不同类型稻种资源对稗草化感潜力差异评价

以120份不同类型稻种资源为研究对象,将田间鉴定和室内叶浸提液处理鉴定方法相结合,对其化感作用差异进行了鉴定评价.结果表明,在田间不同类型稻种资源对稗草生长的抑制效果大小趋势为地方品种＞选育品种(系)＞引进品种(系)＞杂交水稻(恢复系和不育系),对稗草苗鲜重和苗干重的抑制效果大于对苗高的抑制效果.室内叶浸提液处理鉴定结果,不同类型稻种资源间化感作用差异相对较小,但仍以地方品种较强,并对稗草根长的抑制效果大于对稗草苗高的抑制效果.地方品种中具有较强化感作用的种质资源频率高于其他类型品种,今后要加强对地方品种资源的化感潜力鉴定和评价.     

The potential use of tree-rings to reconstruct streamflow and estuarine salinity in the Valdivian Rainforest eco-region, Chile

Water availability is one of the main limitations for future development and economic activity in many regions of the world. This applies even to areas of relatively high annual rainfall, such as the Valdivian Rainforest eco-region in Chile (35–48°S). Streamflow and water availability are crucial for several economic activities in the eco-region including hydroelectricity, irrigation, salmon farming, sports fishing of introduced trout and tourism. Scientific research focused on the spatial and temporal patterns of streamflow is a key element for planning the future development within the eco-region. In this paper we explore the potential of tree-rings for streamflow reconstruction in this region. Our preliminary results indicate a significant correlation (r=0.59 P<0.001, 1929–2000) between prior summer Río Bueno streamflow (January–April) and the average between a composite tree-ring chronology using Pilgerodendron uviferum from Chile and two composite Austrocedrus chilensis chronologies from Argentinean Patagonia. Similarly, there is a significant correlation (r=0.57, P<0.001, 1943–2002), between the Austrocedrus chronology (40°44′S) at Centinela in Argentinean Patagonia and the previous spring through early autumn (November–April) streamflow for Río Puelo. The tree-ring records used to correlate with Río Bueno and Río Puelo discharges show low-frequency variability and therefore the potential to reconstruct this variability in streamflow for the last 500–780 years. We also found a significant correlation between the composite Pilgerodendron standard ring-width chronology and the current summer water salinity (January–April) at the Reloncavi Estuary (r²=0.60, P<0.01, 1992–2000). Water salinity is a crucial determinant of the carrying capacity of salmon farming. Future research should provide reconstructions of streamflow, water salinity and other water quality attributes from tree-rings. These data will provide inputs to modeling scenarios of future water availability and are crucial to decision-making and planning of resource management and socio-economic development in the Valdivian Rainforest eco-region.     

Comparative analysis of core collection sampling methods for mandarin germplasm based on molecular and phenotypic data

Gene banks have been established to conserve the genetic diversity of crop species. Large germplasm collections lead to management problems (space, maintenance costs, etc.), especially in collections involving species with recalcitrant seeds that must be maintained as growing plants. Core collections (CCs) are thus developed to reduce the size of large germplasm collections while keeping the maximum variability. This also facilitates fine phenotypic evaluation. In this study, several software packages (DARwin, PowerMarker and MSTRAT) and methods (Max length subtree, M strategy, simulated annealing and MinSD) were compared to define a mandarin (Citrus reticulata) CC. One hundred and sixty‐seven accessions were sampled from two germplasm collections, which were genotyped with 50 SSR, 24 InDel and 68 single nucleotide polymorphism markers. All the CC obtained were tested for the maintenance of the genetic variability parameters (Ho and He) of the initial collection, the level of linkage disequilibrium (LD) and the phenotypic diversity retention. The Max length subtree function from DARWin seemed to be the most appropriate method for establishing a CC in C. reticulata. It maintained 96.82% of the allelic richness and 17.96% of the size of the initial collection with only 30 accessions. Besides it did not increase the LD (r² value) of the initial collection and retained the vast majority of the phenotypic variability. However, a CC with 70 accessions would be more helpful for genetic association studies.     

Investigation of Germplasm Resources of the Genus Rhododendron in Baili Nature Reserve in Guizhou

In this study, we investigated Rhododendrons in Baili Rhododendron nature reserve and recorded species and detailed information of their distributions. A total of 33 species belonging to 6 subgenus, 4 sections and 11 subsecions were observed and the altitudes were ranging from 1300m to 1800m. In general, most Rhododendron species grew together in their typical habitats whereas a few species occurred fragmentally. In addition, we evaluated the conservation status of these 33 Rhododendron species. On the basis of available information, we addressed some problems taking into account the population structure and development of tourism, and suggestions regarding conservation and utilization of Rhododendrons were finally proposed.     

