Department of Entomology, Cornell University, NYSAES, 630 W. North St., Geneva, NY 14456, USA.
J Econ Entomol. 2010 Jun;103(3):925-37. doi: 10.1603/ec09263.
Onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), a worldwide pest of onion, Allium cepa L., can reduce onion yield by > 50% and be even more problematic when it transmits Iris yellow spot virus (family Bunyaviridae, genus Tospovirus, IYSV). Because T. tabaci is difficult to control with insecticides and other strategies, field studies on onion, Allium cepa L., resistance to T. tabaci and IYSV were conducted in 2007 and 2008 in two locations in New York state. Forty-nine cultivars were evaluated for resistance by counting the number of larvae weekly and recording leaf damage. In another experiment, the impact of T. tabaci and IYSV on plant growth and yield was examined by spraying half of the plants with an insecticide. Eleven of the 49 cultivars had very little leaf damage and were considered resistant to T. tabaci. Visual assessment indicated that all resistant cultivars had yellow-green- colored foliage, whereas the other 38 had blue-green- colored foliage. The visual assessment of color agreed with data on color taken with a HunterLab Ultra Scan XE colorimeter. The onions 'Colorado 6' and 'NMSU 03-52-1' had the lowest numbers of T. tabaci, suggesting strong antibiosis and/or antixenosis. The other nine cultivars had variable numbers of T. tabaci, indicating a possible combination of categories of resistance. In the nonprotected treatments there were significant reductions in plant height and plant weight in most of the resistant cultivars, but there were reductions in bulb weight only in a few of them. The average of plants infected with IYSV was 10% in 2007 and 60% in 2008. Our findings indicate potential for developing onion resistance to T. tabaci as part of an overall integrated pest management strategy but suggest difficulties in identifying resistance to IYSV.
洋葱蓟马，蓟马 tabaci 林德曼（缨翅目：蓟马科），洋葱，Allium cepa L. 的世界性害虫，可以减少洋葱产量> 50%，当它传播虹膜黄斑点病毒（ Bunyaviridae 科，Tospovirus 属，IYSV）时，问题甚至更严重。由于 T. tabaci 很难用杀虫剂和其他策略来控制，因此 2007 年和 2008 年在纽约州的两个地点对洋葱，Allium cepa L. 对 T. tabaci 和 IYSV 的抗性进行了田间研究。通过每周计数幼虫数量并记录叶片损伤来评估 49 个品种的抗性。在另一个实验中，通过用杀虫剂喷洒一半植物来检查 T. tabaci 和 IYSV 对植物生长和产量的影响。49 个品种中有 11 个品种叶片损伤很小，被认为对 T. tabaci 具有抗性。目视评估表明，所有抗性品种的叶片均呈黄绿色，而其他 38 个品种的叶片呈蓝绿色。颜色的目视评估与 HunterLab Ultra Scan XE 分光光度计采集的数据一致。洋葱 'Colorado 6' 和 'NMSU 03-52-1' 蓟马数量最少，表明具有较强的抗生性和/或抗生性。其他 9 个品种的蓟马数量不同，表明可能存在多种抗性类别。在非保护处理中，大多数抗性品种的株高和株重均显著降低，但只有少数品种的鳞茎重降低。2007 年感染 IYSV 的植物平均为 10%，2008 年为 60%。我们的研究结果表明，洋葱对 T. tabaci 的抗性具有发展潜力，可作为综合虫害管理策略的一部分，但表明鉴定对 IYSV 的抗性存在困难。
