栗疫菌营养体亲和型多样性比较及野生栗栗疫菌交配型的分子检测

在北京周边县区、湖北大老岭山区以及陕西安康地区分别调查栗疫病发生情况,采集病原栗疫菌(Cryphonectria parasitica)菌株并进行营养体亲和性试验.结果表明:北京板栗栽培区和陕西安康地区野生栗栗疫病发病率较高,局部地区危害严重;湖北大老岭山区栗疫病发病率低,危害轻微.北京地区菌株群体营养体亲和型多样性指数(Shannon-Wiener's diversity index)极显著低于湖北菌株群体和陕西菌株群体,而陕西与湖北菌株群体营养体亲和型多样性指数差异不显著.随机选取湖北、陕西野生栗栗疫菌部分菌株,利用特异性引物,通过普通PCR和巢氏PCR,对其交配型进行测定,发现陕西与湖北野生栗菌株群体中均存在MAT-1与MAT-2两种交配型的菌株.通过PCR扩增,在两地的野生菌株群体里均发现同时具有两种交配型基因的菌株,其中,陕西群体此类菌株比例较大,湖北菌株比例较小

Comparison of Vegetative Compatibility Diversity of Cryphonectria parasitica from Wild and Cultivated Chestnut and Molecular Detection of Mating-type of the Pathogens from Wild Chestnut

The incidence of chestnut blight caused by Cryphonectria parasitica in the regions of Beijing, Hubei and Shaanxi was investigated and the pathogen strains collected from these regions were used to detect their vegetative compatibility groups (VCGs). The results showed that the incidence of chestnut blight in Beijing and Shaanxi, varying according to different site conditions, was higher than that in Hubei. The Shannon-Wiener's diversity indexes of the VCGs of strains collected from Hubei and Shaanxi were statistically higher than that of strains from Beijing, whereas no statistical difference between the indexes of Shaanxi and Hubei. In addition, the mating-types of the representative strains selected randomly from Shaanxi and Hubei populations were detected by means of primary and nested PCR with specific primers. The results showed that both populations had two mating-types. Meanwhile, the strains with two mating-types in a single strain were detected as well, showing higher proportion in Shaanxi population than in Hubei population.