Identification of Novel QTL Conferring Sheath Blight Resistance in Two Weedy Rice Mapping Populations
Identification of Novel QTL Conferring Sheath Blight Resistance in Two Weedy Rice Mapping Populations
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DOI：
10.1186/s12284-020-00381-9
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发表时间：
2020-03-23
期刊：
影响因子：
5.5
通讯作者：
Olsen, Kenneth M.
中科院分区：
文献类型：
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作者：
Goad, David M.;Jia, Yulin;Olsen, Kenneth M.
背景 水稻纹枯病 (ShB) 疾病由病原真菌立枯丝核菌引起，在全球范围内造成严重的产量损失。美国杂草稻种群是籼稻和澳大利亚栽培稻的非驯化形式，似乎比当地粳稻栽培稻对 ShB 具有更强的抵抗力。我们使用籼稻作物品种 Dee-Geo-Woo-Gen (DGWG) 与代表美国两种主要杂草生物型稻草壳 (SH) 和黑壳芒 (BHA) 杂交产生的两个 F-8 重组自交系群体绘制了与 ShB 抗性相关的数量性状位点 (QTL)。结果我们在两个作图群体中鉴定出了 9 个 ShB 抗性 QTL。其中五个归因于影响植物高度 (PH) 和抽穗日期 (HD) 的等位基因，这两个生长性状已知与 ShB 抗性高度相关。通过利用将生长性状视为作图模型中协变量的方法，我们能够推断出其余四个 QTL 与 ShB 抗性有关。其中两个 qShB1-2 和 qShB4 与之前确定的 ShB QTL 不同，代表了需要进一步研究的新候选者。结论 我们的研究结果表明，可以通过有利的植物生长性状和中小效应抗性 QTL 的综合作用来提高 ShB 抗性。此外，我们表明，将 PH 和 HD 作为 QTL 作图模型中的协变量是识别新的 ShB 抗性 QTL 的有效方法。
Background Rice sheath blight (ShB) disease, caused by the pathogenic fungus Rhizoctonia solani, causes significant yield losses globally. US weedy rice populations, which are de-domesticated forms of indica and aus cultivated rice, appear to be more resistant to ShB than local japonica cultivated rice. We mapped quantitative trait loci (QTL) associated with ShB resistance using two F-8 recombinant inbred line populations generated from crosses of an indica crop variety, Dee-Geo-Woo-Gen (DGWG), with individuals representing the two major US weed biotypes, straw hull (SH) and black hull awned (BHA). Results We identified nine ShB resistance QTL across both mapping populations. Five were attributable to alleles that affect plant height (PH) and heading date (HD), two growth traits that are known to be highly correlated with ShB resistance. By utilizing an approach that treated growth traits as covariates in the mapping model, we were able to infer that the remaining four QTL are involved in ShB resistance. Two of these, qShB1-2 and qShB4, are different from previously identified ShB QTL and represent new candidates for further study. Conclusion Our findings suggest that ShB resistance can be improved through favorable plant growth traits and the combined effects of small to moderate-effect resistance QTL. Additionally, we show that including PH and HD as covariates in QTL mapping models is a powerful way to identify new ShB resistance QTL.