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41.
Rakesh K. Srivastava Shashi K. Mishra Ashok K. Singh Trilochan Mohapatra 《Euphytica》2012,186(3):855-866
Pea powdery mildew is one of the major constraints in pea production worldwide, causing severe seed yield and quality loss. The resistance is governed by a single recessive gene er1 in majority of resistant cultivars, but er2 and Er3 have also been reported. The objective of the study was to find out tightly linked sequence characterized amplified regions (SCAR) markers to er1 gene using NILs. A total of 620 random amplified polymorphic DNA (RAPD) markers were screened for length polymorphism between seven sets of NILs. The 880 bp polymorphic band of the tightly linked RAPD marker OPX 04880 was cloned, sequenced and a SCAR marker ScOPX 04880 was developed. In a population of completely classified 208 F2 plants (supported by phenotypic data from 208 F2:3 and 4,390 F3:4 families) ScOPX 04880 was linked at 0.6 cM in coupling phase with er1 gene in the order ScOPX 04880–er1–ScOPD 10650. ScOPX 04880 will correctly differentiate homozygous resistant plants from the susceptible accessions with more than 99 % accuracy. In combination with repulsion phase marker ScOPD 10650, ScOPX 04880 can help in an error free marker-assisted selection. 相似文献
42.
Carbon dioxide served as a proxy for biodegradation in the biofiltration of multiple organic solvents in a batch biofilter. The solvents were injected into the batch biofilter system and were biodegraded with the biomass immobilized on a column of fibrous media; the immobilized biomass was acclimated to ethanol in a continuous biofilter. Time profiles of CO2 concentration were obtained for substrate utilization and for biomass endogenous respiration. The CO2 and substrate concentration profiles provided insight for the biodegradation of multiple substrates in a biofilter. Experimental results indicate that the biomass utilized the solvents simultaneously but at different rates. The utilization rates were in the order: acetaldehyde > ethanol > propanol > isopropanol, acetone > methanol > butanol. Isopropanol was transformed to acetone, which was then utilized and converted to CO2, and propanol was also utilized through the formation of an intermediate. The biodegradation of ethanol was inhibited by acetaldehyde. Total CO2 production was contributed by the endogenous respiration of the biomass as well as by the biodegradation of all the substrates present to the biomass, and the total CO2 rate might not reach its maximum potential. 相似文献
43.
Thermal degradation of bending strength of plywood and oriented strand board: a kinetics approach 总被引:2,自引:2,他引:0
The construction industry has relied heavily on wood and wood-based composites, such as oriented strand board (OSB) and plywood
for timber frame construction. Therefore, it is highly imperative to categorize the response of wood-based composites when
exposed to elevated temperatures for a sustained period of time. The essence of fire-resistant structural design is to ensure
that structural integrity be maintained during and after the fire, prevent collapse and maintain means of egress. Another
aspect is to assess post-fire structural integrity and residual strength of existing structure. The objective of this project
was (a) to study the effect of exposure time on bending strength (MOR) of OSB and plywood at elevated temperatures, (b) to
interpret any relationships between different temperature and time of exposure using a kinetics model for thermal degradation
of strength, and (c) to develop a master curve representing temporal behavior of OSB and plywood at a reference temperature.
As much as 1,152 samples were tested in static bending as a function of exposure time and several temperatures. Strength (MOR)
of both OSB and plywood decreased as a function of temperature and exposure time. These results were fit to a simple kinetics
model, based on the assumption of degradation kinetics following an Arrhenius activation energy model. The apparent activation
energies for thermal degradation of strength were 54.1 kJ/mol for OSB and 62.8 kJ/mol for plywood. Furthermore, using the
kinetics analysis along with time–temperature superposition, a master curve was generated at a reference temperature of 150°C
which predicts degradation of strength with time on exposure at that reference temperature. The master curves show that although
plywood has a higher initial strength, OSB performs better in terms of strength degradation after exposure to elevated temperature. 相似文献
44.
Arnica montana is a medicinally important plant due to its broad health effects, and it is used in Ayurvedic, Homeopathic, Unani, and folk medicines. We have used LC-MS(n) (n = 2-5) to detect and characterize in Arnica flowers 11 quantitatively minor fumaric and methoxyoxalic acid-containing chlorogenic acids, nine of them not previously reported in nature. These comprise 1,5-dicaffeoyl-3-methoxyoxaloylquinic acid, 1,3-dicaffeoyl-4-methoxyoxaloylquinic acid, 3,5-dicaffeoyl-4-methoxyoxaloylquinic acid, and 1-methoxyoxaloyl-4,5-dicaffeoylquinic acid (M(r) 602); 3-caffeoyl-4-feruloyl-5-methoxyoxaloylquinic acid and 3-feruloyl-4-methoxyoxaloyl-5-caffeoylquinic acid (M(r) 616); 1,5-dicaffeoyl-4-fumaroyl and 1,5-dicaffeoyl-3-fumaroylquinic acid (M(r) 614); 3,5-dicaffeoyl-1,4-dimethoxyoxaloylquinic acid (M(r) 688); and 1-methoxyoxaloyl-3,4,5-tricaffeoylquinic acid and 1,3,4-tricaffeoyl-5-methoxyoxaloylquinic acid (M(r) 764). All of the structures have been assigned on the basis of LC-MS(n) patterns of fragmentation, relative hydrophobicity, and analogy of fragmentation patterns if compared to caffeoylquinic acids. This is the first time when fumaric acid-containing chlorogenic acids are reported in nature. 相似文献
45.
