Résumé
Under mediterrancan France conditions, all the cultivated varieties and the most part of working collection genotypes belong to rice japonica type. In order to get new plant phenotype s and/or to tranfer some genes of agronomical interest. japonica x indica crosses have been breeded. For the choice of the indica cogenitor, two ways were possible according to the varietal adaptation to local conditions. So crosses were made using either indica genotypes of the working collection or not adapted tropical indica. Despite the well known genetically distant crosses problems (F1 partial sterility, lack of recombination), it was possible to obtain a few good progenies with improved blast resistance and/or grain quality. Moreover. some of japonica x indica genotypes included in 1998 cropping season preliminary trials overyielded the cultivated japonica references that is very promising for the future of this breeding way. The use of not adapted tropical indica varieties as cogenitor curiously seems more efficient than the use of adapted indica. (Résumé d'auteur)