Euchresta horsfieldii (Lesch) Benn. is a highly demanded medicinal plant with many benefits. In vitro propagation through callus induction is an effective method for rapid multiplication in a short time. This research aimed to evaluate the effective concentration of Benzyl Amino Purine and 2,4-Dichlorophenoxiacetic acid on callus induction and organogenesis for in vitro propagation and secondary metabolite production of E. horsfieldii. The design used in this research was a Complete Randomized Design in 2 factors: Benzyl Amino Purine and 2,4-Dichlorophenoxiacetic acid with 5 levels for each concentration. Parameters observed are the percentage of inducted calluses, callus appearance time, the weight of fresh calluses, the weight of dry calluses, the texture of callus, the color of callus, percentage of the formed shoot, shoot appearance time, the height of shoots, the number of leaves, flavonoid compounds of callus, and bioactive compounds. The result showed that the single treatment of Benzyl Amino Purine and 2,4-Dichlorophenoxiacetic was significantly affecting the shoots forming. The concentration of 2,4-Dichlorophenoxiacetic 0 ppm gave the highest average plantlet height by 2.67 cm, increasing the number of shoots by 2.00, and the number of leaves by 5.60. E. horsfieldii cultured in vitro without additional growth regulators had a higher flavonoid content.

Crown flower (Calotropis gigantea) as an herbaceous plant, is wildly recognized for its benefits as a medicinal plant. Phytochemical compounds which are contained in leaves, roots, and flowers of crown flower can be used as medicines. However, crown flower in Indonesia is still not optimal in their utilization. The study aimed to obtain the right concentration of growth regulators Benzyl Amino Purine and Indole Butyric Acid to stimulate optimal growth and secondary metabolites of crown flower. The study used a Completely Randomized Design arranged in a factorial design. The first factor was Benzyl Amino Purine and the second was Indole Butyric Acid. The data obtained were analyzed using analysis of variance with a 5% level test. The interaction of Benzyl Amino Purine and Indole Butyric Acid significantly increased the number of leaves and shoot emergence time. However, medium without Benzyl Amino Purine improved the percentage of root emergence by 100%, the number of roots by 17.2 roots, and plantlet height by 7.45 cm. Optimal concentration was obtained in 3 ppm Benzyl Amino Purine, which produced the high shoot and emergence time, as well as the number of shoots and leaves. Higher flavonoid contents were contained in cultured plants than in conventional cultivation. Optimal growth and phytochemical content give an opportunity to increase the production and the use of crown flower as medicinal plant.