Micropropagation of Dendrocalamus asper {Schult. & Schult. F.} Backer ex k. Heyne): an exotic edible bamboo

Effect of season, media type, carbon source, growth regulators and transplanting media on micropropagation of Dendrocalamus asper, an important bamboo species, was examined. The season of explant collection played an important role in axillary bud sprouting and spring (February?CApril) was found to be the best period for explant collection. Among the different media MS was found to be the best for micropropagation. Maximum numbers (4.83/explant) of shoots were initiated in MS?+?15???M BAP. For shoot multiplication, MS medium supplemented with 10???M BAP and 75???M Adenine sulfate was used. BAP was superior to KIN for both explant establishment, as well as, shoot multiplication. Optimal rooting was achieved in shoots cultured on ? strength MS medium supplemented with 5???M each of IBA and NAA. Regenerated plantlets were acclimatized and hardened in green house using dune sand and vermi-compost (3:1) with 92.34% success and transferred to the field with 100% survival rate. In the field, plants supplied with FYM along with urea showed better growth and development. Macroproliferation, plant multiplication by separating the rooted tillers of well established in vitro raised plantlets after 5 to 6?months of growth in the green house could double the multiplication rate. More than 25000 in vitro raised plants were successfully transferred to the field and no morphological variations in growth were observed, thus proving the potential of tissue culture for raising large scale plantations of D. asper.     

Response of lentil to VA Mycorrhizal inoculation and plant available P levels of unsterile soils

Summary Responses of lentil in unsterile soils at low, medium and high levels of plant available soil P toGlomus fasciculatum inoculation were evaluated. It was observed that growth, dry matter accumulation, nodulation, and nitrogen fixation were considerably improved in VAM inoculated plants over uninoculated control at low and medium levels of plant available soil P.     

A numerical model for the oxygenation of blood in lung capillaries--effect of nth order one-step kinetics of oxygen uptake by haemoglobin

A numerical model is described for the oxygenation of blood in lung capillaries by considering the transport mechanisms of molecular diffusion, convection and the facilitated diffusion due to the presence of haemoglobin. In order to represent the oxygen dissociation curve accurately in the model, the nth order one-step kinetics of oxygen uptake by haemoglobin has been used. The resulting system of coupled, non-linear partial differential equations is solved numerically. It is shown that the blood is required to traverse a larger distance in the capillary before becoming fully oxygenated with nth order one-step kinetics in comparison to first-order one-step kinetics.     

Prostaglandins do not mediate the actions of cholera toxin on pancreatic acini or gastric chief cells from the guinea pig

Recent reports suggest that prostaglandins, rather than cAMP, play a major role in mediating cholera toxin-induced water and electrolyte secretion from rabbit intestinal loops. We examined the role of prostaglandins in mediating toxin-induced pancreatic and gastric exocrine secretion. In these tissues, indomethacin, a potent inhibitor of prostaglandin synthesis, did not alter the stimulatory effects of cholera toxin on increases in cellular cAMP or enzyme secretion. Moreover, the addition of cholera toxin did not alter prostaglandin E2 release from either tissue. In contrast to their effects in rabbit intestinal loops, prostaglandins do not regulate cholera toxin-induced enzyme secretion from the guinea pig pancreas or stomach.     

De novo organogenesis and plant regeneration in <Emphasis Type="Italic">Pongamia pinnata</Emphasis>, oil producing tree legume

Role of Thidiazuron (TDZ) in inducing adventitious organogenesis in Pongamia was studied. TDZ at different concentrations (0, 0.45, 2.27, 4.54, 6.71, 9.08, 11.35, 13.12 and 22.71 μM) were used for induction of caulogenic bud formation in deembryonated cotyledon explants. Each cotyledon was cut into three segments and identified as proximal, middle and distal. Duration of TDZ exposure, influence of the segment and orientation of the explant were studied. TDZ at 11.35 μM concentration was optimum for the induction of shoots and rapid elongation. Shoots induced at higher concentration elongated after several passages in growth regulator free medium, thereby extending the period of differentiation. Exposure of the explant for 20 days yielded more number of buds than 10 days. Proximal segment of the cotyledon was more responsive. Contact of abaxial surface in the medium was more effective and generated more buds than the adaxial side. Buds differentiated and elongated on transfer to MS basal medium for 8–12 passages of 15 days each. Rooting and elongation of shoots was achieved in charcoal supplemented half-strength MS medium. Rooted plantlets survived on transfer to sand soil mixture. The plants were hardened and transferred to green house. This is the first report on in vitro regeneration of Pongamia pinnata via adventitious organogenesis using TDZ. This protocol may find application in studies in genetic transformation, isolation of somaclonal variants and in induction of mutants. It also provides a system to study the inhibitory role of TDZ on shoot differentiation.     

Lipid composition of thylakoid membranes of cadmium treated wheat seedlings.

Cadmium (200 ppm) applied through the rooting medium to 30-day-old wheat plants decreased chlorophyll content, net CO2 exchanges and PSII activity by 34, 54 and 43% respectively. Thylakoid total lipids, total glycolipids, total phospholipids and total neutral lipids decreased by 22, 23, 12 and 25%, respectively, under cadmium treatment. Thylakoid membrane glycolipids had three major constituents, viz. monogalactosyl diacylglycerol, digalactosyl diacylglycerol and sulphoquinovosyl diacylglycerol. Monogalactosyl diacylglycerol and digalactosyl diacylglycerol contents decreased by 32 and 27%, respectively, under cadmium. Cadmium application also decreased the concentration of phosphatidyl glycerol and phosphatidyl choline to the extent of about 57 and 31%, respectively. On the other hand, phosphatidic acid and free fatty acids content showed an increase. These compositional changes in thylakoid membranes might be responsible for reduced PSII activity and rate of photosynthesis as observed under cadmium treatment.     

Transmission of the cri-du-chat syndrome from a maternal balanced translocation carrier,t(5p-;11q+)

Summary A child with cri-du-chat syndrome, 46,XY,5p-, was born to a mother who had two normal children and two abortuses. The mother was shown to carry a balanced translocation. Giemsa and fluorescent banding demonstrate the exact location of the translocated segment. The deleted short arm of chromosome number 5 was shown to be attached to the long arm of chromosome number 11.

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Zusammenfassung Ein Kind mit Cri-du-chat Syndrom und Karyotyp 46,XY,5p- wurde von einer Mutter geboren, die zuvor zwei gesunde Kinder und zwei Aborte gehabt hatte. Bei der Mutter wurde eine balancierte Translokation nachgewiesen; Chiemsa- und Fluorescens-Bandenmuster zeigten die genaue Lokalisation des translozierten Segmentes: Der deletierte kurze Arm des Chromosoms Nr.5 war an den langen Arm vom Chromosom Nr. 11 angeheftet.

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We are indeed indebted to Dr. G. R. Hennigar for facilities and Dr. C. D. Barnett for financial assistance.