Studies on the activities of antioxidant enzymes under induced drought stress in in vivo and in vitro plants of Macrotyloma uniflorum (Lam.) Verdc.

Activities of glutathione reductase, guaiacol peroxidase, catalase and contents of ascorbic acid, Hydrogen peroxide were analysed in in vitro and in vivo plants of Macrotyloma uniflorum under Polyethylene glycol (PEG) induced drought condition. Water stress was induced in in vitro plants by supplementing the regeneration medium with PEG (Mol. Wt. 6000) at the concentrations ranging from 5 to 25% while in in vivo plants by watering PEG solution with the same concentrations. The activities of glutathione reductase and guaiacol peroxidase were increased under induced drought stress condition in both treated samples. On contrary, catalase activities were decreased. The contents of ascorbic acid and hydrogen peroxide were enhanced correspondingly as the concentration of the PEG increased from 5 to 25%. The role of antioxidant enzymes under water stress condition is discussed. Further, the feasibility of mining the novel genes of drought resistance from the in vitro plants of Macrotyloma uniflorum is highlighted

Growth response of in vitro regenerated drymaria cordata (L.) willd. ex roem. & schult. to inoculation with arbuscular mycorrhizal fungi

Drymaria cordata (L.) Willd. ex Roem. & Schult. commonly known as ‘West Indian Chick weed’ is a potential herb used in traditional medicine in the treatment of many ailments. The main active principles therapeutically are known as drymaritin and isovitexin. Arbuscular mycorrhizae (AM) are symbiotic associations between plants and soil fungi that play a vital role in plant growth and development as well as soil quality. In the present investigation, an attempt was made to determine the growth responses of in vitro regenerated Drymaria cordata to inoculation with arbuscular mycorrhizal fungi. Both normal and in vitro regenerated plants of Drymaria cordata were inoculated with Glomus mosseae and Glomus fasciculatum. All the inoculated plants showed significant morphological results over control after a period of 30, 60 and 90 days of inoculation in polyhouse pot experiment. The percent of colonization and the number of spores in the rhizosphere of the in vitro regenerated plants are significantly more than the normal plants. Inoculation of in vitro regenerated plants with Glomus fasciculatum showed maximum mycorrhizal inoculation effect. Mycorrhizal inoculation significantly increased the biomass, root and shoot length, plant height, leaf area, number of branches, number of nodes per branch and internodal length. Such increases were related to the intensity of mycorrhizal association in the root. These findings indicate that mycorrhizal inoculation can be a suitable and alternative method to improve the growth of Drymaria cordata

Regeneration of multiple shoots from the callus cultures of Sauropus androgynous (L.) Merr.

 Morphogenetic potential of shoot tip, leaf and nodal explants of Sauropus androgynous was investigated to develop a reliable plant regeneration protocol via indirect organogenesis. Explants were cultured on Murashige and Skoog’s (MS) medium and Phillips & Collins (L2) medium supplemented with different concentrations of BAP either alone or in combinations with other auxins such as IAA, NAA, 2,4-D and IBA along with GA3. However, L2 medium with hormones was found to be more supportive for induction of profuse callus and subsequent regeneration of shoot buds than the same hormonal composition of MS medium. Maximum number of shoots per culture were differentiated from the organogenic callus raised on L2 + BAP (13.20 µM) + IAA (11.42 µM) + GA3 (1.44 µM). Thus regenerated shoots were rooted on ½ L2 + IAA (2.85 µM). The plantlets were acclimatized for 3-4 weeks in pearlite before transferring them into pots containing soil, sand and manure in 1:1:1 ratio. Nearly 90% of survival was recorded

Organogenesis from the cultures of <i style="">Nothapodytes foetida</i> (Wight) Sleumer raised on TDZ supplemented media

205-209Mature embryos of Nothapodytes foetida (Wight) Sleumer were inoculated on Murashige and Skoog (MS), modified MS (MMS) and Phillips and Collins (L2) media supplemented with TDZ either alone or with BAP and L-glutamine. Both shoot proliferation from the apical region of shoots and differentiation of shoots from the callus were observed from the cultures depending on the type of medium and the hormone combination. Proliferation of shoots from the apical region of shoots and also organogenesis from the callus, formed at the transition zone of primary root and hypocotyl of the young seedling, was obtained on L2+TDZ (0.44 µM)+BAP (2.22 µM)+L-glutamine (0.03 mM). Regeneration from the callus cultures was reported for the first time. The dual role of TDZ in promoting proliferation of shoots and shoot differentiation from the callus, along with beneficial effects of cytokinin and L-glutamine on the morphogenesis, was discussed

Regeneration of multiple shoots from the callus cultures of <i style="">Macrotyloma uniflorum </i>(Lam.) Verdc.

101-105An effective protocol for the regeneration of multiple shoots from the callus, derived from shoot tip and cotyledonary node, was developed for the first time for Macrotyloma uniflorum (Lam.) Verdc. Shoot apices and cotyledonary nodes from 9-d-old aseptically grown seedlings were inoculated onto MS, L2 and MMS media supplemented with various growth regulators. Proliferation of about 17 shoots was obtained on AS supplemented MS medium after 16 d of culture, while about 14 and 20 shoots regenerated from the callus on MMS1+NAA (1.86 μM)+BAP (0.45 μM) and L2+IBA (0.45 μM)+BAP (0.11 μM), respectively after 30 d of culture. Regenerated shoots were rooted on MS+IAA (0.11 µM)+Kn (0.21 µM) with upto 6 roots per shoot. Rooted shoots were sequentially acclimatized by transferring them to sterile distilled water and tap water before planting in various pot mixtures. A maximum of 60% survival rate was noticed on a mixture of soil:sand:manure (1:1:1)