Effect of chemical factors on production of isoflavonoids in Pueraria tuberosa (Roxb.ex.Willd.) DC suspension culture.

Suspension cultures of Pueraria tuberosa, a woody legume, have been established and using different concentrations of growth regulators, sucrose, ammonium and nitrate nitrogen, attempts have been made to improve their isoflavonoid content. The cell cultures grew well on all the treatments. Up to approximately 8 folds increased isoflavonoids content was recorded in the cultures grown in MS medium modified with nitrogen and supplemented with 1 mg 1(-1) of kinetin.

Isoflavonoids production in callus culture of Pueraria tuberosa, the Indian kudzu.

Isoflavonoid contents of different plant parts and callus tissues of the Indian Kudzu, Pueraria tuberosa (Roxb.ex.Willd.) DC are presented. The initial cultures were slow growing, associated with browning of the tissues. The production of four isoflavonoids (puerarin, genistin, genistein and daidzein) in the callus cultures of P. tuberosa was studied by manipulating the plant growth regulators and sucrose concentration in the medium. Organogenesis was not recorded in callus on any of these treatments. Tuber and stem accumulated puerarin, a glycoside of daidzein, at high amounts, 0.65% and 0.054% respectively. However, the daidzein content of the callus tissues grown on Murashige and Skoog medium containing BA (20.9 microM) and sucrose (60 gl(-1)) was significantly higher (0.056%) than in vivo plant material (0.02%) and other comparable culture systems like Genista and Pueraria lobata.

Establishment of embryonic cultures and somatic embryogenesis in callus culture of guggul-Commiphora wightii (Arnott.) Bhandari.

Somatic embryogenesis in callus cultures of Commiphora wightii (Arnott.) Bhandari was achieved. Though the frequency of explants producing embryonic culture was low, immature zygotic embryos were the only suitable explants to produce embryonic callus after reciprocal transfers on media containing 2,4,5-trichlorophenoxy acetic acid (0.1 mgl(-1)) and kinetin (0.1 mgl(-1)) or devoid of growth regulators. All other media failed to produce embryonic callus. Embryonic cells were small, densely filled with cytoplasm and isodiametric as compared to non-embryonic cells, which were large, elongated and vacuolated. Maximum growth of embryonic callus was recorded on modified MS medium (MS-2 medium) supplemented with BA (0.25 mgl(-1)) and IBA (0.1 mgl(-1)). MS-2 salts supported higher growth of callus as compared to tissues grown on B5 medium containing same concentrations of plant growth regulators. Exogenous medium nutrients had no effect on somatic embryo development whereas plant growth regulators had little effect. Asynchronously growing embryos formed plantlets regularly which were successfully transferred to the field conditions.

A method for large-scale multiplication of Curculigo orchioides through bulbil formation from leaf explant in shake flask culture.

An efficient method has been developed for large-scale multiplication of Curculigo orchioides (Hypoxidaceae), an endangered medicinal plant, through direct bulbil formation from leaf explants in shake flask cultures. Leaf-segments (7 x 10 mm) were cultured in B5 liquid medium containing KNO3 (200 mgNL-1), (NH4)2SO4 (50 mgNL-1), benzyl adenosine (2.2 microM), adenine (0.11 mM), indole butyric acid (1.0 microM) and polyvinyl pyrrolidone (250 mgL-1). About 95% of explants produced maximum number of bulbils (546/flask at 6 weeks growth) in the medium. Shake flask cultures yielded 2737 bulbils/L medium whereas static cultures yielded 624 bulbils/L medium. Germination of bulbils was maximum (90.62%) on agar-gelled B5 medium containing benzyl adenosine (2.2 microM) and gibberellic acid (3.5 microM). Plantlets developed in vitro were successfully transferred to soil with a high rate of survivability (90%) and were comparable to natural population in growth and vigour.

Changes in phospholipids, fatty acids, oxidative enzymes, phenolics and protein levels during growth of normal and habituated tissues of Cocculus pendulus.

Cultures of C. pendulus were maintained on hormone free and hormone supplemented (NAA 1.0 mg/l and kinetin 0.5 mg/l) Murashige and Skoog medium. During the growth period, hormone free cultures had higher phenolic content, polyphenol oxidase activity and less protein content, peroxidase and IAA oxidase activity. Activity of all the three oxidising enzymes and phenolic content were high at 16 days growth. Total lipid content was higher (2.7-folds at 15 days) in hormone free cultures. Phospholipid content of both cultures was not markedly dissimilar except PC and DGDG contents. Thus it is evidenced that both the tissues were similar metabolically.

Effect of anti-oxidants and adsorbents on tissue browning associated metabolism in Cocculus pendulus callus cultures.

Explants and callus of C. pendulus produced intense brown substances in the medium which caused necrosis. Various anti-oxidants (ascorbic acid, cysteine and dithiothreitol) and adsorbents (activated charcoal and polyvinyl pyrrolidone) were used in different concentrations to prevent browning of the tissues. These in MS medium affected differently the growth, colour and texture of the tissues. It was concluded that both peroxidase and phenolase were involved in the browning. Increased peroxidase activity and decreased phenolase activity were probably due to more peroxidative oxidation of phenols and unavailability of substrate for phenolase activity. This resulted in faster growth of tissues, which further reduced the phenolase activity.