First information on heterotic groups in pigeonpea [Cajanus cajan (L.) Millsp.]

To break the decades-old yield barrier in pigeonpea [Cajanus cajan (L.) Millsp.] a hybrid breeding technology was successfully developed and the first two hybrids were recently released in India. In order to produce heterotic hybrid combinations, the first logical step is the identification and selection of genetically diverse parents with favorable alleles. In this context, the concept of classifying hybrid parents into different heterotic groups was developed and successfully used in maize and later adopted in other crops. Since hybrid technology in pigeonpea is new, the authors have made the first attempt to identify heterotic groups using SCA effects of 102 crosses generated from line × tester mating and evaluated them at four locations. Based on the performance of hybrids in terms of SCA effects, seven heterotic groups were constituted. Besides this, a scheme to use this information in breeding high yielding hybrids with specific or wide adaptation is also discussed herein. Genetic diversity between lines and tester showed positive association with the heterotic pools generated on the basis of SCA.     

Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats

Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions.     

Estimating carbon sequestration potential of existing agroforestry systems in India

India launched National Agroforestry Policy on 10th February, 2014 which has the potential to substantially reduce poverty in rural India and revive wood based industry, besides integrating food production with environmental services. The policy is not only crucial to India’s ambitious goal of achieving 33 per cent forest and tree cover but also to mitigate GHG emissions from agriculture sector. Dynamic CO2FIX-v3.1 model has been used to estimate the carbon sequestration potential (CSP) of existing agroforestry systems (AFS) for simulation period of 30 years in twenty six districts from ten selected states of India. The observed number of trees on farmers’ field in these districts varied from 1.81 to 204 per hectare with an average value of 19.44 trees per hectare. The biomass in the tree component varied from 0.58 to 48.50 Mg DM ha^?1, whereas, the total biomass (tree and crop) ranged from 4.96 to 58.96 Mg DM ha^?1. The soil organic carbon ranged from 4.28 to 24.13 Mg C ha^?1. The average estimated carbon sequestration potential of the AFS, representing varying edapho-climatic conditions, on farmers field at country level was 0.21 Mg C ha^?1yr^?1. At national level, existing AFS are estimated to mitigate 109.34 million tons CO₂ annually, which may offsets one-third (33 %) of the total GHG emissions from agriculture sector.     

Bacterial Transport from Agricultural Lands Fertilized with Animal Manure

A plot scale study was conducted to determine bacterial transport in runoff from cropland treated with poultry litter and dairy manure applied at phosphorus (P) agronomic rates. Treatments included surface application of dairy manure, surface application of poultry litter, incorporation of dairy manure and control. A rainfall simulator was used to induce runoff 1 and 2 days after manure application. Runoff was analyzed to determine the concentration of indicator bacteria-fecal coliform, Escherichia coli, and Enterococcus. Observed edge-of-field bacterial concentrations were 10² to 10⁵ times higher than Virginia’s in-stream bacteria criteria for primary contact recreation waters. No significant treatment effects were observed on edge-of-field bacteria concentration or yield. Results suggest that the manure application based on agronomic P rates may yield significant bacterial loading to downstream waterbodies if rainfall occurs soon after manure application. This research underscores the need for BMPs that reduce runoff volumes and filter pollutants associated with animal manures.     

Observations on the occurrence of nematophagous fungi in Scotland

A total of 54 nematophagous fungi were isolated from soil samples from 4 different types of habitats in Edinburgh, Scotland. Nematode-trapping fungi included 11 species of Arthrobotrys, 2 each of Dactylellina and Drechslerella and 3 of Stylopage. Fifteen species of endoparasites were isolated. The highest frequency of occurrence in terms of habitat was of Arthrobotrys gephyropaga and Drechslerella brochopaga among predators and that of Harposporium anguillulae among endoparasites. This study indicates equal distribution of both predatory and endoparasitic fungi.     

Brugia malayi: status of host during different stages of infection

The status of glycogen, protein, lipid components, lipid peroxides and a few enzymes of energy metabolism was studied in liver of Mastomys natalensis during the development of Brugia malayi infection. Glycogen and lipid contents were decreased during the patent phase of infection while total protein was slightly altered in latent animals. Phospholipid and triglyceride contents declined at prepatent and patent phase of infection. The levels of lactate and malate dehydrogenases, as well as of adenosine triphosphatases (Na+K+, Mg2+, Ca2+), were significantly elevated and monoamine oxidase activity was decreased at patent phase of infection, while succinic dehydrogenase remained unaltered. The lipid peroxide formation was enhanced in liver during the development of filarial infection.     

Effect of thiourea on the histopathology and the reproductive performance of the male flesh fly Sarcophaga ruficornis (Fabr.)

When newly emerged and 24-hour-old male flesh flies Sarcophaga ruficornis (Fabr.) were fed on food containing 1.5% thiourea for 24 h, there was a small decrease in the size of the testes in both cases. Disturbance in spermatogenesis and histopathological damage were also observed in both cases. However, in the newly emerged flies the effect was mainly on secondary spermatocytes and spermatids, while in the others the effect was more pronounced on spermatogonia. The reproductive performance in respect of the production of larvae was considerably diminished in the newly emerged treated flies and was even further diminished in flies that were 24 h old when treated. The rate of adult emergence, however, remained unaffected for both kinds.