Genetic population structure and trichothecene genotypes of Fusarium graminearum isolated from wheat in southern Brazil
Genetic population structure and trichothecene genotypes of Fusarium graminearum isolated from wheat in southern Brazil
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DOI：
10.1111/j.1365-3059.2011.02515.x
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发表时间：
2012-04-01
期刊：
影响因子：
2.7
通讯作者：
Del Ponte, E. M.
中科院分区：
文献类型：
--
作者：
Astolfi, P.;Reynoso, M. M.;Del Ponte, E. M.
来自巴西南里奥格兰德的140个禾谷镰刀菌分离物样品，代表三个彼此相距至少150 km的群体，基于PCR扩增Tri 3和Tri 12基因的部分和种特异性（Fg 16 F/R）引物对，检查了禾谷镰刀菌烯基因型。利用AFLP分子标记技术对103个禾谷镰刀菌（F. similarytgraminearumsensustricto）的遗传多样性进行了分析。在所有三个人群中，15-ADON基因型占主导地位，其次是NIV基因型（患病率为218%）。所有NIV型分离株均在谱系2中（F.类似于Escherichonale），所有15-ADON型分离株均在谱系7中。具有相同单倍型的分离株是罕见的，基因型多样性是一致的高（=98%的计数），这表明重组发挥了重要作用。在所有位点和所有人群中，移民的数量（Nm）估计在5到6之间，但私人等位基因的高频率（高达30%）表明了历史而不是当代的基因流动。关于连锁不平衡，0.8%，1.5%和2.2%的位点对从三个群体中处于不平衡，这是低于其他地点报道的值。因此，巴西人群与欧洲、北美和亚洲大部分地区的人群不同，在谱系2中存在显著频率（7.8%）的NIV基因型分离株。
A sample of 140 Fusarium graminearum isolates from Rio Grande do Sul, Brazil, representing three populations at least 150 km from one another, were examined for trichothecene genotype based on PCR amplification of portions of the Tri3 and Tri12 genes and a species-specific (Fg16F/R) primer pair. Genetic diversity was assessed in a sample of 103 F.similar to graminearum lineage 7 (F.similar to graminearum sensu stricto) isolates using amplified fragment length polymorphism (AFLP) markers. The 15-ADON genotype was dominant, followed by the NIV genotype (218% prevalence), across all three populations. All NIV-type isolates were in lineage 2 (F.similar to meridionale) and all 15-ADON-type isolates were in lineage 7. Isolates with the same haplotype were rare and genotypic diversity was uniformly high (=98% of the count), suggesting that recombination has played a significant role. The number of migrants (Nm) was estimated between 5 and 6 across all loci and all populations, but the high frequency of private alleles (up to 30%) suggests a historical, rather than contemporary, gene flow. Regarding linkage disequilibrium, 0.8, 1.5 and 2.2% of the locus pairs from the three populations were in disequilibrium, which is lower than values reported in other locations. Thus, Brazilian populations differ from those found in Europe, North America and most of Asia in the presence of a significant frequency (7.8%) of isolates of the NIV genotype in lineage 2.