新疆苜蓿新病毒(BLRV)的鉴定

Identification of a new virus on alfalfa in Xinjiang

中文新疆栽培苜蓿(Medicago sativa)有一种疑似病毒病的病害,种植第2年开始出现植株矮化、枝条细弱、叶片卷缩,种植第4年部分田块发病率达100%。为确定其病原,本研究在乌鲁木齐、昌吉、阿勒泰等地采集了219份发病苜蓿植株,采用菜豆卷叶病毒(BLRV)外壳蛋白基因特异性引物开展RT-PCR检测与分子鉴定。结果表明,在55份样品均可扩增得到一条长955kb的特异性片段,检出率为25%,该片段的序列(登录号:MK263743)与已知菜豆卷叶病毒(BLRV)外壳蛋白核苷酸序列的同源性为85.1%~96.5%,与阿根廷苜蓿菜豆卷叶病毒(登录号:KR261610.1)序列同源性最高,为96.5%。构建的系统发育树确定该病毒为黄症病毒科(Luteoviridae)黄症病毒属(Luteovirus)菜豆卷叶病毒。

A suspected viral disease outbreak was observed on cultivated alfalfa in Xinjiang. In the second year, some alfalfa plants became dwarfed, the branches thinned, and the leaves curled. In the fourth year, the rate of disease incidence in some fields reached 100%. To determine the pathogen, 219 suspected alfalfa samples were collected from Urumqi, Changji, and Altay. RT-PCR molecular detection and identification were carried out using the reported coat protein gene specific primers of bean leafroll virus (BLRV). The results showed that 55 samples could be amplified to obtain a 955 kb specific fragment with a detection rate of 25%. The sequence of this fragment (accession number: MK263743) had a homology of 85.1%– 96.5% with the nucleotide sequence of the BLRV coat protein, and the highest sequence homology (96.5%) was with the BLRV (accession number: KR261610.1) from Argentina. The constructed phylogenetic tree helped in the identification of the virus as belonging to Luteovirus, Luteoviridae.