Meta-topolin Promotes Improved Micropropagation, Photosynthetic Performances, Biomass and Proline Levels of an India Ipecac (Tylophora indica Burm f.)

The significance of a novel aromatic cytokinins, meta-topolin (mT), on in vitro morphogenesis, rhizogenesis and acclimatization competency of tissue culture raised plants of Tylophora indica have been studied. mT an advanced cytokinin was found potential for the development of the micropropagation system as well as growth and establishment of plants ex vitro. Increased multiplication rate was found using mT (5.0 μM) supplemented in Murashige and Skoog (MS 1962) medium, where stimulation of maximum shoot development (12.3 ± 0.22) with a shoot length (5.50 ± 0.00 cm)/explant after 4 weeks of culture duration was attained. The collective consequence of cytokinin-auxin (5.0 μM mT + 0.5 μM NAA) considerably showed the production of 18.2 ± 0.12 mean shoots/explant with shoot length of 5.40 ± 0.00 cm with 90% regeneration rate. The high rooting rates of microshoots (4 cm) were evident on 1/2 strength of MS medium amplified with petite intensity (0.1 μM) of indole-3-butyric acid (IBA) which yielded maximum mean roots (8.64 ± 0.04) and mean root length (4.12 ± 0.03 cm) in 92% cultures. Maximum Chl. a (0.45 ± 0.01 mg/g FW), Chl. b (0.40 ± 0.01 mg/g FW), and carotenoid (0.22 ± 0.02 mg/g FW) contents were recorded at optimal in mT (5.0 μM) concentration. However, the elevated intensity of proline level (0.26 ± 0.02 μg/g FW) was recorded on elevated application of mT (10.0 μM) in the basal medium. The survival rate 96.0 ± 0.91% was ascertained by the acclimatized plants in a planting substrate soilrite. Tylophora plantlets regenerated via the exposure of mT showed significantly improved magnitude of morpho-physiological quality of shoots intensification and root quality, staging of better biomass, pigments, and proline contents followed by inevitably enhanced adaptation potentiality. This standardized rejuvenation/re-establishment protocol may be supportive during the regeneration of novel genotypes of T. indica which could advance agronomic characters during in vitro selection practices along with genetic transformation system/genetic engineering.