Evaluation and characterization of TILLING-based putative mutant populations of papaya cv. Arka Prabhath

Abstract

Manifestation of virus resistance, shelf-life with dwarf stature are important pre-requisites for successful cultivation of papaya in India as it facilitates improved production, productivity and reduced post-harvest loss. One of the methods to create variability is to use mutagens in selected cultivar of papaya. Accordingly, the TILLING-based mutant populations of papaya cv. Arka Prabhath were generated through irradiation of gamma rays ranging from 50 to 500 Gy dosage. In this experiment, the putative mutant populations were evaluated and characterized based on morphological, fruit quality and physiological parameters. Desirable traits such as early flowering, reduced plant height and bearing height, papaya ring spot virus tolerant plants and fruits with extended shelf life were observed in the mutant population. Early flowering and reduced plant height with wide variation was found at 50 Gy wherein the first flowering was on 57 days with 43 cm of plant height in contrast to 80 days in control plants with 79 cm of plant height. Reduced bearing height (40 cm) was observed in 100 Gy with a mean bearing height of 70.65 cm in comparison to control plants (72.97 cm), range being 55 to 115 cm. Further, based on morphological traits twenty-one lines were selected for physiological and fruit quality trait evaluation. Reduction in physiological loss in weight, ethylene evolution rate and respiration rate were observed in the mutant lines treated with 150 Gy dosage. The results advocate the efficacy of gamma induced mutation for developing dwarf cultivar with improved quality and shelf-life of fruits.