小冠花引种试验简结(1982—1985年)     

肖凤 《新疆农业大学学报》1987,(3)

历时四年(1982—1985年)的引种试验证明,小冠花(Coronilla varia L.)确是很好的牧草、绿肥等多用途的植物,在乌鲁木齐的气候条件下,一般年分能够越冬,但遇冬季十分寒冷的年分,常全部死亡,不能越冬。新疆今后宜在冬季比乌鲁木齐市暖和的地区进一步地作引种试验。  相似文献   

Weed detection for site‐specific weed management: mapping and real‐time approaches     

F LÓPEZ‐GRANADOS 《Weed Research》2011,51(1):1-11

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土壤学的新分支——计量土壤学(Pedometrics)的形成与发展   总被引：1，自引：0，他引：1  

史舟  RMLark 《土壤学报》2007,44(5):919-924

计量土壤学(Pedometrics)是土壤学一个新兴的分支,是经过澳大利亚、美国、欧洲等许多国家的土壤学家近三四十年的努力,而逐渐发展建立起来的。在2002年第17届国际土壤科学大会后成立了计量土壤专业委员会,与传统的土壤地理、土壤发生、土壤分类等专业委员会并列。本文就国际上计量土壤学产生的理论背景和技术背景,以及发展过程做一个综合的介绍,对我国在计量土壤学方面的相关工作进行了总结和讨论。  相似文献   

The conservation effects of meadow bird agreements on farmland in Zeeland, The Netherlands, in the period 1989-1995     

David Kleijn  Gerard J.C van Zuijlen 《Biological conservation》2004,117(4):443-451

Meadow bird agreements are the most important Dutch agri-environment schemes, both in terms of uptake and of aim. Meadow bird agreements postpone the first agricultural activities on grassland thus reducing egg and chick mortality due to mowing or grazing. We investigated the conservation effects of meadow bird agreements by analysing settlement densities of meadow birds on 34 fields in 1989, 1992 and 1995 in the province of Zeeland, The Netherlands. We compared territory numbers on fields with meadow bird agreements with paired nearby control fields that were conventionally managed. In 1995, the number of territories of black-tailed godwit (Limosa limosa), lapwing (Vanellus vanellus) and the total number of meadow birds were significantly higher on fields with conservation management. These differences were partly caused by the higher quality (i.e. higher groundwater level) of fields with meadow bird agreements. Population trends were similar on fields with and without meadow bird agreements and the observed difference in settlement density in 1995 was already present in 1989. Furthermore the effectiveness of the scheme did not increase with time. Thus we found no conclusive evidence that the conservation measures themselves did result in higher territory numbers. Currently, we do not have sufficient ecological and behavioural knowledge of meadow birds to explain why the higher reproductive success does not result in higher settlement densities.  相似文献   

The value of marine ecological data collected by volunteers     

Judy Foster-Smith  Stewart M Evans 《Biological conservation》2003,113(2):199-213

Volunteers are potentially a huge scientific resource but there is scepticism among some scientists about the reliability of data collected by inexperienced people. An assessment was therefore made of the ability of a group of 13 volunteers, recruited by the Earthwatch Institute, to collect valid data in a project that aimed to map the distribution and abundance of common littoral organisms on shores of the Isle of Cumbrae, Scotland. The volunteers ranged considerably in age, educational background, knowledge and experience. They were capable of performing straight-forward tasks, such as learning to identify species, recording their occurrence on specific parts of the shore and making length measurements of samples of some gastropods. They made some recording errors during the fieldwork but similar errors were also made by experienced scientists and it is recommended therefore that all ecological studies should include quality control of data whether or not they involve volunteers. The assessment of abundance was problematic. Volunteers’ assessments for some species were inconsistent and there is evidence that individuals interpreted the scale in different ways. It is suggested that these problems stemmed from: (1) a lack of field experience in the volunteers; (2) inadequate guidelines on the use of the abundance scale; and (3) insufficient training before field surveys commenced. However, projects themselves may benefit in unexpected ways from the input of volunteers. They contributed taxonomic and computing skills to the current project. Members of the group also offered new insights by developing hypotheses relating to populations of gastropods during their fieldwork. These were tested and could have formed the basis of longer-term research programmes. There were also educational benefits for the volunteers who were involved in the project. These included increased knowledge of marine issues and clearer understanding of the ways in which scientific studies are undertaken.  相似文献   

Identification of quantitative trait loci for grain yield, seed protein concentration and maturity in field pea (Pisum sativum L.)     

