Synergistic effect of growth regulators and glutamine on regeneration response in high yielding cultivars of wheat (Triticum aestivum L.)

Abstract

The role of growth regulators and glutamine amino acid on regenerative ability from young and old callus cultures of high yielding cultivars of wheat was studied. Callus was induced from immature embryo explants of 1-1.5 mm diameter on Murashige and Skoog (MS) basal medium supplemented with 2 mgll 2, 4-0. Shoot formation was obtained from young calli (10-12 week old) on MS medium without growth regulators. From young calli increase in regeneration frequency was obtained when cytokinin concentration was increased from 1 to 2 mgn. The addition of auxin to cytokinin containing media further increased the regeneration frequency. When the medium contained 2mg/l cytokinin and 0.5 mg/l NAA, an average regeneration frequency of 94% was obtained. Regeneration from old calli (28-30 week old) was obtained only when the medium contained growth regulators. There was a progressive increase in regeneration frequency with the increase in cytokinin concentration from 1 to 3 mgll. The same cytokinin medium when suplemented with low levels of auxin showed 3·6% increase in regeneration frequency. There was pronounced effect of glutamine on old callus cultures in increasing the regenerative ability by 6 to 10% when cytokinin or cytokinin- auxin containing media were supplemented with glutamine. Shoot induction frequency of 55% could be obtained from old callus cultures in a medium containing 3 mgll cytokinin, 0.5 mgll auxin and 150 mg/l glutamine.