Stem Rust Resistance in a Geographically Diverse Collection of Spring Wheat Lines Collected from Across Africa.
Stem Rust Resistance in a Geographically Diverse Collection of Spring Wheat Lines Collected from Across Africa.
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DOI：
10.3389/fpls.2016.00973
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发表时间：
2016
影响因子：
5.6
通讯作者：
Boyd LA
中科院分区：
文献类型：
--
作者：
Prins R;Dreisigacker S;Pretorius Z;van Schalkwyk H;Wessels E;Smit C;Bender C;Singh D;Boyd LA
随着禾柄锈菌Ug 99谱系的出现，sp. triumphilis（Pgt））的小麦秆锈病抗性的新来源，国际上已经进行了集体努力来鉴定对这些小种有效的小麦秆锈病抗性的新来源。对从非洲各地收集的小麦基因型进行了分析，以确定对东部和南部非洲发现的Pgt小种有效的茎锈病抗性。非洲小麦收集包括在肯尼亚、南非、埃塞俄比亚、苏丹、赞比亚、摩洛哥和突尼斯收集的历史基因型，以及目前的南非育种系。贝叶斯聚类和主坐标分析都将来自苏丹的小麦品系放在一个不同的组中，但表明尽管来自非洲各国，但其他小麦品系之间存在一定程度的遗传相关性。幼苗筛选Pgt种族PTKST，系谱信息和标记单倍型分析证实了存在的Sr 2，Sr 36，Sr 24，Sr 31，和Lr 34/Yr 18/Sr 57在一些线。一项全基因组关联研究（GWAS）采用多样性阵列技术（DArT）和茎锈病（Sr）基因相关标记以及茎面积感染（SAI）和反应型（RT）田间表型，收集自2009年在肯尼亚和2011年在南非进行的两个季节的试验，确定了29个标记-性状关联（MTA）。在SAI和RT之间有三个共同的MTA，在染色体6AS上发现了最大的影响MTA。选择两个表现出高水平的成株秆锈病抗性的小麦品系W1406和W 6979来产生双亲作图群体。QTL定位结果表明，只有6AS和3BS染色体上的MTA和Lr 34/Yr 18/Sr 57位点得到了确认。在2BS、2DL、3DL和4D染色体上发现了GWAS未检测到的其他抗秆锈病QTL。
Following the emergence of the Ug99 lineage of Puccinia graminis f. sp. tritici (Pgt) a collective international effort has been undertaken to identify new sources of wheat stem rust resistance effective against these races. Analyses were undertaken in a collection of wheat genotypes gathered from across Africa to identify stem rust resistance effective against the Pgt races found in Eastern and Southern Africa. The African wheat collection consisted of historic genotypes collected in Kenya, South Africa, Ethiopia, Sudan, Zambia, Morocco, and Tunisia, and current South African breeding lines. Both Bayesian cluster and principal coordinate analyses placed the wheat lines from Sudan in a distinct group, but indicated a degree of genetic relatedness among the other wheat lines despite originating from countries across Africa. Seedling screens with Pgt race PTKST, pedigree information and marker haplotype analysis confirmed the presence of Sr2, Sr36, Sr24, Sr31, and Lr34/Yr18/Sr57 in a number of the lines. A genome-wide association study (GWAS) undertaken with Diversiry Arrays Technology (DArT) and stem rust (Sr) gene associated markers and Stem Area Infected (SAI) and Reaction Type (RT) field phenotypes, collected from trials carried out across two seasons in Kenya in 2009 and in South Africa in 2011, identified 29 marker-trait associations (MTA). Three MTA were in common between SAI and RT, with the biggest effect MTA being found on chromosome 6AS. Two wheat lines, W1406 and W6979 that exhibited high levels of adult plant stem rust resistance were selected to generate bi-parental mapping populations. Only the MTA on chromosomes 6AS and 3BS, and the locus Lr34/Yr18/Sr57 were confirmed following QTL mapping. Additional stem rust resistance QTL, not detected by the GWAS, were found on chromosomes 2BS, 2DL, 3DL, and 4D.