Optimizing indirect organogenesis and chlorophyll a fluorescence analysis to ensure high survival rate of Capparis decidua under ex vitro conditions
摘要
Capparis decidua (Forsk.) Edgew (Capparidaceae), an economically important woody medicinal shrub of tropical and warm temperate regions, is facing the threat of depletion in natural habitats due to overexploitation for its fruits, unregulated urbanization, low regeneration rate, habitat degradation, and climate change. In present studies, efforts were done to develop a protocol for in vitro propagation through indirect organogenesis. Nodal explants exhibited high frequency of callogenesis (98.78% ± 1.53) on 5.0 mg L−1 6-benzylaminopurine (BAP) and 1.0 mg L−1 thidiazuron (TDZ) after 25 days (d) of culture. Callus mediated organogenesis achieved on media fortified with 0.5 mg L−1 α-naphthaleneacetic acid (NAA) and BAP (3.0 mg L−1). Microshoots showed high-frequency rhizogenesis (98.67 ± 2.52) on ½ strength Murashige and Skoog (MS) medium fortified with 1.0 mg L−1 indole-3-butyric acid (IBA). Photosynthetic potential of in vitro–raised plantlets was measured using chlorophyll a fluorescence and JIP test. Plantlets, after 28 d of emergence of root primordia, showed highest photosynthetic potential in terms of high values of maximal fluorescence (FM), density of functional photosystem II (RC/CS), quantum yields of photosynthesis (ϕPo) and electron transport (ϕEo), and photosynthesis performance (PIcs). In vitro developed plantlets, having high photosynthetic potential, showed high survival rate (97.52% ± 6.14) under ex vitro conditions. Results show the efficacy of Chl a fluorescence analysis and JIP test for screening the photosynthetic potential of in vitro–propagated plantlets. The developed in vitro protocol can be used for large-scale propagation of C. decidua and can serve as a foundation for future genetic transformation studies to enhance traits against various biotic and abiotic stresses.