Resistance of potato genotypes (Solanum spp.) to Bemisia tabaci biotype B

Abstract

The resistance of 24 potato genotypes to B. tabaci (Genn.) biotype B (Hemiptera: Aleyrodidae) was evaluated in five greenhouse experiments. The first experiment we evaluated the attractiveness and preference for oviposition in a free-choice test (randomized blocks, 24 treatments, and eight replications). In two other experiments we evaluated no-choice preference for oviposition (randomized blocks, six treatments, and ten replications). The whitefly egg-adult cycle was monitored using a statistical design in randomized blocks with five replications. Trichome density was evaluated in an experiment with 24 treatments and six replications, in a completely randomized design. In the free-choice test, potato genotypes NYL 235-4 and IAC-1966 were the most attractive to adults, while cultivars Achat, Aracy Ruiva, and Monte Bonito presented the lowest number of adults. Also in this assay, cultivars Achat, Ibituaçu, Panda, IAC-1966, and Agata presented the lowest number of eggs, while in the no-choice test, only cultivar Achat and IAC-1966 remained resistant. Consequently, for these two genotypes non-preference is the oviposition resistance mechanism. The egg-adult cycle varied from 21 days (cultivar Panda) to 22.5 days (clones IAC-1966 and NYL 235-4). The adult emergence varied from 91.2% (clone IAC-1966) to 99.3% (cultivar Ibituaçu). Clone NYL 235-4 had the greatest number of simple (ST) and glandular (GT) trichomes; while clone IAC-1966 had the lowest number of ST and, clone IAC-6290, of GT. There were significant correlations between adult attractiveness and oviposition preference; between oviposition preference and ST density; and between oviposition preference and GT density. Considering all characteristics, cultivar Achat was the most resistant to B. tabaci biotype B among all potato genotypes studied, while clone NYL 235-4 proved (past tense) to be susceptible.

Resistance of cotton genotypes with different leaf colour and trichome density to Bemisia tabaci biotype B

“…This same relationship has been reported in other crop plants, such as potato (Silva et al. ), melon (Coelho et al. ) and beans (Oriani et al.…”

Resistance Sources and Antixenotic Factors in Brazilian Bean Genotypes Against Bemisia tabaci

“…A positive and significant correlation between the number of adults and eggs was observed in our trials, corroborating with other studies with tomato and soybean (Silva et al 2008, Valle et al 2012, Baldin et al 2017, and indicating that adult whiteflies prefer these surface for feeding and oviposition (Van Lenteren & Noldus 1990). In addition, there was also a negative correlation between trichomes and the number of adults and eggs, unlike studies conducted by other authors with common bean (Oriani et al 2005), which showed positive correlations between egg numbers and density of acicular (long) and unciform (short) trichomes.…”

Infection by the semi-persistently transmitted Tomato chlorosis virus alters the biology and behaviour of Bemisia tabaci on two potato clones

“…Overall, our results suggest that ToCV manipulates the host phenotype on potato in ways that likely enhance its spread by B. tabaci MEAM1 in potato fields. However, it is unclear whether ToCV transmission by B. tabaci MEAM1 is enhanced to a greater extent in plantings of ‘Agata’, which is susceptible to both the whitefly and ToCV (Silva et al ., 2008; Freitas et al ., 2012) and therefore may serve as a better reservoir than the moderately whitefly-resistant Bach-4. On one hand, we did not find that infection by ToCV in ‘Agata’ increases the chances of virus acquisition by B. tabaci MEAM1, as the whiteflies did not discriminate ToCV-infected from mock-inoculated plants of ‘Agata’.…”

“…Here, we investigated whether the behaviour and biology of B. tabaci MEAM1 increases the likelihood of ToCV acquisition, transmission and spread in potato. We selected two potato clones, one susceptible (‘Agata’) and the other moderately resistant (Bach-4) to B. tabaci MEAM1 (Silva et al ., 2008; Rocha et al ., 2012). We specifically tested the following hypotheses for both clones: ( i ) whiteflies orient preferentially to ToCV-infected potato clones compared with non-infected clones; ( ii ) whitefly females prefer to oviposit on ToCV-infected potato clones compared with non-infected clones; ( iii ) whiteflies feeding on the ToCV-infected clone migrate preferentially to the non-infected clone, optimizing the spread of the virus; ( iv ) the life cycle of whiteflies that have been fed on the ToCV-infected potato plants is shorter compared with individuals that have been fed on the non-infected plants; and ( v ) virus manipulation of the plant for enhancing transmission is more pronounced in the susceptible than in the moderately resistant clone, as proposed by Mauck (2016).…”