辽宁省梨黑点炭疽病的病原鉴定及致病性研究

Identification and pathogenicity of Colletotrichum siamense causing tiny black spot anthracnose of Pyrus spp. in Liaoning

梨树是辽宁省果树产业中重要树种之一,广泛分布于省内各地区。近年来,梨果实黑点在辽宁省梨产区广泛发生,严重影响着梨果实品质,为了有效控制病害发生蔓延,生产上急需明确引起梨果实黑点的病原。通过病原菌致病力测定、形态比较,以及基于多基因的系统发育分析,对采自辽宁省的梨黑点病病原菌进行鉴定。结果表明:形态学与分子鉴定均表明梨黑点病病原菌为暹罗炭疽病菌Colletotrichum siamense;C.siamense在不同梨品种上致病性存在显著差异,其中对‘茌梨’(白梨)致病性最强,对‘南果’‘花盖’(秋子梨)最弱。

Pear(Pyrus)industry is one of the most important fruit industries in Liaoning Province,which wide spread through fruit growing area.Recently,symptoms of tiny black spots on near mature pear fruits becomes a serious problem in Liaoning pear growing region.In order to effectively control this disease,it is necessary to clarify its causal agent.In this study,the pathogen causing tiny spot on pear fruits was identified through pathogenicity tests,morphological observe,and phylogenetic analysis of multi-locus sequences(internal transcribed spaces,ITS;actin,ACT;glyceraldehydes-3-phosphate dehydrogenase,GAPDH;β-tubulin gene,TUB2;calmodulin,CAL).The results showed that:both the morphological and molecular identification confirmed that the pathogen was Colletotrichum siamense;It is concluded that the pathogenicity differentiation is present for C.siamense on different pear cultivars,with which‘Chili’(Pyrus bretschneideri Rehd.)showed the most susceptible,and‘Nanguo’‘Huagai’(Pyrus ussuriensis Maxim.)showed the least susceptible.