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Yea Hwang MOON Ji Un OK Shin Ja LEE Jong Kyu HA Sung Sill LEE 《Animal Science Journal》2010,81(6):642-647
A comparative study among Korean native cow (Hanwoo), Holstein dairy cow, Korean native goat and crossbred sheep on the population and marker concentration of ruminal microbes, the activities of carboxymethylcellulase (CMCase), xylanase and amylase, and in situ dry matter (DM) degradability were conducted. Twelve ruminally cannulated animals, three of each species, were used. Animals were fed the same diet containing 40% formula feed and 60% rice straw at the level of 2.5% of body weight. Total viable microbial populations in the rumen fluid were significantly (P < 0.01) greater for bacteria and fungi in goat than those of Holstein. The protozoan population among ruminant species was the reverse from that of bacteria. The concentrations of 2,6‐diaminopimelic acid and chitin as markers for bacteria and fungi in the rumen fluid, respectively, were highest in goat, which is in accordance with the above population data. The concentration of aminoethylphosphonic acid as marker of protozoa was highest in Hanwoo and lowest in sheep (P < 0.01). Goat had the highest (P < 0.01) activities of all the enzymes investigated among ruminants. In situ effective degradation of the DM of rice straw was approximately 19% higher in the rumen of goat compared with other animals. 相似文献
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Stefano Pavan Zheng Zheng Mariya Borisova Petra van den Berg Concetta Lotti Claudio De Giovanni Pim Lindhout Hans de Jong Luigi Ricciardi Richard G. F. Visser Yuling Bai 《Euphytica》2008,162(1):91-98
The recessive gene ol-2 confers papilla-associated and race-non-specific resistance to tomato powdery mildew caused by Oidium neolycopersici. In order to facilitate marker assisted selection (MAS) in practical breeding programmes, we identified two simple sequence repeat (SSR) markers and one cleaved amplified polymorphic sequence (CAPS) marker which are linked to the resistance locus and co-dominantly inherited. Aiming to provide a base for ol-2 positional cloning, we used a large segregating F2 population to merge these markers with all the ol-2 linked amplified fragment length polymorphism (AFLP®) markers previously identified in an integrated genetic map. By screening a tomato bacterial artificial chromosome (BAC) library, we detected two BAC clones containing two expressed sequence tags (ESTs) homologous to the gene mlo, responsible for powdery mildew resistance in barley, as well as an ol-2-linked marker. Chromosomal mapping by Fluorescence in situ Hybridization (FISH) revealed major signals of the two BAC DNAs in the pericentromeric heterochromatin of the short arm of chromosome 4, in the same region where the ol-2 gene was previously mapped. The genetic and cytogenetic co-localisation between ol-2 and tomato mlo-homologue(s), in addition to the similarity of ol-2 and mlo resistances for both genetic and phytopathological characteristics, suggests that ol-2 is likely a mlo-homologue. Thus, a homology-based cloning approach could be more suitable than positional cloning for ol-2 isolation. 相似文献
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A. R. A. USMAN M. I. AL-WABEL Y. S. OK A. AL-HARBI M. WAHB-ALLAH A. H. EL-NAGGAR M. AHMAD A. Al-FARAJ A. AL-OMRAN 《土壤圈》2016,26(1):27-38
Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment.Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar(BC) and organic farm residues(FR) at different application rates of 0.0%(control), 4.0% and 8.0%(weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions. 相似文献
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Alberta油砂地区在两种水文流域森林土壤酸化敏感性研究 总被引：2，自引：0，他引：2
Input of large amounts of N and S compounds into forest ecosystems through atmospheric deposition is a significant risk for soil acidification in the oil sands region of Alberta. We evaluated the sensitivity of forest soils to acidification in two watersheds （Lake 287 and Lake 185） with contrasting hydrological regimes as a part of a larger project assessing the role of N and S cycling in soil acidification in forest ecosystems. Fifty six forest soil samples were collected from the two watersheds by horizon from 10 monitoring plots dominated by either jack pine （Pinus banksiana） or aspen （Populus tremuloides）. Soils in the two watersheds were extremely to moderately acidic with pH （CaCl2） ranging from 2.83 to 4.91. Soil acid-base chemistry variables such as pH, base saturation, Al saturation, and acid-buffering capacity measured using the acetic acid equilibrium procedure indicated that soils in Lake 287 were more acidified than those in Lake 185. Acid-buffering capacity decreased in the order of forest floor 〉 subsurface mineral soil 〉 surface mineral soil. The most dramatic differences in percent Ca and Al saturations between the two watersheds were found in the surface mineral soil horizon. Percent Ca and Al saturation in the surface mineral soil in Lake 287 were 15% and 70%, respectively; the percent Ca saturation value fell within a critical range proposed in the literature that indicates soil acidification. Our results suggest that the soils in the two watersheds have low acid buffering capacity and would be sensitive to increased acidic deposition in the region. 相似文献
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T. A. Borisova G. E. D'Souza D. Miller 《Aquaculture Economics & Management (Blackwell Science)》2013,17(1):73-98
