Effect of gamma radiation on morphological and molecular character of Sphenostylis stenocarpa (Hoechst. ex. A. Rich.) Harms.

Abstract

Genetic variation in two varieties of Sphenostylis stenocarpa (Hochst.ex A.Rich.) Harms was created using different doses of gamma-rays with the aim of increasing variability among the landraces for better morpho-agronomic characteristics. The two varieties responded differently to the doses of the treatment. The mutagen stimulated the germination percentage in both varieties. The highest germination percentage was observed at 200Gy for Tss86 while for Tss10 it was observed at 25Gy. It showed variation on the germination and growth parameters evaluated. The highest plant height (74.17±4.42) for Tss10 was observed at 25Gy while for Tss86, 100Gy gave the highest mean of 79.6±8.02. Molecular evaluation revealed variation in the patterns of RAPD profile between irradiated plants and control. The RAPD primers showed 82.9% polymorphism. Also, as observed from the similarity coefficient values, the trend of the genetic variability was not proportional to the doses of the gamma ray. The similarity indices ranged from 0.09 to 0.60 with 3 distinct cluster groups identified at 0.64. The variant of Tss86 at 250Gy was found to be the most diverse. Thus, this integrated approach can be used for carrying out the mutation-assisted breeding and subsequent selection of desired mutants using molecular markers in AYB.