Supramolecular phospholipids–polyphenolics interactions: The PHYTOSOME® strategy to improve the bioavailability of phytochemicals

The poor and/or erratic oral bioavailability of polyphenolics can be improved using the PHYTOSOME^®1 delivery system, a strategy that enhances the rate and the extent of solubilization into aqueous intestinal fluids and the capacity to cross biomembranes. Phospholipids show affinity for polyphenolics, and form supramolecular adducts having a definite stoichiometry. This article reviews the preparation and characterization of PHYTOSOME^® complexes and their activity in various medicinal (cardiovascular, anti-inflammatory, hepatoprotective, anticancer) and cosmetic (skin aging) realms of application.     

Sunflower allelopathy for weed control in agriculture systems

Recent developments in weed science and allied aspects have involved several interdisciplinary approaches. In this context, indiscriminate use of herbicides for weed control has become a questionable subject, which besides controlling the weeds, the chemical herbicides are harmful in many ways to soil, crops, other plants and the environment as a whole. Taking into consideration ecologically sound weed management, in modern days the reliance on chemical herbicides has decreased and a shift towards naturally occurring biological herbicides has received great attention throughout the world. Sunflower is an annual dicotyledonous plant, herbaceous, erect, and a native of North America. It is thermo and photo-insensitive, hence it can be grown year round in sub-tropical and tropical countries. Only two spp. Helianthus annuus L. and Helianthus tuberosum are cultivated for food, the remaining spp., are ornamentals weeds and wild plants. However, H. annuus is allelopathic and inhibits the growth and development of other plants thus reducing their productivity. Sunflower is a major oil-yielding crop in India and its cultivation in northwest India started 25 to 30 years ago in areas located in the plains. In this region, rice-wheat rotation became very popular owing to its high yields; however, these crops are highly infested by weeds, thus farmers use herbicides for their control. Hence, this rotation consumes a maximum quantity of herbicides in this region, which has resulted in several problems viz., environmental pollution, human health hazards, and development of herbicide resistance in weeds. Thus, serious ecological questions about the reliance on herbicides for weed control in this rotation have been raised. One of the alternatives to overcome these problems is with the use of allelopathic strategies, including the use of weed-smothering crops for weed management and for the sustainability of agriculture. The field, pot culture, and laboratory studies have shown that inclusion of sunflower crops in rotation and intercropping considerably reduced the weed population in the current and succeeding crops. Rhizosphere soil of sunflower drastically smothered the weed germination, population, and biomass. The residual suppression effect of sunflower also persisted in the next crop up to 75 days. Thus, it is conceptualized that the inclusion of such oilseed crops before the rice crop in the rice-wheat rotation may provide satisfactory weed control in the succeeding rice crops and may minimize the use of herbicides. Likewise, the replacement of sorghum by summer sunflower oilseed crops may also help in the control of summer as well as winter weeds. More studies in this direction may provide avenues for satisfactory weed management in agro-ecosystems and may help to minimize the use of herbicides and thereby pave the way to develop sustainable agricultural practices for biodiversity conservation and enhancing biological integrity.     

Nitrogen transport in plants,with an emphasis on the regulation of fluxes to match plant demand

Physiological methods, especially the use of isotopes of N, have allowed for the detailed characterizations of the several putative transport systems for nitrate and ammonium in roots of higher plants. In the last decade, the cloning of genes that appear to encode both high- and low-affinity transporters represent major advances, as well as substantiating the inferences based on earlier physiological methods. Nevertheless, the unexpected plethora of genes that have been identified now presents even greater challenges, to resolve their individual functions and to attempt to place these functions in a whole plant/environmental context.     

Seedling indices of four tree species in nursery and their correlations with field growth in Tamil Nadu, India

Selection of quality seedlings in nursery is important for raising fast-growing trees for production of fuelwood and other products. In order to identify the morphophysiological variables that can be used in nursery for selection purpose, a study on growth, drymatter production, and rate of photosynthesis was undertaken with seedlings of four tree species, viz, Acacia nilotica, Albizzia lebbeck, Dalbergia sissoo and Eucalyptus camaldulensis. The species varied significantly in growth, drymatter production and photosynthetic rate in nursery. E. camaldulensis was the fastest in growth and A. nilotica had maximum number of leaves. Total drymatter production was maximum in D. sissoo followed by A. lebbeck. The rate of photosynthesis was maximum in D. sissoo followed by A. nilotica and lowest in A. lebbeck. Among the various seedling attributes, height, number of leaves per plant, rootweight and photosynthetic rate exhibited significant correlations with seedling drymatter. Seedling diameter showed weak positive correlations with drymatter of both seedlings as well as two-year old field trees. However, number of leaves per plant, rootweight, shootweight and leafweight showed significant correlations with two-year field tree drymatter, the strongest correlation (r = 0.96, P = 0.001) was found between number of leaves per plant and field tree drymatter. Although plant height and leaf photosynthetic rate showed a positive correlation with two-year field growth, the relationship was statistically non-significant. The study reveals that maximum value for leaf number and dryweight of seedling components such as root, shoot and leaf can be used as criteria for selecting nursery stocks for field planting in semiarid conditions.This revised version was published online in November 2005 with corrections to the Cover Date.     

