INDUCED VARIABILITY IN PHYSIOLOGICAL CHARACTERS OF Physalis peruviana L. THROUGH 60Co GAMMA RAYS APPLIED TO THE SEED

Abstract

Mutation induction is an alternative to induce natural genetic variability, increase the genetic variability in a population, and obtain parental genotypes in breeding programs. Uchuva (Physalis peruviana L.), known as golden berry, is a Solanaceae fruit that produces a bittersweet berry, and its seeds germinate slowly. This study evaluated the effect of gamma rays ⁶⁰Co on seed germination and seedling vigor of P. peruviana L. Plants were sowed under a greenhouse with UVII720 plastic cover from August to October 2015. Treatments included 16 doses of gamma rays ⁶⁰Co (Gy): 0, 5, 10, 20, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300 and 350. The experiment was designed under a completely randomized design with four replications. Radiation did not affect percentage of germination or number of leaves, but seedlings of irradiated seeds emerged 8 d earlier than the control. At 300 to 350 Gy, seedling survival was less than 50 %. Seedlings irradiated with 125, 150, 200 and 225 Gy doses had higher plant height and stem diameter. SPAD readings and root length were higher in control seedlings. Internode length was higher with 125, 150, 175 and 200 Gy. Application of gamma rays ⁶⁰Co changes germination rate and some traits related with seedlings vigor and seedlings establishment of golden berry.