Response of melon accessions to doses of Co60 gamma rays and their effects on the morphology of the M1 generation

The aim of this study was to verify the response of the melon accessions MR1 and C14 to gamma radiation in terms of germination and morphology.The melon accessions came from the germplasm collection of the Federal Rural University of the Semi-arid Region, and were submitted to five doses of gamma radiation (0, 100, 200, 300, 400 Gy) in four replications, each comprising 25 seeds, at the Center for Nuclear Energy in Agriculture of the University of São Paulo. The seeds were grown in a greenhouse at UFERSA employing a completely randomised design. The germination potential, rate and index were evaluated during the first stage of the trial. During the second stage, the germinated plants were transplanted into eight-litre buckets containing substrate and sand, in four replications of 15 plants each. The inflorescence, leaf blade and fruit were evaluated. The IMAGE J image analysis software was used to obtain the leaf and fruit data. The germination potential varied for the gamma-ray doses being tested, while the germination rate and index were not affected; phenotypic variations were seen in the leaves. The gamma-ray doses had no effect on the germination process.