Determination of mutagenic sensitivity and its manifestations on papaya (Carica papaya L.) cv. Arka Prabhath

Abstract

Papaya is an important fruit crop of the family Caricaceae which needs the improvement in terms of virus resistance and shelf life with dwarf stature. Mutation breeding technique has been considered as an efficient tool adopted by plant breeders to create variability in papaya. The mutation frequency and population structure of the mutants directly depend upon the type of mutagen and the time of exposure. Irrespective of the used mutagens, the ultimate induced mutations are random and therefore determination of mutagenic sensitivity is important pre-requisite. Based on this, investigation on the induction of mutation in papaya cv. Arka Prabhath was carried out with the objective of creating genetic variability through physical mutagen. In this study, papaya seeds were irradiated with five different dose of gamma rays ranging from 50 Gy to 500 Gy. The results revealed that gradual reduction in germination, survival of seedlings and delayed germination with increase in dosage of gamma rays. Based on probit analysis, LD50 (Lethal dose) was fixed at 186.24 Gy. Total seven types of chlorophyll mutants were observed as a result of mutation. Mutagenic efficiency and effectiveness were higher in a lower dose of gamma treatment (50 Gy).