小麦品种慢叶锈性的研究

Investigation on Slow-Rusting in Wheat Varieties Infected with Puccinia recondita f.sp.Tritici

小麦慢叶锈品种具有侵染率低、潜伏期长、孢子堆小、产孢量少、严重度低、病害进展曲线下面积小和病害虽流行但产量损失不显著等特点.潜伏期和扬花期平均病害严重度与产量损失的关系最密切,因此测定某一小麦品种的潜伏期(x_1)和平均病害严重度(x_2)(田间感病对照品种发病达50%或95%时),可以作为衡量该品种慢(快)叶锈性的两个指标和选种的依据.用y=94.67-3.10x_1+0.51x_2估测由叶锈造成的小区产量损失(y)有一定可靠性(R=0.96).用聚类分析法把供试品种分为慢锈、中慢、中快和快锈品种类型.苗期和成株期慢叶锈性有一定的吻合性.

Twenty-two wheat cultivars were used to investigate slow-rusting infected separately with Chinese race l , 2, 3 of Puccinia recondita f. sp. tritici. The components of rust development, latent period, infection frequency, uredia size and uredospore production per square centimeter of leaf surface were related to each other and to the area under the disease progress curve (AuDPC) , mean rust severity of modified cob scale (heading and soft dough growth stage)and reduced yield per plot, as indicated by significant correlation coefficients (r = 0.79-0.97). The reduction in yields of slow-rusting cultivars infected with puccinia recondita f, sp, tritici was significantly lower than that in the yields of fast-rusting cultivars. The multiple linear regression analysis to seven components indicated that latent period (x1) and mean rust severity(A2)were the major components reducing wheat yield (y). The equation estimating yield reduction was expressed to y = 94.67 - 3.10?1 + 0.51x2(R = 0.96) The latent period and mean rust severity compared to check cultivars may be used to estimate the slow-or fast-rusting levels of wheat cultivars, The wheat cultivars were divided into slow-, midslow-, fast- and midfast-rusting types by hieachical clustering methods according to the slow-rusting components.