Effects of Growth Regulators, Organic Nitrogen Sources, Various Nutrient, and Non-Nutrient Adjuvants on Somatic Embryogenesis in Red Sandalwood (Pterocarpus Santalinus)

The effects of growth regulators, organic nitrogen sources (amino acids and casein hydrolysate), coconut water, polyethylene glycol, dexamethasone, putrescine, sodium nitroprusside, and calcium chloride were studied on somatic embryogenesis and plantlet regeneration in Pterocarpus santalinus using immature zygotic embryo. The maximum frequency (83.33 percent)of embryogenesis, number of globular-staged embryos (88.00), number of cotyledonary-staged embryos (10.66), and number of plantlets (8.66)were obtained at 4 mg/l 2,4-D (2,4-Dichlorophenoxyacetic acid)?+?0.1 mg/l BAP (6-Benzylaminopurine). Amino acids (proline, glutamine, tryptophan, and phenylalanine)and polyethylene glycol enhanced somatic embryogenesis. The addition of proline, glutamine, tryptophan, and phenylalanine at 100 mg/l each +?2 percent polyethylene glycol with 4 mg/l 2,4-D?+?0.1 mg/l BAP resulted in maximum embryogenic frequency (100 percent), number of globular-staged embryos (155.00), number of cotyledonary-staged embryos (33.33), and number of plantlets regenerated (15.33). The plantlets obtained were acclimatized well and survived 100 percent in laboratory and greenhouse environments. The non-embryogenic and embryogenic development were discerned by histological examination. The study might have prospects concerning molecular studies and large-scale multiplication of P. santalinus or other endangered legume woody species.