首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 0 毫秒
1.
Antioxidants are usually considered with regard to plant defense mechanisms due to the oxidative stress or their importance for human health or both. In the present research, a comprehensive study was made to test the relationship between the antioxidant content in apple peel and the whole fruit in two growing seasons. Antioxidants were mainly localized in the apple peel, but cultivars exhibited very high biodiversity in the distribution pattern. High or very high correlation coefficients between apple peel glutathione reductase and catalase activity as well as ascorbate, glutathione, and anthocyanins concentrations and the whole fruit were discovered on the basis of both fresh and dry weight basis in two growing seasons: 2004 and 2005. In the case of ascorbate peroxidase activity and phenolics or flavonol contents, it was proven only in 2005. It seems that apple peel could be a good marker of health values as well as antioxidant potential of apple fruit. Additional arguments, as compared to the previous study, were incorporated to support the suggestion of glutathione reductase as worth considering as an environmental stress marker and/or signalling molecule.  相似文献   

2.
设施栽培油桃果实发育期钙营养特性的比较研究   总被引:3,自引:0,他引:3  
以设施栽培的曙光油桃为试材,分析了果实发育过程中果实不同部位、叶片、新梢、根系的钙含量变化,并与露天栽培的树体进行了比较。结果表明:1)设施内油桃果皮钙含量呈先升后降趋势,而设施外的呈先降后升趋势;果实其他部位的钙含量的变化在设施内和设施外的较为一致,果肉和果柄的钙含量均随果实发育而含量降低,果核钙含量呈先升后降的趋势,种子钙含量在生长后期波动较大;油桃果皮和果肉钙含量均表现为设施外的>设施内的。2)随果实的生长发育,设施内、外油桃叶片钙含量逐渐增加,至成熟期达到稳定水平;设施内油桃新梢钙含量前期增加后期降低,至果实成熟期又出现增长高峰,设施外油桃的新梢钙含量波动较大,出现三次高峰。3)设施内油桃根系钙含量变化较为平稳,设施外的根系钙含量变化较大。4)设施栽培的油桃树体各器官钙含量均低于露天栽培的钙含量。  相似文献   

3.
4.
The cultivated varieties and landraces of Cucurbitaceae growing in Egypt are presented, 27 taxa, belonging to three genera, six species, and five subspecies. These characters are arranged according to their usefulness for identifications as follow: fruit characters, seed characters and trichome type. Fruit characters are a good taxonomic tool at varietal level when combined with the other vegetative characters. Two keys to 27 cultivated varieties of Cucurbitaceae (Cucumis, Cucurbita and Luffa) were constructed using the DELTA software system. One key is used for identification, and then the other is used as a confirmatory key. Those keys were built using 36 morphological characters include vegetative, floral, fruit and seed characters. There is a significant correlation between seed size and growth parameters. The growth parameters of the studied taxa included leaf length/size, petiole length and corolla length. There is a highly positive, significant correlation between seed volume and leaf size (r = 0.81831, P ≤ 0.001), seed volume and petiole length (r = 0.79112, P ≤ 0.001), seed volume and leaf length (r = 0.83566, P ≤ 0.001), and seed volume and corolla length (r = 0.59108, P ≤ 0.001).  相似文献   

5.
6.
The present study, using RAPD analysis, was undertaken to characterize genetic variation in three forms of V. angularis, cultivated, wild and weedy forms, and their relationships. The materials used consisted of 171 individuals (plants) or cultivars from 23 populations including 5 wild populations, 6 weedy populations, 6 cultivated populations and 6 populations with plants having wild and weedy or intermediate morphology, denoted here as complex populations. The materials used were collected on Honshu Island, Japan and seeds collected directly from the field were germinated for DNA extraction. In addition, 6 landrace accessions of V. angularis from the genebank were also analyzed. Genetic variation was highest in the wild form (Hg= 0.132; GD = 0.388), followed by the weedy form (Hg= 0.124; GD = 0.341) and the least in the cultivated form (Hg= 0.079; GD = 0.274). Intra-population genetic variation was high in the weedy and in the wild populations. However, inter-population was greater than intra-population genetic variation for all groups of populations studied in the V. angularis complex. 93% of the total diversity in the present study was exhibited by plants from complex populations and specific RAPD bands were found in these populations. Our results provide evidence that complex populations would be a logical focus for efforts to conserve the V. angularis complex in situ. Our results suggest that weedy populations are usually an ecotype of the wild form adapted to a different habitat.  相似文献   

