Intraspecific evolution of Rhizoctonia solani AG-1 IA associated with soybean and rice in Brazil based on polymorphisms at the ITS-5.8S rDNA operon
Intraspecific evolution of Rhizoctonia solani AG-1 IA associated with soybean and rice in Brazil based on polymorphisms at the ITS-5.8S rDNA operon
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DOI：
10.1007/s10658-005-2231-7
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发表时间：
2005-10-01
影响因子：
1.8
通讯作者：
Ceresini, PC
中科院分区：
文献类型：
--
作者：
Ciampi, MB;Kuramae, EE;Ceresini, PC
立枯丝核菌 AG-1 IA 引起大豆和水稻叶枯病。尽管立枯丝核菌 AG-1 IA 是影响巴西和世界其他地区大豆和水稻的主要病原体，但有关其遗传多样性和进化的信息却很少。本研究试图揭示巴西大豆和水稻中具有流行病学意义的立枯丝核菌 AG-1 IA 基因型的起源、移动和扩增模式。为了推断从大豆和水稻中取样的 R. solani AG-1 IA 的种内进化，使用 Clement 等人的统计简约算法构建了 ITS-5.8S rDNA 测序单倍型网络。 （2000）分子生态学9：1657-1660。与世界其他地区的样本 (0.431) 相比，巴西大豆样本 R. solani AG-1 IA (0.827) 具有更高的单倍型多样性（Nei M 1987，分子进化遗传学哥伦比亚大学出版社，纽约：512p.）。在美国中南部分支 (3-2) 中，来自马托格罗索州、一种来自托坎廷斯、一种来自马拉尼昂和一种来自古巴的 R. solani AG-1 IA 的四种单倍型占据了网络的顶端，表明其起源较晚。假定的祖先单倍型可能起源于马托格罗索州或马拉尼昂州。虽然在 32 个大豆病原体分离株的样本中发现了 16 种不同的单倍型，但整个水稻样本 (n=20) 由单一单倍型（单倍型 5）代表，并在全球范围内分布。嵌套分支分析的结果表明，美国中南部分支（3-2）主要由大豆单倍型组成，其基因流动受到距离隔离的限制（或在无性物种中受距离限制的传播）。
Rhizoctonia solani AG-1 IA causes leaf blight on soybean and rice. Despite the fact that R. solani AG-1 IA is a major pathogen affecting soybean and rice in Brazil and elsewhere in the world, little information is available on its genetic diversity and evolution. This study was an attempt to reveal the origin, and the patterns of movement and amplification of epidemiologically significant genotypes of R. solani AG-1 IA from soybean and rice in Brazil. For inferring intraspecific evolution of R. solani AG-1 IA sampled from soybean and rice, networks of ITS-5.8S rDNA sequencing haplotypes were built using the statistical parsimony algorithm from Clement et al. (2000) Molecular Ecology 9: 1657-1660. Higher haplotype diversity (Nei M 1987, Molecular Evolutionary Genetics Columbia University Press, New york: 512p.) was observed for the Brazilian soybean sample of R. solani AG-1 IA (0.827) in comparison with the rest of the world sample (0.431). Within the south-central American clade (3-2), four haplotypes of R. solani AG-1 IA from Mato Grosso, one from Tocantins, one from Maranhao, and one from Cuba occupied the tips of the network, indicating recent origin. The putative ancestral haplotypes had probably originated either from Mato Grosso or Maranhao States. While 16 distinct haplotypes were found in a sample of 32 soybean isolates of the pathogen, the entire rice sample (n=20) was represented by a single haplotype (haplotype 5), with a worldwide distribution. The results from nested-cladistic analysis indicated restricted gene flow with isolation by distance (or restricted dispersal by distance in nonsexual species) for the south-central American clade (3-2), mainly composed by soybean haplotypes.