 38 pairs polymorphic marker between two parents, and the result was verified by analyzing Chinese Spring nullisomic-tetrasomic and ditelosomic lines. According to inoculation test, the resistance to powdery mildew in N9628-2 was controlled by a single dominant gene （X^2= 0.038 and 0.068 in Shaan 160×N9628-2 and Shaanyou 225×N9628-2, respectively; X^2 0.05 = 3.84）. Two markers Xwmc553 and Xwme684 on chromosome 6A generated polymorphic DNA fragments between the resistant and susceptible pools, indicating the resistance gene might be located on chromosome 6A and linked to the two markers. The resistance gene was further located on chromosome 6AS by the absence of the above polymorphic DNA fragments only in Chinese Spring 6A 6AL ditelosomic lines. The genetic distances between the resistance gene and the two markers, calculated by Kosambi＇s formula, were 10.99 �
出处
《作物学报》
CAS
CSCD
北大核心
2008年第1期84-88,共5页
Acta Agronomica Sinica
基金
陕西省重大科技攻关专项项目(2006kz05-G3)
关键词
普通小麦
小伞山羊草
白粉病
抗性基因
SSR分析
Triticum aestivum L.
Aegilops umbelluata
Powdery mildew
Resistance gene
SSR analysis
