Somatic embryogenesis was achieved in four leguminous tree species, that is, Acacia catechu, Acacia arabica, Hardwickia binata, and Dalbergia sissoo using immature zygotic embryos as explants on Murashige and Skoog (MS) medium supplemented with 0.25-1.0 mg/l Kn (kinetin) and 2.0-3.0 mg/l 2,4-D