Antimicrobial activity of some Indian mosses

The present study was designed to evaluate the antimicrobial activity of ethanolic extracts of 15 Indian mosses. The antibacterial activity of ethanolic extracts was investigated against five G(+) and six G(-) bacterial strains. Antimycotic activity was assayed against 8 fungi. Sphagnum junghuhnianum, Barbula javanica, Barbula arcuata, Brachythecium populeum, Brachythecium rutabulum, Mnium marginatum and Entodon cf rubicundus were found to be most active against all the organisms.     

Stability Indices for Weed Management Systems in Forage Oat (Avena sativa L.)

A set of integrated weed management systems was assessed in forage oat ( Avena sativa L.), cv. Kent, to compare efficiencies inter se in terms of mean forage productivity over different locations and different years, and relative agronomic effectiveness. Results for seven weed management systems were obtained for three consecutive years, i.e. 1995–96, 1996–97 and 1997–98, at five locations of the Indian subcontinent. Two systems – use of weeder-cum-mulcher at the 3- and 6-week crop stages (WCS) and use of weeder-cum-mulcher at the 4 WCS plus application of 2, 4-D at 0.37 kg a.i. ha^–1 at 6 WCS – were found to be effective and consistent over locations from year to year and over years from location to location. Pooled analysis over years and locations showed manual weeding at 4 WCS plus application of 2, 4-D at 0.37 kg a.i. ha^–1 at 6 WCS, on the one hand, and use of weeder-cum-mulcher at 3 WCS plus manual weeding at 5 WCS, on the other, to have equal efficiencies and to be more beneficial than the other treatments. Recommendation of the latter system is of particular interest as this system merely involves mechanical operations which provide the benefits of soil mulching and carry no risk of biotoxicity due to herbicides in crop plants or adverse effects on soil through uninterrupted use of chemicals.     

Enhancement of Growth and Yield of Glycine max Plants with Inoculation of Phosphate Solubilizing Fungus Aspergillus niger K7 and Biochar Amendment in Soil

Addition of biochar in agriculture soil and bioinoculation of several fungi have been proved to benefit the growth and yield of crops; however, these have been mostly studied separately. Therefore, to perceive the effect of biochar along with Aspergillus niger K7, the present investigation was planned in soybean. Maximum solubilization was found at 20°C in vitro. Further, the strain was morphologically and molecularly identified. In plant-soil experiment, all the treatments showed a significant (p < 0.05) increase in growth, root nodulation, and yield of soybean plants; however, biochar supplemented with K7 treatment was the best. Hence, it can be concluded that the addition of both bioinoculant and biochar simultaneously can be a good practice to improve soil fertility and crop yield. To the best of our knowledge, this is the first report on comparative study of the effect of biochar and phosphorus (P)-solubilizing K7 strain on growth, yield and P uptake in soybean plants grown in Kumaon Himalayas.     

冷湿层积法对印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana）种子萌发的影响

研究赤霉素(GA3),冷湿和温度 对五个种源的印度冷杉(Abies pindrow)和长叶云杉(Picea smithiana)种子萌发的影响.种子被浸泡在GA3 (10 mg(L-1)中24小时,然后在3(5(C温度的条件下冷藏15天.设计4个温度(10(C, 15(C, 20(C 和 25(C)条件来促进种子的萌发.结果表明,浸泡和冷湿处理明显增加种子的萌发率.在10 (C时种子的萌发率最高.总体结果表明,种子被浸泡在GA3 (10 mg(L-1)中24小时,冷湿藏15天,可以有效地促进印度冷杉和长叶云杉的种子萌发.统计数据表明,浸泡处理、温度和种源以及与温度的相互作用都对种子的萌发有明显的影响.     

Kinetics and Adsorption-Desorption Behavior of AM Nitrification Inhibitor in Mollisols

Kinetics and adsorption-desorption behavior of a potent nitrification inhibitor, 2-amino 4-chloro 6-methyl pyrimidine (AM), was examined in Mollisol samples of different depths. Adsorption of AM was better accounted by pseudo-second order kinetics. Adsorption and desorption data of AM onto soil samples of different depths conformed to single surface Freundlich isotherm model. The values of ln K varied from ?0.1515 (0–15 cm) to 1.5171 (45–60 cm) and of 1/n from 0.9961 (45–60 cm) to 1.3237 (30–45 cm). Computed values of desorption capacity (ln K’) varied from 3.4734 (0–15 cm) to 4.0674 (45–60 cm) while that of 1/n´ from 0.0017 (45–60 cm) to 0.0367 (0–15 cm). Intensity of desorption (1/n´) had significant positive correlation with soil electrical conductance and clay content. The values of desorption index (n´/n) varied from 14.60 (0–15 cm) to 472.33 (30–45 cm) indicating high degree of irreversibility of adsorbed AM and hence poor leaching from these soils.