Genetic diversity of Rhizoctonia solani associated with potato tubers in France
Genetic diversity of Rhizoctonia solani associated with potato tubers in France
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DOI：
10.3852/10-231
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发表时间：
2011-11-01
期刊：
影响因子：
2.8
通讯作者：
Steinberg, Christian
中科院分区：
文献类型：
--
作者：
Fiers, Marie;Edel-Hermann, Veronique;Steinberg, Christian
土传真菌立枯丝核菌(Rhizoctonia Solani)是许多植物的病原菌，对世界各地的农作物造成严重危害。菌丝融合群(AG)3菌株侵染马铃薯，造成严重的产量损失和减产。对法国立枯丝核菌菌株的遗传多样性的研究可以确定种群的结构，并建立针对该病原菌的适宜的控制策略。对从马铃薯主要产区块茎中分离的73个法国菌株和从其他9个国家分离的31个菌株进行了系统发育分析，包括核糖体RNA(RRNA)的内部转录间隔区序列(ITS1和ITS2)，(Ii)Tell基因的一部分，以及(Iii)通过扩增片段长度多态性(AFLP)建立的总DNA指纹图谱。对水稻纹枯病菌ITS区序列的测定表明，在我们收集的样品中有3个不同的AGG(60个AG3个PT，8个AG2-I和5个AG5)。通过对首次用于研究立枯丝核菌遗传多样性的基因tef-1α的测序，确定了属于同一AG的菌株的分组。约42%的ITS序列和72%的tef-1α序列含有多态位点，表明立枯丝核菌的细胞内或不同核之间存在多个拷贝的ITS和tef-1α基因。系统发育树显示，与ITS序列相比，tef-1α序列中的AGs具有更大的遗传多样性。AFLP分析表明，菌株之间的多样性更大，表明从土豆中分离的法国菌株不是克隆群体。此外，菌株的地理来源或分离它们的品种与它们的遗传多样性之间没有关系。
The soilborne fungus Rhizoctonia solani is a pathogen of many plants and causes severe damage in crops around the world. Strains of R. solani from the anastomosis group (AG) 3 attack potatoes, leading to great yield losses and to the downgrading of production. The study of the genetic diversity of the strains of R. solani in France allows the structure of the populations to be determined and adapted control strategies against this pathogen to be established. The diversity of 73 French strains isolated from tubers grown in the main potato seed production areas and 31 strains isolated in nine other countries was assessed by phylogenetic analyses of (i) the internal transcribed spacer sequences (ITS1 and ITS2) of ribosomal RNA (rRNA), (ii) a part of the gene tell] a and (iii) the total DNA fingerprints of each strain established by amplified fragment length polymorphism (AFLP). The determination of the AGs of R. solani based on the sequencing of the ITS region showed three different AGs among our collection (60 AG 3 PT, 8 AG 2-I and 5 AG 5). Grouping of the strains belonging to the same AG was confirmed by sequencing of the gene tef-1 alpha used for the first time to study the genetic diversity of R. solani. About 42% of ITS sequences and 72% of tef-1 alpha sequences contained polymorphic sites, suggesting that the cells of R. solani strains contain several copies of ITS and the tef-1 alpha gene within the same nucleus or between different nuclei. Phylogenetic trees showed a greater genetic diversity within AGs in tef-1 alpha sequences than in ITS sequences. The AFLP analyses showed an even greater diversity among the strains demonstrating that the French strains of K solani isolated from potatoes were not a clonal population. Moreover there was no relationship between the geographical origins of the strains or the variety from which they were isolated and their genetic diversity.