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151.
152.
Small-scale Forestry - Homestead forests in the Teknaf Peninsula ecologically critical area of Cox’s Bazar in Bangladesh have not been widely studied. This paper explores floristic diversity... 相似文献
153.
Deen Dayal Giri Prabhu Nath Shukla Priti Singh Kapil Deo Pandey 《Soil biology & biochemistry》2007,39(9):2424-2426
Soil samples were collected from Panchamarhi dry deciduous forest in Satpuda Biosphere Reserve, India to determine the effect of hill slopes and altitude on the population size of methanotrophic bacteria. Population size, in range of 4×105-3.6×107 g−1 dry soil, was negatively correlated with altitude and increased exponentially (r2=0.97, P<0.001) at steep slope (60°) while logarithmically (r2=0.97, P<0.001) at low slope (45°). Soil organic C, total N, and soil moisture increased while C/N ratio and temperature decreased down the hill slope. The results indicated that nutritional status of the soil across the slopes determines the methanotrophic bacterial population size. 相似文献
154.
Kotha Sammi Reddy Muneshwar Singh Awadesh Kumar Tripathi Mahavir Singh Manbendra Nath Saha 《植物养料与土壤学杂志》2003,166(2):232-238
The influence of 30 years of cropping with different fertilizer and farmyard manure (FYM) inputs on the contents and depth distribution of organic C, total N (Nt), soil mineralizable N, and organic and inorganic N fractions was investigated in an Eutrochrept. Continuous application of 100 %NPK(+S), 150 %NPK(+S), and 100 %NPK(+S)+FYM led to a marked increase in organic C, total N, hydrolyzable N (viz., amino acid N, hydrolyzable NH4‐N, hexose amine N, and unidentified hydrolyzable N), and nonhydrolyzable N as compared to an adjacent fallow. The contents of the various organic N fractions were largest in surface soil and thereafter decreased with the depth. However, at 30 – 45 cm depth the content of organic C was not affected by the different treatments except 100 %NPK(+S)+FYM. On the other hand, continuous cropping without fertilization resulted in a depletion of total hydrolyzable N in control over fallow by 27.2 % (0–15 cm), 19.6 % (15–30 cm), and 4.7 % (30–45 cm). The incorporation of FYM with 100 %NPK(+S) resulted in greater contents of soil mineralizable N as compared to 100 %NPK(+S) (0–15, 15–30 cm). The proportion of hydrolyzable N (57–76 % of Nt) decreased and that of nonhydrolyzable N (22–40 % of Nt) increased with depth. The proportion of amino acid N (19–26 % of Nt), hexose amine N (2.1–3.5 % of Nt) and unidentified hydrolyzable N (17–27 % of Nt) decreased with depth. All organic soil N fractions including even nonhydrolyzable N in surface and subsurface soils were highly significantly correlated with soil mineralizable N derived from incubations under waterlogged and aerobic conditions. The best correlation to mineralizable N was found for amino acid N and the least significant correlation for nonhydrolyzable N. 相似文献
155.
Being a toxic metalloid and group I carcinogen, Arsenic (As) poses a threat to plants, especially to crops which are consumed by human beings, and sooner or later results in hyper/hypopigmentation and skin cancer. It is a well‐known fact that South‐East Asia is suffering from groundwater As contamination, and according to a recent report, the contamination has been found also in Hungary, Mexico, Argentina, Australia, United States, etc. Thus, As contamination has become a global problem. As is toxic even at low concentration because it has no known function as nutrients. Arsenite (III) and arsenate (V) are the main phytoavailable forms of inorganic arsenic. Being analogous to phosphate, As(V) is transported by a phosphate‐cotransport system in plants, whereas As(III) is transported through ‘OsNIP2.1’ (member of aquaporin superfamily) in rice. Besides, ‘AsSe1’ (As‐accumulation gene), ‘AsTol’ (As‐tolerance gene) and ‘OsACR2.1’ (an arsenate reductase gene) have also been identified. The production of phytochelatins (PCs), a metal‐binding thiol peptide, in response to As stress may hold a way of proper As tolerance in plants but still needs a thorough study. However, with the proper knowledge of arsenic speciation, transportation, accumulation, overexpression in crop plants may result in ways to develop arsenic tolerant transgenics. 相似文献
156.
Objective To evaluate the reproductive efficiency of horse farms in north-east Victoria and identify aspects of management to be targeted for improving reproductive efficiency. Design Retrospective study. Procedure Records from seven Thoroughbred (TB) and four Standardbred (STB) studs in north-east Victoria from 1990 to 2001 were reviewed; 8813 cycles in 4455 mares were analysed. TB mares were inseminated by natural mating, whereas STB mares (89%) were artificially inseminated. Results The overall early pregnancy rate per cycle was 68.8% for TB mares and for STB mares, 68.3%. Multiple pregnancy per cycle was more frequent in TB (8.3%) than in STB (4.6%) mares (P < 0.001). Early embryonic death occurred in 7.1% of TB and 7.5% of STB pregnancies. TB mares had fewer inseminations per cycle (1.03) than STB mares (1.43) (P < 0.001). There was a significantly lower proportion of barren reproductive status within the TB than the STB mares. Pregnancy rate per cycle among stallions ranged from 48% to 79%. Conclusions On-farm pregnancy rates in both breeds were higher than previously reported and likely reflect improvements in reproductive management. The disparity between breeds in the inseminations per cycle and proportion of barren mares exposed the differing structures of the two industries, and presents a target for improving the reproductive efficiency in STBs. The difference between breeds in the multiple pregnancy rate per cycle likely reflects the higher ovulation rate of TB mares. The variability in pregnancy rate per cycle between the 22 stallions was associated with differences in individual inherent fertility and the quality of stallion management. 相似文献
157.
