Morphological, phylogenetic and biological characteristics of Ectropis obliqua single-nucleocapsid nucleopolyhedrovirus.
The tea looper caterpillar, Ectropis obliqua, is one of the major pests of tea bushes. E. obliqua single-nucleocapsid nucleopolyhedrovirus (EcobSNPV) has been used as a commercial pesticide for biocontrol of this insect. However only limited genetic analysis for this important virus has been done up to now. EcobSNPV was characterized in this study. Electron microscopy analysis of the occlusion body showed polyhedra of 0.7 to 1.7 mum in diameter containing a single nucleocapsid per envelope of the virion. A 15.5 kb genomic fragment containing EcoRI-L, EcoRI-N and HindIII-F fragments, was sequenced. Analysis of the sequence revealed that the fragment contained eleven potential open reading frames (ORFs): lef-1, egt, 38.7k, rr1, polyhedrin, orf1629, pk-1, hoar and homologues to Spodoptera exigua multicapsid NPV (SeMNPV) ORFs 15, 28, and 29. Gene arrangement and phylogeny analysis suggest that EcobSNPV is closely related to the previously described Group II NPV. Bioassays on lethal concentration (LC(50) and LC(90)) and lethal time (LT(50) and LT(90)) were conducted to test the susceptibility of E. obliqua larvae to the virus.
Ma
Xiu-cui
XC
Institute of Insect Sciences, Zhejiang University, 268 Kaixuan Road, Hangzhou, Zhejiang 310029, China.
Xu
Hai-Jun
HJ
Tang
Mei-Jun
MJ
Xiao
Qiang
Q
Hong
Jian
J
Zhang
Chuan-Xi
CX
D000818:Animals; D001681:Biological Assay; D004279:DNA, Viral / Q000032:analysis; D007814:Larva / Q000821:virology; D007915:Lepidoptera / Q000254:growth & development / Q000821:virology*; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D010572:Pest Control, Biological; D010802:Phylogeny; D017422:Sequence Analysis, DNA
D004279:DNA, Viral