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1.
Two strains (derepressed-nitrogen fixing, Mac-27 and phosphate solubilizing, PS-21) of Azotobacter chroococcum were inoculated in fish culture ponds, singly and in combination with inorganic fertilizers (urea, single superphosphate–SSP). Physico-chemical parameters of pond waters, plankton production and fish biomass were studied. Inoculation of A. chroococcum (Mac-27) enhanced nitrogenase activity and rate of nitrogen fixation. A slight reduction in nitrogen fixation and nitrogenase activity was noticed when urea at 96 kg ha–1 y–1 was mixed with the biofertilizer (Mac-27). Inoculation of PS-21 enhanced phosphate solubilization, but Kjeldahl-nitrogen concentration values remained low in comparison with controls. On the other hand, inoculation of Azotobacter (either strain) enhanced the accumulation of ammonium-N, nitrite-N and nitrate-N. A significant (p < 0.05) reduction in dissolved oxygen (DO) concentration also took place when Azotobacter (both Mac-27 and PS-21) was inoculated in fish ponds. However, when used along with inorganic fertilizers, the reduction was not significant. The pH values were only slightly lowered when the phosphate-solubilizing strain (PS-21) of Azotobacter was inoculated. Inoculation of biofertilizer enhanced plankton production, net primary productivity and fish biomass. However, highest values in most of these parameters were noticed only in ponds that were treated with the higher doses of inorganic fertilizers (urea 192 kg and SSP 1500 kg ha–1 y–1). © Rapid Science Ltd. 1998 相似文献
2.
A field experiment was conducted in a randomized block design with three replications over 2 years to evaluate the effect of wheat cultivar and dual inoculation of Azotobacter chroococcum (Azc) and arbuscular mycorrhiza fungi (AMF, Glomus fasciculatum) on root characters and AMF infection in three crosses of wheat. The experimental material comprised four wheat parents, WH‐147, WH‐157, WH‐542 and PBW‐175, and three F1 crosses, WH‐147 ×WH‐157, WH‐147 × WH‐542 and WH‐147 × PBW‐175. Comparison of treatment averages, i.e. control (mineral nutrients 60 kg N + 30 kg P2O5 + 12.5 kg ZnSO4 ha?1, as in other two treatments), AMF and AMF + Azc, revealed that inoculation of Azc led to an increase in AMF infection in roots. Maximum root biomass was obtained in F1 hybrids WH‐147 × WH‐157 in the AMF treatment and in WH‐147 × PBW‐175 receiving AMF + Azc. Total root length and AMF infection of roots was maximum in WH‐147 × PBW‐175 for all the treatments during both years. A positive association between AMF infection in roots and Azotobacter survival in the rhizosphere was apparent. Similarly, maximum A. chroococcum counts were observed 80 and 120 days after sowing in the AMF + Azc treatment in cross WH147 × PBW175. 相似文献
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Climate is a critical factor affecting forest ecosystems and their capacity to produce goods and services. Effects of climate change on forests depend on ecosystem-specific factors including dimensions of climate (temperature, precipitation, drought, wind etc.). Available information is not sufficient to support a quantitative assessment of the ecological, social and economic consequences. The present study assessed shifts in forest cover types of Western Himalayan Eco-region (700?4500 m). 100 randomly selected samples (75 for training and 25 for testing the model), genetic algorithm of rule set parameters and climatic envelopes were used to assess the distribution of five prominent forest cover types (Temperate evergreen, Tropical semi-evergreen, Temperate conifer, Subtropical conifer, and Tropical moist deciduous forests). Modelling was conducted for four different scenarios, current scenario, changed precipitation (8% increase), changed temperature (1.07°C increase), and both changed temperature and precipitation. On increasing precipitation a downward shift in the temperate evergreen and tropical semi-evergreen was observed, while sub-tropical conifer and tropical moist-deciduous forests showed a slight upward shift and temperate conifer showed no shift. On increasing temperature, an upward shift in all forest types was observed except sub-tropical conifer forests without significant changes. When both temperature and precipitation were changed, the actual distribution was maintained and slight upward shift was observed in all the forest types except sub-tropical conifer. It is important to understand the likely impacts of the projected climate change on the forest ecosystems, so that better management and conservation strategies can be adopted for the biodiversity and forest dependent community. Knowledge of impact mechanisms also enables identification and mitigation of some of the conditions that increase vulnerability to climate change in the forest sector. 相似文献
4.
HY Jang YH Kim BW Kim IC Park HT Cheong JT Kim CK Park HS Kong HK Lee BK Yang 《Reproduction in domestic animals》2010,45(6):943-950
Melatonin, the major secretory product of the pineal gland, scavenges a variety of reactive oxygen and nitrogen species in vivo and in vitro, indicating that melatonin is a potent function as an antioxidant. The objective of this study was to investigate the effect of melatonin in the presence or absence of hydrogen peroxide (H2O2) on sperm characteristics (motility, viability, survival rate, membrane integrity, lipid peroxidation (LPO) and mitochondria activity) and also to examine the developmental rates to the blastocysts stage of porcine oocytes fertilized in vitro with semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ). The sperm were treated with melatonin in the presence or absence of H2O2 for 3, 6, 9 and 12 h at 37°C and then analysed for the sperm characteristics. The porcine embryos were produced by in vitro maturation and in vitro fertilization (IVM/IVF) using semen treated with or without melatonin (100 nm ) in the presence or absence of H2O2 (250 μm ) for 6 h. The semen characteristics, including motility, viability, survival rate, membrane integrity and mitochondria activity, were higher in the groups that were treated with melatonin in comparison to other groups, irrespective of incubation periods. Malondialdehyde levels in control, melatonin and melatonin + H2O2 groups were lower than H2O2 only group. A positive correlation was shown among motility, viability, survival rate and membrane integrity, but a negative correlation was observed between LPO and the other evaluation methods. The developmental rates to blastocysts of IVM/IVF porcine oocytes fertilized by semen treated with melatonin were significantly increased compared with any other groups, with the cell number of blastocysts shown to have a similar trend to the developmental rates. These results demonstrate that melatonin can improve the semen characteristics during in vitro storage and support the developmental ability of IVM/IVF embryos in pigs. 相似文献
5.
