Universitaet Hohenheim, State Plant Breeding Institute, Stuttgart, Germany.
BMC Genet. 2012 Mar 12;13:14. doi: 10.1186/1471-2156-13-14.
Fusarium graminearum sensu stricto (s.s.) is an ubiquitous pathogen of cereals. The economic impact of Fusarium head blight (FHB) is characterized by crop losses and mycotoxin contamination. Our objective was to associate SNP diversity within candidate genes with phenotypic traits. A total of 77 F. graminearum s.s. isolates was tested for severity of fungal infection (= aggressiveness) and deoxynivalenol (DON) production in an inoculated field experiment at two locations in each of two years. For seven genes known to control fungal growth (MetAP1, Erf2) or DON production (TRI1, TRI5, TRI6 TRI10 and TRI14) single nucleotides polymorphic sites (SNPs) were determined and evaluated for the extent of linkage disequilibrium (LD). Associations of SNPs with both phenotypic traits were tested using linear mixed models.
Decay of LD was in most instances fast. Two neighboring SNPs in MetAP1 and one SNP in Erf2 were significantly (P < 0.05) associated with aggressiveness explaining proportions of genotypic variance (pG) of 25.6%, 0.5%, and 13.1%, respectively. One SNP in TRI1 was significantly associated with DON production (pG = 4.4).
We argue that using the published sequence information of Fusarium graminearum as a template to amplify comparative sequence parts of candidate genes is an effective method to detect quantitative trait loci. Our findings underline the potential of candidate gene association mapping approaches to identify functional SNPs underlying aggressiveness and DON production for F. graminearum s.s populations.
禾谷镰刀菌（s.s.）是一种普遍存在的谷物病原体。镰刀菌头腐病（FHB）的经济影响的特征是作物损失和霉菌毒素污染。我们的目的是将候选基因内的 SNP 多样性与表型特征联系起来。在两年的两个地点的接种田间试验中，共测试了 77 个禾谷镰刀菌（s.s.）分离株的真菌感染严重程度（=侵袭性）和脱氧雪腐镰刀菌烯醇（DON）的产生。对于已知控制真菌生长的七个基因（MetAP1、Erf2）或 DON 产生（TRI1、TRI5、TRI6、TRI10 和 TRI14），确定了单核苷酸多态性（SNP）并评估了连锁不平衡（LD）的程度。使用线性混合模型测试了 SNPs 与两种表型特征的关联。
LD 的衰减在大多数情况下都很快。MetAP1 中的两个相邻 SNP 和 Erf2 中的一个 SNP 与侵袭性显著相关（P < 0.05），分别解释了 25.6%、0.5%和 13.1%的基因型方差（pG）。TRI1 中的一个 SNP 与 DON 产生显著相关（pG = 4.4）。
我们认为，使用禾谷镰刀菌的已发表序列信息作为模板来扩增候选基因的比较序列部分是检测数量性状基因座的有效方法。我们的研究结果强调了候选基因关联作图方法识别禾谷镰刀菌（s.s.）群体侵袭性和 DON 产生的功能 SNP 的潜力。
