广东梅州蜜柚柑橘黑斑病菌的检验鉴定

近年,柑橘黑斑病成为阻碍我国柑橘鲜果出口贸易的瓶颈,广东梅州名优鲜果蜜柚生产基地也遇到类似情况。该病发生后,病果果皮表面产生许多圆形病斑,初呈红褐色,中间凹陷,直径多为2~3mm,后期病斑逐渐转为褐色至黑褐色,病斑中部明显可见细小的黑色粒点状分生孢子器。病果分离物的培养性状与形态特征与柑橘黑斑病菌(柑橘球座菌,Guignarida citricarpa)一致。采用真菌ITS通用引物和柑橘球座菌特异性引物,从病斑组织基因组DNA及分离物基因组DNA中分别扩增得到541bp和396bp的片段。BLAST分析表明:扩增到的片段均与GenBank中已知柑橘球座菌菌株的rDNAITS序列相似性最高,分别为97%和98%。根据分离菌株的培养性状和形态特征及ITS区序列分析结果,将梅州蜜柚上的柑橘黑斑病菌鉴定为柑橘球座菌(Guignarida citricarpa Kiely)。

Inspection and identification of Guignardia citricarpa,the cause of citrus black spot of Citrus grandis in Meizhou Guangdong

Recent years,the disease of citrus black spot becomes a obstacle to export trade of citrus fruit in China.The production area of honey pomelos(Citrus grandis)with high-quality in Meihzhou Guangdong has also met similar situation.After infection of the disease,on the peel surface of the pomelos appears many circular necrotic spots.At the beginning,the spots are red brown and depressed in the middle,mostly 2~3 mm in diameter.Later,the spots gradually turn brown to dark brown,some small protruding black pycnid...