Neeru Narula Prof. Dr BS Saharan Vivek Kumar Ranjana Bhatia LK Bishnoi BPS Lather 《Archives of Agronomy and Soil Science》2013,59(1):69-77
High nitrogen fixing, phosphate solubilizing, phytohormones producing isolates of Azotobacter, Azospirillum, Acetobacter and Pseudomonas were used as inoculants for cotton. Important cultures were selected on the basis of their effect on root/shoot length and chemotactic behaviour. Selected bioinoculants were earlier tested for their beneficial properties like nitrogen fixation (ARA), ammonia excretion, IAA production etc. These bio-inoculants were further tested for phosphate solubilization property. Various chosen strains were tested with Desi (HD 123) and American (H 1098) cotton under field conditions (as for wheat). Plant height and boll weight were determined at the time of harvesting whereas survival rate of inoculated bacteria was determined after 30, 80 and 130 days respectively. In the year 2000–01, on the basis of boll number and boll weight plant?1 AVK 51 (36; 76.2?g plant?1), HT 57 (27; 56.9?g plant?1), AC18 (33; 61.5?g plant?1), Ala 27 (36; 61.4?g plant?1) and Pseudomonas (34; 71.3?g plant?1) were identified as significant both for American and desi cotton varieties. Highest survival rate was observed with Mac 68 (33.4 × 105) followed by HT54 (31.5 × 105) after 30 days of sowing, which decreased after 80 days and remained constant up to 130 days. This trend was observed with all the cultures. Similar results were observed in 2001–02. 25?kg ha?1 N saving was observed with A. chroococcum (AVK51) bioinoculant for cotton crop. 相似文献
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7.
A S Narula 《The Indian veterinary journal》1969,46(12):1103-1104
8.
Mehrotra Arnav Pannu Urmila Chopra Ashish Narula H. K. Singh Harvinder Patel A. K. 《Tropical animal health and production》2020,52(5):2259-2264
Tropical Animal Health and Production - Early selection of ewes for better reproductive performance may reduce generation interval and increase genetic gains. Considering this, the present study... 相似文献
9.
Assessment of Genetic Variability in the Coding Sequence of Melatonin Receptor Gene (MTNR1A) in Tropical Arid Sheep Breeds of India
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VK Saxena BK Jha AS Meena HK Narula D Kumar SMK Naqvi 《Reproduction in domestic animals》2015,50(3):517-521
Seasonal behaviour in sheep, which varies in tropical and temperate environmental conditions, is a matter of study, because it can provide a clue to address the problem of seasonality in sheep. Melatonin receptor is the membrane‐bound G‐coupled receptor, sensing the message of photoperiodic cues thorough melatonin. Restriction fragment length polymorphism (RFLP) studies were carried out to assess the variability of gene at G612A and C606T SNPs in MTNR1A gene, which have been studied to be markers for out‐of‐season breeding. Allelic frequency distribution corresponded to higher frequency of GG and CC genotype, in tropical arid sheep breed in comparison with temperate region sheep breed. PCR amplification of MTNR1A gene of 30 animals was performed and single nucleotide polymorphisms (SNPs) identification was carried out using Lasergene software. Seven SNPs/mutations were identified, but most of them were synonymous, except the one G706A, leading to substitution of valine by isoleucine. Polyphen‐2 analysis of G706A mutation revealed that it is a benign mutation. Two important SNPs C426T and G555A, which were identified in temperate sheep breeds, could not be traced in Magra and Marwari breeds of sheep. Thus, the Magra and Marwari breeds of tropical, arid region demonstrated the presence of both polymorphic SNPs markers G612A and C606T, associated with out‐of‐season breeding. GG and CC genotypes were having a higher prevalence in the studied population. 相似文献
10.
Sapna Chauhan Kunal Wadhwa Manjula Vasudeva Neeru Narula 《Archives of Agronomy and Soil Science》2013,59(12):1365-1385
During the current investigation, 51 bacterial isolates/mutants of Azotobacter chroococcum, Azospirillum spp. and Gluconacetobacter diazotrophicus were tested for antifungal activity against three fungal pathogens, namely Rhizoctonia solani cotton, Rhizoctonia solani rice and Fusarium oxysporum tomato using a dual-culture technique under laboratory conditions. Ten isolates/mutants were found to be inhibitory against R. solani cotton, six against R. solani rice and twelve against F. oxysporum tomato. Nearly 50% of the isolates/mutants were siderophore positive. The antimicrobial substance was found to be extracellular and proteinaceous in nature, but in some strains it was found to be associated with other complex material also. Almost all the positive isolates/mutants showed production of antibiotic and antifungal compounds. On the basis of this study, in vitro results under laboratory conditions were reproduced in pot experiments in the greenhouse and chosen isolates/mutants of A. chroococcum were found to be effective biocontrol agents against R. solani cotton (disease index 16.7%) and R. solani rice (2.5%) in cotton crop, whereas in guar, the crop disease index was 2.5% against R. solani cotton, 13.3% against R. solani rice and 0% against F. oxysporum tomato in tomato crop compared with their respective checks. 相似文献