PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

To establish an efficient haploid production system for melon breeding, this study was conducted at the Laboratory of Universiti Malaysia Kelantan, Kelantan, Malaysia, in 2023, to evaluate the effects of cold pretreatment, surface sterilisation duration, and plant growth hormone concentrations on callus induction and embryogenesis in anther culture of Cucumis melo cv. Glamour, an important commercial melon cultivar. Early morning, unpollinated male flowers were harvested from 35 to 45-day-old plants. Sodium hypochlorite (NaOCl) containing Tween-20 was used as a surface sterilisation solution for anthers at 4, 7, and 4 °C after cold pretreatment for 10, 20, and 30 minutes. Cultures were established on Murashige and Skoog (MS) basal medium supplemented with varying concentrations of 2, 4-D and BAP. Incubation was carried out at 25±2 °C under dark conditions. A ruler and graph paper were used to measure average callus size. Embryogenic structures were morphologically screened and validated through flow cytometry. All treatments resulted in 100% callus induction, but callus size and quality varied with treatment conditions. The 3-day cold pretreatment significantly enhanced callus formation, while 20-minute sterilisation was optimal for healthy, viable callus. The medium containing 2, 4-D (5.0 mg/L) and BAP (0.5 mg/L) produced the largest callus and highest proliferation rate, whereas BAP (4.0 mg/L) combined with NAA (0.05 mg/L) was most effective for inducing embryogenesis. A flow cytometry analysis revealed that most calli were mixoploid. The results contribute to the development of a new protocol for anther culture in C. melo, which may be useful in improving the melon crop.