Varietal difference of plant regeneration from callus of sorghum mature seed

Mature seeds of 250 sorghum varieties were cultured to evaluate ability of callus formation and plant regeneration. Twenty germinated seeds were placed on callus induction medium and cultured for 30 days. The composition of callus induction medium was MS supplemented with 2 mg/l 2, 4-D, 30 g/l sucrose, 2 g/l Gelrite and pH was adjusted to 6.0 before autocraving. The composition of callus maintenance medium was the same as callus induction medium except that the concentration of 2, 4-D was reduced to 1 mg/l and the calli were cultured for 30 days. The composition of plant regeneration was the same as callus induction medium except that 2, 4-D was omitted. After 30 days of culture on the regeneration medium, plant regeneration was evaluated. In this culture system, most varieties formed compact yellowish calli. Type of plant regeneration was organogenesis and distinct somatic embryogenesis was not observed. In many cases only root formation was observed. Five varieties showed relatively high ability of plant regeneration. They were CK602, CKW5809, PE932 203, PE954 068 and PE954 110. Among the variety groups, Kafir group varieties showed relatively high ability of callus formation and plant regeneration. These five varieties and Kafir group varieties may be useful for iu vitro study of sorghum which requires plant regeneration.