Aquaculture industry development has been recognized to be an important step in improving a state's economy. However, local producers are facing significant competition from international, national, and other state producers. In this paper, the focus is on competition among local producers. The objective is to examine how interactions among industry participants determine prices and profitability of individual fish growers. The application involves the trout sector of the West Virginia aquaculture industry. Using a game theoretic framework, the Bertrand oligopoly model, and a combination of data from primary and secondary sources, price competition among producers is modeled under different supply and demand scenarios. Factors such as production volume and cost, location relative to market outlets, supply dependability, and proximity to other competitors and markets influence the profitability and competitive position of individual producers. Results also show that, as expected, the entrance of new growers results in a reduction of the sales price, and creates more favorable conditions for sales outlets. In contrast, the appearance of new sales outlets results in an expected increase in sales prices and producers' profits. Implications are derived for the West Virginia aquaculture industry and for other areas where an abundant natural resource base combined with a rapidly growing aquaculture industry are linked to a growing competition for markets and, hence, producer profitability and survival. 相似文献
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Brian Bennett Tatiana Borisova Anura Amarasinghe 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):331-345
ABSTRACT As adoption of genetic modification (GM) technologies grows, so do questions about consumer acceptance. While willingness to consume GM crop products has been studied extensively, similar studies of GM fish and seafood are lacking. Econometric analyses of U.S. survey data reveal that older, higher income, non African American males are most likely to consume GM fish and seafood. The results can contribute to our understanding of GM fish and seafood consumption decisions which, in turn, can be used to identify and exploit the niche market for GM fish products. 相似文献
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Regularities of the moisture regime of soddy-podzolic soils in Moscow Meshchera region under the impact of different surface planning operations were studied in the recreational zone. Soil moisture was determined in the samples taken with an auger. Data on the dynamics of soil moisture in 2014–2016 under different surface conditions—natural and artificial covers (backfill, mulching materials, and paving elements)— were obtained. A reliable (at the level of significance α = 0.05) increase in the soil water content in the 1-m-deep layer was observed on average for all years of research in three experimental variants: a “dry creek” cover with a possible additional inflow of water, mulching of a flat soil surface with shell rock, and mulching with pine needles. The increase in the soil water reserves on these plots reached 31.4, 22.5, and 19.4% in comparison with the control, where the average soil water reserves did not exceed 112 mm of the water layer and were close to the water content at 0.7 of the field water capacity (108 mm of the water layer). In comparison with the control, the unsealed areas of the soil within the rockery and within the paved surface were characterized by the decrease in the water storage by 4.0 and 11.2–30.7% during relatively wet and dry years, respectively. In wet years, this difference was statistically insignificant; in dry years, it was significant. The analysis of chronoisopleths of soil moisture attested to differentiation of the studied variants according to the degree of moistening of the soil profiles. 相似文献
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During the dry growing seasons of 2011 and 2012, mulching of a sod-podzolic soil with coniferous litter maintained the moisture of the upper soil layer at high and fairly stable levels. By varying the spruce litter thickness, it is possible to maintain optimum conditions for acidophilic plants characterized by varying responses to the soil moisture content. In dry years (PER 0.5–0.8), the degree of influence of the mulch layer on the soil moisture content is closely related to the magnitude of the moisture deficit calculated for a warm season. 相似文献
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Vladimir L.Gavrikov Ruslan A.Sharafutdinov Anastasyia A.Knorre Nina V.Pakharkova Olga M.Shabalina Irina N.Bezkorovaynaya Irina V.Borisova Marina G.Erunova Rem G.Khlebopros 《林业研究》2016,27(4):907-912
In the context of global carbon cycle management, accurate knowledge of carbon content in forests is a relevant issue in contemporary forest ecology. We measured the above-ground and soil carbon pools in the darkconiferous boreal taiga. We compared measured carbon pools to those calculated from the forest inventory records containing volume stock and species composition data. The inventory data heavily underestimated the pools in the study area(Stolby State Nature Reserve, central Krasnoyarsk Territory, Russian Federation). The carbon pool estimated from the forest inventory data varied from 25(t ha-1)(low-density stands) to 73(t ha-1)(highly stocked stands). Our estimates ranged from 59(t ha-1)(lowdensity stands) to 147(t ha-1)(highly stocked stands). Our values included living trees, standing deadwood, living cover, brushwood and litter. We found that the proportion of biomass carbon(living trees): soil carbon varied from99:1 to 8:2 for fully stocked and low-density forest stands,respectively. This contradicts the common understanding that the biomass in the boreal forests represents only16–20 % of the total carbon pool, with the balance being the soil carbon pool. 相似文献