Callusing and regeneration of plantlets via somatic embryogenesis from inflorescence cultures of Triticum aestivum L.: role of genotype and long-term retention of morphogenic potential

Abstract

In the present investigation we have succeeded in obtaining a high frequency of regeneration of plantlets via somatic embryogenesis from callus derived from immature inflorescence explains of Triticum aestivum var, 'Sonalika'. The explants were cultured on MS medium supplemented with 2,4-D, casein hydrolysate and coconut milk. A large number of embryoids germinated, to form plantlets on the medium when 2, 4-D was omitted altogether or provided at low concentration. Plantlets were transferred to soil under natural environmental conditions and were shown to have the normal chromosome number of 2n=6x=42. Experiments with nineteen other varieties show that there is a marked effect of genotype both on initiation of callusing as well as on regeneration. So far 'Sonahka' has proved to be the most responsive among varieties tested by us. With callus of the variety 'Sonalika.', we also conducted an investigation on long-term retention of regenerative potential. During Song-term culture, for about 12 months, the morphogenic potential gradually diminished and was finally lost, but the regeneration potential could be restored by subculturing at very short intervals.