Nitrification inhibitors from the roots of Leucaena leucocephala

The nitrification inhibition (NI) bioassay guided fractionation of the methanol extract of lyophilized and milled roots of Leuceana leucocephala resulted in the isolation of four compounds, 1-4, as confirmed from their 1H and 13C NMR spectral data. Compound 1, gallocatechin, was the most active NI inhibitor at 12 microg/mL. Epigallocatechin, 2, and epicatechin, 4, isolated as mixtures, were not assayed individually for their NI inhibitory activities against the nitrification bacterium Nitrosomonas europaea.     

Cultivars of apple fruits that are not marketed with potential for anthocyanin production

The red coloration of apple skin is mainly due to anthocyanins that are reported to possess health benefits. The aim of the present study was to determine the anthocyanin content in three underutilized Malus pumila Mill cultivars, Cranberry, Kerr, and Niedzwetzkyana, and confirm their anti-inflammatory and antioxidant activities. Our analysis revealed that the three cultivars studied contained primarily cyanidin-3-O-glucosyl rutinoside (1) at >99%. The anthocyanin was purified by C-18 medium pressure liquid chromatography and characterized by NMR spectral methods. The quantification of anthocyanins in M. pumila cultivars revealed that Cranberry, Kerr, and Niedzwetzkyana contained 1.12, 0.55, and 0.36 mg/g of fresh weight of 1, respectively. The lipid peroxidation (LPO) and cyclooxygenase enzyme (COX) inhibitory activities of 1 in water were compared with the activities of cyanidin-3-O-rutinoside (2) and cyanidin-3-O-glucoside (3) found in cherries and berries. There is a significant increase in LPO and COX enzyme-inhibitory activities of anthocyanin when tested in water compared to using dimethylsulfoxide as the carrier. The LPO inhibition of anthocyanins 1, 2, and 3 were 53.3, 68.3, and 87.9, respectively, at a 0.25 microM concentration. They inhibited the COX-1 enzyme by 42.7, 45.2, and 50.4 and COX-2 by 52.7, 61.5, and 68.5, respectively, at 5 microM. The LPO inhibitory values for commercial standards, BHA, BHT, and TBHQ, were 85, 89, and 94%, respectively at 1 microM. Similarly, positive controls aspirin, celecoxib, and robecoxib inhibited COX-1 and -2 enzymes by 68.6, 40.7, and 0% and 26.6, 72.2, and 92.4%, respectively, at 60, 26, and 32 nM.     

River dolphin distribution in regulated river systems: implications for dry‐season flow regimes in the Gangetic basin

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Comparative efficacy of BAC-derived recombinant SB-1 vaccine and the parent wild type strain in preventing replication, shedding and disease induced by virulent Marek’s disease virus

A widely used vaccine against Marek’s disease (MD) in poultry is the virus SB-1, which is antigenically-related to the causative agent, Marek’s disease herpesvirus. We recently cloned the SB-1 genome as an infectious bacterial artificial chromosome, BAC, (pSB-1). The protective efficacies and replication kinetics of pSB-1 and the parent strain (SB-1) were compared in an experimental model of MD induced by a virulent strain, RB-1B. Although vaccine virus replication and shedding was lower for pSB-1 than for SB-1, both vaccines reduced replication and shedding of RB-1B, and were equally effective in protecting chickens against MD. With the cloning of pSB-1, we have now generated full length genomic clones of MD vaccine virus strains belonging to each of the three serotypes. Vaccine viruses derived from each of these clones demonstrated protective efficacies at levels similar to those produced by the respective parent viruses, demonstrating their suitability to be used as vaccine candidates.     

Impact of field fungal contamination of barley on ensiling properties,nutritional quality and the microbiome of barley silage

Barley varieties of differing fungal disease resistance were grown in triplicate plots at Lacombe and Lethbridge, Alberta with the disease resistant variety (FR) sprayed with a foliar fungicide to maximize differences in field fungal disease. Both varieties were harvested at soft dough and ensiled in minisilos to assess differences in fungal contamination on ensiling properties, nutritional quality, aerobic stability and associated bacterial and fungal microbiomes. Data were analysed as repeated measures with the effect of treatment × time (duration of ensiling or aerobic exposure) included in the model. The percentage leaf area diseased by net form net blotch was higher (p < 0.05) in the untreated barley cv. Sundre (UN, 59.1% leaf area affected at Lacombe and 25.2% at Lethbridge) than in the FR barley cv. Chigwell (0.7% leaf area affected at Lacombe and 0.1% at Lethbridge). Fungal resistant barley had a lower (p < 0.01) acid and neutral detergent fibre content. Relative abundance of Xanthomonadales was higher (p = 0.02) for FR than UN, while Lactobacillales dominated the bacterial microbiome after 60 day of ensiling in both silages. Bacillales dominated both FR and UN after 21 day of aerobic exposure. Fungal resistant fresh barley forage had a tendency (p = 0.10) for a greater relative abundance of Pleosporales, while UN had higher (p < 0.01) Hypocreales. Mould counts were lower (p = 0.01) for FR than UN after 7 day of ensiling. Fungal resistant barley had minimal influence on the fungal community that contributed to the aerobic deterioration of barley silage.     

