Portals of Entry for Gram-Negative Bacteria in a Freshwater Prawn Hatchery

We sought the source of gram-negative bacteria associated with giant freshwater prawns in a hatchery that was previously observed with severe mortality of prawn larvae during the sixth to seventh zoea stages. After thorough disinfection, the gram-negative bacterial microflora of broodstock, larvae, larval rearing tank (LRT) water, and other intake systems were examined for bacteria. Enterobacteriaceae and Vibrio were the major bacteria isolated from the larvae. The present study suggests that Enterobacteriaceae may be introduced via the broodstock and Vibrio via the LRT water.     

Role of soil physicochemical characteristics on the present state of arsenic and its adsorption in alluvial soils of two agri-intensive region of Bathinda,Punjab, India

Journal of Soils and Sediments - Arsenic (As) contamination of groundwater has received significant attention recently in district Bathinda, due to consequent health risk in this region. Soil is...     

Genetics,genomics and breeding of groundnut (Arachis hypogaea L.)

Groundnut is an important food and oil crop in the semiarid tropics, contributing to household food consumption and cash income. In Asia and Africa, yields are low attributed to various production constraints. This review paper highlights advances in genetics, genomics and breeding to improve the productivity of groundnut. Genetic studies concerning inheritance, genetic variability and heritability, combining ability and trait correlations have provided a better understanding of the crop's genetics to develop appropriate breeding strategies for target traits. Several improved lines and sources of variability have been identified or developed for various economically important traits through conventional breeding. Significant advances have also been made in groundnut genomics including genome sequencing, marker development and genetic and trait mapping. These advances have led to a better understanding of the groundnut genome, discovery of genes/variants for traits of interest and integration of marker‐assisted breeding for selected traits. The integration of genomic tools into the breeding process accompanied with increased precision of yield trialing and phenotyping will increase the efficiency and enhance the genetic gain for release of improved groundnut varieties.     

Evaluation of fipronil nanoformulations for effective management of brown plant hopper (Nilaparvata lugens) in rice

In this paper, we report the development, characterization and bioefficacy evaluation of fipronil nanoformulations against brown plant hopper (BPH); Nilaparvata lugens in rice. Nanoformulations were characterized for nanosizing and stability under variable conditions. Bioefficacy of nanoformulations were evaluated under field condition at farms of Indian Agricultural Research Institute, New Delhi during Kharif 2015. At milking stage BPH populations were above economic threshold level; followed by foliar application of fipronil nanoformulations at four doses (viz., 30, 45, 60 and 90 g a.i./ha) along with commercial formulation of fipronil. The mean mortality clearly indicated that all the insecticidal treatments were significantly superior over untreated control where, highest mortalities were observed in nanodispersions followed by monolithic dispersion and commercial formulation of fipronil. Treated plots 7 days after application @ 60 g a.i./ha has shown 93.47%, 86.89% and 80.47% reduction BPH population in nanodispersion, encapsulated monolithic dispersion and commercial formulation treated plots respectively. In comparison to commercial formulation @ 60 g a.i./ha yield has increased by 0.56 t ha^?1 (28.76%) and 0.26 t ha^?1 (14.04%) in nanodispersion and monolithic dispersion.     

Development of NILs from heterogeneous inbred families for validating the rust resistance QTL in peanut (Arachis hypogaea L.)

Heterogeneous inbred families segregating for rust resistance were identified from the two crosses involving susceptible (TAG 24 and TG 26) and resistant (GPBD 4) varieties of peanut. Rust‐resistant (less than score 5) and rust‐susceptible (more than score 5) plants were identified in each HIF and evaluated under rust epiphytotic conditions. The set of plants belonging to the same HIF, but differing significantly in rust resistance, not in other morphological and productivity traits, was regarded as near‐isogenic lines (NILs). Largely, rust‐resistant NILs had GPBD 4‐type allele, and susceptible NILs carried either TAG 24 or TG 26‐type allele at the three SSR loci (IPAHM103, GM1536 and GM2301) linked to a major genomic region governing rust resistance. Comparison of the remaining genomic regions between the NILs originating from each of the HIFs using transposon markers indicated a considerably high similarity of 86.4% and 83.1% in TAG 24 × GPPBD 4 and TG 26 × GPBD 4, respectively. These NILs are useful for fine mapping and expression analysis of rust resistance.     

