Seed abortion in Pongamia pinnata (Fabaceae)

In Pongamia pinnata only one of the two ovules develops into a seed in most of the pods. Since pollen was not found to be limiting and reduced fertilization could not completely explain the observed frequency of seed abortion, it implied an effect of postfertilization factors. Aqueous extracts of developing seeds and maternal tissue (placenta) did not influence abortion in vitro, suggesting that abortion may not be mediated by a chemical. Experimental uptake of 14C sucrose in vitro indicated that both the stigmatic and the peduncular seed have similar inherent capacities of drawing resources, but the peduncular seed is deprived of resources in the presence of the stigmatic seed. This deprivation of the peduncular seed could be offset by supplying an excess of hormones leading to the subsequent formation of two seeds in a pod. The prevalence of single-seeded pods in P. pinnata seems therefore to be a result of competition between the two seeds for maternal resources. The evolutionary significance of single-seeded pods in P. pinnata is discussed with respect to possible dispersal advantage enjoyed by such pods

Characterization and classification of major coconut growing soils in South Eastern Ghats of Tamil Nadu, India

Six soil series representing major coconut growing soils of the Eastern Ghats in Krishnagiri district of Tamil Nadu State, India, were evolved from granite gneiss and alluvium parent materials. Characterization of different soil properties was done using a detailed soil survey at 1:10000 scale. The soils were neutral to moderately alkaline in reaction (7.31 to 9.19), non-saline, poor to moderately well-drained and moderately shallow (<75 cm) to very deep (>150 cm) in depth. The soils were sandy to clay in texture, sub-angular blocky to crumb in structure, dark reddish-brown to brown, very low to high in OC content (0.06 to 2.70%), low to medium in AWC (3.44 to 22.39%), low to high in CEC (4.70 to 54.0 cmol (p+) kg-1) and having high base saturation (77 to 100%). The soils also had sizable amounts of exchangeable sodium (4.29 to 33.46%), which was maximum in P5, P6 and P1, and high clay content in P5 and P2. The distribution of CaCO3 in different depths was found to be maximum in P4 and P1. The soil orders identified in the coconut area were Inceptisols, Entisols, Alfisols and Vertisols. Assessment of soil resources and identification of yield-limiting soils factors on coconut could be by way of better management and improved productivity

Soil fertility status of coconut and arecanut growing soils

The present study was undertaken to assess the soil fertility status of major coconut and arecanut growing soils in different agro-climatic conditions of Karnataka. Based on the agro-climate variability, thirty typical soil pedons representing five different agro-climatic zones (ACZs) of Karnataka, namely, eastern dry zone (EDZ), southern dry zone (SDZ), southern transitional zone (STZ), hilly zone (HZ), and coastal zone (CZ) were studied for their physicochemical properties. The study revealed that soils of semi-arid (EDZ and SDZ) and sub-humid (STZ) zones have near neutral to moderately alkaline reaction and humid region soils (coastal and hilly zones) have high acidity. The soils are non-saline with low cation exchange capacity. Greater soil organic carbon was recorded in arecanut soils than coconut under all ACZs except coastal zone. The major nutrients status of the soil samples indicated that the available nitrogen is low in all the pedons; the pooled data of available nitrogen content was higher in arecanut (166.3 kg ha-1) than coconut (152.6 kg ha-1), and hilly zone soils recorded higher available nitrogen. A wide range of available P2O5 was noticed in coconut and arecanut soils, ranging from 1.0 to 64.2 kg ha-1. The coconut soils (11.5 kg ha-1) recorded higher available P2O5 than arecanut soils (9.62 kg ha-1) when data were pooled. The soils were low to medium in available potassium, and a higher available K2O content was recorded in arecanut soils (151.7 kg ha-1) compared to coconut (110.1 kg ha-1). The available K2O ranged from 66.8 to 511.7 kg ha-1 in the surface and 37.6 to 461.2 kg ha-1 in sub-surface soils

Preparation of Silver Decorated Reduced Graphene Oxide Nanohybrid for Effective Photocatalytic Degradation of Indigo Carmine Dye

Background: Even though silver decorated reduced graphene oxide (Ag-rGO) shows max- imum absorptivity in the UV region, most of the research on the degradation of dyes using Ag-rGO is in the visible region. Therefore the present work focused on the photocatalytic degradation of indigo carmine (IC) dye in the presence of Ag-rGO as a catalyst by UV light irradiation. Methods: In this context, silver-decorated reduced graphene oxide hybrid material was fabricated and explored its potential for the photocatalytic degradation of aqueous IC solution in the UV region. The decoration of Ag nanoparticles on the surface of the rGO nanosheets is evidenced by TEM analysis. The extent of mineralization of the dye was measured by estimating chemical oxygen demand (COD) values before and after irradiation. Results: The synthesized Ag-rGO binary composites displayed excellent photocatalytic activity in 2 Χ 10-5 M IC concentration and 5mg catalyst loading. The optical absorption spectrum of Ag-rGO showed that the energy band-gap was found to be 2.27 eV, which is significantly smaller compared to the band-gap of GO. 5 mg of Ag-rGO was found to be an optimum quantity for the effective degrada- tion of IC dye. The degradation rate increases with the decrease in the concentration of the dye at al- kaline pH conditions. The photocatalytic efficiency was 92% for the second time. Conclusion: The impact of the enhanced reactive species generation was consistent with higher pho- tocatalytic dye degradation. The photocatalytic mechanism has been proposed and the hydroxyl radi- cal was found to be the reactive species responsible for the degradation of dye. The feasibility of reus- ing the photocatalyst showed that the photocatalytic efficiency was very effective for the second tim

