Effect of Genotype, Explant Age and Medium Composition on Callus Production and Plant Regeneration from Immature Embryos of Sorghum PDF

Keywords

immature embryos, high tannin sorghum, tissue culture

Abstract

Regenerable callus was obtained from immature embryos of high-tannin sorghum (Sorghum bicolor L. Moench) genotypes. Immature embryos collected 1 to 2 weeks after pollination produced high frequency regenerable callus when cultured on basal medium containing Murashige and Skoog (MS) inorganic salts, modified Gamborg (B5) vitamins and supplemented with 2,4- D (2 mg/L). Coconut water (Cw, 10%) and/or zeatin (2.2 mg/L) promoted callus production in certain genotypes. Frequent subculturing on the same medium under dark conditions reduced pigment formation. The genotypes differed in their ability to form callus as well as in subsequent regeneration. Shoots were obtained from nodular callus subcultured on the same basal medium supplemented with IAA (1.0 mg/L) and zeatin (2.2 mg/L). Casein hydrolysate, CH (1.0 g/L) enhanced shoot formation. The highest number of regenerated plants (70, 41, 18 and 17) were obtained in lines IS8768, G522A, BR64 and RTX430, respectively. These lines are rated high in tannin