COMPATIBILITY OF CROSSES BETWEEN WILD TOLERANT TO VIRUSES AND CULTIVATED POPULATIONS OF HUSK TOMATO

Abstract

Viral diseases present a challenge for the Mexican agriculture, since up to now there is no possible to eradicate viruses due to their difficult control. In the husk tomato (Physalis spp.) crop, yield losses due to viral diseases can be up to 80 %. One option to deal with this problem is genetic improvement by incorporating tolerance or resistance to virus attack. The aim of this study was to determine the compatibility of crosses between virus-resistant wild populations and susceptible cultivated populations, estimate the effects of general and specific combining ability, maternal and reciprocal effects, and to study their heterosis. A diallel cross design was used between wild and cultivated populations, which were evaluated in the field with and without inoculation of a mixture of the five viruses that attack the crop (AMV, CMV, TEV, TMV and TSWV). All the crosses showed compatibility, since populations belong to the same species. Maternal effects were the most important, so it is recommended to use cultivated populations as females and wild populations as males for the incorporation of virus resistance. Of the wild populations, parent 170 BNGEN was the most appropriate for incorporating virus resistance into cultivated varieties. Significant values of heterosis were estimated with respect to the mean parent for yield and fruit size, so non-additive effects are important in determining these characteristics. The wild populations and the crosses in which they participated maintained their yield and fruit size even in the presence of viruses, which opens the possibility of generating virustolerant husk tomato varieties.