Effects of Gamma Rays on Cocona (Solanum sessiliflorum Dunal)

Harvesting hairy fruits of current cocona (Solanum sessiliflorum Dunal) is a painful task because the hair is itching. Therefore, growers would be interested in hairless fruit type planting materials. Breeding for this character depends on the amount of genetic variety present within the species. In the case of limited genetic variability occurring naturally, one can be created using mutagenic agents. Gamma rays were used in the course of the present study on cocona seeds of genotype CUB-08 at 100, 150, 200, 300 and 400 Gy. Irradiated seeds were sown in styrofoam seedling trays, then transplanted in the open field, three months later, following a randomized block design with four replications and seven plants per plot, in the Agricultural experimental station of the National Institute for Amazonian Research (Instituto Nacional de Pesquisas da Amazônia).

The 100 and 150 Gy radiations led to germinating vigor and fruit pilosity variability whereas 200 Gy decreased the germination rate, and 300 and 400 Gy were totally deleterious. Therefore, gamma rays 100-150 Gy could be used to enhance genetic diversity for fruit pilosity and for fruit number as well.