Somatic embryogenesis from cultures of shoot apices, cotyledon and young leaves of in vitro shoots of Agave vera-cruz Mill. was studied. Embryogenic callus was obtained when explants were cultured on Murashige and Skoog's (MS) medium (1962) supplemented with L 2 vitamins, 4.52 μM 2,4-dichlorophenoxyacetic acid (2,4-D) or 5.37 μM ∝-naphthalene acetic acid (NAA). Somatic embryos differentiated from this embryogenic callus upon subculture to maturation/conversion medium containing cytokinin either alone or with auxin and L-glutamine. The best combination of growth regulators for development of somatic embryos was found to be 5.37 μM naphthalene acetic acid plus 0.91 μM zeatin and 40 g/l sucrose. The conversion frequency of somatic embryos to plantlets varied from 46-50%. Rooted plantlets were transferred directly to pots containing a soil, sand, and manure mixture without any hardening phase with 96-98% survival of the plantlets. Based on the histological observations, the potential origin of the somatic embryo is discussed.

A B S T R A C TCurcuma karnatakensis, a member of Zingiberaceae, is endemic to the state of Karnataka, India. The structure and physicochemical properties of starch isolated from rhizomatous rootstocks of two samples -A and B were analyzed for the first time. Sample A contains 76.4 AE 0.3% of starch, of which 86.6 AE 0.4% is amylose, while sample B has 75.0 AE 0.4% of starch containing 84.6 AE 0.4% of amylose according to UV-Vis spectrophotometric analysis. The shape of the starch granules in both the samples is polygonal and cuboidal with a smooth surface, as revealed by SEM studies. The X-ray diffractogram indicated A type of polymorphs in contrast to other Curcuma species, where B types are reported. Since its high amylose content leads to an increased tendency to retrogradation and the formation of resistant starch, this taxon could become one of the major dietary sources of starch in the future. In addition, a source rich in amylose specifies its prospective application in the pharmaceutical and biodegradable film industry.

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