Long-term organic nutrient managements foster the biological properties and carbon sequestering capability of a wetland rice soil

Monitoring the qualitative and quantitative changes of soil organic carbon (SOC) is very much essential to keep the soil viable and productive for long-term sustainability. Impact of long-term (36 years) enforcement of organic and inorganic nutrient management practices on changes in physio-chemical, microbiological properties and enzymatic activities of flooded rice soil was assessed along with soil carbon pools. The results revealed that the fractions of SOC, microbial biomass carbon, culturable microbial counts and dehydrogenase and β-glucosidase activities increased significantly in green manure amended soil. The population of functional microbial groups, namely denitrifiers and methanotrophs was high in farm yard manure applied soil, while methanogens population was high in green manure application. Higher nitrifier population was evident in inorganic or integrated organic and inorganic fertilizer. Continuous application of recommended levels of chemical fertilizers did not greatly affect biological activities in the soil. Fourier Transform Infrared Spectroscopy analysis of humic acid revealed that organic fertilized soil fractions were more aliphatic with greater diversity than did the inorganic fertilized soil fractions. This study emphasizes the importance of organic manure and underscores the recommended dose of inorganic fertilizer to maintain the soil biological properties in flooded rice soil.     

Effect of Different Feeding Levels of Plant‐ingredient‐based Feed on Fillet Fatty Acid Profile,Carcass Trait,and Sensory Characteristics of Indian Major Carps in Earthen Pond Polyculture

The objective of the present study was to evaluate the effect of plant‐ingredient‐based feeds on fillet fatty acid profiles, proximate composition, carcass traits, and sensory characteristics of three Indian major carps (IMCs), Catla catla, Labeo rohita, and Cirrhinus mrigala, when fed at different levels of their body weight. An experimental feed was prepared with only plant ingredients. The IMCs were fed twice daily at 1.0, 1.5, 2.0, and 2.5% of their body weight for 150 d in 0.06‐ha earthen pond polyculture systems. The maximum growth and best feed utilization was achieved with feeding at 2% of fish biomass in the ponds. Fillet yield and lipid recovery increased significantly (P < 0.05), with increasing feeding level up to 2% of body weight and plateaued thereafter. In fillets, eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) concentration increased with increasing feeding levels. Carcass traits, sensory characteristics, and consumer acceptance of IMC fillets were not influenced by feeding plant‐ingredient‐based feeds at different feeding rates.     

High prevalence and genotypes of Toxoplasma gondii isolated from organic pigs in northern USA

The ingestion of undercooked pork infected with Toxoplasma gondii is considered an important source of transmission of this parasite. While T. gondii infection in confinement raised market pigs (market pigs are typically used for fresh, unprocessed pork products) in the USA has decreased significantly over the last 20 years, infection levels in pigs with access to the outdoors can be quite high. An upsurge in consumer demand for 'organically raised', 'humanely raised' and 'free range' pork products has resulted in increasing numbers of hogs being raised in non-confinement systems. To determine T. gondii infection rate in these organic pigs, prevalence of T. gondii in organically raised pigs in two establishments (Farm 1, Farm 2) in Michigan was investigated. Serum and tissue samples from 33 pigs on the farm were available for T. gondii evaluation at slaughter. Serological testing was performed using both ELISA and the modified agglutination test (MAT). Antibodies to T. gondii were detected by both ELISA and MAT in 30 of 33 animals with MAT titers of 1:25 in three, 1:50 in six, 1:100 in seven, 1:200 in 13, and 1:400 in one. Hearts of all 33 pigs were bioassayed for T. gondii in mice; T. gondii was isolated from 17 pigs including one from a seronegative (both ELISA and MAT) pig. Genetic typing of 16 of the 17 T. gondii isolates using the SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico loci revealed clonal Type II from Farm 1 and clonal Type III on Farm 2. These results revealed very high prevalence of T. gondii in organic pigs for the first time in USA, indicating potentially increased health risk of consuming organic swine products.     