7.
The escalating threats to ecosystems worldwide have lead to a need for efficient methods to breed animals in captivity and to prepare captive-born animals for release back to the wild. However, life in captivity may lead to modifications in the animal’s behaviour mainly by genetic changes, including behavioural adaptations such as reduced predator responses. Such modifications may seriously affect survival after a reintroduction. The present study was a first screening of behavioural and morphological variation between different captive populations in standardized test situations using red junglefowl as a model species. The birds were tested in three different test situations in order to measure anti-predatory behaviour, social behaviour and exploratory behaviour. The results of this study clearly show that there are behavioural differences between the captive populations which potentially can be crucial for the animals in a reintroduction situation. However, the extent to which these differences are due to genetic changes caused by small breeding populations or adaptations to the different captive environments is not yet known, although morphological differences found suggest that genetic variation may cause some of the behavioural differences as well. The differences found imply that life in captivity can affect an animal’s behaviour and even though the red junglefowl is merely used as a model here, this suggests that these aspects may be important to consider also in other species where reintroduction is a more central motive for keeping the animals in captivity.  相似文献   

8.
9.
Citrus germplasm is conserved in genebanks at sites around the world to provide genetic resources for breeding and research programs. The value of genebank collections is particularly evident as diseases and climate change threaten citrus production areas. We provide historical, inventory, and maintenance information about national citrus collections in Russia and in the United States. The Russian Research Institute of Floriculture and Subtropical Crops (RRIFSC) in Sochi, Russia maintains a collection of 132 citrus accessions representing 50 taxa. Southern Russia is one of the most northerly citrus growing areas in the world and many accessions in the RRIFSC collection were specifically selected for cold tolerance to facilitate citrus production in this region. Tree response data taken during the frequent severe winters in Sochi has provided an understanding of the relative cold tolerance of many RRIFSC accessions. Particularly noteworthy is the array of cold-tolerant lemon accessions maintained at the RRIFSC. The Aurantioideae collections at the United States Department of Agriculture (USDA), Agricultural Research Service (ARS) National Clonal Germplasm Repository for Citrus and Dates (NCGRCD) and at the University of California Citrus Variety Collection in Riverside, California, maintain 1328 accessions of citrus cultivars and wild relatives. Because of federal and state quarantine regulations, accessions at this facility are tested for graft-transmissible pathogens and undergo therapy to eliminate known pathogens. In contrast to Sochi, desert-adapted lemon and grapefruit varieties are a major interest of the California-based collection. The collection of citrus and citrus relatives is being screened for resistance and/or tolerance genes to diseases such as huanglongbing which is currently threatening the US citrus industry. Through collaborative exchange efforts, the diversity in the two genebanks could be expanded to increase availability of desirable genetic resources to breeding and research communities throughout the world.  相似文献   

10.
In vitro and in vivo studies of the health and nutritional properties of durian (Durio zibethinus Murr.) were compared with snake fruit (Salacca edulis Reinw.) and mangosteen (Garcinia mangostana). Dietary fibers, minerals, and trace metals were comparable. Total polyphenols (mg of GAE/100 g of FW) and flavonoids (85.1+/-6.1) were significantly higher (p<0.05) than in snake fruit (217.1+/-13.2 (mg of CE/100 g of FW)), durian (309.7+/-19.3 and 61.2+/-4.9), and mangosteen (190.3+/-12.1 and 54.1+/-3.8). Antioxidant activity (microM TE/100 g of FW) of durian measured by DPPH and ABTS assays (228.2+/-13.4 and 2016.3+/-81.1) was significantly higher (p<0.05) than in snake fruit (110.4+/-7.9 and 1507.5+/-70.1) and mangosteen (79.1+/-5.9 and 1268.6+/-62.3). HPLC/DAD analysis of durian (microg/100 g of FW) showed that quercetin (1214.23+/-116.7) was present at levels three times that of caffeic acid, and twice as high as p-coumaric and cinnamic acids. The correlation coefficients between the bioactive compounds of fruits and their antioxidant activities were high (R2=0.99). Male Wistar rats (25) were divided into five dietary groups: the control group was fed the basal diet (BD); in addition to BD, the cholesterol (Chol) group was supplemented with 1% of Chol; the diets of the Chol/Durian, Chol/Snake, and Chol/Mangosteen groups were supplemanted with 5% of these fruits, respectively. It was found that diets supplemented with durian, and to a lesser degree with snake fruit and mangosteen, significantly hindered the rise in plasma lipids and the decrease in antioxidant activity. The nutritional values were comparably high. In conclusion, it could be suggested that inclusion of studied tropical fruits, especially durian, in known disease-preventing diets could be beneficial.  相似文献   

