不同肠段中氨基酸螯合锌吸收特点的研究

用 50日龄Wistar纯系雄性大鼠 ,以体内原位结扎肠段灌注技术结合放射性同位素示踪技术 ,通过与氯化锌比较 ,研究了十二指肠和空肠对氨基酸螯合锌 (以赖氨酸螯合锌和蛋氨酸螯合锌为代表 )的吸收特点。试验中观察了向结扎肠段灌注含不同形态锌的灌注液后 ,不同时间 (5 ,1 5 ,30 ,60 ,90 ,1 2 0min)血液中6 5Zn比放射性的动态变化 ,1 2 0min (试验结束 )时结扎肠段6 5Zn的消失率 ,不同组织器官中6 5Zn的比放射性的变化。试验结果表明 ,和空肠相比 ,十二指肠对 3种锌源的吸收率高 ;和氯化锌相比 ,十二指肠和空肠对 2种氨基酸螯合锌的吸收率高     

石斛兰组织培养和细胞学观察

以石斛兰杂交种的茎尖、茎节和幼嫩小叶片作为外植体均可诱导出愈伤组织。愈伤组织在同一培养基上可同时出现不定芽和拟原球茎，两者都能进一步发育成完整幼苗。拟原球茎和不定芽分别来自愈伤组织的表层细胞和深层细胞。由愈伤组织、不定芽和拟原球茎交错在一起的团块可以多次切割继代培养，进行大量无性繁殖。     

不同密度对露草地被的影响

露草作为一种温室藤蔓花卉通常作室内吊挂及盆栽摆放应用,通过对地被栽培的露草生态习性、生长状况、生长量调查与分析,初步探索出其地被应用的可行性及适宜定植密度,使其四季常青的枝叶、美丽的花朵、良好的匍匐性及快速生长铺地能力等特性得以发挥。     

Fish assemblages as influenced by environmental factors in streams in protected areas of the Czech Republic

Abstract –  Three streams of comparable size located in different landscape-protected areas were selected for studying the effect of environmental factors on fish assemblages using indirect (detrended correspondence analysis, DCA) and direct (canonical correspondence analysis, CCA) gradient analysis. DCA of species showed well a gradient of assemblage changes in the longitudinal profile. DCA of sites stressed the variability between the fish assemblages of the three streams. This pattern was then confirmed by the highly significant between-stream CCA. In the within-site CCA, environmental factors explained 50.7% variability for presence–absence data and 58.3% for the relative abundance data. The analysis revealed that number of ponds and land use are the most influential factors of the strongest environmental gradient. However, in the partial CCAs, factor substratum type explained the largest proportion of the variability affecting fish in their habitat choice. Generally, presence–absence and relative abundance data of fish gave similar results in both DCA and CCA analyses; the same environmental factors proved to be important in both data type analyses. The environmental factors explain more variability than the regional (between-stream) one. The total proportion of variability explained by the presence–absence data analysis was 71.9% and in the relative abundance analysis even 80.8%. The environmental factors measured during the field survey explain 2.1- and 3.4-times more assemblages' variability than factors measured from a hydrological map.     

旱地豌豆新品种定豌2号丰产栽培综合配套技术研究

在旱农区农田生态条件下,采用常规与二次回归正交结合的设计方法,多点同步研究定豌2号高产与密度、氮磷施用量及配比间的关系和相关效应,钼肥、保水剂高效施用技术,并在试验基础上同时进行生产示范验证。根据试验示范结果,选用相应分析程序进行计算机模拟寻优,得到定豌2号产量1 950~2 653 kg/hm2的技术方案65套。该方案95%置信域:播种量109.5~148.5万株/hm2,施N 45~64.5 kg/hm2,P2O5112.5~147kg/hm2,N∶P2O5约为1∶2.37,沟施植物保水剂7.5 kg,每1 000 g种子用钼酸铵4 g拌种。     

春大豆高产栽培个体及群体发展动态指标的研究

通过对黑农 4 1和石豆 2号高产试验田测定 ,得出了实现 4 375 .5kg·hm-2 籽粒产量时 ,各个重要生育时期的群体数量、干物质积累、叶面积指数的动态指标 ,及其相应各个时期的个体质量动态指标。产量结构为 :收获31.5万株·hm-2 ,单株粒数 70 ,百粒重 2 0 g。     

Molecular markers and ex situ conservation of the European elms (Ulmus spp.)

The enormous losses suffered by the European elms during recent Dutch elm disease outbreaks led to concern over the conservation of elm genetic resources, and the subsequent establishment of a series of ex situ collections. However, as ex situ collections are inevitably finite in size, some consideration needs to be given to selecting which samples to include in them. To contribute towards this process for European ex situ elm collections we have undertaken genetic studies on a Europe-wide sample of 535 individuals. A major aim has been to use genetic markers to clarify the identification of samples to ensure that the ex situ collections contain a representative spread of taxonomic diversity. This is important given the paucity of mature elms in the landscape due to Dutch elm disease. The lack of mature material (critical for identification) compounds identification problems in what was already a taxonomically difficult group. Our data (derived from random amplified polymorphic DNA and inter-simple sequence repeats) have provided a useful supplement to morphology in undertaking such sample identifications. The molecular data served to highlight mis-identified samples and led to extensive revisions of sample identities within individual countries. Our results were less useful in detecting regional intra-specific genetic structure, and do not provide sufficient information for prioritising within-species sample selections.     

家猪13/17罗伯逊易位染色体着丝粒DNA的FISH检测

根据已报道的家猪着丝粒卫星DNA序列设计引物,对家猪基因组DNA进行PCR扩增,得到AC2卫星DNA序列。用PCR法将D ig-dUTP插入目的片段中得到标记DNA,然后利用荧光原位杂交方法检测13/17易位染色体。研究结果显示杂交信号位于所有端着丝粒染色体和13/17易位染色体的着丝粒区域,表明13号染色体和17号染色体虽然融合为一条亚中着丝粒染色体,但仍含有端着丝粒AC2卫星DNA,13/17易位染色体的AC2卫星DNA未发生缺失。     

论人参种植业发展途径

讨论了传统伐林栽参模式的缺陷及农田栽参、林下护育山参的优势,明确了农田栽参是我国人参种植业发展的首要途径;林下护育山参是人参种植业发展的主要途径;同时提出解决老参地问题是目前人参种植业的关键所在。     

Can place names be used as indicators of landscape changes? Application to the Doñana Natural Park (Spain)

This work broaches the possibility of using place names as indicators of original landscapes that have been much transformed. The reconstruction of landscape elements from place names is commonly disputed because such daring notion is impossible to demonstrate. The present case avoids this by making a preliminary study of changes in the landscape using conventional methods. With the knowledge gained from objective and reliable sources, the possibility is analyzed of whether place names are a reflection of landscape changes taking place over a considerable period of time (the last few centuries). It is concluded that, for the present case study, in natural areas with a high rate of change of land use (Doñana Natural Park), place names indicate not only changes in the landscape, but also how such changes are perceived. In the study area, this is especially clear regarding the fens.