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1.
Ved Prakash Ranjan Bhattacharyya Govindan Selvakumar Samaresh Kundu Hari Shanker Gupta 《植物养料与土壤学杂志》2007,170(2):224-233
This study aims to examine the effects of long‐term fertilization and cropping on some chemical and microbiological properties of the soil in a 32 y old long‐term fertility experiment at Almora (Himalayan region, India) under rainfed soybean‐wheat rotation. Continuous annual application of recommended doses of chemical fertilizer and 10 Mg ha–1 FYM on fresh‐weight basis (NPK + FYM) to soybean (Glycine max L.) sustained not only higher productivity of soybean and residual wheat (Triticum aestivum L.) crop, but also resulted in build‐up of total soil organic C (SOC), total soil N, P, and K. Concentration of SOC increased by 40% and 70% in the NPK + FYM–treated plots as compared to NPK (43.1 Mg C ha–1) and unfertilized control plots (35.5 Mg C ha–1), respectively. Average annual contribution of C input from soybean was 29% and that from wheat was 24% of the harvestable aboveground biomass yield. Annual gross C input and annual rate of total SOC enrichment from initial soil in the 0–15 cm layer were 4362 and 333 kg C ha–1, respectively, for the plots under NPK + FYM. It was observed that the soils under the unfertilized control, NK and N + FYM treatments, suffered a net annual loss of 5.1, 5.2, and 15.8 kg P ha–1, respectively, whereas the soils under NP, NPK, and NPK + FYM had net annual gains of 25.3, 18.8, and 16.4 kg P ha–1, respectively. There was net negative K balance in all the treatments ranging from 6.9 kg ha–1 y–1 in NK to 82.4 kg ha–1 y–1 in N + FYM–treated plots. The application of NPK + FYM also recorded the highest levels of soil microbial‐biomass C, soil microbial‐biomass N, populations of viable and culturable soil microbes. 相似文献
2.
Perumal P Selvaraju S Selvakumar S Barik AK Mohanty DN Das S Das RK Mishra PC 《Reproduction in domestic animals》2011,46(4):636-641
This study was aimed to assess the effect of pre-freeze addition of cysteine hydrochloride and glutathione (GSH) on post-thaw sperm functional parameters and field fertility. The experimental bulls (n = 6) aged 4-6 years were used for this study. A total of 36 ejaculates (six ejaculates per bull) were collected and divided into three groups, group I (control), group II (5 mm cysteine hydrochloride) and group III (5 mm GSH). The extended semen samples with and without additives were filled in mini straw using automatic filling and sealing machine and cryopreserved in liquid nitrogen. Post-freeze seminal traits were recorded after thawing at 37°C for 30 s. The curvilinear velocity (VCL) and amplitude of lateral head displacement values were significantly (p < 0.05) higher in GSH than the cysteine and control groups. Post-thaw plasmalemma integrity was significantly (p < 0.01) higher in GSH group when compared to cysteine and control groups. The loss of acrosomal integrity was significantly (p < 0.01) lower in GSH than in cysteine and control groups. Addition of GSH non-significantly (p = 0.1) improved mitochondrial membrane potential (MMP) (per cent) than control group. This study indicates that the addition of cysteine and GSH suggestive (p = 0.08) of reducing lipid peroxide levels. The conception rate (%) in glutathione group was significantly (p < 0.05) higher than that in cysteine (68 vs 58) and control (49) groups. The post-thaw sperm progressive forward motility (r = 0.4) had moderate, but no significant correlation with conception rate. However, post-thaw straight-line velocity (r = 0.7), loss of acrosomal integrity (r = -0.8) and MMP (r = 0.9) had significant (p < 0.05) correlation with field fertility. This study indicates that the use of glutathione as semen additive may be used for improving post-thaw semen quality and overall augmentation of pregnancy in cows. 相似文献
3.
