| Traditional varieties of tomato and pepper have an excellent organoleptic quality and reach high selling prices in local markets. Therefore, these materials are suitable for an on-farm in situ conservation. Different studies were carried out in order to achieve this objective: survey and collection, morphological, agronomical and molecular characterisation and evaluation, analysis of organoleptic and nutritive characteristics, genetic improvement and in vitro culture.; During the survey, 57 new tomato accessions were collected, establishing the factors involved in the abandonment of traditional varieties and the high risk of genetic erosion.; Characterisation, during two years, of 103 accessions of tomato has provided valuable data, used to typify traditional varieties. Great diversity has been found in these materials, especially at the fruit level. Variation found in yield and fruit weight may allow the improvement of uniformity and productivity through simple selections. Molecular characterization has showed limited differences among accessions with different origins and morphology. Probably, these varieties share most part of their genome, with differences restricted to relatively few loci responsible of fruit shape, colour and size.; An important diversity in vitamin C sugars and organic acids has been found among traditional varieties of tomato, establishing organoleptic quality profiles, which have been related to sensory perception. First results suggest an important role of aroma compounds in flavour determination. Cultivation under mesh-houses does not appreciably affect organoleptic quality of traditional varieties of tomato, whilst it contributes to a reduction of virus incidence, allowing a profitable cultivation of non-resistant varieties.; Several accessions of varieties "Valenciano", "Muchamiel", "De penjar" and "Forma pimiento" have been selected to carry out backcrossing programmes in order to introgress virus resistance genes Tm-1, Tm-22, Sw-5 and Ty-1. Gene Tsw is also being introgressed in one accession of pepper.; Finally, as genetic engineering is the most appropriated method to introduce resistance genes without affecting the genetic background, in vitro regeneration methods have been developed for selected accessions of traditional varieties of tomato and pepper. This will allow genetic transformation of selected varieties. |
