Genetic Constitution and Pathogenicity of Lolium Isolates of Magnaporthe oryzae in Comparison with Host Species-Specific Pathotypes of the Blast Fungus.
Genetic Constitution and Pathogenicity of Lolium Isolates of Magnaporthe oryzae in Comparison with Host Species-Specific Pathotypes of the Blast Fungus.
复制标题
稻瘟病黑麦草分离株的遗传组成和致病性与稻瘟病菌宿主物种特异性致病型的比较。
作者：
Y. Tosa;K. Hirata;H. Tamba;S. Nakagawa;I. Chuma;C. Isobe;J. Osue;A. S. Urashima;L. D. Don;M. Kusaba;H. Nakayashiki;A. Tanaka;T. Tani;N. Mori;S. Mayama
摘要通过DNA分析、交配试验和致病性测定，对多年生黑麦草灰斑病病原菌进行了分离鉴定。所有的prg分离物与小麦分离物是可互作的，并且在由rDNA-internal transcribed spacer 2序列构建的树状图上聚类到作物分离物组（CC组）。由于CC组对应于新提出的种Magnaporthe magnaporthe，因此所有prg分离物均被指定为M。米。然而，MGR 586、MGR 583和Pot 2的DNA指纹图谱显示，prg分离物分为两个不同的群体，即，TALF分离株和WK分离株。TALF分离株仅对黑麦草属种具有毒性，而WK分离株的特异性较低，表明灰叶斑病不仅可由黑麦草属特异性分离株引起，也可由特异性较低的分离株引起。我们将TALF分离物命名为Lolium致病型。TALF分离株的DNA指纹图谱虽然一致，但核型多样，表明它们的基因组结构不稳定。
ABSTRACT Fungal isolates from gray leaf spot on perennial ryegrass (prg isolates) were characterized by DNA analyses, mating tests, and pathogenicity assays. All of the prg isolates were interfertile with Triticum isolates and clustered into the crop isolate group (CC group) on a dendrogram constructed from rDNA-internal transcribed spacer 2 sequences. Since the CC group corresponded to a newly proposed species, Magnaporthe oryzae, all of the prg isolates were designated M. oryzae. However, DNA fingerprinting with MGR586, MGR583, and Pot2 showed that the prg isolates are divided into two distinct populations, i.e., TALF isolates and WK isolates. The TALF isolates were virulent only on Lolium species, whereas the WK isolates were less specific, suggesting that gray leaf spot can be caused not only by Lolium-specific isolates but also by less specific isolates. We designated the TALF isolates as Lolium pathotype. The TALF isolates showed diverse karyotypes in spite of being uniform in DNA fingerprints, suggesting that theyare unstable in genome organization.