11.
中欧温室规范中风荷载取值的对比   总被引:2,自引:1,他引:1  
童乐为  金健  周锋 《农业工程学报》2013,29(21):174-181
为了更好地指导温室结构设计与优化,该文对中欧温室结构规范中风荷载的取值方法进行了比较。首先简要比较了中欧温室规范中风荷载的定义和计算方法,然后分别对2种规范中关于基本风压、风压高度变化系数及结构体型系数的规定进行了详细地探讨。比较结果表明,中欧温室风荷载在计算思路上相近,但在参数的定义及选取方面,中国温室荷载规范存在一些不合理性。该文还根据中欧的不同规定,利用结构分析软件SAP2000对某典型温室进行了风荷载效应的计算对比,结果表明采取欧洲温室规范计算所得的结构内力值更高,并对中国温室荷载规范进一步的修订提出了一些建议。  相似文献   

12.
BACKGROUND: In sub-Saharan Africa, underweight and micronutrient deficiencies account for an estimated 25% of the burden of disease. As the coverage of national health systems expands, increased opportunities exist to address the needs of children and women, the most vulnerable to these deficiencies, through high-quality nutrition services. OBJECTIVES: To assess health providers' knowledge and practice with regard to essential nutrition services for women and children in Burkina Faso, Mozambique and Niger, in order to assist the development of a standard guide and tools to assess and monitor the quality of the nutrition services delivered through national health systems. FINDINGS: The three surveys reveal the extent of missed opportunities to deliver nutrition services during routine prenatal, postnatal and child-care consultations for the prevention and treatment of highly prevalent nutritional deficiencies. CONCLUSION: A commitment to improving the quality of facility-based nutrition services is necessary to impact on the health outcomes of women and children 'covered' by national health systems. Rigorous assessment and monitoring of the quality of nutrition services should inform health programme and policy development. Building on the lessons learned in these three assessments, Helen Keller International has developed a standard Guide and Tools to assess the quality of the nutrition services delivered through national health systems. These tools can be adapted to assess ongoing nutrition services in health facilities, provide a framework for nutrition programming, inform the development of pre-service as well as in-service nutrition training curricula for providers, and evaluate the impact of nutrition training on providers' practices.  相似文献   

13.
14.
The burgeoning global market for soil microbial inoculants for use in agriculture is being driven by pressure to increase sustainable crop production by managing pests and diseases without environmental impacts. Microbial inoculants, based predominantly on bacteria and fungi, are applied to soil as alternatives to conventional inorganic fertilizers (biofertilizers) or to carry out specific functions including biocontrol of pests and diseases (biopesticides), or for bioremediation and enhancement of soil characteristics. While some soil inoculants such as rhizobia have a long and successful history of use, others have performed inconsistently in the field and failed to live up to their promise suggested by laboratory testing. A more precise understanding of the ecology and modes of action of inoculant strains is key to optimizing their efficacy and guiding their targeted use to situations where they address key limitations to crop production. This will require greater collaboration between science disciplines, including microbiology, plant and soil science, molecular biology and agronomy. Inoculants must be produced and formulated to ensure their effective establishment in the soil and practicality of implementation alongside existing cropping practices. New approaches to strain selection and construction of beneficial microbial consortia should lead to more efficacious inoculant products. Extensive and rigorous field evaluation of inoculants under a range of soil and environmental conditions has rarely been undertaken and is urgently needed to validate emerging inoculant products and underpin successful implementation by growers, especially in a market that is largely unregulated at present.  相似文献   

15.
针对红壤、棕壤、褐土、黑土4种中国典型的Cd污染土壤,应用Ca(OH)2、Ca(H2PO4)2以及层状双金属氢氧化物(Layered Double Hydroxides,LDHs)、水化氯铝酸钙(CaAl-Cl LDH)开展钝化修复,并从土壤Cd的生态风险和健康风险角度进行修复效果对比研究。分析钝化剂对土壤pH值、土壤Cd的赋存形态以及土壤Cd直接经口摄入的生物可给性的影响,并对修复机理进行深入探究。结果表明,在Ca(OH)2、Ca(H2PO4)2和CaAl-Cl LDH各自相对最优施用量下,3种钝化剂均可显著降低土壤Cd的活性系数(P<0.05),平均降幅分别为16.1%、56.9%和29.2%,可降低土壤Cd的作物吸收量及Cd对周边生态环境的风险。此外,施用CaAl-Cl LDH能显著且更为有效地降低土壤Cd的生物可给性(P<0.05)及Cd对人体的健康风险,在胃和小肠阶段的平均降幅为19.2%和33.0%,其中胃阶段分别达到施用Ca(OH)2和Ca(H2PO4)2的3.11和1.99倍,小肠阶段为5.99和2.72倍。该研究为Cd污染土壤钝化修复剂的开发、改进和选择提供了科学依据和参考。  相似文献   

16.