Effect of arsenic (As) and lead (Pb) on glycogen content and on the activities of selected enzymes involved in carbohydrate metabolism in freshwater catfish,Heteropneustes fossilis

Heavy metals show a wide range of effect on fishes, out of which arsenic (As) and lead (Pb) are among the leading heavy metal toxicants. These heavy metals are known to alter different biochemical parameters, including glycogen level, in different tissues of fishes. Glycogen level in fish serves as the main source of energy; hence, in this study, the acute toxicity test of As and Pb and their effect on the glycogen content and the enzymes involved therein (glycogen phosphorylase, glycogen synthase, hexokinase, phosphofructokinase and pyruvate kinase) were studied in the liver and muscle tissues of Heteropneustes fossilis. The 96 h LC50 values of As2O3 and PbCl2 on H. fossilis were found to be 35.09 ppm and 66.20 ppm, respectively. On acute exposure to 96 h LC50 values of As2O3 and PbCl2, the glycogen concentration showed a gradual decrease in both liver and muscle tissues of H. fossilis. However, on chronic exposure (LC50/20th ppm), the glycogen content in liver and muscle of H. fossilis was depleted till 20 days; whereas after 30 days, the glycogen level was recovered in both the tissues. The activities of glycogen metabolic enzymes (glycogen phosphorylase and glycogen synthase) and few selected glycolytic enzymes (hexokinase, phosphofructokinase and pyruvate kinase) were also altered in H. fossilis when exposed to acute and chronic concentration of As2O3 and PbCl2. Our present results showed that As and Pb induced toxicity stress on the catfish, H. fossilis, which might have caused to alter the carbohydrate metabolism in the fish.     

Curcumin, a major constituent of turmeric, corrects cystic fibrosis defects

Cystic fibrosis is caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). The most common mutation, DeltaF508, results in the production of a misfolded CFTR protein that is retained in the endoplasmic reticulum and targeted for degradation. Curcumin is a nontoxic Ca-adenosine triphosphatase pump inhibitor that can be administered to humans safely. Oral administration of curcumin to homozygous DeltaF508 CFTR mice in doses comparable, on a weight-per-weight basis, to those well tolerated by humans corrected these animals' characteristic nasal potential difference defect. These effects were not observed in mice homozygous for a complete knockout of the CFTR gene. Curcumin also induced the functional appearance of DeltaF508 CFTR protein in the plasma membranes of transfected baby hamster kidney cells. Thus, curcumin treatment may be able to correct defects associated with the homozygous expression of DeltaF508 CFTR.     

Efficient inhibition of the Alzheimer's disease beta-secretase by membrane targeting

beta-Secretase plays a critical role in beta-amyloid formation and thus provides a therapeutic target for Alzheimer's disease. Inhibitor design has usually focused on active-site binding, neglecting the subcellular localization of active enzyme. We have addressed this issue by synthesizing a membrane-anchored version of a beta-secretase transition-state inhibitor by linking it to a sterol moiety. Thus, we targeted the inhibitor to active beta-secretase found in endosomes and also reduced the dimensionality of the inhibitor, increasing its local membrane concentration. This inhibitor reduced enzyme activity much more efficiently than did the free inhibitor in cultured cells and in vivo. In addition to effectively targeting beta-secretase, this strategy could also be used in designing potent drugs against other membrane protein targets.     

Development of a DNA marker for distinguishing CMS lines from fertile lines in rice (Oryza sativa L.)

