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

Abstract

Enhancing virus resistance and extending shelf life, coupled with a dwarf stature, are critical factors for
successful papaya cultivation in India. These attributes facilitate increased production and productivity and help
reduce postharvest losses. Using mutagens in selected papaya cultivars is one of the methods to create variability
in papaya. Hence, the TILLING-based mutant populations of papaya cv. Arka Prabhath was generated through
irradiation of gamma rays ranging from 50 to 500 Gy dosage. This experiment evaluated and characterized the
putative mutant populations based on morphological, fruit characters 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 the control plant 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 compared to control plants (72.97 cm). Further,
twenty-one lines were selected based on morphological traits for physiological and fruit character 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 cultivars with improved shelf life of fruits.