Juliano T.V. Resende, Wilson Roberto Maluf, David L. Nelson, Marcos Ventura Faria, Maria das Graças Cardoso
Published: May 15, 2002
Genet. Mol. Res. 1 (2) : 106-116
Cite this Article:
J.T.V. Resende, W.Roberto Maluf, D.L. Nelson, M.Ventura Faria, Mdas Graça Cardoso (2002). Inheritance of acylsugar contents in tomatoes derived from an interspecific cross with the wild tomato Lycopersicon pennellii and their effect on spider mite repellence. Genet. Mol. Res. 1(2): 106-116.
About the Authors
Juliano T.V. Resende, Wilson Roberto Maluf, David L. Nelson, Marcos Ventura Faria, Maria das Graças Cardoso
Corresponding author: W.R. Maluf
E-mail: wrmaluf@ufla.br
ABSTRACT
Acylsugars present in Lycopersicon pennellii are responsible for the high levels of pest resistance often found in this wild tomato taxon. We investigated the inheritance of acylsugar contents in segregating populations of the interspecific tomato cross L. esculentum x L. pennellii and estimated correlations between leaflet acylsugar contents and the levels of mite repellence. Acylsugar contents were quantified with the Sommogy-Nelson colorimetric method in the acessions L. esculentum ‘TOM-584’ (P1, low acylsugars), L. pennellii ‘LA-716’ (P2, high acylsugars), in the interspecific F1 (P1 x P2) and in the F2 (P1 x P2) generations. Mite resistance was assessed by a repellence test. Broad-sense heritability of acylsugar contents was moderately high (h2b = 0.476). Frequency distributions in the P1, P2, F1 and F2 can be explained by the action of a single major locus, with near-complete dominance of the L. esculentum allele for low-acylsugar content over the L. pennellii allele for high content. Indirect selection for high levels of acylsugars in leaflets led to correlated increases in the levels of mite repellency, indicating that acylsugars may be the main factor involved in mite resistance.
Acylsugars present in Lycopersicon pennellii are responsible for the high levels of pest resistance often found in this wild tomato taxon. We investigated the inheritance of acylsugar contents in segregating populations of the interspecific tomato cross L. esculentum x L. pennellii and estimated correlations between leaflet acylsugar contents and the levels of mite repellence. Acylsugar contents were quantified with the Sommogy-Nelson colorimetric method in the acessions L. esculentum ‘TOM-584’ (P1, low acylsugars), L. pennellii ‘LA-716’ (P2, high acylsugars), in the interspecific F1 (P1 x P2) and in the F2 (P1 x P2) generations. Mite resistance was assessed by a repellence test. Broad-sense heritability of acylsugar contents was moderately high (h2b = 0.476). Frequency distributions in the P1, P2, F1 and F2 can be explained by the action of a single major locus, with near-complete dominance of the L. esculentum allele for low-acylsugar content over the L. pennellii allele for high content. Indirect selection for high levels of acylsugars in leaflets led to correlated increases in the levels of mite repellency, indicating that acylsugars may be the main factor involved in mite resistance.
Keywords: Tomato, Allelochemical, Acylsugars, Pest resistance, Trichomes, Spider mites, Tetranychus evansi, Lycopersicon esculentum, Lycopersicon pennellii