Role of genotypes, growth regulators and amino acids on callus induction and plant regeneration from different developmental stages of inflorescence in wheat

Abstract

Plant regeneration from immature inflorescence on MS media with different growth regulators and amino acids in different genotypes of wheat was studied. The immature inflorescence explants of 2-3 mm size were taken from three inflorescence sizes viz. 0-1, 1-2 and 2-3 cm. Callus induction studies were conducted on 9 different media containing three levels of 2, 4-0 (1, 1.5, 2 mgtl), supplemented with 150 mgIJ glutamine and 200 mgtl casein hydrolysate, and further supplemented with 10 mgtl proline. Calli were induced at all the levels of 2, 4-0 in callusing media and from all the genotypes with a range of 42-96%. Inflorescence size of 1-2 cm and media containing 2 mg/l, 2, 4-0 with different amino acids was the best combination for inducing callus. 10-12 week old calluses obtained at a particular level of 2,4-0 (1, 1.5, 2 mgtl) irrespective of the presence of amino acids were grouped together and cultured on regeneration media containing either 1 mgtl cytokinin (SAP, kinetin) or cytokinin with 0.2 mgtl NAA auxin. Oifferent parameters such as genotype, level of 2,4-0 in callusing media, inflorescence size, regeneration media and most of the interactions were found to have significant effect on shooting response. Considering all the possible parameters, high shooting response of 75 to 95% was obtained In different genotypes. In summary a genotype showed high shooting response when callus was induced at 2 mgtl 2,4-0 with amino acids and explants taken from 1-2 cm inflorescence size and cultured on regeneration media containing both cytokinin and auxin.