Improving soil organic carbon pools through inclusion of summer mungbean in cereal-cereal cropping systems in Indo-Gangetic plain     

Kali Krishna Hazra  Probir Kumar Ghosh  Madasur Subbabhat Venkatesh  Chaitanya Prasad Nath  Narendra Kumar  Mohan Singh 《Archives of Agronomy and Soil Science》2018,64(12):1690-1704

Long-term effect of mungbean inclusion in lowland rice-wheat and upland maize-wheat systems on soil carbon (C) pools, particulate organic C (POC), and C-stabilization was envisaged in organic, inorganic and without nutrient management practices. In both lowland and upland systems, mungbean inclusion increased very-labile C (Cfrac₁) and labile C (Cfrac₂) in surface soil (0–0.2 m). Mungbean inclusion in cereal-cereal cropping systems improved POC, being higher in lowland (107.4%). Lowland rice-based system had higher passive C-pool (11.1 Mg C ha^?1) over upland maize-based system (6.6 Mg C ha^?1) indicating that rice ecology facilitates the stabilization of passive C-pool, which has longer persistence in soil. Organic nutrient management (farmyard manure + full crop residue + biofertilizers) increased Cfrac₁ and carbon management index (CMI) over inorganic treatment. In surface soil, higher CMI values were evident in mungbean included cropping systems in both lowland and upland conditions. Mungbean inclusion increased grain yield of cereal crops, and yield improvement followed the order of maize (23.7–31.3%) > rice (16.9–27.0%) > wheat (lowland 7.0–10.7%; upland 5.4–16.6%). Thus, the inclusion of summer mungbean in cereal-cereal cropping systems could be a long-term strategy to enrich soil organic C and to ensure sustainability of cereal-cereal cropping systems.  相似文献   

Estimates of direct and maternal (co)variance components as well as genetic parameters of growth traits in Nellore sheep     

Satish Kumar I  Vijaya Kumar C  Gangaraju G  Sapna Nath  Thiruvenkadan A.K. 《Tropical animal health and production》2017,49(7):1431-1438

In the present study, (co)variance components and genetic parameters in Nellore sheep were obtained by restricted maximum likelihood (REML) method using six different animal models with various combinations of direct and maternal genetic effects for birth weight (BW), weaning weight (WW), 6-month weight (6MW), 9-month weight (9MW) and 12-month weight (YW). Evaluated records of 2075 lambs descended from 69 sires and 478 dams over a period of 8 years (2007–2014) were collected from the Livestock Research Station, Palamaner, India. Lambing year, sex of lamb, season of lambing and parity of dam were the fixed effects in the model, and ewe weight was used as a covariate. Best model for each trait was determined by log-likelihood ratio test. Direct heritability for BW, WW, 6MW, 9MW and YW were 0.08, 0.03, 0.12, 0.16 and 0.10, respectively, and their corresponding maternal heritabilities were 0.07, 0.10, 0.09, 0.08 and 0.11. The proportions of maternal permanent environment variance to phenotypic variance (Pe²) were 0.07, 0.10, 0.07, 0.06 and 0.10 for BW, WW, 6MW, 9MW and YW, respectively. The estimates of direct genetic correlations among the growth traits were positive and ranged from 0.44(BW-WW) to 0.96(YW-9MW), and the estimates of phenotypic and environmental correlations were found to be lower than those of genetic correlations. Exclusion of maternal effects in the model resulted in biased estimates of genetic parameters in Nellore sheep. Hence, to implement optimum breeding strategies for improvement of traits in Nellore sheep, maternal effects should be considered.  相似文献   

Comparative efficiency and accuracy of variable area transects versus square plots for sampling tree diversity and density     

Cheryl D. Nath  Raphaël Pélissier  Claude Garcia 《Agroforestry Systems》2010,79(2):223-236

Agroforestry systems have been recognized as areas with high conservation potential, and there is a need to quickly assess the biodiversity and tree stocking density available in these systems. However, it is not clear if the commonly used fixed area plot is most efficient for sampling such landscapes, or if a different method could provide equivalent data with less effort. Thus, a field and simulation-based study was carried out to compare the efficiency and accuracy of a variable area transect versus the fixed area square plot. Field efficiency tests were carried out in three habitat types, robusta coffee plantations, arabica coffee plantations and a privately owned forest fragment, in Kodagu, southern India. A simulation study of bias, precision and accuracy of the two methods for tree density estimation also was carried out using various spatial distribution patterns and densities. The variable area transect was significantly more efficient per unit effort in the field than the fixed area square plot. In the simulation tests both methods performed equally well under random spatial distribution. However, under simulated aggregated distribution both methods were positively biased (square plot up to 12% at low density, variable area transect 9–12% at all densities), and under simulated regular distribution the variable area transect was slightly negatively biased (−5 to −7% at medium to high density). The variable area transect thus can be recommended over the square plot for rapid assessment of tree diversity and density, when the vegetation is expected to be randomly dispersed.  相似文献   

Molecular evidence supports hypervariability in Phytophthora colocasiae associated with leaf blight of taro     

