Establishment of an efficient callus induction and plant regeneration system in some wheat (Triticum aestivum L.) cultivars grown in Sudan
A procedure for callus induction and plant regeneration was developed for wheat (Triticum aestivum) cultivars grown in Sudan. Mature embryos of cultivar Khaleefa removed from surface sterilized seeds were used as explants. For callus induction, explants were cultured on Murashige and Skoog medium (MS) supplemented with different levels (1.5 to 4.0 mg/l) of 2,4-dichlorophenoxy acetic acid (2,4-D), indole-3- butyric acid (IBA) and indole-3- acetic acid (IAA). After 4 weeks of culture, the highest callus fresh weight (0.05 ± 0.01 g) was obtained on MS medium supplemented with 2.0 mg/L of 2,4-D. For shoot regeneration, the developed calli were transferred to MS medium without growth regulators or with different levels (0.1 to 3.0 mg/l) of 5-phenylcarbamoylamino-1,2,3-thiadiazole (thidiazuron) (TDZ), benzyladenine (BA) and kinetin (KN) alone or in combination with 2.0 mg/L of 2,4-D. After 6 weeks of culture, the best result for regeneration percentage (40%) was obtained on MS medium without growth regulators. Callus derived shoots were rooted most effectively in half-strength MS medium without or with different levels of IBA. To determine the genotypic effect, the developed procedure was used to evaluate the regeneration ability of other 5 Sudanese wheat cultivars. Significant differences were observed between genotypes for plant regeneration ability, indicating that these criteria are genotype dependent. The acclimatized regenerated plants were morphologically uniform with normal leaf shape and growth pattern under greenhouse conditions.
Key words: Triticum aestivum, callus induction, regeneration, 2,4-dichlorophenoxyacetic acid (2,4-D), genotypes.