Genetic variation and host-parasite specificity of Striga resistance and tolerance in rice: the need for predictive breeding.
Genetic variation and host-parasite specificity of Striga resistance and tolerance in rice: the need for predictive breeding.
复制标题
DOI：
10.1111/nph.14451
复制
发表时间：
2017-05
期刊：
影响因子：
--
通讯作者：
Scholes JD
中科院分区：
文献类型：
--
作者：
Rodenburg J;Cissoko M;Kayongo N;Dieng I;Bisikwa J;Irakiza R;Masoka I;Midega CA;Scholes JD
寄生杂草Striga asiatica和Striga hermonthica对非洲高地造成毁灭性的产量损失。关于水稻基因型间的寄主抗性和耐受性的遗传变异，以及与独脚金属物种和生态型间的毒力差异的关系知之甚少。不同的水稻基因型表型为上述性状在S. asiatica-（坦桑尼亚）和S. hermonthica-侵扰领域（肯尼亚和乌干达）和在控制条件下。鉴定了具有生态型特异性或广谱抗性的新水稻基因型。田间鉴定的抗性在受控条件下得到证实，证明抗性主要由遗传决定。抗独脚金基因型有助于在独脚金侵染条件下的产量安全性，尽管谷物产量也由基因型特异性产量潜力和耐受性决定。耐受性是减轻独脚金对宿主生长和生理影响的生理机制，与抗性无关，这意味着这些性状的高、中或低水平的任何组合都可以在水稻基因型中找到。 独脚金的毒力因物种和生态类型而异。独脚金诱导的宿主损害的程度是由寄生虫毒力与宿主植物抗性和耐受性的遗传决定水平之间的相互作用引起的。这些新的发现支持了基于宿主抗性和寄生虫毒力知识的预测育种策略的需要。
The parasitic weeds Striga asiatica and Striga hermonthica cause devastating yield losses to upland rice in Africa. Little is known about genetic variation in host resistance and tolerance across rice genotypes, in relation to virulence differences across Striga species and ecotypes. Diverse rice genotypes were phenotyped for the above traits in S. asiatica‐ (Tanzania) and S. hermonthica‐infested fields (Kenya and Uganda) and under controlled conditions. New rice genotypes with either ecotype‐specific or broad‐spectrum resistance were identified. Resistance identified in the field was confirmed under controlled conditions, providing evidence that resistance was largely genetically determined. Striga‐resistant genotypes contributed to yield security under Striga‐infested conditions, although grain yield was also determined by the genotype‐specific yield potential and tolerance. Tolerance, the physiological mechanism mitigating Striga effects on host growth and physiology, was unrelated to resistance, implying that any combination of high, medium or low levels of these traits can be found across rice genotypes. Striga virulence varies across species and ecotypes. The extent of Striga‐induced host damage results from the interaction between parasite virulence and genetically determined levels of host–plant resistance and tolerance. These novel findings support the need for predictive breeding strategies based on knowledge of host resistance and parasite virulence.