Partial resistance to powdery mildew in soft red winter wheat
Partial resistance to powdery mildew in soft red winter wheat
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软红冬小麦对白粉病的部分抗性
DOI：
10.1094/pd-80-1359
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
D. Hershman
中科院分区：
文献类型：
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作者：
W. L. Pearce;D. A. Sanford;D. Hershman
小麦白粉病（Erysiphe graminis f.）小麦赤霉病（Triticum sp. triangulum）是一种严重危害软红冬小麦（Triticum aestivum）的病害。在选择抗性时，一种策略是将部分抗性纳入育种群体。本研究的目的是（i）估计部分抗性遗传白粉病，（ii）确定哪个生长阶段是最佳的衡量白粉病预测产量损失方面，和（iii）衡量与白粉病产量损失。1991年，我们在肯塔基州列克星敦附近的一个重复试验中评价了来自一个单交群体的94个F3系，认为这些F3系是部分抗性分离的。在1993年的一个重复试验中对混合F5代进行了评价.根据叶片感染（LI）、旗叶和Feekes生长阶段（GS）9和10.5的对向两片叶上的白粉病指数对植物进行评级。仅在存在白粉病的最上面的叶上评估感染的严重程度。广义遗传力估计值范围为0.31（LI，1991）至0.65（严重程度，1991）。感染严重程度的遗传率在GS 9时显著高于GS 10.5（0.57 vs 0.34）。GS 9的感染严重度与任何白粉病等级的产量也具有最强的相关性（r = -0.55; P < 0.01）。在2年的研究中，我们观察到与白粉病相关的平均产量损失为20%。我们的数据表明，GS 9比GS 10.5更好地评估白粉病的可能产量损失和遗传力。
Powdery mildew (caused by Erysiphe graminis f. sp. tritici) is a disease that can cause significant yield loss in soft red winter wheat (Triticum aestivum). In selecting for resistance, one strategy is to incorporate partial resistance into breeding populations. The objectives of this study were to (i) estimate heritability of partial resistance to powdery mildew, (ii) determine which growth stage is optimal for measuring powdery mildew in terms of predicting yield loss, and (iii) measure yield loss associated with powdery mildew. In 1991, we evaluated 94 F 3 lines from a single-cross population believed to be segregating for partial resistance in a replicated experiment near Lexington, KY. The bulked F 5 progeny were evaluated in a replicated experiment in 1993. Plants were rated according to leaf infected (LI), an index of powdery mildew on the flag leaf and the subtending two leaves at Feekes growth stages (GS) 9 and 10.5. Severity of infection was assessed only on the uppermost leaf on which powdery mildew was present. Broad sense heritability estimates ranged from 0.31 (LI, 1991) to 0.65 (severity, 1991). Heritability of severity of infection was considerably higher at GS 9 than at GS 10.5 (0.57 versus 0.34). Severity of infection at GS 9 also had the strongest correlation with yield (r = -0.55; P < 0.01) of any powdery mildew rating. We observed an average yield loss of 20% associated with powdery mildew over the 2 years of the study. Our data indicate that GS 9 is better than GS 10.5 for evaluating powdery mildew in terms of likely yield loss and heritability.