Fontes de resistência a Bemisia tabaci entre as sub-amostras de tomateiro do Banco de Germoplasma de Hortaliças da UFV

• Autor(a) principal: Sena, Maria Elisa de
• Data de Publicação: 2009
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4683
• topic: Fitoquímicos; Mosca branca; Tricomas; Phytochemicals; Whitefly; Trichome; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA::MELHORAMENTO VEGETAL

Whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is an important pest of Lycopersicon esculentum. The injuries caused by adults and nymphs are sucking of sap, injection of toxins and transmission of fitoviroses. The use of resistants varieties is a alternative to managmant of this pest. In order to have these varieties is important the selection of sources of resistance, study of mechanisms and causes this resistance. Thus, this work aimed to select sources of resistance to B. tabaci of the 103 tomato plants accessions of the Horticultural Germplasm Bank of Federal University of Viçosa (HGB-UFV). The experiment was conducted in greenhouse of the DBA-UFV. The characteristics evaluated were number of adults/plant, eggs/plant and nymphs/plant. Were calculates the number of eggs/adult, nymphs/egg and the index resistance of the accessions compared with commercial cultivar Santa Clara. Were evaluated the number of trichome/0.04 cm2 of the leaf, the identification and the quantification of the chemical compounds from in the hexanic extraction in each tomato accessions. Differences were observed in the densities adults/plant, eggs/plant, nymphs/plant, eggs/adult and e nymphs/egg. 20 peaks were identified in the gas chromatogram from hexanic extracts of the leaves of 103 tomato plants accessions (HGB-UFV). Observed significant positive correlation (p<0.05) between hydrocarbons undecane, tritecane, octadecane, hexacosane and nonacosane with adults and nymphs B. tabaci. Significative differences were observed in the trichomes density/0.04 cm2 and significant positive correlation betweem the trichomes density and the number of eggs/plant. The accections HGB-225, HGB-327, HGB-630, HGB- 813, HGB-985, HGB-2029, HGB-2030, HGB-2055, HGB-2057, HGB- 2060, HGB-2062 e HGB-2068 were the more resistants to B. tabaci in all characteristics evaluated. The resistance mechanisms associated to these HGBs were antixenosis and antibiosis. The causes were chemical and morphological.