Journal of Horticulture and Postharvest Research

Abstract Purpose: A study was carried out to investigate the influence of different fruit development stages on the physicochemical attributes, total phenolics, and antioxidant activity of two Iranian melon varieties for optimal harvest time. Research method: The research was conducted two times i.e. in 2023 and in 2024. It was a factorial experiment in a Completely Randomized Design (CRD) with four replications. The factors were developmental stage harvest (three stages, viz., 30, 40, and 50 days after fruit set) and variety (two varieties, viz., ‘Chaghercheh’ and ‘Zamcheh’). Findings: There were significant differences among the different harvest times in all parameters evaluated for both varieties. The fresh weight and related dimensions, and thickness and percentage of pulp of the fruits increased throughout the developmental stages, while fruit firmness, peel thickness, percentages of peel and seed showed a descending trend in the same period. At 50 days after fruit set, both melon varieties exhibited high levels of total soluble solids and pH, but low titratable acidity, resulting in high maturity index. As the fruits developed and matured, levels of ascorbic acid, total phenolics, and antioxidant activity reduced dramatically in both varieties. Also, statistically significant differences were detected between the two melon varieties in all factors measured. The antioxidant activity positively correlated with total phenolics (r = 0.910) and ascorbic acid (r = 0.891). Research limitations: No limitations were found. Originality/Value: Overall, the data of this research revealed that the degree of maturity and the variety are main parameters controlling the physicochemical characteristics, total phenolics, and antioxidant activity of melon. Also, the study provides basis for optimal harvest time for ‘Chaghercheh’ and ‘Zamcheh’ melon varieties.

Abstract Purpose: The efficiency of callus induction as source of bioactive compound is a critical step in the cell suspension culture for commercial production of important secondary metabolites. One of the main factors affecting callus efficiency is the developmental stage of explants. On the other hands, it has been declared that the optimization of medium composition has a significant influence on callogenesis and increment of biomass.  Research method: The aim of this study was the evaluation of different developmental stages of saffron corms as a source of explant preparation (immature and mature corms), plant growth regulators (PGRs) combinations (1-Naphthaleneacetic acid (NAA); 2, 4-dichlorophenoxyacetic acid (2,4-D); 6-Benzyladenine (BA) and kinetin (Kin)) and type of medium (Gamborg (B₅) medium and Murashige and Skoog (MS) medium) in callus induction in saffron corms to increase cell biomass. The media were supplemented with different combinations of 1-Naphthaleneacetic acid or 2, 4-dichlorophenoxyacetic acid (2, 4, 8 mgL^-1) as auxins and 6-Benzyladenine or kinetin (1, 4, 8 mgL^-1) as cytokinin. Findings: The results showed that mature corms harvested in May had the best developmental stage for callogenesis. The maximum callus formation was recorded in B₅ medium supplemented with 2,4-dichlorophenoxyacetic acid (4 mgL^-1) and kinetin (1 mgL^-1) with 2.61 g fresh weight. Limitations: No limitations to report. Originality/Value: This protocol for sampling explant and callus formation was found to make suitable sources of plant material for further study in production of bioactive compounds via cell suspension cultures.