Androgenic potential of different tomato genotypes induced by colchicine and cold pretreatments

The androgenic potential of four tomato lines (Micro-Tina, Micro-Gemma, Moneymaker and MsK8 as parents) and their hybrids were studied through colchicine (250 mg/l) and cold (4°C for 72 h) pretreatments of isolated anthers. The pretreated anthers were cultured on induction medium. Statistical analysis showed that there was significant differences between genotypes for the studied traits. The lines MsK8 and Micro-Gemma had a considerably higher frequency of callus formation (CF) and shoot regeneration (SR) as well as greater callus diameters (CD) than that of other parents. The highest frequency of CF and SR belonged to hybrid MsK8 × Micro-Tina, and the longest CD possessed by Micro-Tina × Micro-Gemma. The mean values for hybrid’s CF, CD, and SR were significantly higher than those of the parents. In total, heterosis (hybrid vigor) was observed for the studied traits and heterozygous genotypes had a higher frequency of androgenic potential compared with homozygous parents.