Nonpreference of whitefly for oviposition in tomato genotypes

Abstract

The silverleaf whitefly is one of most important pests of tomato (Lycopersicon spp.). The use of host plant resistance to control this insect is an interesting, potentially useful technique, but in demand of more research. The objectives of this work were to evaluate the oviposition non-preference of Bemisia tabaci (Gennadius, 1889) biotype B for different tomato plant genotypes, evaluating the correlation between oviposition preference and pubescence in the genotypes, and analyzing the abaxial and adaxial surfaces of Lycopersicon pennellii leaflets under the scanning electron microscope. Four wild tomato genotypes, LA 716 (L. pennellii); PI 127826 and PI 127827 (L. hirsutum); PI 134417 (L. hirsutum f. glabratum), and two commercial genotypes, Santa Clara and Bruna VFN hybrid (L. esculentum) were evaluated for number of eggs cm-2 in free and no-choice oviposition tests, using randomized block design and completely randomized design, respectively. The number of trichome was measured in 4 mm² and coefficients of correlation between number of trichomes and number of eggs were calculated. The wild genotypes LA 716 and PI 134417 were less preferred showing oviposition nonpreference resistance type in both tests. The Bruna VFN and Santa Clara were more preferred in free-choice test, while wild genotypes PI 127826 and PI 127827 were more preferred in no-choice test. L. pennellii leaflets presented glandular trichomes type IV in both surfaces. Santa Clara genotype presented higher density of trichomes, and B. tabaci biotype B presented higher preference to oviposition.

Role of allelochemicals and trichome density in the resistance of tomato to whitefly

“…& D. M. Spooner (=Lycopersicon hirsutum), 'LA-716' of S. pennellii Correl (=L. pennellii), and 'PI 134417' of S. habrochaites, respectively (CARTER; SACALIS; GIANFAGNA, 1988;FREITAS et al, 2002;TOSCANO;BOIÇA JÚNIOR;MARUYAMA, 2002).…”

Influence of trichomes on attractiveness and ovipositional preference of Bemisia tabaci (Genn.) B biotype (Hemiptera: Aleyrodidae) on tomato genotypes

“…Tomato genotypes with high density of trichomes are positively correlated to the oviposition of B. tabaci (Heinz & Zalom 1995, Snyder et al 1998, Toscano et al 2002, Fancelli et al 2005, especially due to the presence of the type V non-glandular trichome. Therefore, we aimed at evaluating the infl uence of trichomes on 17 tomato genotypes in the attractiveness and ovipositional preference of B. tabaci B biotype.…”

Comportamento de oviposição da mosca-branca Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae) biótipo B em tomateiro

“…O maior número de ovos encontrado na face abaxial pode estar associado à alta densidade de tricomas em tomateiro, já que esse é considerado um fator de suscetibilidade da cultura à praga (Heinz & Zalom 1995, Toscano et al 2002, Fancelli et al 2003. É possível que a alta densidade de tricomas na face abaxial seja a causadora da não ocorrência isolada de ovos, uma vez que em tal situação é improvável a constatação de área foliar sem tricomas.…”

“…No tomateiro, a resistência por antibiose e antixenose às moscas-brancas está relacionada principalmente com a densidade e o tipo de tricoma (Barten et al 1994, Toscano et al 2002, Muigai et al 2003, Fancelli et al 2005. Baldin et al (2005), ao avaliar os possíveis mecanismos de resistência de diferentes genótipos de tomateiro (Lycopersicon spp.)…”