The Exploitation and Utilization of Lycophyte and Fern Resources in Xishuangbanna,Yunnan

Xishuangbanna lies in the south of Yunnan. The composition and distributive regulation of lycophytes and ferns in Xishuangbanna are studied in this paper. As a result, 363 species of wild lycophytes and ferns which belong to 76 genera and 31 families are found in this area. The six species rich families are Polypodiaceae, Athyriaceae, Thelypteridaceae, Aspleniaceae, Pteridaceae and Selaginellaceae. The geographical distribution of the species shows that this flora mainly consists of Tropical Asia elements. Terrestrial species are the richest of this flora, followed by epiphytic and lithophytic species. The lycophytes and ferns resources of Xishuangbanna are abundant. However, the exploitation and utilization of this group of plants are ignored. This study investigated lycophytes and ferns resources of Xishuangbanna. Medicinal, edible and ornamental ferns in Xishuangbanna have been clearly researched and their utilization and protection have been discussed.     

Ungulate carcass transport strategies at the Middle Palaeolithic site of Abric Romaní (Capellades,Spain)

We evaluated the skeletal profiles from several levels of the Neanderthal site of Abric Romaní, focusing on the methodology proposed by Faith and Gordon (2007): differences in the skeletal distribution of animals in accordance with their size and weight; the statistical correlation between the skeletal profiles and standard food utility index; and the anatomical diversity of size-weight categories. Results indicate an unconstrained transport strategy in all levels and all size-weight categories. However, we also found differences in the skeletal distribution of medium-sized and large animals, which may be due to different transport strategies. These characteristics suggest that the superposition of transport and occupation events could be responsible for our results. In addition, we applied the same analysis to Hadza assemblages, which revealed similar results to those found at Abric Romaní. The most striking feature of the Hadza assemblages examined is the superposition of transport events as a result of successive occupation/deposition events. This suggests that the transport strategies used by Neanderthals at Abric Romaní are also characterized by a high degree of diversity in transport decisions.     

基于SRAP标记的薏苡种质资源遗传多样性及DNA指纹图谱构建

利用SRAP分子标记对从各主要产地收集到的90份薏苡种质进行遗传多样性分析,其中68份收集于福建省,6份来自中国台湾,16份来自浙江、辽宁、山东、河南、云南、江苏、湖南、广东、上海等省(市)。结果表明,从88对SRAP引物组合中筛选出26对引物进行SRAP扩增,共扩增出185条带,其中具有多态性的有157,占总数的84.86%,表明90份薏苡种质表现出丰富的遗传多样性。基于SRAP标记利用系统聚类法将90份薏苡种质资源分为4大类,与形态性状分类结果有一定的相似性;利用16对SRAP引物构建了73份薏苡种质资源的DNA指纹图谱,为薏苡遗传研究、品种选育与资源保护提供了依据。     

中国普通菜豆种质资源朊蛋白变异及多样性分析

朊蛋白是研究普通菜豆遗传多样性的一种重要且有效的生化标记。本试验通过SDS-PAEG凝胶电泳检测中国普通菜豆种质资源的朊蛋白变异类型,分析中国普通菜豆种质资源的遗传多样性及组成特点。来自中国13个省(自治区)的445份供试材料共检测到S、Sb、Sd、B、C、CA、T、PA、To、H、H1、CH 12种朊蛋白类型,表明中国普通菜豆种质朊蛋白变异类型丰富,遗传多样性水平较高。其中,Sb型朊蛋白种质最多,占比29.0%;T型其次,占比28.1%。依据朊蛋白类型在不同基因库的特异性,将研究材料明显地区分为中美基因库和安第斯基因库两大类。研究还发现中国普通菜豆种质资源中地方种质朊蛋白类型变异丰富,多样性明显高于现代育成品种或品系。最后,对种质朊蛋白类型与百粒重、子粒颜色、粒型进行相关性分析,结果表明朊蛋白类型与百粒重呈极显著正相关,而朊蛋白类型与子粒颜色、粒型2个性状之间无明显相关性。本研究结果将为普通菜豆种质资源的保护及有效地挖掘优质种质资源提供理论依据。     

Molecular identification of livestock breeds: a tool for modern conservation biology

Global livestock genetic diversity includes all of the species, breeds and strains of domestic animals, and their variations. Although a recent census indicated that there were 40 species and over 8000 breeds of domestic animals; for the purpose of conservation biology the diversity between and within breeds rather than species is regarded to be of crucial importance. This domestic animal genetic diversity has developed through three main evolutionary events, from speciation (about 3 million years ago) through domestication (about 12000 years ago) to specialised breeding (starting about 200 years ago). These events and their impacts on global animal genetic resources have been well documented in the literature. The key importance of global domestic animal resources in terms of economic, scientific and cultural heritage has also been addressed. In spite of their importance, there is a growing number of reports on the alarming erosion of domestic animal genetic resources. This erosion of is happening in spite of several global conservation initiatives designed to mitigate it. Herein we discuss these conservation interventions and highlight their strengths and weaknesses. However, pivotal to the success of these conservation initiatives is the reliability of the genetic assignment of individual members to a target breed. Finally, we discuss the prospect of using improved breed identification methodologies to develop a reliable breed‐specific molecular identification tool that is easily applicable to populations of livestock breeds in various ecosystems. These identification tools, when developed, will not only facilitate the regular monitoring of threatened or endangered breed populations, but also enhance the development of more efficient and sustainable livestock production systems.