玉米种质资源对纹枯病的抗性鉴定与评价

在人工接种条件下,对国内常用的285份玉米种质资源进行抗纹枯病大田鉴定与评价,未发现免疫材料,抗病材料很少.高抗、抗和中抗材料的比例分别为1.0%、3.2%、13.7%;绝大多数材料属于感病或高感,分别占29.8%、52.3%.株高、主穗位高、主穗位高/株高之比值与病情指数呈负相关,病斑高、病斑高/株高、病斑高/主穗位高之比值与病情指数呈正相关,可以将病斑高度与主穗位高度的比值作为抗性鉴定与评价指标之一.采用带菌麦粒在拔节中后期定位接种,以病斑到达的叶鞘位作为病情和抗性评价体系是较为准确和规范的方法.

Identification and Evaluation of Maize Germplasm for Resistance to Corn Sheath Blight(Rhizoctonia solani)

Two hundred and eighty-five maize germplasm were identified and evaluated for resistance to sheath blight caused by Rhizoctonia solani. No immune germplasm was found. The percentage of highly resistant, resistant and moderately resistant germplasm were 1.0%, 3.2%, 13.7%, respectively. Most of the tested germplasm were susceptible. The percentage of susceptible and highly susceptible germplasm were 29.8%, 52.3 %, respectively. Plant height, ear height, the ratio of ear height and plant height were negatively correlated with the disease index. The lesion height, the ratio of lesion height, plant height and ear height were positively correlated with the disease index. The ratio of lesion height and ear height could be used to evaluate the resistance of maize to corn sheath blight.