中国苜蓿地方品种亲缘关系的研究 Ⅰ 种子贮藏蛋白标记

利用ＳＤＳ—ＰＡＧＥ方法对我国１８ 个苜蓿地方品种和北美９ 个苜蓿基本种质来源的代表品种各２０ 粒单粒种子贮藏蛋白及１４ 份豆科牧草种（品种）种子贮藏蛋白进行了分析,根据电泳分析结果计算品种间的欧氏遗传距离,并进行聚类分析。１４ 份豆科牧草种（品种）种子贮藏蛋白的电泳分析结果表明,种内种子贮藏蛋白带谱差异较小,同属不同种间的差异明显,而属间的差异明显大于种间。在聚类分析中,以３．６１ 的遗传距离划分时,１４ 份材料被分为４ 组,分属于４ 个属,这与分类上是一致的。我国１８ 个苜蓿地方品种间的平均遗传距离为０．５７,以０．５ 的遗传距离进行划分时,１８ 个品种可分为７ 组,品种间亲缘关系的远近与品种的地理分布有一定的相关性。北美９ 个苜蓿品种间的平均遗传距离为０．８９,聚类结果表明,杂花苜蓿（Ｍｅｄｉｃａｇｏｓａｔｉｖａ ｓｓｐ． ｖａｒｉａ）与紫花苜蓿（Ｍｅｄｉｃａｇｏ ｓａｔｉｖａ ｓｓｐ． ｓａｔｉｖａ）之间的遗传差异相对较小,而与黄花苜蓿（Ｍｅｄｉｃａｇｏ ｓａｔｉｖａ ｓｓｐ． ｆａｌｃａｔａ）间的遗传差异相对较大。与北美９ 个苜蓿品种相比,我国苜蓿地方品种间的遗传差异较小,这与我国苜蓿地方品种的地理分布相对较窄,品种间基     

Genetic relationships in cultivars of hop, Humulus lupulus L., determined by RAPD analysis

Random amplified polymorphic DNA (RAPD) was used to evaluate the genetic variability and relationship of 65 hop cultivars from all the major hop-growing regions in the world. Twenty-eight selected random primers used in the RAPD reaction generated an average of 38.6%) polymorphic fragments, which was sufficient to produce 47 different RAPD profiles among the cultivars examined. The level of genetic variability was much higher than previously reported. Genetic similarity was estimated and UPGMA cluster analysis was performed using the RAPD data. Cluster analysis separated the cultivars into genetically related RAPD groups which were compared with pedigree data and grouping of the hop cultivars by essential oil type. The RAPD groups, strongly supported by pedigree data, gave more precise information on the level and distribution of genetic variability within hop cultivars than characterization by essential oils. Cultivars were divided into American and European groups, supporting the distinction between two geo-graphically distinct hop germplasms. Five genetically distinct groups revealed differences within the European germplasm, reflecting past hop breeding practices which have been adopted in different regions. The use of RAPD markers for hop germplasm characterization and genetic diversity study is discussed.     

Mixed-species plantations of Acacia mangium and Eucalyptus grandis in Brazil: 1. Growth dynamics and aboveground net primary production

Nitrogen fertilizer inputs increased sharply over the last decade in Brazilian eucalypt plantations. Due to the economic and potential environmental cost of fertilizers, mixed plantations with N-fixing species might be an attractive option to improve the long-term soil N status. A randomized block design was set up in southern Brazil, including a replacement series and an additive series design, as well as a nitrogen fertilization treatment. The development of mono-specific stands of Eucalyptus grandis (0A:100E) and Acacia mangium (100A:0E) was compared with mixed plantations in proportions of 1:1 (50A:50E), and other stands with different densities of acacia for the same density of eucalypts. The objective was to assess the effect of inter-specific interactions on the early development of the two species. Aboveground biomass was measured 6, 12, 18 and 30 months after planting, sampling 6–10 trees of each species per treatment at each age, and allometric equations were established in 0A:100E, 100A:0E, 50A:50E and 50A:100E. The height and basal area of E. grandis seedlings were enhanced by 12% and 30%, respectively by N fertilization at age 1 year. Inter-specific competition led to a stratified canopy, with suppression in acacia growth earlier for basal area than for height. The mean number of stems per acacia tree at 36 months after planting was significantly higher in pure stands (3.7), than in 50A:50E (2.7) and in the additive series (between 1.6 and 1.8). H/D ratios were highly sensitive to inter-tree competition for the two species. The suppressed acacia understorey in mixed-species stands did not influence biomass production and partitioning within eucalypts. This pattern led to biomass accumulation combining the two species in 50A:100E that was about 10% higher than in 0A:100E, from age 12 months onwards. Aboveground net primary production (ANPP) amounted to 25 Mg ha⁻¹ and 37 Mg ha⁻¹ from age 18 to 30 months in 100A:0E and 0A:100E, respectively. Acacia ANPP in 50A:100E amounted to 2 Mg ha⁻¹ over the same period, as a result of substantial inter-specific competition. An increment in biomass production in these very fast-growing eucalypt plantations was achieved introducing acacia as an understorey and not in the 50A:50E design, as observed in other studies.     

Light distribution in scattered-trees open woodlands in Western Spain

We have studied the percentage of radiation transmitted through the tree canopy to the underlying pasture and crops in dehesas of Southwest Spain by means of fish-eye photographs taken at different distances from the tree. Thirty-six trees were studied covering all the diametric classes (0.1–14 m canopy width) of two stands, with mean density of 19 mature trees ha⁻¹. Intercepted light decreased with distance following an logistic curve, indicating a rapid increase in the light availability with distance from the tree. For mature trees, radiation was constant beyond 20 m. Applying a multivariable regression light equation, distance, stem diameter and canopy width explained more than 88% of the light variability for each orientation studied. A simple model was built up from light equations, tree growth curves and allometric relationships. From this model, we have estimated that radiation available for crops and pasture decreased up to 21% due to the presence of trees in a standard dehesa with 24 mature trees ha⁻¹ and 13% of canopy cover. In addition, we have generated different radiation maps of virtual dehesas differing in tree age, density and arrangement, which could be useful to determine optimal tree planting schemes and consequent pruning and thinning regimes.     

