INFLUENCE OF PLANT GROWTH REGULATORS ON MACRO AND MICROPROPAGATION OF ENDEMIC SUCCULENT PLANT Caralluma diffusa (WIGHT) N.E.Br

The present study was intended to establish a better protocol for macropropagation (vegetative) and micropropagation techniques for an endangered and highly valued medicinal plant, Caralluma diffusa by using different plant growth regulators. Stem cuttings were individually treated with five different concentrations of IBA and NAA for root formation. Rooting and shooting attributes of stem cuttings were significantly higher in cuttings treated with 800 ppm of IBA. Shoot tip explants cultured on MS medium supplemented with BAP, Kn, TDZ, IAA, IBA, NAA and GA3 either individually or in various combinations were used to determine shoot multiplication and root regeneration abilities. Highest percentage (84%) of shoot regeneration and maximum number of shoots per explant (5.3) with an average shoot length of 6.1cm were achieved on the medium fortified with 1.5 mg/L BAP. The directly regenerated in vitro shoots were transferred onto the MS medium supplemented with various concentrations of BAP and 0.5 mg/L GA3 in order to induce multiple shoots. The subsequent subculture exhibited maximum shoot proliferation with expanded shoot length in 2nd, 3rd and 4thgeneration subcultures when treated with 1.5 mg/L BAP in combination with 0.5 mg/L GA3. When in vitro shoots were cultured on half strength MS medium for rooting, the medium supplemented with 0.8 mg/L IBA exhibited better result. In vitro regenerated plantlets were acclimatized and transferred to wild habitat, of which 94% plantlets survived and grew successfully. The present study result revealed a successful protocol for germplasm conservation techniques to preserve C. diffusa, an endangered herb.