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101.
Many psittacine species are threatened in the wild and also rare in captivity. Therefore, successful conservation and breeding programs are important to save these species. Unfortunately, clutches in conservation programs are frequently infertile. Semen evaluation is beneficial to investigate the causes of infertility and is advisable before artificial insemination (AI). In this study, we analyzed the semen of cockatiels (Nymphicus hollandicus) using two different methods and investigated different insemination dosages for AI. Cockatiels (n = 30) were divided into two groups (group A: nine males; group B: six males). The males in group B were endoscopically sterilized, whereas the males in group A were used as semen donors. In the first part of the study, the semen of males in group A was evaluated by semen analysis. Semen samples were collected by the massage technique and examined using a conventional light microscope and a computer-assisted semen analyzer for comparison. Results demonstrated that the evaluations of motility, progressive motility, and sperm concentration, but not of live/dead ratio, correlated strongly for both methods. However, the results for sperm concentration, progressive motility, and live/dead ratio differed significantly. In the second part of our study, the volume and quantity of spermatozoa of the semen samples were adjusted and used for AI of females of group B. Intravaginal insemination with 250,000 spermatozoa resulted in five of 17 (29%) eggs fertilized; however, intracloacal insemination resulted in only four of 57 (7%) eggs fertilized at 232,000 and 250,000 spermatozoa but none at higher or lower dosages. 相似文献
102.
Srůtková D Spanova A Spano M Dráb V Schwarzer M Kozaková H Rittich B 《Journal of microbiological methods》2011,87(1):10-16
Bifidobacterium longum is considered to play an important role in health maintenance of the human gastrointestinal tract. Probiotic properties of bifidobacterial isolates are strictly strain-dependent and reliable methods for the identification and discrimination of this species at both subspecies and strain levels are thus required. Differentiation between B. longum ssp. longum and B. longum ssp. infantis is difficult due to high genomic similarities. In this study, four molecular-biological methods (species- and subspecies-specific PCRs, random amplified polymorphic DNA (RAPD) method using 5 primers, repetitive sequence-based (rep)-PCR with BOXA1R and (GTG)5 primers and amplified ribosomal DNA restriction analysis (ARDRA)) and biochemical analysis, were compared for the classification of 30 B. longum strains (28 isolates and 2 collection strains) on subspecies level. Strains originally isolated from the faeces of breast-fed healthy infants (25) and healthy adults (3) showed a high degree of genetic homogeneity by PCR with subspecies-specific primers and rep-PCR. When analysed by RAPD, the strains formed many separate clusters without any potential for subspecies discrimination. These methods together with arabionose/melezitose fermentation analysis clearly differentiated only the collection strains into B. longum ssp. longum and B. longum ssp. infantis at the subspecies level. On the other hand, ARDRA analysis differentiated the strains into the B. longum/infantis subspecies using the cleavage analysis of genus-specific amplicon with just one enzyme, Sau3AI. According to our results the majority of the strains belong to the B. longum ssp. infantis (75%). Therefore we suggest ARDRA using Sau3AI restriction enzyme as the first method of choice for distinguishing between B. longum ssp. longum and B. longum ssp. infantis. 相似文献
103.
Understanding infield predator dispersal is crucial for designing predator conservation programmes. A study aimed at evaluating methods of collecting insects in protein-marking studies and monitoring predator movement was conducted. Results indicate that collection by sweep net does not result in false positives and predator groups displayed distinct dispersal patterns. 相似文献
104.
105.
以555份芒(Miscanthus sinensis)种质资源为研究对象,根据26个表型性状数据,按地理来源、植物区系和单一性状进行分组,分别采用简单比例法、平方根法和多样性指数法确定组内取样数,再根据聚类和随机2种方法进行组内个体选择。依照上述方案共构建出19个具有代表性的芒初选核心种质样本库。通过平均相似系数、性状符合度、数量性状变异系数和遗传多样性指数等4项检测指标对上述19种构建方案进行比较,最终确定了按"植物区划分组+多样性指数确定取样数+聚类选择个体"为芒初级核心种质构建的最佳方案。通过此方法建立起的芒初级核心种质资源共83份,占总资源的14.95%,且新构建的初级种质资源与总资源性状符合度达到100%。 相似文献
106.
Silvia Danise Stefano Dominici 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2014,47(2):229-243
Twenty‐five Neogene–Quaternary whales hosted in Italian museum collections and their associated fauna were analysed for evidence of whale‐fall community development in shallow‐water settings. The degree of bone articulation, completeness of the skeleton and lithology of the embedding sediments were used to gather information on relative water depth, water energy, sedimentation rate and overall environmental predictability around the bones. Shark teeth and hard‐shelled invertebrates with a necrophagous diet in close association with the bones were used as evidence of scavenging. Fossil bone bioerosion, microbially mediated cementation and other mollusc shells in the proximity of the remains informed on past biological activity around the bones. The results are consistent with the hypothesis that shallow‐water whale falls differ from their deep‐water counterparts. Taphonomic pathways are more variable on the shelf and whale carcasses may not go through all steps of the ecological succession as recognised in the deep sea. Whilst the mobile scavenger and the enrichment opportunistic stages are well represented, chemosynthetic taxa typical of the sulphophilic stage were recovered only in one instance. The presence of a generalist fauna among the suspension feeding bivalves and carnivorous gastropods, and the extreme rarity of chemosynthetic taxa, suggest that predatory pressure rules out whale‐fall specialists from shallow shelf settings as in analogous cold seep and vent shallow‐water communities. 相似文献
107.
