SSR-based genetic linkage analysis of resistance to crown rust (Puccinia coronata f. sp lolii) in perennial ryegrass (Lolium perenne)
SSR-based genetic linkage analysis of resistance to crown rust (Puccinia coronata f. sp lolii) in perennial ryegrass (Lolium perenne)
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DOI：
10.1046/j.1365-3059.2003.00884.x
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发表时间：
2003-10-01
期刊：
影响因子：
2.7
通讯作者：
Jones, ES
中科院分区：
文献类型：
--
作者：
Dumsday, JL;Smith, KF;Jones, ES
冠锈病(Puccinia coronata f.sp.)多年生黑麦草(Lolium Perenne)是一种严重危害牧草和草坪的叶部病害。以前的遗传学研究已经检测到了定性和定量的抗性机制，而对遗传系统的解释由于有性繁殖病原体内部的变异而变得复杂。利用从三个不同地理位置采集的复合夏孢子群体，鉴定了黑麦草的抗性和感病亲本基因型。以黑麦草亲本维德特(6)和维多利亚(9)为亲本进行F-1定位，获得了一个双向伪测交作图群体。双亲对采集于同一地理区域(哈密尔顿，维多利亚)的病原菌群体表现出中等抗性，但在F-1群体中，检测到与抗性相关的一系列性状的显著变异。表型数据的统计分析表明一个主基因效应，因此使用图谱分配的简单序列重复(SSR)标记的批量分离分析来扫描基因组。多年生黑麦草连锁群(Lg)2是一个与抗性关联较强的标记。通过对11个LG2 SSR标记的分析，确定了xlpssrh03f03和xlpssrk02e02位点之间存在一个或多个抗冠锈病基因(LpPc1)的区间。抗性基因决定因素遗传自双亲，高达80%的总表型变异由分离自维德特(6)的标记解释，高达26%的变异由分离自维多利亚(9)的标记解释。这两个因素共同导致了效应的相加增加，完全抵抗的个体需要来自父母双方的决定因素。与燕麦B连锁群具有保守的共线关系，B连锁群是燕麦抗冠锈病基因簇的定位。讨论了本研究对多年生黑麦草抗病分子标记辅助选择的意义。
Crown rust (caused by Puccinia coronata f. sp. lolii) is a serious foliar disease of the pasture and turfgrass perennial ryegrass (Lolium perenne). Previous genetic studies have detected both qualitative and quantitative resistance mechanisms, and interpretation of the genetic system is complicated by variation within the sexually reproducing pathogen. Resistant and susceptible parental genotypes of ryegrass were identified using a composite urediniospore population collected from three geographically distinct locations. A two-way pseudo-testcross mapping population was obtained as the F-1 progeny of the pair-cross between ryegrass parental genotypes Vedette(6) and Victorian(9). Both parents showed intermediate resistance against a pathogen population collected in a single geographical zone (Hamilton, Victoria), but in the F-1 population, significant variation for a range of resistance-associated characters was detected. Statistical analysis of phenotypic data suggested a major gene effect, hence bulked segregant analysis with map-assigned simple sequence repeat (SSR) markers was used to scan the genome. A marker showing strong association with resistance was assigned to linkage group (LG) 2 of perennial ryegrass. Analysis of 11 LG2 SSR markers defined an interval between loci xlpssrh03f03 and xlpssrk02e02 as containing the gene or genes (LpPc1) conferring crown rust resistance. Resistance gene determinants were inherited from both parents, with up to 80% of the total phenotypic variation explained by markers segregating from Vedette(6) and up to 26% of the variation explained by markers segregating from Victorian(9). The two contributions together resulted in an additive increase in effect, with fully resistant individuals requiring determinants from both parents. A conserved syntenic relationship was observed with linkage group B of Avena strigosa, which is the location of a cluster of resistance genes to the oat form of crown rust. The implications of this study for marker-assisted selection of disease resistance in perennial ryegrass are discussed.