Bag Sudeep, Schwartz Howard F, Cramer Christopher S, Havey Michael J, Pappu Hanu R
Department of Plant Pathology, Washington State University, Pullman, WA, 99164, USA.
Mol Plant Pathol. 2015 Apr;16(3):224-37. doi: 10.1111/mpp.12177. Epub 2014 Dec 4.
Iris yellow spot virus (IYSV) is in the genus Tospovirus, family Bunyaviridae, with a single-stranded, tri-segmented RNA genome with an ambisense genome organization. Members of the other genera in the family infect predominantly vertebrates and insects.
IYSV is present in most Allium-growing regions of the world.
Virions are pleomorphic particles of 80-120 nm in size. The particle consists of RNA, protein, glycoprotein and lipids.
IYSV shares the genomic features of other tospoviruses: a segmented RNA genome of three RNAs, referred to as large (L), medium (M) and small (S). The L RNA codes for the RNA-dependent RNA polymerase (RdRp) in negative sense. The M RNA uses an ambisense coding strategy and codes for the precursor for the GN /GC glycoprotein in the viral complementary (vc) sense and a non-structural protein (NSm) in the viral (v) sense. The S RNA also uses an ambisense coding strategy with the coat protein (N) in vc sense and a non-structural protein (NSs) in the v sense.
The virus is transmitted by Thrips tabaci Lindeman (Order: Thysanoptera; Family: Thripidae; onion thrips) and with less efficiency by Frankliniella fusca Hinds (tobacco thrips). HOST: IYSV has a relatively broad host range, including cultivated and wild onions, garlic, chives, leeks and several ornamentals. Some weeds are naturally infected by IYSV and may serve as alternative hosts for the virus.
IYSV symptoms in Allium spp. are yellow- to straw-coloured, diamond-shaped lesions on leaves and flowering scapes. Diamond-shaped lesions are particularly pronounced on scapes. As the disease progresses, the lesions coalesce, leading to lodging of the scapes. In seed crops, this could lead to a reduction in yield and quality. Early to mid-season infection in bulb crops results in reduced vigour and bulb size.
Resistant varieties are not available, but a limited number of accessions with field tolerance have been identified. Integrated disease management tactics, including sanitation, crop rotation, thrips management, maintenance of optimal plant vigour, soil fertility, irrigation and physical separation of bulb and seed crops, can mitigate the effect of the disease. Virus code: 00.011.0.85.009 Useful link: http://www.alliumnet.com/.
鸢尾黄斑病毒（IYSV）属于番茄斑萎病毒属，布尼亚病毒科，具有单链、三段式RNA基因组，基因组结构为双义。该科其他属的成员主要感染脊椎动物和昆虫。
IYSV存在于世界上大多数种植葱属作物的地区。
病毒粒子为多形性颗粒，大小为80 - 120纳米。粒子由RNA、蛋白质、糖蛋白和脂质组成。
IYSV具有其他番茄斑萎病毒属病毒的基因组特征：由三个RNA组成的分段RNA基因组，分别称为大（L）、中（M）和小（S）。L RNA以负义编码RNA依赖的RNA聚合酶（RdRp）。M RNA采用双义编码策略，在病毒互补（vc）义中编码GN /GC糖蛋白的前体，在病毒（v）义中编码一种非结构蛋白（NSm）。S RNA也采用双义编码策略，在vc义中编码外壳蛋白（N），在v义中编码一种非结构蛋白（NSs）。
该病毒由烟蓟马（缨翅目；蓟马科；葱蓟马）传播，由富兰克林花蓟马（烟草蓟马）传播的效率较低。
IYSV具有相对广泛的寄主范围，包括栽培和野生洋葱、大蒜、韭菜、葱以及几种观赏植物。一些杂草自然感染IYSV，可能作为该病毒的替代寄主。
葱属作物上的IYSV症状表现为叶片和花茎上出现黄色至稻草色的菱形病斑。花茎上的菱形病斑尤为明显。随着病情发展，病斑会融合，导致花茎倒伏。在种子作物中，这可能导致产量和品质下降。鳞茎作物在生长季早期至中期感染会导致活力下降和鳞茎变小。
目前没有抗性品种，但已鉴定出少数具有田间耐受性的种质。综合病害管理策略，包括卫生措施、作物轮作、蓟马管理、维持最佳植株活力、土壤肥力、灌溉以及鳞茎和种子作物的物理隔离，可以减轻病害的影响。病毒代码：00.011.0.85.009 有用链接：http://www.alliumnet.com/