Negative diffraction pattern dynamics in nonlinear cavities with left-handed materials

We study a ring cavity filled with a slab of a right-handed material and a slab of a left-handed material. Both layers are assumed to be nonlinear Kerr media. First, we derive a model for the propagation of light in a left-handed material. By constructing a mean-field model, we show that the sign of diffraction can be made either positive or negative in this resonator, depending on the thicknesses of the layers. Subsequently, we demonstrate that the dynamical behavior of the modulation instability is strongly affected by the sign of the diffraction coefficient. Finally, we study the dissipative structures in this resonator and reveal the predominance of a two-dimensional up-switching process over the formation of spatially periodic structures, leading to the truncation of the homogeneous hysteresis cycle.Comment: 8 pages, 5 figure

Metabolic pathway genes for editing to enhance multiple disease resistance in plants

Diseases are one of the major constraints in commercial crop production. Genetic diversity in varieties is the best option to manage diseases. Molecular marker-assisted breeding has produced hundreds of varieties with good yields, but the resistance level is not satisfactory. With the advent of whole genome sequencing, genome editing is emerging as an excellent option to improve the inadequate traits in these varieties. Plants produce thousands of antimicrobial secondary metabolites, which as polymers and conjugates are deposited to reinforce the secondary cell walls to contain the pathogen to an initial infection area. The resistance metabolites or the structures produced from them by plants are either constitutive (CR) or induced (IR), following pathogen invasion. The production of each resistance metabolite is controlled by a network of biosynthetic R genes, which are regulated by a hierarchy of R genes. A commercial variety also has most of these R genes, as in resistant, but a few may be mutated (SNPs/InDels). A few mutated genes, in one or more metabolic pathways, depending on the host–pathogen interaction, can be edited, and stacked to increase resistance metabolites or structures produced by them, to achieve required levels of multiple pathogen resistance under field conditions

Effect of storage methods and seed rhizome treatment on the field performance of ginger

An experiment was conducted to evaluate the effect of different storage methods and seed rhizome treatment on the field performance of ginger var. Humnabad. Four storage methods were selected for the study viz., rhizomes kept in sand layers (indoor), 250 gauge polyethylene bag with 0.5% vents (indoor), Zero energy cool chamber (ZECC) either in open condition or in polyethylene bag with 0.5% vents. The seed rhizomes were treated with fungicide viz., Ridomil MZ (3 g L-1), bio-control agent Trichoderma harzianum (5 g kg-1 seed rhizome) and no seed treatment as the control. Highest germination (98.89%), plant height (52.3 cm), leaf area index (25.75), number of tillers clump-1 (19.7), pseudostem girth (3.41 cm) and fresh rhizome yield (22.35 t ha-1) were recorded in rhizome stored in ZECC treated with T. harzianum whereas, the rhizome stored in sand layer with no seed treatment recorded the lowest levels of germination (75.56%), plant height (33.6 cm), leaf area index (9.73), number of tillers clump-1 (12.6), pseudostem girth (2.32 cm) and fresh rhizome yield (11.84 t ha-1). &nbsp

Definitions of Violence: African-American and Iraqi Refugee Adolescents\u27 Perceptions

This article explores the perceptions of urban African-American and Iraqi refugee adolescents regarding community violence, school violence, family violence and dating/intimate partner violence. A subset of participants from a larger study on violence and trauma was selected to participate in the current study. Using a card-sort exercise, participants identified situations as violent or not violent. Iraqi youth identified noticeably more behaviors as violence than African-American youth. Few significant gender differences emerged. Findings of important cultural differences provide implications for violence prevention programming

Fishes and Corals of the World Listed in CITES Appendices

The first global 'Census of Marine Life (2010)' estimated that there are over 2, 30,000 species of organisms living in our Oceans. This census has analyzed the diversity, distribution and abundance of life in the world's oceans. It has been revealed that, the marine life is highly biologically diverse and it has been explored only partially so far. It is estimated that there are almost 22,000 fish species in the world, which is more than the total number of mammals, reptiles, amphibians, and birds combined and every year 100 new species are added to this list. Fish are divided into two major types. The first type is cartilaginous fish, which includes Sharks, Skate and Rays. The second type is the bony fish, which have a complete bony skeleton and are covered with bony scales. Bony fishes are the most common and account for over 90% of all fish.With all this diversity within; the ocean is a major contributor for the world food production. According to FAO (2010), the total world fish production has touched 88 million tons, out of which, inland capture fisheries contributed 11 million tons and the oceans contributed the rest of 77million ton