BACKGROUND: Diamondback moth, Plutella xylostella (L.), is a major insect pest of crucifers in the biodiversity‐rich north‐western Indian Himalayan hills. The present investigation was aimed at determining the susceptibility pattern of P. xylostella populations collected from different locations of this region to autochthonous and standard Bacillus thuringiensis strains. RESULTS: Among the reference as well as indigenous B. thuringiensis strains tested, sub spp. kurstaki HD‐1, kurstaki HD‐73, galleriae HD‐8, local galleriae/colmeri strain BtOa1 and some of their Cry1 class toxins were found to be highly toxic. Surprisingly, the sub sp. tolworthi HD‐125, local tolworthi strain BtHa1 and Cry9 class toxins were found to be non‐toxic. Midgut homogenate from fourth‐instar larvae was found to activate 130 kDa protoxin from the local tolworthi strain BtHa1 into 68 kDa toxin, but failed to exert any larval mortality, probably owing to lack of receptor binding. CONCLUSION: The present study provides valuable baseline susceptibility data for the deployment of B. thuringiensis‐based control methods, as well as for future monitoring of development of resistance in P. xylostella to B. thuringiensis in this ecologically sensitive region. Copyright © 2008 Society of Chemical Industry 相似文献
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5.
Nagalakshmi R. Gujjar Selvakumar Govindan Abraham Verghese Sudhagar Subramaniam Ravi More 《Phytoparasitica》2017,45(4):453-460
Gut microbes play an important role in insect morphogenesis, nutrition, development of resistance against parasitoids and detoxification of toxic compounds. A culture-based approach is therefore an useful tool for the characterization of cultivable microbial communities associated with the insect gut. In the present study an attempt was made to decipher the gender specificity of gut bacterial communities of two major fruit fly species of India viz., Bactrocera dorsalis (Hendel) and Bactrocera cucurbitae (Conquillett) (Diptera: Tephritidae). Based on molecular identification, B. dorsalis females were found to predominantly harbor the bacterial species Enterobacter cloacae, Enterobacter asburiae and Citrobacter freundii, while B. dorsalis males were found to harbor Providencia rettgerii, Klebsiella oxytoca, Enterococcus faecalis and Pseudomonas aeruginosa The cultivable diversity from females of B. cucurbitae comprised mainly of Morganella morganii and Bacillus pumilis while B.cucurbitae males were predominantly colonized by aerobic endospore formers viz., Bacillus cereus, B. licheniformis and B. subtilis. The above findings have thrown light on a distinct pattern of gender specific gut bacterial colonization in fruit flies, which have to be factored in for the formulation of fruit fly management strategies. 相似文献
6.
Temperature-induced alterations in the activity of the enzyme lactate dehydrogenase (LDH) were evaluated in the freshwater
prawn Macrobrachium malcolmsonii in three groups of juveniles: controls maintained at 27±2 °C; test prawns exposed to 35 °C; test prawns exposed to 15 °C.
Changes in LDH activity and lactate levels in key tissues were assessed after 48 hrs. LDH in the skeletal muscle of the prawns
was also subjected to kinetic analysis at different temperatures. Native polyacrylamide gel electrophoresis (PAGE) analysis
and colorimetric estimation revealed decreased LDH activity (compared to controls) in the gill, heart and haemolymph, but
not in the skeletal muscle or hepatopancreas, of test prawns exposed to 15 °C; however, lactate levels were significantly
lower in all the tissues of these test prawns. Conversely, prawns exposed to 35 °C revealed elevated LDH activity in all the
tissues, barring the skeletal muscle, while lactate levels were significantly higher (compared to controls) in all the tissues
of these prawns. Kinetic analysis of LDH in the skeletal muscle at different assay temperatures revealed temperature-dependent
kinetic properties. The differences observed in LDH activity and levels of lactate in various tissues of prawns exposed to
low and high temperatures suggest aerobic and anaerobic patterns of pyruvate metabolism at respective temperatures. The results
obtained by kinetic analysis of LDH in the skeletal muscle suggest the occurrence of an adaptative response involving this
enzyme that enables M. malcolmsonii to cope with effects of thermal stress.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Selvakumar Dhandapani Stephanie Evers Karl Ritz Sofie Sjgersten 《Soil Use and Management》2021,37(1):138-150