Kedar Nath Mohanta Satyendra Nath Mohanty Joykrushna Jena & Narottam Prasad Sahu 《Aquaculture Research》2008,39(11):1131-1140
One of the three iso-nitrogenous (30% crude protein) and iso-energetic (15.0 MJ kg−1 diet) oil cake-based diets (groundnut, D-1; soybean, D-2 and mustard, D-3) was fed to the fingerlings (6.61 ± 0.06 g) of silver barb ( Puntius gonionotus ) for 120 days in triplicate fertilized ponds (0.04 ha) with a stocking density of 9000 fish ha−1 . Fish were fed at 10% of their body weight for the first month, followed by 3% in the second and 2.5% in the third and fourth months of the culture period. The fish fed diets D-1, D-2 and D-3 grew from initial weights of 6.67, 6.67 and 6.50 g to 320.23, 298.23 and 305.13 g respectively. No significant variation ( P >0.05) was found in the growth and nutrient utilization of fish fed different dietary treatments. Net profits of Indian Rupees 67 385, 59 535 and 65 790 ha−1 were obtained in fish fed D-1, D-2 and D-3, respectively, within 120 days of culture. The results of this study suggest the possibility of the use of mustard oil cake as a dietary protein source for pond culture of silver barb in addition to groundnut and soybean oil cakes without compromising the growth, nutrient utilization, production performance and economics of culture of this fish. 相似文献
158.
Jute fibers have immense potential to be used as natural fillers in polymeric matrices to prepare biocomposites. In the present study jute fibers were surface treated using two methods: i) alkali (NaOH) and ii) alkali followed by silane (NaOH+Silane) separately. Effects of surface treatments on jute fibers surface were characterized using fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) analyses. Further, the effects of surface treatments on jute fibers properties such as crystallinity index, thermal stability, and tensile properties were analyzed by X-ray diffraction method (XRD), thermo gravimetric analysis (TGA), and single fiber tensile test respectively. The effects of surface treatment of jute fibers on interphase adhesion between of poly(lactic acid) (PLA) and jute fibers were analyzed by performing single fiber pull-out test and was examined in terms of interfacial shear strength (IFSS) and critical fiber length. 相似文献
159.
Mitadru Mukherjee Barada Padhy Bharathkumar Srinivasan Pradosh Mahadani Sk Yasin Baksh Ravindra Donde Onkar Nath Singh Lambodar Behera Padmini Swain Sushanta Kumar Dash 《水稻科学》2018,25(6):308-319
A total of 17 simple sequence repeat (SSR) markers linked to QTLs (qDTYs) governing grain yield under reproductive stage (RS) drought stress were used to assess the genetic relationship and prospecting new donors for qDTYs among 32 popular upland rice genotypes. These SSR markers generated a total of 36 alleles with an average allele count of 2.1 per locus. Polymorphic information content value of the markers ranged from 0.376 to 0.662 with an average value of 0.484. The expected heterozyogosity ranged from 0.381 to 0.632. STRUCTURE analysis divided the 32 genotypes into three sub-populations. Subsequent phenotyping revealed that all the tolerant genotypes were grouped into one sub-population, whereas the moderately tolerant and susceptible genotypes were grouped into separate sub-populations. Phylogenetic tree constructed by the unweighted neighbour-joining method also divided the genotypes into three clusters. The grouping pattern of genotypes into the clusters was similar to that into the STRUCTURE analysis, on the basis of drought tolerance level. The average value of genetic dissimilarity coefficient among the genotypes was observed to be 0.486. Furthermore, by combining genotyping data with phenotyping data, 16 new donors for 6 qDTYs were identified. 相似文献
160.
Jayanti Singh Kavindra Nath Tiwari 《Industrial Crops and Products》2012,35(1):224-229
In vitro clonal propagation of Clitoria ternatea has been achieved by employing decapitated embryonic axes (DEAs) explants. The explants induced multiple shoots on cytokinin-containing medium. Several cytokinins [6-benzylaminopurine (BAP), 6-furfuryl aminopurine (KIN) and thidiazuron (TDZ)] were assayed. The best response was achieved with 2 mg l−1 BAP in which 100% of cultures produced 6.0 ± 0.14 shoots per explant. MS + 1 mg l−1 gibberellic acid (GA3) was the most suitable for shoot elongation. Regenerated shoots were rooted in half-strength Murashige and Skoog (MS) medium with 0.2 mg l−1 indole-3-butyric acid (IBA). Plantlets were successfully acclimatized and established in soil, and they were morphologically indistinguishable from the source plant. The plantlets attained maturity and flowered normally. The efficient regeneration protocol reported here provides an important method of micropropagation of this plant. Furthermore, this protocol may be used for genetic transformation of this valuable medicinal plant for its further improvement. 相似文献