Size at maturity for grooved Tanner crab (Chionoecetes tanneri) along the U.S. west coast (Washington to California)

We conducted a multiyear study to examine interannual variability in the mean size (carapace width, mm), maturity size (mm) and depth (m) for grooved Tanner crab (Chionoecetes tanneri (Rathbun, 1893)) along the U.S. west coast. An additional goal was to provide updated estimates of carapace width (mm) at 50% maturity (W₅₀) for male and female grooved Tanner crab and assess changes over time. Randomly selected samples came from trawl surveys undertaken annually by the Northwest Fisheries Science Center at depths of 55 to 1280 m. We used allometric relationships between carapace width (CW) and either abdominal width (AW) (females) or chela length (CL) (males) to determine functional maturity by sex. We evaluated maturity by fitting logistic regression models to proportion mature grooved Tanner crab. W₅₀ varied significantly between males (125.2 mm) and females (89.1 mm) but interannual differences were slight. The annual mean CW were greater for mature males (139.9–143.4 mm) relative to females (98.8–100.4 mm). The average sizes of immature grooved Tanner crab varied between sexes with males (75.7–84.6 mm) larger than females (66.7–71.9 mm). Size frequency distributions indicated little overlap in the size of mature male and female grooved Tanner crab but considerable overlap between immature grooved Tanner crab. The best model expressing complexity in growth incorporated width, sex and maturity stage. Depth ranged from 195–1254 m with the average depth of a mature grooved Tanner crab (females, 737 m; males, 767 m) significantly shallower than an immature (females, 949 m; males, 918 m) grooved Tanner crab.     

Stakeholder perceptions of the socio-ecological role of nature-based solutions in the Les Glòries Park,Barcelona

The ongoing effects of the climate emergency and the recognition of the need to redesign cities to cope with future socio-environmental changes and increase the quality of life of urban inhabitants has pushed many cities to embrace the ‘re-naturalization’ of public space through Nature-based Solutions (NbS). Les Glòries park (Barcelona) is an ongoing massive urban transformation project that incorporates NbS as a multifunctional tool. It attempts to respond to complex environmental, social, and economic urban problems while at the same time mitigating and adapting to hazards, such as floods and droughts, both predicted to increase in the Mediterranean region due to climate change. While NbS are also expected to improve environmental quality, not much attention has been given to how those strategies would intersect with citizens’ expectations and visions of public space and the uneven socio-environmental relations they can enforce. Through a case of urban development of a new large green area in Barcelona, this article aims to discern different perceptions by the local community and planners on the socio-ecological role of NbS and the implications this has for sustainable urban transitions. In-depth interviews were held with 25 key stakeholders and users, complemented by the analysis of secondary data from the town council of Barcelona about the perception of the space by residents living in the surrounding neighborhoods of the park. The results of this paper show that perceptions around NbS are strongly divided into three groups: the believers, the opposers and the skepticals. These results contribute to nuance NbS, as they do not provide universal benefits, neither for nature nor for society, and that they are subject to urban tensions derived from inequities, conflicts, tradeoffs, and particularly from divided visions of what the ‘re-naturalization’ of cities should look like.     

基于TEEI特征的高校设备管理新体系

本文提出在以人为本理念下,高校设备管理呈现出TEEI特征,即劳动工具性、技术状态发展性、配置效益性、占用激励性等四大特征。以此为基础,高校应构建设备管理新体系,在实际运行中正确处理人与物、数量与品质和结构、效益与规范三对关系。     

Assessing topographic patterns in moisture use and stress using a water balance approach

Through its control on soil moisture patterns, topography’s role in influencing forest composition is widely recognized. This study addresses shortcomings in traditional moisture indices by employing a water balance approach, incorporating topographic and edaphic variability to assess fine-scale moisture demand and moisture availability. Using GIS and readily available data, evapotranspiration and moisture stress are modeled at a fine spatial scale at two study areas in the US (Ohio and North Carolina). Model results are compared to field-based soil moisture measurements throughout the growing season. A strong topographic pattern of moisture utilization and demand is uncovered, with highest rates of evapotranspiration found on south-facing slopes, followed by ridges, valleys, and north-facing slopes. South-facing slopes and ridges also experience highest moisture deficit. Overall higher rates of evapotranspiration are observed at the Ohio site, though deficit is slightly lower. Based on a comparison between modeled and measured soil moisture, utilization and recharge trends were captured well in terms of both magnitude and timing. Topographically controlled drainage patterns appear to have little influence on soil moisture patterns during the growing season. In addition to its ability to accurately capture patterns of soil moisture in both high-relief and moderate-relief environments, a water balance approach offers numerous advantages over traditional moisture indices. It assesses moisture availability and utilization in absolute terms, using readily available data and widely used GIS software. Results are directly comparable across sites, and although output is created at a fine-scale, the method is applicable for larger geographic areas. Since it incorporates topography, available water capacity, and climatic variables, the model is able to directly assess the potential response of vegetation to climate change.     

云南杜英科猴欢喜属Sloanea L.的初步研究

本文对云南猴欢喜属Sloanea L.植物进行了较全面的整理。以传统分类学方法,在仔细研究模式标本的基础上,归并了2种1变种;报道了中国分布新记录1种。云南计有本属植物10种1变种。文中还讨论了种间关系。