Roggero Piero, Masenga Vera, Tavella Luciana
Istituto di Virologia Vegetale, CNR, Strada delle Cacce 73, I-10135 Torino, Italy.
Di.Va.P.R.A. Entomologia e Zoologia applicate all' Ambiente "C. Vidano", Università, Via L. da Vinci 44, I-10095 Grugliasco, Torino, Italy.
Plant Dis. 2002 Sep;86(9):950-954. doi: 10.1094/PDIS.2002.86.9.950.
Isolates of Tomato spotted wilt virus (TSWV) severely and systemically infecting commercial pepper cultivars with resistance introgressed from Capsicum chinense PI152225 were found in Albenga (northwestern Italy) in July 2000. Experimentally, these resistance-breaking (RB) isolates overcame the resistance in C. chinense PI152225, but they produced infection in other hosts similarly to non-RB isolates from the same area. The RB isolates were indistinguishable from TSWV by serology and electron microscopy, and they were efficiently transmitted by Frankliniella occidentalis. Such isolates were recovered on the same farm in tomato, pepper, and artichoke 2 and 12 months later, suggesting natural spread from the resistant plants and survival. The RB isolates survived in experimental mixed infections with a non-RB isolate in susceptible pepper and C. chinense, but cross-protection in pepper acted against them. Commercial TSWV-resistant pepper but not resistant tomato cultivars from different companies were susceptible to these RB isolates after mechanical inoculation. Similar isolates were not detected among TSWV samples collected from 1993 to 2000 in the area. The management of TSWV and thrips using resistant pepper cultivars is discussed.
2000年7月，在意大利西北部的阿尔本加发现了番茄斑萎病毒（TSWV）分离株，这些分离株严重且系统性地感染了携带来自中国辣椒PI152225的抗性基因渗入的商业辣椒品种。实验表明，这些抗性突破（RB）分离株克服了中国辣椒PI152225中的抗性，但它们在其他宿主上产生的感染情况与来自同一地区的非RB分离株相似。通过血清学和电子显微镜观察，RB分离株与TSWV无法区分，并且它们能够被西花蓟马有效传播。2个月和12个月后，在同一个农场的番茄、辣椒和洋蓟上再次发现了此类分离株，这表明它们从抗性植株自然传播并存活了下来。RB分离株在易感辣椒和中国辣椒中与非RB分离株的实验性混合感染中存活，但辣椒中的交叉保护作用对它们有效。不同公司的商业TSWV抗性辣椒品种（但不包括抗性番茄品种）在机械接种后对这些RB分离株敏感。在该地区1993年至2000年收集的TSWV样本中未检测到类似的分离株。本文还讨论了利用抗性辣椒品种对TSWV和蓟马进行管理的问题。
