食用向日葵产量性状的遗传研究     

杨海峰  段学艳  卫玲  刘博 《作物杂志》2020,36(5):93-7

以食葵不育系17-A26为母本、恢复系17-C19为父本,构建P₁、P₂、F₁、F₂、B₁和B₂ 6个世代群体,研究了产量相关性状盘径、单株总粒数、结实率、百粒重、粒长和粒宽的后代变异及遗传率。结果表明,6个性状均为数量性状,变异幅度排序为单株总粒数>粒长>盘径>结实率>百粒重>粒宽,狭义遗传率排序为百粒重>粒长>单株总粒数>粒宽>盘径>结实率。根据遗传进度结果,百粒重、粒长、单株总粒数和粒宽宜早代根据表型选择,盘径宜晚代选择,结实率宜晚代结合多环境联合选择。  相似文献   

西北工业大学金叶信息技术学院中心绿地景观设计     

卿平勇 《中南林业调查规划》2005,24(3):21-24

探讨了西北工业大学金叶信息技术学院中心绿地的景观设计方案,本着生态可持续发展、以人为本和浓郁文化内涵的原则,创造一个以自然景观和人文景观相结合的优美环境,为师生提供具有园林艺术氛围的学习、交流、休闲、娱乐和生活的场所.  相似文献   

Landscape change under indirect effects of human use: the Savanna of Central Chile     

Eduardo R. Fuentes  Reinaldo Avilés  Alejandro Segura 《Landscape Ecology》1989,2(2):73-80

The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.  相似文献   

NATURAL LANDSCAPES AND STRATEGIES OF REGIONAL SUSTAINABLE DEVELOPMENT IN EBINUR LAKE REGION IN XINJIANG   总被引：1，自引：0，他引：1  

罗明灿  扬林  张树森 《林业研究》1996,7(2):16-19

m0uurn0NTheecologicalintegrityOfallworidisdependedonourcomPrehensi0nandrepetOthestrUctUre,fonchonandchangsOflandscaPe.However,dwtngndalPrachcePr0Cess,theunmpdeveloPmenandmaremadediswtanceusuallycausethetwadationofenvironmenquality,andalsocausethech~soforiginalcharacteriSticsoflandscare.TheObjechveofthisstudyistorebulltaho-.mogeruzelandscapeStrUctUreandanimProvedecologicalenvironnent.Ebinurlakeregion(includeEbinurlake--thesecondlargestlakeinXinjiang)locatesinBortalaMongOliaAutonomousS…  相似文献   

潜江小城镇景观规划     

彭凤 《湖北农学院学报》2001,21(2):188-191

潜江小城镇的水资源丰富但开发落后，绿系统不完善，街景缺乏工艺性。在对现状调查分析的基础上，提出了对过境公路、水体、街景进行动感空间、情感空间规划的建议，对乡土化设计、恢复性设计进行了探讨。  相似文献   

合理调整山西人民食物结构的策略与途径     

程创基  刘克治  聂儒峰  刘喜文 《山西农业大学学报(自然科学版)》1991,(2)

合理调整我国人民的食物结构是提高全民族身体素质,推进社会文明进步,具有深远的战略意义的一项国策。调整国民食物结构是一个科学性,政策性很强,社会涉及面广,地区人群民食习惯差别大的极为复杂的动态系统工程。作者针对山西省情实际,从追朔我国饮食传统,膳食民习,食物资源及演变趋向探求,提出合理调整山西人民食物结构的策略与途径。  相似文献   

Wetland effects on lake water quality in the Minneapolis/St. Paul metropolitan area     

Naomi E. Detenbeck  Carol A. Johnston  Gerald J. Niemi 《Landscape Ecology》1993,8(1):39-61