Vishnu Sukumari Nath  Muthukrishnan Senthil  Vinayaka Mahabaleswar Hegde  Muthulekshmi Lajapathy Jeeva  Raj Shekhar Misra  Syamala Swayamvaran Veena  Mithun Raj 《European journal of plant pathology / European Foundation for Plant Pathology》2013,136(3):483-494

The oomycete Phytophthora colocasiae that causes taro leaf blight is the most devastating disease of taro and is widely distributed worldwide. Molecular and phenotypic techniques were employed for assessing and exploiting the genetic variability among four populations of P. colocasiae obtained from a fine spatial scale (multiple leaf blight lesions on single taro leaf). Phenotypic characters such as virulence, morphology and mating type showed no variation. ITS characterization revealed detectable polymorphism among isolates of P. colocasiae. The mean number of haplotypes (H), haplotype diversity (HD), nucleotide diversity (π), and nucleotide substitution rate (θ) among analyzed sequences were 6.75, 1.00, 0.069, and 0.088 respectively. High levels of inter and intra specific variation were detected by random amplified polymorphic DNA (RAPD) assays. Moderate genetic diversity (H?=?0.2651) was observed among populations of P. colocasiae. Analysis of molecular variance (AMOVA) confirmed that most of the genetic variability was confined to within a population (63.54 %). The coefficient of genetic differentiation among populations (G _ST ) was 0.2007 and estimates of gene flow (Nm) among populations was 1.991 migrants per generation. Cluster analysis using UPGMA revealed that individuals from the same population failed to cluster in one distinct group. The results of the study reveal considerable genetic diversity among and within populations of P. colocasiae obtained from fine spatial scale. The possible mechanisms and implications of this genetic variation are discussed.  相似文献   

Micropropagation of Darjeeling orange (Citrus reticulata Blanco) by shoot-tip grafting     

S. Mukhopadhyay  Jaishree Rai  B. C. Sharma  Anita Gurung  R. K. Sengupta  P. S. Nath 《The Journal of Horticultural Science and Biotechnology》2013,88(3):493-499

Summary

Micropropagation of Darjeeling orange (Darjeeling mandarin) was done by shoot-tip grafting on the local rootstocks rough lemon, sour orange and Rangpur lime. Seedlings of these plants were raised in MS medium in standard conditions of temperature, light duration and plant age. Microbuds (0.2 mm long), aseptically excised from the scion, were grafted onto the decapitated rootstock seedlings. The micrografts in culture medium were grown under standard lighting. Rootstock seedlings showed optimum growth at 25–30°C. Optimum growth of the micrografts resulted from treatment in complete darkness for 4 d after grafting followed by exposure to 750 W for 16 h d^?1 for 15 d and 1500–2000 W for 16 h d^?1 for 39 d. The success of micrografting depended on the age of the rootstock seedling which was 21 d, 14 d and 14 d for sour orange, rough lemon and Rangpur lime respectively. The micrografts were then double grafted to the two year old rootstocks seedlings of the respective species and the age of the micrografts for the successful double grafts was also standardized. The survival rate was high with 40 d, 45 d and 45 d micrografts on sour orange, rough lemon and Rangpur lime respectively. The double-grafts were then indexed for tristeza virus and greening disease after six months’ growth in an insect-proof screenhouse and found to be free from these graft transmissible diseases.  相似文献   

Lack of evidence for an association between MHC diversity and the development of bovine neonatal pancytopenia in Holstein dairy cattle     

Ballingall KT  Nath M  Holliman A  Laming E  Steele P  Willoughby K 《Veterinary immunology and immunopathology》2011,141(1-2):128-132

Bovine neonatal pancytopenia (BNP), a disease of neonatal calves, has been described in a number of European countries since 2006. The disease results in high mortality of calves aged 1-4 weeks and is characterised by severe bone marrow pathology resulting in profound thrombocytopenia and consequent haemorrhagic diathesis. A number of hypotheses including a novel virus infection, plant toxins, a vaccine associated isoimmune disease, or a genetic defect have been suggested to explain the aetiology of this disease. However, as the number of cases in affected herds remains small, it is hypothesised that the genetic background of the calf may influence disease susceptibility. To test this we focused on the class II region of the major histocompatibility complex (MHC) which is often associated with variations in immune response and susceptibility to antibody mediated autoimmune disease. Forty-three cases of BNP and sixty-eight controls were genotyped at the polymorphic class II MHC-DRB3 locus. Twenty DRB3 alleles were identified with seven appearing at frequencies ≥ 0.05. A comparison of the allelic frequencies between diseased and control groups showed that there was no evidence for any significant differences, suggesting that the MHC does not appear to be a predisposing risk factor in the development of BNP in Holstein dairy cattle.  相似文献   

Analysis of relationship between crop growth parameters,yield and physical environment within the crop canopy of sesame (Sesamum Indicum) at different sowing dates: Untersuchung der beziehungen zwischen wachstumsparametern,ertrag und physischer umwelt im pflanzenbestand von sesam (Sesamum Indicum) bei verschiedenen aussaatterminen     

R Nath  PK Chakraborty  P Bandopadhyay  CK Kundu  A Chakraborty 《Archives of Agronomy and Soil Science》2013,59(6):677-682

