Population Structure and Pathotype Diversity of the Wheat Blast Pathogen Magnaporthe oryzae 25 Years After Its Emergence in Brazil
Population Structure and Pathotype Diversity of the Wheat Blast Pathogen Magnaporthe oryzae 25 Years After Its Emergence in Brazil
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DOI：
10.1094/phyto-11-12-0294-r
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发表时间：
2014-01-01
期刊：
影响因子：
3.2
通讯作者：
McDonald, Bruce A.
中科院分区：
文献类型：
--
作者：
Nunes Maciel, Joao L.;Ceresini, Paulo C.;McDonald, Bruce A.
自1985年在巴西首次报道以来，由稻瘟病菌（无性型：Pyricularia）引起的小麦稻瘟病在南美洲变得越来越重要，该疾病仍在蔓延。我们使用11个微卫星位点，以阐明在中西部，东南部和巴西南部的麦田小麦稻瘟病病原体的人口结构。在小麦感染群体中没有发现细分，这与大空间尺度上的高水平基因流相一致。虽然克隆分数相对较高，两个交配型的独特型（MAT 1 -1和MAT 1 -2）是不是在相似的频率，克隆校正的人口从区联邦和戈亚斯，米纳斯三角洲，和圣保罗配子平衡。基于这些研究结果，我们提出，小麦稻瘟病病原体的人口表现出混合生殖系统，其中有性生殖是其次是本地分散的克隆。用当地小麦品种进行苗期毒力测定，在当前群体中区分出14个致病型。离头毒力测定在同一小麦品种上区分出8个毒力群。幼苗和穗部反应之间没有相关性。
Since its first report in Brazil in 1985, wheat blast, caused by Magnaporthe oryzae (anamorph: Pyricularia oryzae), has become increasingly important in South America, where the disease is still spreading. We used 11 microsatellite loci to elucidate the population structure of the wheat blast pathogen in wheat fields in central-western, southeastern, and southern Brazil. No subdivision was found among the wheat-infecting populations, consistent with high levels of gene flow across a large spatial scale. Although the clonal fraction was relatively high and the two mating type idiomorphs (MAT1-1 and MAT1-2) were not at similar frequencies, the clone-corrected populations from Distrito Federal and Goias, Minas Triangle, and Sao Paulo were in gametic equilibrium. Based on these findings, we propose that populations of the wheat blast pathogen exhibit a mixed reproductive system in which sexual reproduction is followed by the local dispersal of clones. Seedling virulence assays with local wheat cultivars differentiated 14 pathotypes in the current population. Detached head virulence assays differentiated eight virulence groups on the same wheat cultivars. There was no correlation between seedling and head reactions.