Performance of rice (Oryza sativa (L.)) under AWD irrigation practice—A brief review

Paddy and Water Environment - Alternate wetting and drying (AWD) is an irrigation technique where water is applied to the field a number of days after disappearance of ponded water. This is in...     

Concepts and perceptions of biodiversity in community forestry,Nepal

International and national development programs in Nepal place high priority on management of forests for biodiversity. Communities are expected to embrace and cooperate in this endeavour for biodiversity conservation, yet little research has been carried out to understand community viewpoints on biodiversity conservation, or even to ascertain people’s understanding of the concept of biodiversity. This paper explores perceptions and concepts related to biodiversity and its conservation held by people involved in community forestry in Nepal. Data were obtained from in-depth individual interviews and focus group discussions carried out in two contrasting geographical districts. The results show that the Western term ‘biodiversity’, translated into Nepalese as jaiwik bibidhata, is new and confusing to most forest people, who interpret the term in a variety of ways. People’s perceptions of biodiversity vary widely and a considerable gap exists between policy-makers and forest users in the understanding and interpretation of this Nepalese term and its related concepts. These findings have important implications for the design and implementation of development programs and in formulation of forest policy in Nepal.     

Effects of a microbial inoculant and(or) sugarcane molasses on the fermentation, aerobic stability, and digestibility of bermudagrass ensiled at two moisture contents.

Tifton 81 bermudagrass was harvested and ensiled either directly (D; 32.4% DM) or wilted (W; 44.1% DM). Four treatments applied to each harvesting method were 1) control (C), or no additive; 2) dried cane molasses (M) at 5% of DM; 3) microbial inoculant (I; Pioneer 1174); and 4) a combination of Treatments 2 and 3 (MI). Wilting reduced the rate of decline of silage pH (P = .001) and produced silages with greater lactic acid concentrations (P = .069), lower acetic acid (P = .001) and ammonia contents (P = .001), and greater in vitro OM (IVOMD; P = .001) and ADF digestibilities (IVADFD; P = .001). These high-quality silages were less stable under aerobic conditions, as evidenced by greater average temperatures (P = .001) and greater yeast and mold counts (P = .001). Adding M to D forage resulted in silage with lower pH (P = .001), greater concentration of lactic acid (P = .001), greater IVOMD (P = .092), and lower acetic acid (P = .009) and ammonia concentrations (P = .002) than inoculated D silage. Wilted silage treated with MI averaged lower pH (P = .025), greater lactic acid content (P = .001) and IVOMD (P = .001), and lower acetic acid (P = .001) and ammonia concentrations than silages treated with M or I alone. These results indicate that wilting improved bermudagrass silage the most, and that the addition of molasses and inoculant to wilted bermudagrass further enhanced silage quality.     

Suberin Biopolymer in Rice Root Exodermis Reinforces Preformed Barrier Against Meloidogyne graminicola Infection

Exploration of novel genetic resources against root-knot nematode (RKN) is necessary to strengthen the resistance breeding program in cultivated rice, and investigations on the role of genotype-specific root anatomy in conferring a structural barrier against nematode invasion are largely underexplored. Here, we reported a highly-resistant rice germplasm Phule Radha that conferred remarkably lower RKN parasitic fitness in terms of reduced penetration and delayed development and reproduction when compared with susceptible cultivar PB1121. Using histological and biochemical analyses, we demonstrated that an enhanced suberin deposition in the exodermal root tip tissue of Phule Radha compared to PB1121 can effectively form a penetrative barrier against RKN infection, and this preformed barrier in the control tissue did not necessarily alter to a greater extent when challenged with RKN stress. Using qRT-PCR analysis, we showed that a number of suberin biosynthesis genes were greatly expressed in the exodermis of Phule Radha compared to PB1121. In sum, the present study established the role of rice exodermal barrier system in defense against an important soil-borne pathogen.     

