花生条纹病毒株系生物学特性及壳蛋白基因序列分析

Biological characters and sequence analysis of coat protein gene ofChinese strains of peanut stripe virus (PStV)

根据在花生上的症状，将５个ＰＳｔＶ中国分离物划分为轻斑驳、斑块和坏死三个株系类型。在其它鉴别寄主上，５个ＰＳｔＶ分离物有相似的症状。轻斑驳株系对花生主茎高度影响不明显，荚果减产２１．０％～３５．６％，种子带毒率高；而斑块型株系分别降低花生主茎高度和荚果产量９．２％～１６．３％和３０．３％～５４．４％，种子带毒率低。５个分离物能被豆蚜以不同效率传播。３个ＰＳｔＶ中国分离物壳蛋白基因均由８６１个核苷酸组成，核苷酸序列同源性为９９．５％～１００％，氨基酸序列同源性为１００％。它们与ＰＳｔＶ美国株系同源性最高，与印度尼西亚株系同源性次之，而与泰国株系同源性最低。

Five Chinese isolates of PStV were classified into three groupsmild mottle, blotch and necrosis, primarily on the basis of their reactions on peanut. All five isolates had nearly same host reactions on other indicator plants. Mild mottle strain had little effect on peanut growth and reduced pod yield by 21.0%35.6%. Blotch strain decreased the height of main stem and pod yield by 9.2%16.3% and 30.3%54.4%, respectively. Mild mottle strain had higher seed transmission rate than that of the blotch strain. The five PStV isolates were transmitted by Aphis craccivora at different efficiency. 861 bp nucleotide sequences of coat protein (CP) gene was determined for three isolates W1, W2 and G. The identity among three isolates was 99.5%100% at nucleotide level and 100% at amino acid level. Chinese PStV strains were most closely related to each other, close to PStV US strains, less close to PStV Indonesia strains and least to PStV Thailand strains in term of sequence identity of the virus CP gene.