Gamma-ray induced pedigreed mutant population of tossa jute (Corchorus olitorius L.): a key resource for forward and reverse genetics.

Abstract Narrow genetic diversity in available germplasm is a serious limiting factor for academic progress and agronomic improvement of crops like Corchorus olitorius, an economically important bast fibre crop. Mutation breeding, with its proven ability to improve qualitative as well as quantitative traits, can be employed to augment germplasm diversity. In the present study, gamma-rays were used to treat the seeds of two promising varieties, JRO 204 and JRO 8432; LD50 doses for gamma-rays were 200 Gy and 300 Gy for JRO 204 and JRO 8432, respectively. Irradiation of two varieties has resulted in the development of a large number of macro-mutants, such as twisted bark, extreme dwarf, non-abscission leaf, soft stem, hard stem and round pod mutants. Morphological and anatomical studies of these mutants gave new light on secondary growth in the species. In addition to the academic utility, these mutants will prove of immense importance to plant breeders aiming to improve fibre quality. Moreover, novel mutants will help to develop new plant architecture suitable for diversified applications of the genus.