Microclimatic differences between young longleaf-pine silvopasture and open-pasture

Information is needed relative to changes that occur in microclimatic conditions in the early stages of open-pasture to pine silvopasture conversion in the Southeastern USA. This research tested the hypothesis that microclimatic conditions would vary between young-pine silvopasture and open-pasture. The research was conducted in a longleaf-pine (Pinus palustris Mill.)-bahiagrass (Paspalum notatum Flugge) silvopasture and adjacent open bahiagrass pasture at Americus, Georgia. Longleaf-pine was planted in the bahiagrass pasture in December 2000; the trees were not pruned or thinned until the study was completed. Microclimatic parameters (air temperature, soil temperature at 5 and 10 cm, wind speed, gust speed, wind direction, humidity, dew point, rainfall, soil-moisture content, total solar radiation, and photosynthetically active radiation) were collected from November 2005 to October 2008 using HOBO^© weather stations located in each pasture type. Data were analyzed to determine overall, as well as seasonal, monthly, and diurnal differences between pasture types. Evapotranspiration was calculated from air temperature, wind speed, relative humidity, and total solar radiation. With the exception of rainfall, overall average values for all microclimatic parameters were different between pasture types. Silvopasture had higher overall average values for air temperature, soil temperature at both depths, and soil water content, but lower values for all remaining microclimatic parameters. Seasonal, monthly, and diurnal differences between pasture types were also detected for several parameters. The results suggested that water loss can be significantly reduced in the early stages of open-pasture to longleaf-pine silvopasture conversion in the Southeastern USA.     

Differential responses of macrophages to Salmonella enterica serovars Enteritidis and Typhimurium

Macrophages are major effectors against Salmonella infection, and also transport bacteria between host tissues and provide a protected site for intracellular bacterial replication. We hypothesized that differences in chicken macrophage responses to Salmonella enterica serovar Enteritidis (SE) and serovar Typhimurium (ST) played a role in preferential infection of eggs by SE compared with ST. To test this hypothesis, we determined bacterial phagocytosis and intracellular viability and macrophage nitric oxide (NO) production following in vitro infection with SE or ST in the presence or absence of interferon-gamma (IFN-gamma). The effects of bacterial components, lipopolysaccharide (LPS), outer membrane proteins (OMP) and flagella, on NO production were also assessed. Our results showed: (1) in the presence or absence of IFN-gamma, the percentage macrophages phagocytizing SE and ST was similar; (2) the number of intracellular viable SE was significantly reduced compared with ST in the presence or absence of IFN-gamma; (3) increased macrophage necrosis was seen in the presence of IFN-gamma and ST; (4) Salmonella infection acted synergistically with IFN-gamma in induction of nitric oxide production; and (5) in the absence of IFN-gamma, macrophages produced significantly greater NO following treatment with SE outer membrane protein or flagella compared with ST OMP or flagella, while in the presence of IFN-gamma significantly less NO was produced following treatment with SE-LPS compared with ST-LPS. These results suggest that differential responses of chicken macrophages to SE versus ST may result in increased macrophage death with ST, which could result in an increased inflammatory response as compared to SE.     

Lipoxygenase Metabolites of α-linolenic Acid in the Development of Resistance in Pigeonpea, Cajanus cajan (L.) Millsp, Seedlings Against Fusarium udum Infection

Lipoxygenase (LOX) activity was measured in germinating pigeonpea Cajanus cajan seedlings, resistant (ICP-8863) and susceptible (ICP-2376) to wilt fungus, before and after infection with Fusarium udum. LOX activity was significantly higher in the resistant than in the susceptible cultivars of pigeonpea and was enhanced further in response to infection with Fusarium udum. This increase in LOX activity in the resistant cultivars of pigeonpea appears to be due to the induction of lipoxygenase isozymes in response to infection. Analysis of the endogenous LOX metabolites in pigeonpea seedlings revealed the predominant formation of 13-hydroperoxyoctadecadienoic acid (13-HPODE) in healthy seedlings and 13-hydroperoxyoctadecatrienoic acid (13-HPOTrE) in infected seedlings. Further studies on the effects of LOX metabolites on the growth and multiplication of Fusarium udum showed that HPOTrEs, LOX metabolites of -linolenic acid, are more anti-fungal compared to HPODEs, LOX metabolites of linoleic acid.     

