海南湛江柑桔疫霉种的鉴定及交配型研究

IDENTIFICATION AND MATING TYPE OF PHYTOPHTHORA SPECIES ON CITRUS TREES IN HAINAN AND ZHANJIANG

1988～1990年,从海南和湛江地区发生柑桔脚腐病的11个柑桔园采集了大量的病组织和病株基部的土壤样品,经分离共获得48个疫霉分离菌,根据孢子囊形态、脱落性、卵孢子产生、最高生长温度和淀粉利用能力等将其鉴定为寄生疫霉(Phytophthora parasitica Dast)柑桔褐腐疫霉(P.citrophthora R.E.& E.H.Smith)和辣椒疫霉(P.capsici Leonian)。这三种疫霉均是柑桔树的致病菌,其中寄生疫霉和柑桔褐腐疫霉的出菌率高,认为是这两个地区柑桔脚腐病的主要致病菌,而辣椒疫霉在中国柑桔园是首次发现。交配型测定结果以寄生疫霉的A^1,交配型占绝对优势。

During 1988～1990,many diseased tissues and soils infected with foot rot ofcitrus were collected from citrus orchards in Hainan and Zhanjiang.A totalof 48 isolates of Phytophthora spp.were obtained and all isolates were identified to be:P.parasitica Dast,P.Citrophthora R.E.& E.H.Smith and P.Cap-sici Leonian.P.Capsici is a new record in citrus orchard.in China All ofthem were pathogenic to citrus.It was considered that P.parasitica and P.citrophthora were the main causal agent of foot rot of citrus in those tworegions because they have a high frequency of occurrence A^1 mating type ofP.parasitica is dominant.