Tropical peatlands are unique and globally important ecosystems for carbon storage that are generally considered nutrient poor. However, different nutrient and trace element concentrations in these complex ecosystems and their interactions with carbon emissions are largely unknown. The objective of this research was to explore the concentrations of macro‐ and micronutrients and othertrace elements in surface peats, and their relationship with greenhouse gas emissions in North Selangor peatlands subjected to different land use. All nutrient and trace element concentrations except chromium exhibited significant differences between sites. Most macronutrients and some micronutrients showed significant differences between seasons, typically with a reduction over time from wet to dry seasons, possibly due to leaching. CO2 emissions were positively related to organic matter content and manganese concentrations and negatively correlated with selenium. CH4 emissions were positively correlated with organic matter content, manganese, copper, barium, cobalt and aluminium, and negatively correlated with molybdenum, selenium, lithium and vanadium. This research has detected loss of essential nutrients over time, aiding to increase nutrient limitation in tropical peatlands due to drainage. The observed significant correlation between trace elements and greenhouse gas emissions strengthens the importance of including trace element analyses in understanding the biogeochemical functions of these understudied peatlands. 相似文献
8.
M. Jayaprakashvel M. Selvakumar K. Srinivasan S. Ramesh N. Mathivanan 《European journal of plant pathology / European Foundation for Plant Pathology》2010,126(2):229-239
The aim of the study is to investigate the biocontrol mechanisms of Trichothecium roseum MML003 against the rice sheath blight (ShB) pathogen, Rhizoctonia solani as the former exhibited strong antagonistic activity against the latter. It has been found that T. roseum MML003 did not show any hyperparasitic interaction against R. solani. Further, it did not produce siderophores and hydrogen cyanide. However, the culture filtrate of T. roseum MML003 strongly inhibited the mycelial growth and sclerotial formation, its germination and viability, which proved that
the biocontrol activity is antibiosis-mediated. The extracellular crude antifungal metabolites of T. roseum MML003 were thermo and photo-stable. Potted plant experiment showed that the crude metabolites of T. roseum MML003 effectively reduced the ShB disease in rice up to 47.7%. Thus, this study assumes significance as it provided further
scope for the identification of antifungal metabolites from T. roseum MML003 and their possible use against sheath blight disease of rice. 相似文献
9.
Kathiravan Periasamy Kataria Ranjit S. Mishra Bishnu P. Dubey Praveen K. Selvakumar M. Tyagi Neetu 《Tropical animal health and production》2010,42(5):1021-1026
The present study aimed at identifying single-nucleotide polymorphic (SNP) sites in different coding and non-coding regions
of lactoferrin gene in Indian riverine buffaloes. A total of 102 animals from six different river buffalo breeds were screened
at six bubaline lactoferrin gene loci. Single-strand conformation polymorphism (SSCP) analysis revealed monomorphic patterns
at three loci LtfE2, LtfE11, and LtfE14 while a total of eight distinct patterns were observed in the other three loci viz.
LtfE5, LtfE10, and LtfE16 which correspond to respective exons and their flanking regions. Sequence analysis of different
SSCP variants revealed the presence of two SNP sites within the coding (exon 16) region and five SNP sites in flanking non-coding
regions (intron 4 and intron 9). Both SNPs within exon 16 were found to be synonymous. The SNPs and haplotypes identified
in the present study could serve as potential markers for association with susceptibility/resistance to mastitis in buffaloes. 相似文献
10.
Goldenseal (Hydrastis canadensis) has emerged as one of the top five herbal supplements in the world-wide market. A convenient method for the determination of the quality and possible adulteration of goldenseal products is thin-layer chromatography (TLC). TLC analysis of 10 goldenseal samples using two solvent systems and spray reagents was conducted. Five of these samples contained both hydrastine and berberine, four contained berberine and one did not contain either of these alkaloids. These TLC results were verified by HPLC analysis. 相似文献