Metabolic responses of juvenile GIFT strain of Nile tilapia (Oreochromis niloticus) to dietary L‐tryptophan supplementation

A 60‐day indoor feeding trial was conducted to evaluate the effects of dietary tryptophan supplementation on growth performances, whole‐body chemical composition, expression of muscle growth‐related genes (MyoD, myogenin and myostatin), and haematological and biochemical responses of juvenile genetically improved farmed tilapia (GIFT). Five corn–soy‐based isonitrogenous and isoenergetic diets were formulated to contain graded levels of dietary tryptophan (2.6, 3.2, 3.7, 4.2 and 4.8 g/kg of diet). Each diet was randomly assigned to triplicate groups of 30 fish (5.3 ± 0.1 g) per experimental unit, which were fed thrice a day (9:00, 13:00 and 17:00 hr). Maximum growth performances and feed utilization were observed in fish fed tryptophan at 3.7 g/kg of diet. There was no significant (p > .05) effect on whole‐body composition and amino acid profile by dietary tryptophan supplementation. However, significant (p < .05) differences were observed in plasma metabolites and the mRNA expression of MyoD, myogenin and myostatin. Serum cortisol level was found significantly lowest in fish fed tryptophan at 3.7 g/kg of diet. Second‐order polynomial regression analysis of weight gain and nitrogen gain against dietary tryptophan levels indicated that the optimum dietary tryptophan requirement for maximum growth and feed utilization of juvenile GIFT tilapia was 3.8 g/kg of diet.     

Applications of Genie Male Sterility in Plant Breeding

The possible applications of genie male sterility (GMS) in plant breeding arc reviewed and discussed. The basic contribution of GMS is that it provides a means of genetic emasculation which can be applied for the massive production of hybrids. There are two main fields of application: (1) the production of hybrid varieties and (2) inter- and intraspecific hybridization and back-crossing programmes for the introduction of genetic variation into crop varieties. Several schemes have been proposed for using GMS in hybrid breeding in different crops. These are discussed under four headings: genetic methods, cy-togenetic methods, temporary restoration of fertility and manual pollination. The application of GMS in hybridization intended for the introduction of alien genes is discussed as well as factors affecting the pollination of genie male steriles.     

Equilibrium and Kinetic Studies on Biosorption of Heavy Metals by Leaf Powder of Paper Mulberry (Broussonetia papyrifera)

Paper mulberry (Broussonetia papyrifera) leaf powder was used to remove heavy metal ions from aqueous solutions. The specific uptakes of Cu (II), Pb (II), and Cd (II) by the leaf powder were 43.40?±?0.2, 43.9?±?0.5, and 30.65?±?0.9 mg g^?1, respectively, when 500 mg L^?1 of the metal solutions were used. The data fitted well to the Langmuir isotherm. The process followed the pseudo-second-order kinetic equation and intraparticle diffusion played an important role in the adsorption process. On the basis of the calculated thermodynamic parameters such as standard enthalpy (??H°), entropy (??S°) and free energy change (??G°), it was inferred that the sorption process was endothermic and spontaneous in nature. The surface properties of the leaf powder (revealed by scanning electron microscopic observations) were suitable for the metal adsorption process. Energy dispersive X-ray fluorescence analysis confirmed the sequestration of the metal ions by the leaf powder. Fourier transform infrared spectroscopy implicated that different functional groups on the leaf powder were involved in the metal adsorption process. The results obtained from this study implicated that the B. papyrifera leaf powder was a good choice as a metal adsorbent. This abundantly available natural and eco-friendly biosorbent could be effectively used to develop a technology in the future.