A method developed to evaluate the cumulative effect of wetland mosaics on water quality was applied to 33 lake watersheds in the seven-county region surrounding Minneapolis-St. Paul, Minnesota. A geographic information system (GIS) was used to record and measure landscape variables derived from aerial photos. Twenty-seven watershed land-use and land-cover variables were reduced to eight principal components which described 85% of the variance among watersheds. Relationships between lake water quality variables and the first six principal components plus an index of lake mixis were analyzed through stepwise multiple regression analysis. A combination of three landscape components (wetland/watershed area, agriculture/wetlands, and forest/soils components) explained 49% of the variance in a trophic state index, even though most of the lakes examined were already highly eutrophic, and thus were influenced by internal loading. The regression equations explained a range of 14 to 76% of the variation in individual water quality variables. Forested land-use was associated with lower lake trophic state, chloride, and lead. High lake trophic state was associated with agricultural land-use and with wetland distance from the lake of interest. The extent of wetlands was associated with low total lead and high color in lakes downstream. Wet meadows or herbaceous, seasonally-flooded wetlands contributed more to lake water color than did cattail marshes.  相似文献   

Change in spatial characteristics of forest openings in the Klamath Mountains of northwestern California,USA   总被引：4，自引：0，他引：4  

Carl N. Skinner 《Landscape Ecology》1995,10(4):219-228

Change in the spatial characteristics of forest openings was investigated in three forested watersheds in north-western Siskiyou County, California totalling approximately 24,600 hectares. Watersheds with minimal human disturbance were chosen for study. However, fire suppression has been pervasive throughout. Characteristics of forest openings (area, perimeter, distance between neighboring openings) were measured on aerial photographs taken 41 years apart. An index of regional form was determined for the landscape. Shape complexity for each opening was calculated using two indices based upon fractals. Significant differences were found using the Kolmogorov-Smirnov two-sample test between the perimeters, areas, distance from sample point to nearest opening, and distance between neighboring openings. The perimeters and areas became smaller, and the distances from the sample point to the nearest opening and between neighboring openings became greater over the 41 years between aerial photo sets. The estimated area occupied by openings decreased from 25.8 % to 15.6 % of the study area. No significant difference was found in the shape of the openings except as the shape indices were influenced by changes in size of the openings.This article was written and prepared by U.S. Government employees on official time, and it is therefore in the public domain and not subject to copyright.  相似文献   

Landscape-ecological mapping of the Netherlands   总被引：1，自引：0，他引：1  

Kees J. Canters  Cees P. den Herder  Aart A. de Veer  Paul W. M. Veelenturf  Rein W. de Waal 《Landscape Ecology》1991,5(3):145-162

The Landscape-ecological Mapping of the Netherlands project (LMN project) started in 1983 with the aim of establishing a landscape-ecological database for use in developing and evaluating national land-use plans. The project, working with grid cells of 1 km², has four working objectives: a) development of mapping potential for basic landscape-ecological data, b) assessment of susceptibility to interventions, c) evaluation of significance for nature conservation and d) production of vulnerability maps, as a combination of susceptibility and significance. In addition to information on soil, groundwater, ecotopes, flora and fauna, the database also incorporates information on physiographical features and entire landscapes. The resulting database is a geographic information system (GIS). This article describes the second phase of the project (1985–1989), covering the Randstad area, and focusses on the methods and the applications potential of the database.  相似文献   

A review of models of landscape change   总被引：23，自引：1，他引：22  

William L. Baker 《Landscape Ecology》1989,2(2):111-133

Models of landscape change may serve a variety of purposes, from exploring the interaction of natural processes to evaluating proposed management treatments. These models can be categorized as either whole landscape models, distributional landscape models, or spatial landscape models, depending on the amount of detail included in the models. Distributional models, while widely used, exclude spatial detail important for most landscape ecological research. Spatial models require substantial data, now more readily available, via remote sensing, and more easily manipulated, in geographical information systems. In spite of these technical advances, spatial modelling is poorly developed, largely because landscape change itself is poorly understood.To facilitate further development of landscape models I suggest (1) empirical multivariate studies of landscape change, (2) modelling of individual landscape processes, (3) explicit study of the effect of model scale on model behavior, and (4) scaling-up results of studies, on smaller land areas, that have landscape relevance.  相似文献