Acessibilidade / Reportar erro

Resistance mediated by alelochemicals of tomato genotypes to the silverleaf whitefly and to two-spotted spider mites

The objective of this work was to assess the degree of resistance to the whitefly (Bemisia argentifolii) and to the two-spotted spider mite (Tetranychus urticae) of tomato hybrids resulting from crosses between high-zingiberene (ZGB) lines and high-acylsugar (AS) lines, as compared to their parental lines and to commercial vouchers. High-AS lines, high-ZGB lines, double heterozygous (ZGB+AS) hybrids, hybrids heterozygous for ZGB and hybrids heterozygous for AS were tested. The wild accessions PI 127826 and LA-716 were used as high-ZGB and high-AS vouchers, respectively, while the genotypes Debora Max and TOM-684 were used as vouchers for low ZGB and AS. The genotypes were submitted to resistance tests to the whitefly and repellency to the spider mite. Double heterozygous (ZGB+AS) hybrids were more resistant to whiteflies than the commercial vouchers, but less resistant than the high-ZGB or the high-AS lines. Double heterozygous (ZGB+AS) hybrids were more repellent to the spider mite than the commercial vouchers, and their repellency to mites was similar to that of high-ZGB or high-AS lines. There was no synergistic effect between ZGB and AS, for both resistance to the whitefly and repellency to the two-spotted spider mite, in the double heterozygous (ZGB+AS) genotypes.

Bemisia argentifolii; Lycopersicon esculentum; Tetranychus urticae; allelochemicals; varietal resistance; sesquiterpene


Embrapa Secretaria de Pesquisa e Desenvolvimento; Pesquisa Agropecuária Brasileira Caixa Postal 040315, 70770-901 Brasília DF Brazil, Tel. +55 61 3448-1813, Fax +55 61 3340-5483 - Brasília - DF - Brazil
E-mail: pab@embrapa.br