用慢白粉指数评价小麦品种的慢白粉性

An Evaluation of Slow mildewing Resistance of Wheat Cultivars by Index for Slow mildewing

１９９２～１９９４年在５个品种田间成株倒２叶和倒３叶上，以重复３次或４次测定了品种慢白粉抗性的４种组分。提出用慢白粉指数（ＩＳＭ）表达品种的抗病性。ＩＳＭ是病害最终严重度与单菌落面积之乘积，将其进行方差分析和ＳＳＲ测验（Ｐ＝０．０５），按显著性差异分群，ＩＳＭ较低的品种具有慢白粉抗性。该法使各品种在慢白粉程度序列中的位置明确体现出来，便于综合评价品种的慢白粉抗性。陕２１３小麦为慢白粉品种。

The experiments for powdery mildew caused by Blumeria graminis f.sp. tritici were made on the 5 wheat cultivars in 1992～1994.The four components of slow mildewing resistance were detected on the adult plants in the field with three or four replications.With that,Index for slow mildewing (ISM) was first put forward to express the resistance of cultivars.The final serious degree (S) of the powdery mildew and area of single colony (A) were detected on the first or the secondary leaf below flag.ISM was A multiplied by S.ISM was analysed by variance analysis and was tested by SSR ( P =0.05),so that the cultivars applied were grouped on the basis of significant difference between cultivars in slow mildewing degree.The cultivars of lower ISM were considered to possess slow mildewing resistance.The slow mildewing resistance of cultivars was expressed by using this method and the place of each cultivar in sequence of slow mildewing degree was shown clearly,exhibiting an advantage of valuing the level of slow mildewing resistance of cultivars.The cultivar Shaan 213 belongs to the slow mildewing cultivar and when inoculated with 13 races,it is a nonspecific resistance.