辣木果荚腐病病原菌分离及鉴定

Isolation and identification of pathogens causing pod rot of Moringa oleifera

  • 摘要: 【目的】明确辣木果荚腐病病原菌种类及其分类地位,为辣木果荚腐病防治提供理论依据。【方法】对云南省西双版纳州辣木种植基地感病、带黑色颗粒物病残体的辣木果荚进行症状观察、病原菌分离培养、致病性测定、显微形态特征观察、ITS和β-tubulin基因序列分析。【结果】辣木果荚腐病病原菌的分生孢子不分隔、透明,孢子顶端呈尖锥形弯曲,基部平截,具油滴,大小为15.7~22.1μm×2.5~4.3μm;厚垣孢子壁厚,呈黑褐色,簇生或成链状。该菌株ITS和β-tubulin基因的序列与Colletotrichum chlorophyti菌株IMI103806的同源性高达99%(ITS登录号:GU227894;TUB2登录号:GU228188)。多基因联合系统发育分析结果表明,供试菌株与兰生炭疽菌(C. chlorophyti)具有很近的遗传关系。【结论】兰生炭疽菌(C. chlorophyti)能侵染辣木引起果荚腐病,是为害辣木果荚的致病菌。

     

    Abstract: ObjectiveIn order to provide theory basis for controlling pod rot of Moringa oleifera, the pathogen was i-dentified, and its taxonomic status was studied. MethodThe infected M. oleifera pods with black particles were collected from M. oleifera planting base in Xishuangbanna, Yunnan province. Based on disease symptom observation, morphological characteristics of pathogen, pathogenicity, rDNA-ITS and β-tubulin gene sequence analysis, the pathogen causing pod rot of M. oleifera was identified. ResultThe conidia of pathogen were aseptate, hyaline, smooth, curved with tapered ends and a truncated base, and ranged from 15.7-22.1 μm×2.5-4.3 μm in size. Chlamydospores were dark brown, thick-walled, and fascicled or catenulate. The gene sequences of ITS and TUB2 gene showed 99% homology with Colletotrichum chlorophyti strain IMI103806 (ITS accession number: GU227894; TUB2 accession number: GU228188). Multi-gene phylogenetic analysis showed that the tested strain had the closest genetic relationship with C. chlorophyti. ConclusionC. chlorophyti can cause pod rot of M. oleifera, which is pathogen damaging pod of M. oleifera.

     

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