Resistance to Bemisia tabaci in tomato wild relatives

Abstract

Bemisia tabaci is one of the most threatening pests in agriculture, particularly in Solanaceous crops such as tomato and pepper that are cultivated in the open field. Pesticide application is often not effective and hazardous to humans and environment. The exploitation of plant natural defenses that are present in wild relatives of tomato, may offer a solution. To evaluate resistance parameters and to identify plant material with high levels of resistance, we screened a number of accessions of tomato wild relatives using three methods; a free-choice test in a screenhouse in Indonesia, a no-choice test with clip-on cages in a greenhouse and a leaf disc test in a climate-room in the Netherlands. Antibiosis resulting in low adult survival was the major component for resistance in tomato. However, other resistance component(s) may play a role as well. In some accessions there was a change in the resistance level over time. Several resistance parameters used in the different tests were well correlated. The best resistance source was an accession of Solanum galapagense, which had not been identified as being resistant in the past. This is of particular interest as this species is closely related to the cultivated tomato, which may facilitate introgression of the resistance component(s). Whitefly non-preference and resistance were associated with the presence of type IV trichomes. Other mechanisms might be involved since some accessions without type IV trichomes showed low nymphal density. The leaf disc test is a good in vitro alternative for the clip-on cage whitefly resistance screening, as shown by the high correlation between the results obtained with this test and the clip-on cage test. This offers breeders the possibility to carry out tests more efficiently.

Novel resistance mechanisms of a wild tomato against the glasshouse whitefly

“…Hybrids produced using this species supported the fewest eggs and were the least attractive hosts of the whitefly. Firdaus et al (2012) also considered oviposition and found one accession of L. pimpinellifolium to be resistant on the basis of supporting low levels of egg-laying, as corroborated by the present work.…”

“…However, as statistical output matched that from the other four runs (where this assumption was not violated), results of run 1 were retained and included herein. Firdaus et al (2012) examined a range of wild tomato relatives for resistance to B. tabaci. They found that L. pimpinellifolium showed little evidence of being less preferable to B. tabaci based upon free choice assays, which is in contrast to the findings presented here.…”

“…Although these whiteflies were excluded from subsequent analysis, a chi-squared analysis revealed that there was no significant difference in the number of whiteflies which avoided the 'Elegance' or the wild tomato leaves compared to those which chose to land on the leaf (Χ 2 = 2, df = 1, p > 0.05, N = 24 for both). Many whitefly resistance mechanisms in tomato have been found to be surface based, including type IV trichomes which reduce whitefly feeding efficiency (Firdaus et al 2012). Rodríguez-López et al (2011) monitored the feeding behaviour B. tabaci on the commercial 'Moneymaker' strain of tomato and the ABL14-8 tomato breeding line.…”

“…Many studies have investigated the ability of wild tomato species to resist B. tabaci, e.g. Firdaus et al (2012), Rodríguez-López et al (2011) (which both included accessions of the wild tomato species considered here), Firdaus et al (2013) andde Resende et al (2009). Work to elucidate the source of whitefly resistance in wild tomato species has also been attempted.…”

Re-evaluation of the Mungbean [Vigna radiata (L.) Wilczek] Genotypes for Resistance to Mungbean Yellow Mosaic Virus (MYMV) under Screen-House Conditions

“…In fact, spontaneous field-exposure infection has been shown to be largely inefficient, as many plants escape infection, even under heavy inoculation pressure (Vidaysky et al, 1998). To identify plant materials having high level of resistance, screening of genotypes using force feeding methods (Firdaus et al, 2012;Taggar et al, 2013;Sulistyo and Inayati, 2016)and agroinoculation methods (Al Abdallat et al, 2010;Karthikeyan et al, 2011;B Sai et al, 2017) has been exploited in several crops including mungbean. Therefore, it is essential to screen genotypes through forced feeding methods, which can ensure 100% infection rate, and a standardized inoculum pressure.…”