Rodríguez-Álvarez C I, Muñiz M, Nombela G
Department of Plant Protection, Institute for Agricultural Sciences (ICA), Spanish National Research Council (CSIC), Serrano 115 Dpdo., Madrid 28006, Spain.
Bull Entomol Res. 2017 Dec;107(6):768-776. doi: 10.1017/S0007485317000281. Epub 2017 Apr 11.
Whitefly, Bemisia tabaci, is one of the most important pests of tomato, Solanum lycopersicum L. The Mi-1 gene mediates tomato resistance to the Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED) species of B. tabaci, three species of root-knot nematodes, Meloidogyne spp., and the potato aphid, Macrosiphum euphorbiae. Tomato seedlings bearing the Mi-1 gene are resistant to nematodes soon after germination but resistance to aphids is developmentally regulated; a reliable conclusion about Mi-1 resistance to B. tabaci was not available to date. In the present work, 3-, 5- and 8-week-old plants of the tomato cultivars Motelle and Moneymaker (bearing and lacking the Mi-1 gene, respectively) were simultaneously tested under free-choice (antixenosis) and no-choice (antibiosis) conditions, to assess the real influence of plant age on the Mi-1-mediated resistance to the MED species of B. tabaci. Subsequently, plants of the same age but with different level of development were compared to check whether the plant size can also affect this tomato resistance. Obtained results demonstrated that Mi-1-mediated resistance to B. tabaci is developmentally regulated, as variations in the age of bearing-Mi-1 plants affects most infestation parameters tested. Differences between cultivars with and without the Mi-1 gene were significant for 8- but not for 3-week-old plants. For 5-week-old plants, differences between cultivars were less pronounced than in older plants, expressing an intermediate level of resistance in Motelle. Plant size also influenced whitefly infestation and reproductive activity on the resistant cultivar. However, plant age has more impact than plant size on the Mi-1-mediated resistance of tomato to B. tabaci.
烟粉虱，即烟粉虱（Bemisia tabaci），是番茄（Solanum lycopersicum L.）最重要的害虫之一。Mi-1基因介导番茄对中东 - 小亚细亚1型（MEAM1）和地中海型（MED）烟粉虱、三种根结线虫（Meloidogyne spp.）以及马铃薯蚜（Macrosiphum euphorbiae）的抗性。携带Mi-1基因的番茄幼苗在萌发后不久对线虫具有抗性，但对蚜虫的抗性受发育调控；迄今为止，关于Mi-1对烟粉虱的抗性尚无可靠结论。在本研究中，对番茄品种Motelle和Moneymaker（分别携带和不携带Mi-1基因）的3周龄、5周龄和8周龄植株，在自由选择（排趋性）和无选择（抗生性）条件下同时进行测试，以评估植株年龄对Mi-1介导的对MED烟粉虱抗性的实际影响。随后，比较相同年龄但发育水平不同的植株，以检查植株大小是否也会影响番茄的这种抗性。获得的结果表明，Mi-1介导的对烟粉虱的抗性受发育调控，因为携带Mi-1基因植株的年龄变化会影响所测试的大多数侵染参数。对于8周龄植株，有和没有Mi-1基因的品种之间差异显著，但对于3周龄植株则不显著。对于5周龄植株，品种间差异不如 older植株明显，Motelle表现出中等水平的抗性。植株大小也影响抗性品种上粉虱的侵染和繁殖活动。然而，植株年龄对番茄Mi-1介导的对烟粉虱抗性的影响大于植株大小。
