海南黄灯笼辣椒顶死病病原病毒的分离鉴定

从海南省黄灯笼辣椒顶死病株上分离纯化得到一个病毒分离物.研究结果表明,该病毒分离物能通过汁液磨擦接种侵染供试植物中的4科11种植物,可由桃蚜传播;提纯病毒粒子呈球形,直径28～30 nm,外壳蛋白分子量约为28 ku;分离物与CMV抗血清在ELISA测定中呈阳性反应;提取病毒分离物RNA,应用RT-PCR方法克隆了病毒外壳蛋白（CP）基因.CP基因675 bp,编码218个氨基酸.对CP基因序列分析表明,该病毒分离物的CP基因核苷酸序列与黄瓜花叶病毒亚组Ⅰ分离物的同源性均在92.1%以上,所推导的氨基酸序列同源性在96.3%以上,而与亚组Ⅱ分离物的核苷酸序列同源性均低于77.3%,所推导的氨基酸序列同源性均低于80.7%.据此将该病毒分离物鉴定为黄瓜花叶病毒,归属于亚组Ⅰ.

Etiological Identification of Tip Necrosis Disease in Capsicum chinense in Hainan

An isolate of cucumber mosaic virus (CMV) was obtained from Capsicum ch inense leaves whose tip showed necrosis. The study of the host responses to viru s infection suggested that the isolate could infect plants of 11species from 4 f amilies, and was transmitted by Myzus persicae. Electron microscopy study reveal ed that the purified virus particle was spherical in shape and 28~30 nm in diame ter. The molecular weight of the coat protein (CP) subunit was about 28 ku based on SDS-PAGE. The isolate showed positive reaction when detected with the CMV an tiserum by ELISA. The CP gene was amplified by RT-PCR using the genomic RNA as t emplate and a pair of primers specific to CMV. Sequencing results showed that th e CP gene of the isolate had 675 bp encoding 218 amino acids. The nucleotide seq uences and amino acid sequences of the isolate shared over 92.1 % and 96.3 % hom ology with those of other isolates belonging to the subgroup I of CMV, respectiv ely, but less than 77.3 % and 80.7 % homology with those of other isolates belon ging to the subgroup II, respectively. In this context, the isolate was identifi ed as an isolate of CMV, belonging to the subgroup I.