Variations in Callus Formation and Plant Regeneration in African Rice (Oryza glaberrima Steud)

Eighteen cultivars of African (Oryza glaberrima) and two of Asian rice (O. sativa) were assessed for callus growth and plant regeneration. Mature seeds were used for callus initiation on media containing 2.2 mg · l(-1) 2,4-D with or without coconut milk. There were significant differences between the 20 cultivars in the size of calli produced. Addition of coconut milk increased callus size in most cultivars. Plant regeneration abilities by the cultivars were determined on two media. Calli of 16 cultivars were able to regenerate plants. The medium containing 0.2 mg · l(-1) NAA and 11 mg · l(-1) BA was more suitable for plant regeneration than that with 0.1 mg · l(-1) IAA and 0.2 mg · l(-1) kinetin.