ISHS Acta Horticulturae 546: International Symposium on Molecular Markers for Characterizing Genotypes and Identifying Cultivars in Horticulture
MOLECULAR MARKERS AND GENETIC BASE BROADENING IN LYCOPERSICON SPP. |
| Authors: | G. Saavedra, W. Spoor, L. Harrier |
| Keywords: | tomato, RAPD, microsatellites, incorporation, interspecific crosses |
| Abstract:
Genetic variability utilised in modern crops is limited because of bottlenecks produced during the domestication process, breeding new cultivars outside the native region and past selection pressures. Tomato (Lycopersicon esculentum L.) is one of many autogamous crop species in which germplasm has been severely reduced by these processes. The concept of genetic base broadening has been introduced to mitigate this lack of diversity in modern crops, with the aim to utilise more effectively the rich genetic resources available in wild relatives, old varieties, and landraces. This presentation reviews the evolution of F2 populations using molecular marker approaches in three genepools created from different specific and inter-specific crosses. Molecular markers used include as Random Amplified Polymorphic DNA (RAPD) and microsatellites, and were analysed by Popgene programme version 1.31. Analysis involved 15 RADP and 12 microsatellite polymorphic primers. Bands were scored and produced a genetic distance matrix, heterozygosity and gene diversity index. Results demonstrated both the lack of variability within L. esculentum accessions and the huge amount of genetic resources available useful for breeding. The richness of available gene pools in wild relatives, make these plants an interesting case for study of genetic base broadening programmes to assure better responses in future breeding generations to biotic and abiotic stresses | |
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