A reliable and effective method for regenerating Uraria picta (Jacq.) in vitro using nodal explants sourced from mature seed-derived seedlings

Abstract

Uraria picta (Jacq.) is also called Prishnaparni derived from Sanskrit, is a strong healing plant utilized in Ayurvedic and traditional Chinese medicine. While seeds can propagate it, the success rate is only up to 46 %, and seedlings are susceptible to damping-off disease. These seeds' small size and hard coating contribute to their low viability. This research intended to develop a frequent in vitro regeneration method for U. picta by investigating how different growth regulators impact explant establishment and growth. Shoot and nodal segments from in vitro-germinated Uraria picta plants were used, along with various combinations of 2,4-D, BA, and IAA. The addition of 2 mg L⁻¹ 2,4-D to MS media proved to be the most successful method for inducing and increasing callus formation from shoot and node explants during indirect organogenesis. The successful multiple shoot formation was achieved by culturing 2–3 cm nodes from in vitro grown plants on MS medium containing 1 mg L⁻¹ of BA in order to produce numerous shoots (22.00 shoots). This medium formulation resulted in the fastest shoot bud initiation (5.50 days) and the highest shoot frequency (99.0 %). MS media without hormones was the most effective for rooting, resulting in a rooting time of 6.87 days and a rooting frequency of 82.5 %. Following completion of the rooting process, the newly grown plants were subjected to a hardening phase, and the use of soil: cocopeat (1:1) and vermiculite: Perlite (2:1) blends resulted in a 90 % survival rate for U. picta plants.