In-vitro effects of sucrose and ascorbic acid on induction and shelf-life of micro-tuber of cassava (Manihot esculenta Crantz) genotypes

Abstract

Background: Cassava production faces threat from postharvest physiological deterioration (PPD). The PPD is usually observed within the first 72 hours of harvest. Therefore, extending the shelf-life of cassava root-tubers by few days could reduce appreciable financial losses. Objective: This study is aimed to investigate effects of sucrose and ascorbic acid on induction and shelf-life of micro-tubers of cassava cultivars using an In-vitro model. Method: Effect of sucrose (30, 45, 60, 75 and 90 g/L) on the micro-tuber induction was determined after 45 days in these cultivars (TME 1333 and TME 2060). The optimal level was later combined with ascorbic acid (0, 25, 50, 75 and 100 mg/L) to investigate its effect on micro-tubers shelf-life during a 10-day storage. Each study was laid out in factorial under CRD with 5 replications. Results: The 30 g/L sucrose (control) produced the utmost number of micro-tubers (4.33), highest length (6.68 cm), and fresh weight (0.1495 g). The cultivar ‘TME 2060’ had longer (5.26 cm) and higher fresh weight (0.1079 g) than ‘TME 1333’ with 5.04 cm and 0.0977 g respectively. Ascorbic acid (100 mg/L) significantly delayed the discolouration of micro-tubers over a 10-day storage. Also, the 100 mg/L ascorbic acid produced the least percentage of deteriorated micro-tubers. Conclusion: Results demonstrate the roles of sucrose and ascorbic acid in micro-tuber formation and antioxidant activity in delaying PPD. Therefore, we propose for In-situ production (via breeding strategy) of vitamin C-fortified cassava varieties in order to control the incidence of PPD and in turn improve farmer`s economy.