Vol. 11, Issue 7 (2022)

Author(s):
G Subhiga, S Kavitha, J Renugadevi and S Manonmani

Abstract:
Cryo-conservation is the most effective strategy for the long-term preservation of papaya seeds. Before the creation of a secure cryo-conservation method for papaya seeds suitable vitrification treatments involving loading solution in combination with plant vitrification solution 2 (PVS2) have to be standardized. In this study the optimal vitrification treatment was determined using the Differential Scanning Calorimetry (DSC). The results showed that the formation of ice nucleation was observed in the DSC thermogram at a temperature of (-36.64 ⁰C-Onset, -41.62 ⁰C-Midpoint and -46.64 ⁰C-End point) for 9% moisture content control seeds, the temperature of (-34.76 ⁰C-Onset, -40.81 ⁰C -Midpoint and -45.43 ⁰C-End point) for 10% moisture content control seeds and the temperatures of (-37.65 ⁰C-Onset, -40.36 ⁰C-midpoint and End point -45.77 ⁰C) for 11% moisture content control seeds. Similarly the ice nucleation for various vitrification treatment combinations was observed at the temperature range of (-31.25 ⁰C to -41.21 ⁰C-Onset, -35.32 ⁰C to -46.54 ⁰C-Midpoint and -39.49 ⁰C to -53.34⁰C-End point) for 9% moisture content seeds, (-29.16 ⁰C to -40.43 ⁰C-Onset, -35.67 ⁰C to -45.43 ⁰C-Midpoint and -37.41 ⁰C to -52.87 ⁰C -Endpoint) for 10% moisture content seeds and (-31.43⁰C to -40.83 ⁰C-Onset, -32.61 ⁰C to -46.46 ⁰C-Midpoint and -36.67 ⁰C to -54.36 ⁰C-Endpoint) for 11% moisture content seeds. Among the twenty-seven treatment combinations tested the treatment LP5 of 9% moisture content and LP5 and LP6 of 10% moisture content was discovered as best treatments for cryo-conservation of papaya seeds due to the formation of glass transition events in the vitrified seed tissues.