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11.
Association mapping identifies quantitative trait loci (QTLs) by examining the marker-trait associations that can be attributed to the strength of linkage disequilibrium between markers and functional polymorphisms across a set of diverse germplasm. In this study, association mapping was performed to detect QTL-linked and genome wide SSR markers linked to phenolic compounds of extraction meal in a population of 49 genetically diverse oilseed rape cultivars of dark-seeded, winter-type oilseed rape accessions. Correction for population structure was performed using 559 genome wide SSR markers. Results showed that seed colour is an important contributor to seed meal quality. Totally, 52 SSR markers linked to phenolic compounds were detected, five of them being QTL linked markers. Some of these markers were already mapped on Brassica napus chromosomes that contain known QTL controlling oilseed rape meal quality traits. Our results demonstrate that association mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection.  相似文献   
12.
Much of inland Australia has been in perpetual drought since 1997 except during 2010 when above average rainfall occurred. It has been the worst drought since 1788 when European settlement began. Water scarcity poses a serious threat to the sustainability of the irrigated agriculture in major irrigation systems across the Murray-Darling Basin (MDB). There is a need for water-saving measures and a structured approach to assess water loss in earthen supply channels. This paper presents such an approach to assess and reduce seepage losses for improving irrigation efficiencies. Main elements of this approach are the following: field measurements, hydrologic modelling, potential options for seepage reduction, economic analysis and financing water-saving investments. Using data from two irrigation systems in the southern MDB, a case is made for reducing seepage water losses in irrigation supply channels in a cost-effective manner using low-cost technologies. Increasing the level of security for investments in water-saving programs provides incentives to key stakeholders to achieve water-saving targets. Considering the value of water recovered from reducing seepage loss at irrigation system level, this study demonstrates how reducing just one component (seepage) from the total water losses in irrigation systems can help improve water supplies as well as the environmental flows. Potential options for financing infrastructure improvement for saving irrigation water are proposed and discussed.  相似文献   
13.
Lycoriella auripila (Winnertz) (Diptera: Sciaridae) is one of the most frequently seen pests of cultivated mushrooms, Agaricus bisporus (Lange) Imbach. The effects of different concentrations of diazinon, imidacloprid and deltamethrin, and tobacco extract were tested against L. auripila on varieties 737 and A15 of button mushroom. Also, economic injury level (EIL) of fungus gnat was evaluated on variety 737. Different varieties of button mushroom were cultured and weight of harvested mushrooms was recorded to provide an estimate of yield loss. A linear regression analysis was used to determine the relationship between pest density and mushroom yield. Imidacloprid was the most effective insecticide against L. auripila on both varieties and caused 100 % control at the highest tested concentration. The lowest concentration of diazinon (500 ppm a.i.) increased pest emergence on 737 and A15. This is possibly due to the hormoligosis. Deltamethrin and tobacco extract were ineffective against fungus gnat between both varieties. High levels of adults of L. auripila were associated with significant reduction in mushroom yield. EIL were calculated according to the number of L. auripila required to cause the critical yield loss from the predictive model and by control costs, mushroom price, and the reduction of injury due to spraying by imidacloprid and diazinon. The lowest values of EIL were related to imidacloprid compared with diazinon. This is due to the different efficiency of these two insecticides, for it causes mortality in population of L. auripila. Based on this research, for the first time clear EILs are introduced to the button mushroom growers for treatment of L. auripila.  相似文献   
14.
为了查明阿尔泰山两河源国家级自然保护区树附生地衣物种组成成分,以及探讨影响该地区树附生地衣群落分布格局与环境因素之间的关系,以附生地衣覆盖度为指标,应用除趋势对应分析(DCA)对样点进行分组,运用典范对应分析(CCA)分析附生地衣分布与环境因素的关系,结果表明:1)阿尔泰山两河源自然保护区树附生地衣共有49种隶属于15科30属。2)根据DCA分析将该地区树附生地衣划分为3个样点组,样点组1共有地衣22种,总盖度为2.639%,物种多样性指数为1.603;样点组2共有地衣27种,地衣总盖度为3.717%,物种多样性最大为1.972;样点组3:共有地衣12种,地衣总覆盖度为1.036%,物种多样性最小量为0.871。3)CCA排序结果表明:低海拔区,人为干扰强度高,地衣多样性较低;中海拔区,森林郁闭度高,湿度适中,干扰较少,地衣多样性较高;高海拔区,森林郁闭度较低,树种较少,光强度较强,干扰较少,主要以壳状地衣为主,多样性较低。  相似文献   
15.
We evaluated,for the first time in Turkey,the productivity of a feller buncher during clear-cut operations of two Brutian pine stands located in Canakkale,northwestern Turkey with different diameter classes and terrain conditions.In the first stand with 24.6 cm average DBH,the feller buncher cut full trees and moved them to roadside.In the second stand with 34.3 cm average DBH,the feller buncher cut trees in two stages due to their larger diameters and the relatively steep and rough terrain conditions of the site.The effects of specific stand features,DBH and tree height measurements were assessed through statistical analysis in relation to productivity.The results indicate that the average productivity for the first stand was about 118 m^3h^-1,while it was about 80 m3h-1 in the second stand.Even though tree diameter and volume were higher in the second stand,productivity decreased by32.3%due to extra time spent on the two-stage cutting operation.The results revealed that harvesting operations should be planned carefully and the right equipment selected by accounting for different tree sizes,terrain conditions and machine specifications in order to better understand their effects on production.  相似文献   
16.
