In the recent years, methods based on the genetic manipulation of fiuit ripening have been developed with the aim of increasing the storage life and improving the quality of fruits. For instance, the down regulation of tomato polygalacturonase (PG) gene expression by antisense RNA prevented pectin degradation and gave an improved shelf-life and thus technological qualities. Even though European laboratories have been the leaders in controlling fruit physiology through manipulation of gene expression, the commercial feasability of this strategy has up to the present been demonstrated only in the USA by the release into the US market of aIltisense PG tomatoes in 1994.
All the studies reported so far have been carried out with the tomato as a model plant. The four partners of this project have previously collaborates within the Famework of an EC ECLA1R programme (AGRE 0015) to develop these technologies at the pre-competitive level, for another type of fzruit, the melon. Two pure lines of melon expressing an antisense ACC oxidase gene have been generated. These exhibit a strong reduction of ethylene production and a delayed ripening.
The present project, placed under the coordination of an SME seed companyn consists of a demonstration programme aimed at releasing onto the market new commercial genotypes with a longer shelf-life and of better eating quality. These commercial genotypes with improved postharvest handling qualities are expected to enlarge the market for cantaloupe melons in Europe and improve the competitiviness of European producers
The programme will consist of: (i) characterizing in depth the agronomical traits of two
transgenic melons expressing an ACC oxidase-antisense gene, (ii) generating commercial Fl hybrids by crossing these new genotypes with other genitors harboring appropriate agronomical characteristics such as precocity and resistance to pathogens, (iii} evaluating the effect of the transgene on the agronomical performance of the new commercial F1 hybrlds (physiology of the plant, yield under various environmental conditions, stress and pest resistanceo harvest dater quality of fruit...),( iv) preparing the procedure for placing on the market the new genotypes according to the official criteria of EU and the member states concerned with the project, and (v) testing the acceptability by consumers through the usual commercial channels of the seed company partner.
Funding SchemeDEM - Demonstration contracts
RG6 6AS Reading