B. Tar'an  T. Warkentin  D.J. Somers  D. Miranda  A. Vandenberg  S. Blade  D. Bing 《Euphytica》2004,136(3):297-306

Breeding efforts to improve grain yield, seed protein concentration and early maturity in pea (Pisum sativum L.) have proven to be difficult. The use of molecular markers will improve our understanding of the genetic factors conditioning these traits and is expected to assist in selection of superior genotypes. This study was conducted to identify genetic loci associated with grain yield, seed protein concentration and early maturity in pea. A population of 88 recombinant inbred lines (RILs) that was developed from a cross between 'Carneval' and 'MP1401' was evaluated at 13 environments across the provinces of Alberta, Manitoba and Saskatchewan, Canada in 1998, 1999 and 2000. A linkage map consisting of 193 AFLPs (amplified fragment length polymorphism), 13 RAPDs (random amplified polymorphic DNA) and one STS (sequence tagged site) marker was used to identify putative quantitative trait loci (QTL) for grain yield, seed protein concentration and early maturity. Four QTL were identified each for grain yield and days to maturity, and three QTL were identified for seed protein concentration. A multiple QTL model for each trait showed that these genomic regions accounted for 39%, 45% and 35% of the total phenotypic variation for grain yield, seed protein concentration and days to maturity, respectively. The consistency of these QTL across environments and their potential for marker-assisted selection are discussed in this report.  相似文献   

Extensive Theorms of Topolgical Degree for Multi-valucd Mapping     

WEI Shu-guang  ZHANG Mou 《保鲜与加工》2004,(6):99-101

The extension of topological degree for single-valued mapping is introduced by Chen wenyuan in \. We firstly prove an inequality for Hausdorff metric in Banach space. Then, by using the inequality, it has been established that extension of topolical degree for upper semicontinuous multi-valued mapping.  相似文献   

Molecular mapping of major genes and quantitative trait loci determining flowering time in response to photoperiod in barley   总被引：8，自引：0，他引：8  

A. Börner    G. H. Buck-Sorlin  P. M. Hayes    S. Malyshev  V. Korzun 《Plant Breeding》2002,121(2):129-132

Two major genes (eam8 and eam10) and two quantitative trait loci (QTL) determining flowering time in barley were associated with restriction fragment length polymorphism markers. The loci eam8 and eam10 were found to map in regions of chromosomes 1HL and 3HL, respectively, already estimated from previous classical linkage analyses. While investigating doubled haploid lines of a spring habit barley mapping population, two QTL for flowering time were detected on chromosomes 1HL and 7HS, respectively, when the material was grown under long photoperiod conditions. When growing the same lines under short photoperiod, no QTL were discernible. Allelic and homoeologous relationships with flowering time loci described earlier in barley and other Triticeae species are discussed.  相似文献   

水稻新黄绿叶基因YGL9的分子定位     

张天泉  郭爽  邢亚迪  杜丹  桑贤春  凌英华  何光华 《作物学报》2015,41(7):989-997

叶色突变体是研究高等植物光合作用、叶绿素代谢途径、叶绿体结构与功能分子机制的理想材料。本研究从EMS(ethyl methane sulfonate)处理的缙恢10号(Oryza sativa L.ssp.indica)诱变群体中发现了一个苗期呈现黄绿色、抽穗期渐变为淡绿色的叶色突变体,命名为yellow green leaf 9(ygl9)。与野生型相比,ygl9苗期和分蘖期光合色素极显著降低,抽穗期光合色素显著降低,气孔长度、气孔导度和蒸腾速率极显著增加,净光合速率无明显变化。透射电镜观察表明,ygl9的嗜锇小体增多、基粒模糊、基质片层减少且疏松,但叶绿体结构基本完整。遗传分析显示该突变性状受1对隐性核基因调控。利用西农1A/ygl9 F2群体中的759株隐性单株,最终将YGL9定位在第3染色体短臂SSR标记S03-1和In Del标记Ind03-19之间,遗传距离分别为0.13 c M和0.07 c M,物理距离为63 kb。本研究为YGL9基因的克隆和功能分析奠定了基础。  相似文献   

高校图书馆超期罚款存在的问题及其解决措施          下载免费PDF全文

王琳琳 《农业环境科学学报》2011,(6)

从图书馆超期罚款的法律支持、处罚标准、处罚手段等方面分析了图书馆超期罚款存在的弊端,并提出了相应的对策。  相似文献