ISHS Acta Horticulturae 542: VII International Symposium on the Processing Tomato
INHERITANCE AND QTL ANALYSIS OF ANTHRACNOSE RESISTANCE IN THE CULTIVATED TOMATO (Lycopersicon esculentum) |
| Authors: | J.R. Stommel, Y. Zhang |
| Keywords: | Colletotrichum, disease resistance, molecular markers, vegetable breeding |
| Abstract:
Genetic characterization of anthracnose resistance in tomato (Lycopersicon esculentum Mill.) was accomplished using populations developed from crosses between an anthracnose susceptible cultivar, ‘US28,’ and three resistant breeding lines. These lines varied in their degree of anthracnose resistance and relative stage of adaptation for commercial use. Anthracnose lesion diameters were scored in inoculated fruit of parental, F1, F2, and backcross generations within each cross. A RAPD analysis of an F2 population derived from the cross of ‘US28’ and a highly resistant line, 115-4, was utilized to detect quantitative trait loci (QTLs) for anthracnose resistance. Heritabilities for resistance were moderate and declined as relative anthracnose susceptibility of the resistant parent increased coincident with increasing horticultural adaptation. Genetic variance for anthracnose resistance was primarily additive. The minimum number of effective factors conditioning anthracnose resistance declined during attempts to transfer high levels of resistance exhibited by unadapted small-fruited germplasm into adapted breeding lines. Putative RAPD markers linked to loci that influence resistance were identified. The phenotypic variation for anthracnose resistance explained by any individual QTL was small. | |
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