Keough Stacy, Han Jinlong, Shuman Tyler, Wise Kiersten, Nachappa Punya
Department of Biology, Indiana University-Purdue University Fort Wayne, Fort Wayne, IN 46805 (
Department of Botany and Plant Pathology, Purdue University 915 W State Street, W Lafayette, IN 47907.
J Econ Entomol. 2016 Oct;109(5):1979-87. doi: 10.1093/jee/tow145. Epub 2016 Jul 14.
Soybean vein necrosis virus (SVNV) is an emerging Tospovirus that is now considered to be the most widespread soybean virus in the United States. SVNV is transmitted from plant-to-plant by soybean thrips, Neohydatothrips variabilis (Beach). We hypothesized that a positive interaction between the host plant, SVNV, and the vector may have resulted in the widespread distribution of the virus in a short span of time. Our study found that SVNV-infected N. variabilis females produced significantly more offspring compared with non-infected females. No other life-history trait varied between SVNV-infected and non-infected thrips. There was considerable variation in SVNV copy number in infected thrips ranging from 10(2) -10(6) Moreover, there was a significant negative correlation between SVNV copy number and fecundity in infected N. variabilis This suggests that excessive virus accumulation may result in lower viability of N. variabilis In choice tests, SVNV-infected N. variabilis preferred to feed on non-infected leaflets compared with infected leaflets. Vector competence assays indicated that Frankliniella tritici and Frankliniella fusca can transmit SVNV, but at a lower efficiency than N. variabilis Comparison of life history of between the primary and secondary vectors showed that N. variabilis had the highest fecundity, but F. tritici had the shortest development time and greatest larval survival. Taken together, the increased fecundity of SVNV-infected N. variabilis, their apparent preference for non-infected host plants, in conjunction with the ability of secondary vectors to survive and reproduce on soybean may, in part, explain the rapid spread of SVNV in the United States.
大豆脉坏死病毒（SVNV）是一种新出现的番茄斑萎病毒属病毒，目前被认为是美国分布最广泛的大豆病毒。SVNV通过大豆蓟马，即变异新蓟马（比奇）在植株间传播。我们推测宿主植物、SVNV和传毒介体之间的正向相互作用可能导致了该病毒在短时间内广泛传播。我们的研究发现，感染SVNV的变异新蓟马雌虫比未感染的雌虫产生的后代显著更多。在感染SVNV和未感染的蓟马之间，没有其他生活史特征存在差异。感染蓟马体内的SVNV拷贝数存在相当大的差异，范围从10²到10⁶。此外，感染变异新蓟马体内的SVNV拷贝数与繁殖力之间存在显著负相关。这表明病毒的过度积累可能导致变异新蓟马的生存能力降低。在选择试验中，与感染的小叶相比，感染SVNV的变异新蓟马更喜欢取食未感染的小叶。传毒能力测定表明，西花蓟马和烟蓟马能够传播SVNV，但效率低于变异新蓟马。对主要传毒介体和次要传毒介体的生活史进行比较发现，变异新蓟马的繁殖力最高，但西花蓟马的发育时间最短，幼虫存活率最高。综上所述，感染SVNV的变异新蓟马繁殖力增加、它们对未感染宿主植物的明显偏好，再加上次要传毒介体在大豆上生存和繁殖的能力，可能在一定程度上解释了SVNV在美国的快速传播。