C. Grenier P. J. Bramel-Cox M. Noirot K. E. Prasada Rao P. Hamon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(1-2):190-196
A large collection, such as the sorghum [Sorghum bicolor (L.) Moench] landrace collection held at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT),
represents a challenge for the maintenance of both the accessions of and the information documented for the germplasm collection.
The accessibility and knowledge of the landrace collection are the essential factors for an efficient utilization of the genetic
resources by both breeders and farmers. Different sampling strategies, either random or non-random, were proposed to obtain
subsets of reduced size (core collection). Three subsets were established; a random sampling within a stratified collection
(logarithmic strategy: L); a sample based upon morpho-agronomic diversity (principal component score strategy: PCS); and a
sample based upon an empirical knowledge of sorghum (taxonomic strategy: T). Comparisons of these three samples for morpho-agronomic
characterization and passport information were assessed to determine their impact on phenotypic diversity. For their overall
diversity, the three subsets did not differ, as shown with the two-dimensional representation of the morpho-agronomic diversity
and the Shannon-Weaver diversity indices. When comparisons for morpho-agronomic and passport data were considered, the PCS
subset looked similar to the entire landrace collection. The L subset showed differences for characters associated with the
photoperiod reaction that was considered in the stratification of the collection. The T subset was the most distinct from
the entire landrace collection as it over-represented the landraces selected by farmers for specific uses and covered the
widest range of geographical adaptation and morpho-agronomic characteristics.
Received: 5 October 1999 / Accepted: 3 November 1999 相似文献
108.
Assessment of genetic diversity within and among germplasm accessions in cultivated sorghum using microsatellite markers 总被引:6,自引:0,他引:6
Y. Djè M. Heuertz C. Lefèbvre X. Vekemans 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,100(6):918-925
Microsatellite markers are increasingly being used in crop plants to discriminate among genotypes and as tools in marker-assisted
selection. Here we evaluated the use of microsatellite markers to quantify the genetic diversity within as well as among accessions
sampled from the world germplasm collection of sorghum. Considerable variation was found at the five microsatellite loci analysed,
with an average number of alleles per locus equal to 2.4 within accessions and 19.2 in the overall sample of 25 accessions.
The collection of sorghum appeared highly structured genetically with about 70% of the total genetic diversity occurring among
accessions. However, differentiation among morphologically defined races of sorghum, or among geographic origins, accounted
for less than 15% of the total genetic diversity. Our results are in global agreement with those obtained previously with
allozyme markers. We were also able to show that microsatellite data are useful in identifying individual accessions with
a high relative contribution to the overall allelic diversity of the collection.
Received: 10 August 1999 / Accepted: 27 August 1999 相似文献
109.
Maksimova I. V. Matorin D. N. Plekhanov S. E. Vladimirova M. G. Volgin S. L. Maslova I. P. 《Russian Journal of Plant Physiology》2000,47(6):779-785
The effects of light and temperature conditions on the maintenance of some red microalgae (order Porphyridiales) in collections were studied. Periodical subculturing on solid and liquid media was used for maintenance. Halophilic species P. aeruginosa, P. cruentum, and P. sordidum were lost in 2.5 months if kept in darkness. The viability of algae in the dim light slightly declined in 4–5 months and was species-dependent. The results were compared with earlier obtained data on mesophilic Chlorococcales. For the green algae, darkness proved to be the optimal condition, while their viability markedly decreased at light. It was suggested that this discrepancy was caused by the presence of phycobiliproteins in the cells of red algae. Dim light conditions are optimal for the synthesis of phycobiliproteins, which are rapidly destroyed in darkness, thus leading to cell death. 相似文献
110.
针对快速、实时、有效采集并录入生态环境野外调查大样本量、多源数据的需求,充分应用移动GIS技术、移动智能终端、3G等现代信息技术优势,提出了基于ArcGIS for Mobile的移动数据采集方案,研究解决了包括系统运行机制、数据访问模式、移动数据库技术等面向全国生态环境野外调查的移动GIS关键技术,设计并研发野外调查移动数据采集系统。该系统采用C#和Java语言,以SQL Server 2008 为服务器端的数据库环境,在Microsoft Visual Studio 2008集成开发环境上实现设计开发,并在全国生态环境10年变化遥感调查与评估项目土地覆盖类型地面核查、生态系统参数野外观测等工作中予以应用。实践检验表明:该系统实现了野外调查数据的数字采集、智能校验、实时上传与有效管理,简化了填报程序,规范了填报内容,提高了工作效率,能够为生态环境相关的调查数据采集提供信息化支持。 相似文献