新疆辣椒轻微斑驳病毒的分离鉴定

ISOLATION AND IDENTIFICATION OF PEPPER MILD MOTTLE TOBAMOVIRUS IN XINJIANG

从石河子露地辣椒病株上分离到一株病毒分离物（代号Ｐ—２），引起辣椒轻微斑驳。该分离物经人工接种能侵染５科９种植物。感染的辣椒种子可传毒，但桃蚜不能传播，Ｐ—２致死温度９０℃，稀释限点１Ｏ－９，体外保毒期５０天以上。病毒颗粒呈杆状，稍弯曲，大小为２９５±１０×１７ｎｍ：辣椒病组织超薄切片可见大量以平行或交叉排列的病毒集结体。该分离物与辣椒轻微斑驳病（ＰＭＭＶ）抗血清呈阳性反应。在辣椒上与ＴＭＶ无任何交叉保护，ＳＤＳ—聚丙烯酰胺凝胶电泳测得：Ｐ—２蛋白亚基由单一组分组成，分子量为１７ｋＤ，其氨基酸组成明显不同于ＴＭＶ。琼脂糖凝胶电泳测得：该分离物ＲＮＡ的分子量为２．１０×１０６。根据上述特性，认为该分离物隶属于ＰＭＭＶ。这是该种病毒在我国的首次报道。

viral isolate, named P-2, causing pepper mild mottle was obtained from the field shihezi, Xinjiang. Nine plant species from 5 families could be infected by artifical inoculation.The P-2 was easily transmitted by seeds, but failed to be transmitted by aphids (Myzuspersicae)Its thermal inactivation point was 90 ℃, dilution end point 10-9, and longevityin vitro above 50 days. The viral particles were rod-shaped with more or less winding,being295±10×17nm in size. The electron microscopy of the ultrathin-section of the infected pepperleaf showed crosshatched and angled-layered aggregates. In SDS-immunodiffusion tests in agargel, the purified P-2 reacted strongly with antiserum to PMMV. Cross protection testsbetween the P-2 and TMV on pepper did not indicate any relationship. Polyacrylamide gelelectrophoresis of SDS-treated virus showed one polypeptide of MW 17000 dalton, and theamino acid composition of the virus was found to be very different from TMV. A singleRNA of 2.1×10 6 dalton was measured by agarose gel electrophoresis.Based on the above results, it is concluded that the P-2 isolate belongs to the group ofTobamovirus, identified as pepper mild mottle virus (PMMV).