Genic SNP markers and legume synteny reveal candidate genes underlying QTL for Macrophomina phaseolina resistance and maturity in cowpea [Vigna unguiculata (L) Walp.].
Genic SNP markers and legume synteny reveal candidate genes underlying QTL for Macrophomina phaseolina resistance and maturity in cowpea [Vigna unguiculata (L) Walp.].
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DOI：
10.1186/1471-2164-12-8
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发表时间：
2011-01-05
期刊：
影响因子：
4.4
通讯作者：
Roberts PA
中科院分区：
文献类型：
--
作者：
Muchero W;Ehlers JD;Close TJ;Roberts PA
菜豆巨藻(Macrophomina Phaseolina)是一种新兴的毁灭性真菌病原菌，在高温和干旱胁迫下给作物生产造成重大损失。越来越多的病害报告强调了病原菌在世界各地的广泛流行及其对作物产量抑制的贡献。在豌豆[Vigna unguulata(L)Walp.]中，已鉴定出有限的低水平寄主抗性来源，其遗传基础尚不清楚。本研究利用基因衍生的单核苷酸多态(SNPs)和扩增片段长度多态(AFLP)，对菜豆根结线虫强抗源进行了鉴定，并对可能的抗性基因座进行了遗传定位。利用田间试验3年的植株死亡数据和2个温室试验的病情严重程度评分，确定了9个数量性状座位(QTL)，对表型变异(R2)的贡献率在6.1%~40.0%之间。根据标记的基因SNPs以及与大豆和紫花苜蓿的同源性，在定位的QTL区间内找到了候选抗病基因。QTL Mac-2解释了最大的R2百分比，并在三个田间和一个温室试验中被鉴定出来，其中QTL峰与来自果胶酯酶抑制基因编码基因的SNP标记位于同一位置。成熟度对抗性表达的影响表现为Mac-6和Mac-7分别与成熟相关衰老QTL Mat-2和Mat-1共定位。ELF4和Flk开花基因的同源基因在相应的同质大豆区域中被发现。在同一群体中，只有3个大斑病抗性QTL与干旱诱导的早衰QTL定位在一起，这表明不同的遗传机制介导了豌豆对干旱胁迫和大斑病侵染的反应。本研究确定了寄主抗性的有效来源。QTL定位和共线分析确定了含有抗性因子的基因组座位，并揭示了具有进一步功能基因组分析潜力的候选基因。
Macrophomina phaseolina is an emerging and devastating fungal pathogen that causes significant losses in crop production under high temperatures and drought stress. An increasing number of disease incidence reports highlight the wide prevalence of the pathogen around the world and its contribution toward crop yield suppression. In cowpea [Vigna unguiculata (L) Walp.], limited sources of low-level host resistance have been identified, the genetic basis of which is unknown. In this study we report on the identification of strong sources of host resistance to M. phaseolina and the genetic mapping of putative resistance loci on a cowpea genetic map comprised of gene-derived single nucleotide polymorphisms (SNPs) and amplified fragment length polymorphisms (AFLPs). Nine quantitative trait loci (QTLs), accounting for between 6.1 and 40.0% of the phenotypic variance (R2), were identified using plant mortality data taken over three years in field experiments and disease severity scores taken from two greenhouse experiments. Based on annotated genic SNPs as well as synteny with soybean (Glycine max) and Medicago truncatula, candidate resistance genes were found within mapped QTL intervals. QTL Mac-2 explained the largest percent R2 and was identified in three field and one greenhouse experiments where the QTL peak co-located with a SNP marker derived from a pectin esterase inhibitor encoding gene. Maturity effects on the expression of resistance were indicated by the co-location of Mac-6 and Mac-7 QTLs with maturity-related senescence QTLs Mat-2 and Mat-1, respectively. Homologs of the ELF4 and FLK flowering genes were found in corresponding syntenic soybean regions. Only three Macrophomina resistance QTLs co-located with delayed drought-induced premature senescence QTLs previously mapped in the same population, suggesting that largely different genetic mechanisms mediate cowpea response to drought stress and Macrophomina infection. Effective sources of host resistance were identified in this study. QTL mapping and synteny analysis identified genomic loci harboring resistance factors and revealed candidate genes with potential for further functional genomics analysis.
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影响因子：
3.2
作者：
Olaya, G;Abawi, GS;Weeden, NF
通讯作者：
Weeden, NF
影响因子：
2.3
作者：
Paris, R. L.;Mengistu, A.;Smith, J. R.
通讯作者：
Smith, J. R.
DOI：
10.1073/pnas.0905886106
发表时间：
2009-10-27
影响因子：
11.1
作者：
Muchero, Wellington;Diop, Ndeye N.;Close, Timothy J.
通讯作者：
Close, Timothy J.
影响因子：
5.4
作者：
Sliwka, J.;Jakuczun, H.;Zimnoch-Guzowska, E.
通讯作者：
Zimnoch-Guzowska, E.
影响因子：
3.3
作者：
Bradshaw, JE;Pande, B;Waugh, R
通讯作者：
Waugh, R