Agroforestry as a strategy for carbon sequestration

During the past three decades, agroforestry has become recognized the world over as an integrated approach to sustainable land use because of its production and environmental benefits. Its recent recognition as a greenhouse gas–mitigation strategy under the Kyoto Protocol has earned it added attention as a strategy for biological carbon (C) sequestration. The perceived potential is based on the premise that the greater efficiency of integrated systems in resource (nutrients, light, and water) capture and utilization than single‐species systems will result in greater net C sequestration. Available estimates of C‐sequestration potential of agroforestry systems are derived by combining information on the aboveground, time‐averaged C stocks and the soil C values; but they are generally not rigorous. Methodological difficulties in estimating C stock of biomass and the extent of soil C storage under varying conditions are compounded by the lack of reliable estimates of area under agroforestry. We estimate that the area currently under agroforestry worldwide is 1,023 million ha. Additionally, substantial extent of areas of unproductive crop, grass, and forest lands as well as degraded lands could be brought under agroforestry. The extent of C sequestered in any agroforestry system will depend on a number of site‐specific biological, climatic, soil, and management factors. Furthermore, the profitability of C‐sequestration projects will depend on the price of C in the international market, additional income from the sale of products such as timber, and the cost related to C monitoring. Our knowledge on these issues is unfortunately rudimentary. Until such difficulties are surmounted, the low‐cost environmental benefit of agroforestry will continue to be underappreciated and underexploited.     

Influence of leguminous cover crops on microbial and selected enzyme activities in soils of a plantation

A study dealing with ecological sustainability of plantation based land use initiated in 1991 in a 19 yr old coconut plantation consists of growing certain leguminous crops like Atylosia, Pueraria, Centrosema and Calopogonium as soil cover in separate plots with lemon grass as live bounds. These cover crops are grown during the rainy season and incorporated into the soil towards the end of the monsoon every year. The effect of such cover crops on soil microbial counts (total counts, fungi, actinomycetes and bacteria), biomass C, organic C, total N and on the activity of enzymes like urease, amidase, L-glutaminase, aryl sulphatase and dehydrogenase was determined in soils (Ap horizon) collected from these plots after 5 years. Soils with cover crops registered significantly higher microbial biomass, biomass C, organic C and total N compared to control. Consequently, all the enzymes were activated to different degrees in soils with cover crops. Significant and positive relationships of enzyme activities with organic C, mineral N and total N suggested that growing cover crops, increased C turnover and N availability and therefore, provided a conducive environment for microbial proliferation, enzyme synthesis and accumulation in the soil matrix.     

Global scale of freshwater prawn farming

In welcoming participants to Giant Prawn 2011, the authors briefly review the current scale of this component of global aquaculture. The expansion of freshwater prawn farming over the 30 years since the first global conference on this topic [Giant Prawn 1980 (GP1980)] is examined. At the time of GP1980, the output of farmed giant river prawns (Macrobrachium rosenbergii) was <3000 t. Almost three decades later (2009) the total annual aquaculture production of all species of freshwater prawns had risen to almost 444 000 t, with a value of US$2.2 billion. The farmed production of M. rosenbergii constituted 51.7% of the global total, while the oriental river prawn M. nipponense (reared totally in China) contributed 47.2%. The contribution of the monsoon river prawn M. malcolmsonii remains quite small so far, and does not show in the above percentages because no recent FAO data are available for this species. In 2007, however, the latter species contributed 1.0% of the total global production of freshwater prawns. The major freshwater prawn producing countries are in Asia (e.g. Bangladesh, China, India, Myanmar, Taiwan, Thailand and Vietnam) but Macrobrachium spp. are also farmed in other continents.     

Agroforestry adoption in Haiti: the importance of household and farm characteristics

Most agroforestry-adoption studies are based on surveys of "non-adopters." An understanding of the circumstances that have led to a change of attitude of the adopters will be valuable in our efforts to enhance adoption rates. This study was undertaken to provide such knowledge based on a large agroforestry extension project involving 200,000 farm families and covering 25% of all rural households in Haiti. A questionnaire-based survey of the project participants was conducted covering 1,540 households and 2,295 fields in four regions of Haiti. Information was recorded about each farm and family member through interviews with farmers and visits to their farms. The results confirmed that farmers make decisions about tree culture based on household- and field characteristics. Different farmers consider trees differently depending upon how they fit into their farm-family strategy. In general, farmers installed tree hedgerows on fields of less secure tenure, of lesser fertility, and steeper slope, while on closer, more fertile fields of greater tenure security, tree seedlings and fruit trees were more common and there was a greater density of mature trees (>10 cm DBH). More money was realized from sale of tree products on actively cropped fields in more secure tenure and having more fertile soil. Older farmers managed a greater density of trees, especially when the land was in secure tenure status. This broad-based study shows that agroforestry implementation strategies in poor countries such as Haiti should be based on a thorough knowledge of how farmers use household and field characteristics to make adoption decisions. It also suggests that agroforestry-adoption studies should account for the dynamic changes occurring during extended time periods.This revised version was published online in November 2005 with corrections to the Cover Date.     

Variability for quantitative traits in exotic hybrid germplasm of sugarcane

The foreign hybrid collection of sugarcane germplasm comprising 399 clones representing 10 geographical groups, was evaluated for nine yield and quality characters, in relation to their place of origin. Discriminant function analysis showed that all the nine variables contributed significantly to the discrimination of the groups, the maximum contribution being cane height. The overall percentage of correct classification was only 48%, with a range from 32% to 73% with respect to individual groups. This suggests an underlying genetic similarity among the groups, which stem largely from their common genetic base. The exceptions were the Hawaii and Mauritius groups, which had distinct identities. The Hawaii group was the most productive group, having maximum yield and sucrose potential. The Puerto Rico group was the best source for juice sucrose. Australian varieties bred for high juice quality did not show the expected level of juice sucrose in the present study. The use in breeding programmes of Hawaiian varieties, which have a broader genetic base and high yield and quality potential, might impart better productivity to commercial varieties.