Novel resistance mechanisms of a wild tomato against the glasshouse whitefly

Abstract

The glasshouse whitefly, Trialeurodes vaporariorum, is an important pest of many crop plants including tomato, Solanum lycopersicum. Many wild tomato species exhibit a higher resistance to whiteflies. Therefore, locating the source of this enhanced resistance and breeding it into commercial tomato species is an important strategy to reduce the impact of pests on crops. Here, we assessed the pest resistance of Lycopersicon pimpinellifolium by comparing oviposition and feeding data from T. vaporariorum on this wild tomato species with data collected from a susceptible commercial tomato, S. lycopersicum var. 'Elegance'. The location of resistance factors was examined by use of electrical penetration graph (EPG) studies on these tomato species. Results show that whiteflies preferentially settled on the commercial tomato more often in 80 % of the replicates when given free choice between the two tomato species and laid significantly fewer eggs on L. pimpinellifolium. Whiteflies exhibited a shorter duration of the second feeding bout, reduced pathway phase probing, longer salivation in the phloem and more non-probing activities in the early stages of the EPG on the wild tomato species compared to the commercial tomato. These findings evidence that a dual mode of resistance is present in this wild tomato against T. vaporariorum: a post-penetration, pre-phloem resistance mechanism and a phloem-located factor, which to the best of our knowledge is the first time that evidence for this has been presented. These findings can be used to inform future breeding strategies to increase the resistance of commercial tomato varieties against this important pest.

An Acylsucrose-Producing Tomato Line Derived from the Wild Species Solanum pimpinellifolium Decreases Fitness of the Whitefly Trialeurodes vaporariorum

“…In recent times, whitefly resistance traits have been reported in wild tomato relatives with red fruits and more closely related to cultivated tomato that can facilitate their use. Thus, whitefly resistance was found in Solanum galapagense S. Darwin and Peralta and Solanum pimpinellifolium L. [25,31,33,46,47]. Interestingly, the traits found in S. galapagense involved in resistance to whiteflies were associated with the presence of type IV leaf glandular trichomes and the acylsugars they produce [41].…”

Choice of Tethering Material Influences the Magnitude and Significance of Treatment Effects in Whitefly Electrical Penetration Graph Recordings

“…Despite the fact that the majority (31/41-75.6%) of whitefly EPG studies were performed well after the recommendation to use the platinum wire tethering protocol (Walker and Janssen 2000), we found that 26/31 published studies still used 10-12.5 μm diameter gold wire as the tethering material (Table 1). Additionally, among (Lei et al 1996) Adults (Lei et al 1997(Lei et al , 1998(Lei et al , 1999(Lei et al , 2001 12.5 T. vaporariorum Adults (Janssen et al 1989;Tosh and Brogan 2014;McDaniel et al 2016) those studies using 2.5 μm platinum wire, quantitative data are not available on the frequencies and durations of various stylet activities because platinum wire studies focused on waveform descriptions rather than replicated experimental sessions (Table 1). Thus, it is not possible to directly determine how the choice of wiring material influences the results obtained from EPG studies with whiteflies.…”

Characterization of Mi1.2 Whitefly (Bemisia tabaci) Resistance Gene

“…The whitefly is an important insect pest of many crop plants, including tomato. Many wild tomato species contains Mi gene, which provides resistance to whitefly (McDaniel et al, 2016). The wild tomato (S. peruvianum) resistance gene Mi encodes a protein with CC-NBS-LRR motifs (Milligan et al, 1998).…”

“…Tomato (Solanum lycopersicum L.) is an important vegetable crop and it is produced worldwide under both the glasshouse and open field (Kaur et al, 2014;McDaniel et al, 2016;Alatar et al, 2017). Whitefly (Bemisia tabaci) of Aleyrodidae family (Order: Hemiptera), is among the most harmful insects of tomato and causes significant yield loss.…”