Michael J. Thomson Marjorie de Ocampo James Egdane M. Akhlasur Rahman Andres Godwin Sajise Dante L. Adorada Ellen Tumimbang-Raiz Eduardo Blumwald Zeba I. Seraj Rakesh K. Singh Glenn B. Gregorio Abdelbagi M. Ismail 《Rice》2010,3(2-3):148-160
This study characterized Pokkali-derived quantitative trait loci (QTLs) for seedling stage salinity tolerance in preparation for use in marker-assisted breeding. An analysis of 100 SSR markers on 140 IR29/Pokkali recombinant inbred lines (RILs) confirmed the location of the Saltol QTL on chromosome 1 and identified additional QTLs associated with tolerance. Analysis of a series of backcross lines and near-isogenic lines (NILs) developed to better characterize the effect of the Saltol locus revealed that Saltol mainly acted to control shoot Na+/K+ homeostasis. Multiple QTLs were required to acquire a high level of tolerance. Unexpectedly, multiple Pokkali alleles at Saltol were detected within the RIL population and between backcross lines, and representative lines were compared with seven Pokkali accessions to better characterize this allelic variation. Thus, while the Saltol locus presents a complex scenario, it provides an opportunity for marker-assisted backcrossing to improve salt tolerance of popular varieties followed by targeting multiple loci through QTL pyramiding for areas with higher salt stress. 相似文献
46.
Preeti Rawat Mohammad F. Khan Manmeet Kumar Akhilesh K. Tamarkar Arvind K. Srivastava Kamal R. Arya Rakesh Maurya 《Fitoterapia》2010
Two new phenolic glycosides (1, 2), along with fourteen known compounds (3–16) have been isolated from the fruit of Cupressus sempervirens. The structures of these compounds were determined by spectroscopic analysis and were evaluated for their inhibitory activity against glycogen phosphorylase and glucose-6-phosphatase enzymes. Compounds 14 showed a moderate inhibition against glucose-6-phosphatase and 15 against glycogen phosphorylase enzymes. 相似文献
47.
Umesh Dimri Rakesh Ranjan Mahesh C. Sharma V. P. Varshney 《Tropical animal health and production》2010,42(3):405-410
Pregnancy is a physiology state accompanied by high energy and oxygen demand that may lead to increased level of oxidative
stress and development of metabolic and reproductive disorders in pregnant water buffaloes. In the present study, the alterations
in serum cortisol and erythrocyte lipid peroxides and superoxide dismutase activities were examined in 28 pregnant water buffaloes
supplemented with antioxidant nutrients, Vitamin E and selenium. Another 14 buffaloes did not receive any treatment during
pregnancy to serve as negative control. Results of the present study suggested that pregnancy is associated with oxidative
stress and supplementation of vitamin E and selenium may be beneficial by alleviating oxidative stress in water buffaloes. 相似文献
48.
Reza Mohammadi Merlyn S. Mendioro Genaleen Q. Diaz Glenn B. Gregorio Rakesh K. Singh 《Plant Breeding》2014,133(5):548-559
Salinity is a major abiotic stress that limits rice production across rice areas as high‐yielding modern rice varieties are generally sensitive to salt stress. The study was conducted to deduce heritability and combining ability estimates of rice for various morphological and physiological traits using a 7 × 7 full‐diallel‐cross analysis at seedling and reproductive stages. The salinity stress treatment was 12 dS m?1 at the seedling stage and 8 dS m?1 at the reproductive stage. Diallel analysis revealed high for salinity tolerance scores and shoot height, moderate for shoot dry weight and root dry weight and low for Na+ and K+ concentrations and K+/Na+ ratio. The low‐to‐moderate narrow‐sense heritability for number of panicles, number of fertile spikelets, grain weight, spikelet fertility and K+/Na+ ratio suggests a large breeding population and delayed selection for tolerance until later generations. Significant maternal effects indicate that selection of the female parent is very important for desired trait development. The results of this study confirmed that salinity tolerance at the seedling and reproductive stages is regulated by a different set of genes that could be pyramided using different donors to enhance the level of tolerance. 相似文献
49.
Over-exploitation of groundwater for irrigation can result in drastic reduction in groundwater level in Jodhpur district of western Rajasthan, India. In this study, we used the long-term trend analysis of seasonal groundwater level data to predict the future groundwater scenario in 33 villages of Jodhpur district, assessed the impact of water harvesting structures on groundwater recharge and explored the non-equilibrium between groundwater recharge and irrigation draft in the study area. Analysis of groundwater level data from 26 observation wells in 33 villages in the pre-monsoon period showed that groundwater level decreased continuously at the rate of 2.07 m/a. With this declining rate, most of the tube wells(including the well with the maximum depth of 193 m) are predicted to become completely dry by 2050. Behavior of temporal groundwater level data in the study period(from 2004 to 2012) can be explained by different geospatial maps, prepared using Arc GIS software. Statistical analysis of the interpolated maps showed that the area with the maximum positive groundwater recharge occupied 63.14% of the total area during 2010–2011 and the area with the maximum irrigation draft accounted for 56.21% of the total area during 2011–2012. Higher groundwater recharge is attributed to the increase in rainfall and the better aquifer condition. Spatial distribution for the changes of average groundwater recharge and draft(2008–2009 and 2011–2012) showed that 68.50% recharge area was in positive change and 45.75% draft area was in negative change. It was observed that the area of the irrigation draft exceeded that of the groundwater recharge in most of the years. In spite of the construction of several shallow water harvesting structures in 2009–2010, sandstone aquifer zones showed meager impact on groundwater recharge. The best-fit line for the deviation between average groundwater fluctuation due to recharge and irrigation draft with time can be represented by the polynomial curve. Thus, over-exploitation of groundwater for agricultural crops has result in non-equilibrium between groundwater recharge and irrigation draft. 相似文献