鹅观草不同居群条锈病和白粉病抗性评价

鉴定不同居群鹅观草种质对条锈病和白粉病的抗性,为牧草及麦类作物抗病基因的选取和抗病品种选育提供遗传资源基础。本研究采用田间接种法对来自国内外的34份鹅观草种质资源(野生资源33份,品种1份)进行了成株期抗病性鉴定和评价。结果表明,种质资源抗病能力存在多样性。34份鹅观草条锈病的严重度、病叶率和病情指数的变异范围分别为11.49%~50.46%,19.85%~74.24%和2.63~37.60,变异系数分别为30.01%,26.54%和49.67%;反应型和发生程度的变异范围分别为1~4和轻发生(1级)至大发生(5级);各病害指标之间均为极显著正相关(P<0.01)。以上5个指标综合聚类分析表明:34份材料中,6份高抗(HR,占17.65%)、4份中抗(MR,占11.76%)、17份中感(MS,占50.00%)和7份高感(HS,占20.59%)。34份鹅观草白粉病的反应型、严重度和植株感病率的变异范围分别为0~4,0~60.00%和0~100%;34份材料聚类分析得知:12份高抗(HR,占35.29%)、5份中抗(MR,占14.71%)、11份中感(MS,占32.35%)和6份高感(HS,占17.65%)。对条锈病和白粉病均具有较好抗性的材料有ZY 1007和Pr 87-88 344,可作为育种材料进一步深入研究。

Resistance of Roegneria kamoji (Poaceae:Triticeae)populations to stripe rust and powdery mildew

Disease-resistant grasses can serve as a germplasm resource to breed resistant varieties of wheat and forage grasses.The aim of this study was to screen populations of Roegneria kamoji for their resistance to two common pathogens,stripe rust (Puccinia striiformis )and powdery mildew (Blumeria graminis ).Adult plants of 34 populations of R.kamoji (33 wild germplasms,and one cultivated variety)from domestic regions or introduced from overseas were evaluated to determine their resistance to the two pathogens in field trials. The degree of disease resistance differed among the 34 populations.Among the 34 populations of R.kamoji in-fected by stripe rust,the disease severity ranged from 11.49% to 50.46%,the disease incidence ranged from 19.85% to 74.24%,and the disease index ranged from 2.63 - 37.60,with a coefficient of variation of 30.01%,26.54%,and 49.67%,respectively.The infection type range and occurrence degree index range were 1-4 and 1-5,respectively.The disease indexes were significantly positively correlated (P <0.01 ).In cluster analyses based on the above indexes,the 34 populations of R.kamoji clustered into four groups:highly resistant (HR),moderately resistant (MR),moderately susceptible (MS),and highly susceptible (HS).The proportion of the 34 populations in the HR,MR,MS,and HS groups was 17.65%,11.76%,50.00%,and 20.59%,respectively.In the powdery mildew field trial,the range of infection type,disease severity,and ratio of diseased plants for the 34 populations of R.kamoji was 0-4,0%-60% and 0%-100%,respective-ly.The proposed resistance classifications were as follows:12 populations for HR,5 populations for MR,11 populations for MS,and 6 populations for HS (35.29%,14.71%,32.35%,and 17.65% of the populations, respectively).These results show that the accessions ZY 1007 and Pr 87-88 344 are resistant to both stripe rust and powdery mildew.Therefore,these accessions would be excellent resources for breeding disease-resistant wheat crops and forage grasses.