Construction of new roads in rural areas is closely linked to market accessibility and economic growth. It also leads to exploitation of natural resources that may accelerate deforestation. These conflicting effects of an improved road network on rural development and depletion of forest resources present a serious challenge to policy makers interested in sustainable development. This paper investigates the effects of road networks on biological and socio-economic behaviour. The analysis was conducted by using a non-linear bio-economic model for a community in southern Zagros, Iran where they manage the adjoining forest according to traditional rules. Data for the model were obtained through village surveys and published resources. The model followed a holistic approach by incorporating a number of livelihood activities, such as, crop cultivation, goat husbandry, charcoal production and hiring out of community labour, along with several logical resource constraints. It was run over a period of 45 years. The results showed that new roads can either fuel forest degradation or contribute to forest protection depending on the choice of policy options. The study concludes that construction of new roads should be accompanied by policies aimed at higher state controls over newly accessible forest areas through regulatory measures, creation of new non-farm employment opportunities and strengthening of traditional institutions through providing extension services for local communities and facilitating NGO involvement so as to minimize the adverse effects on forest resources.  相似文献   
17.
A study was conducted to determine the effect of macronutrients (NPK) in alleviating the adverse effects of simulated acid rain (SAR) on sunflower (Helianthus annuus L.). In addition to control (T0), three different treatments, i.e., SAR (HNO3) of pH 3 (T1), NPK (T2), and SAR + NPK (T3), were applied on two sunflower cultivars, i.e., FH-37 and FH-385. The experiment was set up in CRD (completely randomized design) with four replicates of each treatment. Chlorophyll a, b, total chlorophyll, carotenoids, ion contents (NPK), and gas exchange characters were determined. Acid rain remarkably reduced the chlorophyll pigments, NPK ionic content, photosynthetic rate, transpiration rate, and stomatal conductance, while an increase in internal CO2 concentration and water use efficiency was noted in both the cultivars. The mixture of NPK with SAR exhibited positive impact to lessen the toxicity caused by acid. Among cultivars, FH-385 showed better performance as compared to FH-37.  相似文献   
18.
A solution culture study was conducted to compare the phosphorus (P) remobilization efficiency of four wheat cultivars under induced P deficiency. Wheat cultivars, i.e. Sarsabz, NIA-Sunder, NIA-Amber and NIA-Saarang were initially grown on adequate P nutrition for 30 days and then exposed to P-free nutrient solution for next 15 days to study P remobilization. Completely randomized design (CRD) with ten replicates per cultivar was employed. Cultivars varied for biomass production, P concentration, P uptake, and P utilization efficiency at both harvests. Overall, more than 75% of absorbed P was mobilized from older leaves to younger leaves as well as roots of all cultivars during P-omission period. However, cultivars could not produce significant variations (P < 0.05) in P remobilization, which implied that P remobilization was only a stress response to P deficiency in wheat cultivars and it could not be related to P utilization efficiency of these cultivars.  相似文献   
19.
Growth stage effects on distribution of mineral nutrients or beneficial elements phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chloride (Cl), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), molybdenum (Mo), sodium (Na), silicon (Si) and nickel (Ni), and the elements bromine (Br), rubidium (Rb), strontium (Sr), barium (Ba), lanthanum (La), cerium (Ce), and uranium (U) in two barley (Hordeum vulgare L.) cultivars and how the distribution of these elements changed were determined during the 2006–2007 growing season in a field experiment. Barley plants were sampled from the field at shooting, heading, soft dough, hard dough and harvest stages, and mineral nutrients and other elements concentrations of spike, flag leaf, old leaf, and stem samples were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Distribution patterns varied considerably from element to element. At the end of the season much of the Ca, Mg, S, Si, Fe, Mn, Cu, Ni, Sr, Ba, La, Ce, and U were located in the spikes. However, much of the P, K, Zn, Cl, Na, Br, and Rb remained in the old leaves or stem.  相似文献   
20.
Diacetyl (DA), a natural butter flavorant, is a causative agent for the lung disease obliterative bronchiolitis. Mutagenic properties of 1,2-dicarbonyls have previously been empirically linked to their possible interaction with DNA nucleobases. This study for the first time identifies chemically the adduct of DA with 2-deoxyguanosine. Selective reactivity of DA with 5'-TTTGTTTTT-3' over 5'-TTTTTTTTT-3' indicated its propensity to modify specifically the guanosine residue. Treatment of plasmid DNA, pBR322, with DA induced changes in electrophoretic mobility that are typical of ternary structure disruption. Such DNA nucleobase interaction of DA translated into increased apoptosis in DA-treated SH-SY5Y cells in a dose-dependent manner (IC(50) = 0.114 ± 0.0421 mM). The traditional carbonyl scavengers metformin, 2-thiobarbituric acid, and d-penicillamine protected cells from DA toxicity in proportion to their rates of reaction with DA, with d-penicillamine causing a maximal increase in the IC(50) to 5.23 ± 0.0992 mM when co-incubated with DA.  相似文献   
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