Sugarcane (Saccharum spp.) is a special crop plant that underwent anthropogenic evolution from a wild grass species to an important food, fodder, and energy crop. Unlike any other grass species which were selected for their kernels, sugarcane was selected for its high stem sucrose accumulation. Flowering in sugarcane is not favored since flowering diverts the stored sugar resources for the reproductive and developmental energy needs. Cultivars are vegetatively propagated and sugarcane breeding is still essentially focused on conventional methods, since the knowledge of sugarcane genetics has lagged that of other major crops. Cultivar improvement has been extremely challenging due to its polyploidy and aneuploidy nature derived from a few interspecific hybridizations between Saccharum officinarum and Saccharum spontaneum, revealing the coexistence of two distinct genome organization modes in the modern variety. Alongside implementation of modern agricultural techniques, generation of hybrid clones, transgenics and genome edited events will help to meet the ever-growing bioenergy needs. Additionally, there are two common biotechnological approaches to improve plant stress tolerance, which includes marker-assisted selection (MAS) and genetic transformation. During the past two decades, the use of molecular approaches has contributed greatly to a better understanding of the genetic and biochemical basis of plant stress-tolerance and in some cases, it led to the development of plants with enhanced tolerance to abiotic stress. Hence, this review mainly intends on the events that shaped the sugarcane as what it is now and what challenges ahead and measures taken to further improve its yield, production and maximize utilization to beat the growing demands.

  相似文献   

17.
Qin  Chao  Zheng  Fenli  Xu  Ximeng  Wu  Hongyan  Shen  Haiou 《Journal of Soils and Sediments》2018,18(4):1679-1690
Journal of Soils and Sediments - Rills are basic pathways for runoff, sediment, and pollutant transport at hillslopes within agricultural watershed. The objectives of this study were to investigate...  相似文献   

18.
为了进行乌冈栎生存状况评价并提出相应的保护策略,在瑞云山风景名胜区、桃源洞风景名胜区、邵武将石省级自然保护区和南平茫荡山省级自然保护区,用立木级结构代替年龄结构、重要值、物种多样性、群落相似性系数等指标对乌冈栎群落特征进行研究。结果表明:在4个研究区,乌冈栎均属于衰退型种群,瑞云山和桃源洞风景名胜区的赤楠种群将替代乌冈种群,种群衰退趋势明显;瑞云山风景名胜区和邵武将石省级自然保护区乌冈栎群落优势种显著,物种组成也丰富,而桃源洞风景名胜区和南平茫荡山省级自然保护区乌冈栎群落优势种显著,但物种组成少;在4个研究区之间的乔木层和草本层,Shannon-Wiener指数变幅较大,而Pielou均匀度指数乔木层、灌木层和草本层变幅均不大;瑞云山风景名胜区与桃源洞风景名胜区、邵武将石省级自然保护区与南平茫荡山省级自然保护区群落相似性系数均很大,其中,瑞云山风景名胜区与邵武将石省级自然保护区的群落相似性系数最大(0.65)。  相似文献   

19.
In connection with our previous biochemical comparative study on healthy and diseased Picea trees from polluted areas we have now measured the nutrient contents in the same needle samples. 540 small samples were processed in a very short time (25 min for each sample) using microwave digestion in HNO3. Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Sr, and Zn were then simultaneously determined by ICP-AES analysis. This rapid and simple micromethod is briefly described and results of the comparison between healthy and diseased Picea trees are presented and discussed in the light of our previous results, particularly that of putrescine and polyamines which have been reported to accumulate in response to cell mineral deficiencies.  相似文献   

20.
Variation for 24 morphological traits measured in a greenhouse environment and 36 randomly amplified polymorphic DNA (RAPD) markers was assessed among 318 wild octoploid strawberry (Fragariaspp.) genotypes from diverse habitats across the northern USA. RAPD marker frequencies and certain leaf and flower morphology traits (petiole color, leaf mass/area ratio, leaflet length and width, flower and receptacle diameter, petal width, flowers/inflorescence) were significantly different between the F. chiloensis-platypetala and F. virginiana-glauca species complexes. The proportion of variation accounted for by provenance effects was lower for the RAPD markers than for most morphological traits, especially in the F. virginiana-glauca species complex. Morphological traits of potential adaptive importance group the collection into provenances within each species-complex, and reflect the significant habitat and geographic differences across the region from which the germplasm was collected. Variation among populations within provenances was low for the molecular and most morphological traits, with a much larger amount of variability among plants within populations. Most of the variation for the presumably more selectively-neutral RAPD data was among plants within populations and populations within provenances rather than among the provenances that were recognized based on morphological traits, especially in the F. virginiana-glauca complex. Patterns of diversity for morphological traits must be considered, along with more selectively-neutral molecular characters such as RAPDs, to formulate effective sampling strategies and to properly estimate the quantity and apportionment of diversity within this germplasm.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号