The main objective of the present study was to identify mitochondrial DNA based marker, which can distinguish male sterile and fertile counterparts of the cytoplasmic male sterile (CMS) lines used in production of rice hybrids. Amplified fragment length polymorphism (AFLP) analysis in CMS lines: IR58025A & IR62829A and their respective maintainers: IR58025B & IR62829B identified a polymorphic DNA fragment of about 510 bp size that was present in both CMS (A) and absent in their maintainer (B) lines. Sequencing followed by database analysis of the polymorphic fragment indicated about 97% similarity with mitochondrial NADH gene subunits of rice, maize and wheat. Based on the variable sequence regions, a site specific primer pair (BF-STS-401) was designed. PCR analysis showed that BF-STS-401 could amplify a strong band of 464 bp size in CMS and a faint band of the same size in maintainer line. To act as a positive control and avoid possible errors in PCR, BF-STS-401 was multiplexed with a new primer pair (BF-STS-402), derived from mitochondrial atp9 subunit of rice, producing monomorphic amplification indiscriminately in both CMS and maintainer lines. Both the primer pairs in combination clearly differentiated CMS lines from their corresponding maintainer lines. This primer combination was validated in a set of diverse genotypes consisting of different sources of CMS lines, restorer lines, hybrids, varieties and mixed samples from private seed companies. Our results suggested that the multiplex primer pairs developed in this study can be effectively utilized to assess the genetic purity in commercial seed lots of CMS lines and hybrids of rice.     

Genetics of resistance to Sesamia inferens infestation and its correlation with yield in maize

Sesamia inferens (Walker) causes 25.7–78.9% losses in maize production in South and South‐East Asia. The genetic basis of host plant resistance is the prerequisite for resistance breeding. Twenty‐four populations derived from S. inferens resistant × susceptible inbreds were used to study the genetic regulation of resistance to S. inferens in maize, to determine the importance of genetic effects through generation mean analysis (GMA) and to understand correlation between resistance and yield. Resistant and susceptible inbreds differed significantly in leaf and stem injury ratings (LSIR), a measure of host plant resistance. Mean LSIR range among resistant and susceptible parents was 2.15–2.55 and 7.83–8.22, respectively. The broad‐sense heritability ranged from 0.40 to 0.71, and the mean number of effective factors ranged from 1.9 to 2.6. The resistance against S. inferens was largely governed by additive × additive (i), followed by dominance (d) and additive (a) gene effects. Significant negative correlation (?0.27 to ?0.96) was observed between LSIR and yield. The findings suggest reciprocal recurrent selection for development of new inbreds with resistance followed by their involvement in hybrid development to exploit additive and non‐additive gene effects/variance.     

Detection of occurrence of a recent genetic bottleneck event in Indian hill cattle breed Bargur using microsatellite markers

The effective number of breedable individuals is a crucial determinant for maintaining genetic variability within a population. The population of Bargur, the hill cattle of South India, has gone down drastically by more than 93 % in the past three decades, and only a few thousand animals are available at present. The present study was undertaken to evaluate Bargur cattle for mutation drift equilibrium and to detect the occurrence of recent genetic bottleneck event, if any, in this population. About 50 unrelated animals, true to the type, were sampled and genotyped at 25 microsatellite loci. The mean observed heterozygosity (0.808?±?0.023) was higher than the mean expected heterozygosity (0.762?±?0.008) with 15 out of 25 microsatellite loci exhibiting heterozygosity excess when assumed under Hardy–Weinberg equilibrium. To evaluate Bargur cattle for mutation drift equilibrium, three tests were performed under three different mutation models, viz., infinite allele model (IAM), stepwise mutation model (SMM) and two-phase model (TPM). The observed gene diversity (H _e) and expected equilibrium gene diversity (H _eq) were estimated under different models of microsatellite evolution. All the 25 loci were found to exhibit gene diversity excess under IAM and TPM, while 22 loci were having gene diversity excess under SMM. All the three statistical tests, viz., sign test, standardized differences test, and Wilcoxon sign rank test, revealed significant (P?<?0.01) deviation of Bargur cattle population from mutation-drift equilibrium under all the three models of mutation. Furthermore, the qualitative test of allele frequency distribution in Bargur cattle population revealed a strong mode shift from the normal L-shaped form suggesting that the population had experienced genetic bottleneck in the recent past. The occurrence of genetic bottleneck might have led to the loss of several rare alleles in the population, which point towards the need for efforts to conserve this important cattle germplasm. The present study is the first report in demonstrating the genetic basis of demographic bottleneck in an Indian cattle population.