Effects of colchicine and cold duration pretreatments on androgenesis responses of tomato (Lycopersicon esculentum Mill) via anther culture

The aim of the present study was to optimize the in vitro chromosome-doubling procedure by colchicine pretreatment in tomato anther culture. Anthers of 1.7–2.0 mm long were isolated at prophase-metaphase I and pretreated by different concentrations of colchicine (0, 250, 500 and 750 mg/l) at 4°C for 36 and 72 hrs under dark condition. After colchicine pretreatment, anthers were transferred to a colchicine free medium to callus and shoot induction. Analysis of variance showed that percentage of callus and shoot induction (PCI and PSI) were not influenced by cold pretreatment durations. However, significant differences were observed between cold durations for the number of regenerated (NRP) and the percentage of doubled haploid plants (PDH) ( p < 0.05). Androgenesis responses were affected by different colchicine concentrations and interactive colchicine x cold durations ( p < 0.05). Maximum PCI, PSI, NRP and PDH were belonged to 250 mg/l colchicine and 72 h cold duration. However, colchicine concentrations above than 250 mg/l had negative effect on androgenesis responses of anther cultures in both cold durations.