SEED GERMINATION OF MASBEDDA (Gymnema sylvestre), A RARE MEDICINAL PLANT AS AFFECTED BY pH AND ORGANIC SOLVENTS

The use of plants in treating diseases can be traced to the remote past. However due tolack of organized and scientific cultivation, proper management and awareness of socialfactors, the number of these medicinal plants is decreasing at an alarming rate. Gymnemasylvestre is one of rare medicinal plant species, which has high demand in the market.Since, little information is available on germination dynamics of Gymnema seeds, thepresent investigation was carried out to study the effect of pH and organic solvents ongermination of Gymnema sylvestre seedsFresh seeds taken from the plant were used for the experiment. Five pH solutions (i.e.4,6,7,8 andlO) were used to moist the filter papers in petri dishes, which contained seeds.A separate experiment was carried out to study the effect of organic solvents (i.e.Ethanol, Ether, Xylene, and Acetone) on germination following same procedure withusing distilled water as a control. eRD was used in both experiments with 20 replicateseach containing lO seedsResults showed that significantly (p<0.05) higher germination of seeds (56% and 52%) atpH 4 and 6 respectively, whereas the lowest germination (36%) showed at pH 10. Thehighest germination (62%) was recorded from the seeds treated with distilled water,followed by Xylene (42%) and Ether (39%). A significantly (p<O.05) lower germinationwas showed in Acetone (10%) and Ethanol (6%). According to the findings of theexperiment it can be concluded that slightly acidic media would be the best pH for thegermination of Gymnema sylvestre seeds, whereas the organic solutions showed negativeeffects.

Effect of physiological status on rooting of Masbedda (Gymnema sylvestre) cuttings

Vegetative propagation by means of cuttings is an important method for starting new plants identicalto the parent plants. Many plants can be propagated with good results by cutting, though the successdepends upon the propagator's circumstances, the time of year, and the plant to be propagated. Thepresent study was carried out to investigate the effect of physiological stage on rooting of Gymnemasylvestre stem cuttings.Healthy, double nodded cuttings were made from the mature plant stock established at the Faculty ofAgriculture, University of Ruhuna. The cuttings taken from pre-flowering (Tl), flowering (T2) andpost-flowering (T3) stages were stuck into preformed holes in poly bags filled with moistened rootingmedium which consisted of sand, top soil and compost (1 :1: 1 by volume). They were placed in a shadehouse and watered once a day. The Completely Randomized Design (CRD) was used with tenreplicates. Assessment was done 75 days after for rooting. The percentage survival was not significantly(p ~ 0.05) different between cuttings taken from the pre-flowering (92%) and post-flowering (87%)stages. No significant (p ~ 0.05) differences also in the percentage of callused and rooted cuttingswere recorded between T I and T3. However, number of roots and length of the longest root percutting were significantly (p ~ 0.05) higher in Tl than any other. Furthermore, T2 showed the lowestfigures for all the parameters assessed, indicating that the physiological status of the stock plant at thetime the cuttings are excised is of great importance for the rooting process.

AN ASSESSMENT ON NATURAL REGENERATION OF Gymnema sylvestre, A RARE MEDICINAL PLANT

Gymnema sylvestre R.Br. belonging to family Asclepiadaceae, is naturallyfound in tropical forests of India and in some parts of Sri Lanka. This herb isbest known for its ability to abolish the taste of sugar and has been used inthe treatment of diabetes. A number of commercial herbal products are nowavailable that contain varying amounts of gymnemic acids, the componentresponsible for the action against diabetes. Though the demand for thespecies is increasing rapidly, the commercial cultivation of the species is yetto be expanded. On the other hand it is felt that the natural regeneration ofthis important herb is poor and this study was carried out in Matara Districtof Southern Sri Lanka to assess the natural regeneration of the species.An extensive survey was conducted in order to find the natural habitats andauthenticity was confirmed for the mother plants found in the area.Flowering, fruiting and other important physiological phases of the plantwere monitored and observations were made under natural conditions.Results revealed that Gymnema is propagated naturally by means of seedgermination only. Flowering commences late in the year and mature podsrelease seeds from early February each year. The low moisture content of theseeds at the time of release together with dry environmental conditions resultin very low germination and thus the natural regeneration of the species ispoor though a single mother plant produces thousands of seeds at a season.Therefore, an alternative mode of multiplication should be made available inorder to propagate and to conserve genetic stock of this useful plant

How Does Lead (Pb 2+ ) at Low Concentrations Affect on Spirulina (Arthrospira) platensis

ABSTRACT Spirulina (Arthrospira) platensis, a blue-green photoautotrophic alga has widely been used for the production of high valued protein for human and animal feeding as well. The present study focused on bioaccumulation of Pb 2+ and its effects on growth of S. platensis. , at 2 days of incubation) and decreased as incubation progressed. Bioconcentration factor (BCF) also reached to the peak (1218, 1127, 888, 928 and 1035 for 1, 2, 3, 4 and 5 µg/mL of Pb 2+ respectively) at 2 days of incubation followed by a gradual reduction. No marked differences were found in growth measured as optical density at 560 nm. It could therefore be concluded that no remarkable inhibition on growth of S. platensis is shown when cultured in contaminated water with low concentrations of Pb 2+ . Furthermore, the species sounds potential accumulator of Pb 2+ and thus could be used in detoxifying heavy metal affected aquatic ecosystems