Elevation dependent sensitivity of northern hardwoods to Ca addition at Hubbard Brook Experimental Forest,NH, USA

Acidic deposition has caused a depletion of calcium (Ca) in the northeastern forest soils. Wollastonite (Ca silicate) was added to watershed 1 (WS1) at the Hubbard Brook Experimental Forest (HBEF) in 1999 to evaluate its effects on various functions of the HBEF ecosystem. The effects of Ca addition on foliar soluble (extractable in 5% HClO₄) ions, chlorophyll, polyamines, and amino acids were studied in three hardwood species, namely sugar maple, yellow birch, and American beech. We further analyzed these effects in relation to elevation at Ca-supplemented WS1 and reference WS3 watersheds. Foliar soluble Ca increased significantly in all species at mid and high elevations at Ca-supplemented WS1. This was accompanied by increases in soluble P, chlorophyll, and two amino acids, glutamate and glycine. A decrease in known metabolic indicators of physiological stress (i.e., the amino acids, arginine and γ-aminobutyric acid (GABA), and the diamine, putrescine) was also observed. In general, these changes were species-specific and occurred in an elevation dependent manner. Despite an observed increase in Ca at high elevation for all three species, only sugar maple exhibited a decrease in foliar putrescine at this elevation indicating possible remediation from Ca deficiency. At higher elevations of the reference WS3 site, foliar concentrations of Ca and Mg, as well as Ca:Mn ratios were lower, whereas Al, putrescine, spermidine, and GABA were generally higher. Comparison of metabolic data from these three species reinforces the earlier findings that sugar maple is the most sensitive and American beech the least sensitive species to soil Ca limitation. Furthermore, there was an increase in sensitivity with an increase in elevation.     

Variation in oil content and fatty acid profile of Calophyllum inophyllum L. with fruit maturity and its implications on resultant biodiesel quality

Variation in oil content and fatty acid profile (FAP) of Calophyllum inophyllum; a potential biodiesel feedstock species were studied at different maturity stages and biodiesel quality parameters were estimated based on the FAP. A steady increase in oil content was observed with maturity. Variation in palmitic (16:0) and linoleic (18:2) acids followed exactly opposite trends where palmitic acid content has decreased and linoleic acid content has increased 77 days after anthesis. Oleic acid (18:1) content has shown a steady increase. Stearic acid (18:0) content remained steady up to 68 days after anthesis and then felt slightly in 77 days after anthesis. Linoleic and eicosanoic acids were found to exist in low concentrations demonstrated very little compositional variation with fruit maturity. Estimated biodiesel parameters of all maturity stages were found to comply with industrial standards. Even though 48 days after anthesis had the most ideal FAP for biodiesel production, ∼77 days after anthesis is preferred point to harvest due to higher oil content.     

高油和普通玉米自交系类胡萝卜素和生育酚含量的比较分析

建立了利用高效液相色谱法同时测定玉米籽粒类胡萝卜素和生育酚各组分含量的技术体系,分析了112份黄色胚乳玉米自交系的类胡萝卜素和生育酚含量,其中包括32份高油自交系和80份在生产上广泛应用的普通玉米自交系。结果表明,不同自交系间存在广泛的变异,各组分含量变幅最大的是α-生育酚,含量相差达162倍;变幅最小的是δ-生育酚,含量相差也接近4倍。类胡萝卜素各组分含量在高油和普通玉米自交系之间并没有显著差异,但普通玉米的变异范围更为广泛;高油玉米生育酚各组分含量显著高于普通玉米,其中γ-生育酚、α-生育酚和总生育酚含量的均值分别是普通玉米均值的2.4、2.5和2.4倍。尽管供试的高油玉米材料仅32份,但其生育酚的某些组分比普通玉米具有更广泛的遗传变异。这为进一步的玉米高油、高维生素A原、高维生素E,即“三高”品质成分育种提供了有益参考。