Relation between crop growth parameters of sesame (Sesamum indicum) and the physical environment within the crop canopy at different sowing dates was studied during the summer seasons of 1999 and 2000. The maximum leaf growth rate (LGR) and leaf area index (LAI) was obtained from February 19 sown crop. About 34.4% variation in LGR could be explained through the variation in the physical environmental elements within the crop canopy. The LAI was depressed in the later months of sowing. The February 19 sown crop produced significantly, the highest dry matter production (DMP) in all the stages of crop growth. The regression model indicated that the crop growth rate (CGR) was adversely affected by the ambient temperature and photosynthetic active radiation (PAR) within the crop canopy. Crops sown on 19 February and 1 March produced statistically similar yields. The cultivar Rama produced higher yields than B-67 and Kanke-1. Regression models suggested that the temperature profile and PAR within the crop canopy produced 69 and 39% variation in yield, respectively.  相似文献   

Integrated assessment of diversification of rice-wheat cropping system in Indo-Gangetic plain     

Ravi Kant Singh  Jitendra Singh Bohra  Triyugi Nath  Yeshwant Singh  Kalyan Singh 《Archives of Agronomy and Soil Science》2013,59(5):489-506

Diversification of rice-wheat cropping system may improve the productivity and sustainability of agricultural production in the Indo-Gangetic plane region (IGPR), but the choice of alternative sequences to be used requires integrated assessment of various crop sequences. A long-term field experiment was initiated during 2000–01 on sandy loam soil at Banaras Hindu University, Varanasi, India to assess 10 rice-based cropping sequences – rice-wheat, rice-chickpea, rice-wheat-green gram, rice-wheat-Sesbania (green manure), rice-mustard-green gram, rice-lentil-cowpea (fodder), rice-pea, rice-lentil + mustard (3:1)-cowpea (fodder), rice-maize (cob) + vegetable pea (1:1)-cowpea (fodder) and rice-potato-green gram in randomized block design with four replications. The data contained in this paper are for the year 2002–03 and 2003–04. Substitution of rice-wheat with 300% intensity cropping sequences particularly with rice-potato-green gram resulted in maximum production cost but gave the highest system productivity, net return, benefit:cost ratio, production efficiency, profitability and energy productivity. Inclusion of summer grain/fodder legume or Sesbania for green manuring improved the content of soil organic matter. The soil P status was positively affected in all the sequences and particularly those with summer crops. Decline in soil available K in all the sequences indicated inadequacy of present recommended rate of fertilizer K to all the component crops in different sequences.  相似文献   

Genetics components of rice root architecture and carbon isotopic fractionation parameters: a tracer for breeding in a water-saving irrigation management     

Brito  Giovani G.  Concenço  Germani  Costa  Vladimir E.  Fagundes  Paulo Ricardo R.  da Silva-Filho  João Luis  Parfitt  José Maria B.  Magalhães  Ariano  Silva  Giovana T.  Jardim  Thaís M.  Luccas  Nathália Furtado  Scivittaro  Walkyria B. 《Journal of Crop Science and Biotechnology》2022,25(1):19-32

Journal of Crop Science and Biotechnology - Phenotyping is the major bottleneck in the effort to develop varieties of rice (Oryza sativa L.) suitable for growing under a water-saving irrigation...  相似文献   

Biodiversity, current developments and potential biotechnological applications of phosphorus-solubilizing and -mobilizing microbes: A review   总被引：3，自引：0，他引：3  

Divjot KOUR  Kusam Lata RANA  Tanvir KAUR  Neelam YADAV  Ajar Nath YADAV  Manish KUMAR  Vinod KUMAR  Harcharan Singh DHALIWAL  Anil Kumar SAXENA 《土壤圈》2021,31(1):43-75

As one of the most important and essential macronutrients next to nitrogen,phosphorus(P)is important for plant development,but it is the least mobile nutrient element in plant and soil.Globally,P is mined from geological sediments and added to agricultural soils so as to meet the critical requirements of crop plants for agronomic productivity.Phosphorus exists in soil in both organic and inorganic forms.The various inorganic forms of the element in soil are salts with calcium,iron,and aluminum,whereas the organic forms come from decaying vegetation and microbial residue.There is a huge diversity of plant microbiomes(epiphytic,endophytic,and rhizospheric)and soil microbiomes that have the capability to solubilize the insoluble P and make it available to plant.The main mechanism for the solubilization of inorganic P is by the production of organic acids,which lowers soil pH,or by the production of acid and alkaline phosphatases,which causes the mineralization of organic P.The P-solubilizing and-mobilizing microorganisms belong to all three domains,comprising archaea,bacteria,and eukarya.The strains belonging to the genera Arthrobacter,Bacillus,Burkholderia,Natrinema,Pseudomonas,Rhizobium,and Serratia have been reported as efficient and potential P solubilizers.The use of P solubilizers,alone or in combination with other plant growth-promoting microbes as an eco-friendly microbial consortium,could increase the P uptake of crops,increasing their yields for agricultural and environmental sustainability.  相似文献