63 research outputs found
Conservation assessment of the Drakaea livida (Orchidaceae) ecotypes and an evaluation of methods for their identification
Morphologically cryptic taxa must be accounted for when quantifying biodiversity and implementing effective conservation measures. Some orchids pollinated by sexual deception of male insects contain morphologically cryptic ecotypes, such as the warty hammer orchid Drakaea livida (Orchidaceae). This species is comprised of three cryptic pollination ecotypes, which can be distinguished based on differences in pollinator species and floral volatiles. The present study aims were: (a) to investigate the geographic range of the three D. livida ecotypes, enabling assessment of their conservation status; and (b) to test the efficacy of different methods of identifying the D. livida ecotypes. Three methods of ecotype identification were assessed: morphometric analysis, genome size comparison, and analysis of chemical volatile composition of labellum extracts from pollinated flowers. MaxEnt species distribution models revealed that each ecotype has a different predicted geographic range, with small areas of overlap at the range margins. One ecotype is known from just ten populations over a limited geographic area, the majority of which has been cleared for agriculture, and urban development. While there was broad overlap between the ecotypes in individual morphological traits, multivariate analysis of morphological traits provided correct assignment to ecotype in 87% of individuals. Using the labellum of pollinated flowers, screening for volatile chemical compounds associated with particular ecotypes returned an even higher correct assignment rate, of 96.5%. As such, we advocate that the use of volatiles from the labellum of recently pollinated flowers is an effective way to determine the ecotype of unknown individuals of D. livida, with minimal impact on the flowering plant
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Research and Design of a Routing Protocol in Large-Scale Wireless Sensor Networks
无线传感器网络,作为全球未来十大技术之一,集成了传感器技术、嵌入式计算技术、分布式信息处理和自组织网技术,可实时感知、采集、处理、传输网络分布区域内的各种信息数据,在军事国防、生物医疗、环境监测、抢险救灾、防恐反恐、危险区域远程控制等领域具有十分广阔的应用前景。 本文研究分析了无线传感器网络的已有路由协议,并针对大规模的无线传感器网络设计了一种树状路由协议,它根据节点地址信息来形成路由,从而简化了复杂繁冗的路由表查找和维护,节省了不必要的开销,提高了路由效率,实现了快速有效的数据传输。 为支持此路由协议本文提出了一种自适应动态地址分配算——ADAR(AdaptiveDynamicAddre...As one of the ten high technologies in the future, wireless sensor network, which is the integration of micro-sensors, embedded computing, modern network and Ad Hoc technologies, can apperceive, collect, process and transmit various information data within the region. It can be used in military defense, biomedical, environmental monitoring, disaster relief, counter-terrorism, remote control of haz...学位:工学硕士院系专业:信息科学与技术学院通信工程系_通信与信息系统学号:2332007115216
SSR data for 27 populations of P. teres fsp teres from barley and barley grass
17 SSR loci, 27 populations from barley and barley grass. Data in GenAlex format
Host specialisation and disparate evolution of Pyrenophora teres f. teres on barley and barley grass
Abstract Background Pathogens evolve in an arms race, frequently evolving virulence that defeats resistance genes in their hosts. Infection of multiple hosts may accelerate this virulence evolution. Theory predicts that host diversity affects pathogen diversity, with more diverse hosts expected to harbour more diverse pathogens that reproduce sexually. We tested this hypothesis by comparing the microsatellite (SSR) genetic diversity of the barley leaf pathogen Pyrenophora teres f. teres (Ptt) from barley (monoculture) and barley grass (outbreeding). We also aim to investigate host specificity and attempt to track virulence on two barley cultivars, Maritime and Keel. Results Genetic diversity in barley Ptt populations was higher than in populations from barley grass. Barley Ptt populations also had higher linkage disequilibrium levels, indicating less frequent sexual reproduction, consistent with the Red Queen hypothesis theory that genetically diverse hosts should select for higher levels of sexual reproduction of the pathogen. SSR analyses indicate that host-associated Ptt populations do not share genotypes and have independent evolutionary histories. Pathogenicity studies showed host specificity as host-associated Ptt isolates could not cross-infect hosts. Minimum spanning network analyses indicated two major clusters of barley Ptt. One cluster represents Maritime virulent and isolates from Western Australia (WA). Low PhiPt population differentiation between WA populations and those from Maritime and Keel, indicated a WA origin of the Maritime and Keel virulences. The main minimum spanning network cluster is represented by a panmictic population structure, represented by isolates from all over Australia. Conclusions Although barley Ptt populations are more diverse than barley grass Ptt populations, this may be a result of the size and number of founder Ptt populations to Australia, with larger and more barley Ptt populations introduced. More frequent sexual reproduction of Ptt on barley grass support the Red Queen Hypothesis and suggest evolutionary potential of pathogens on diverse hosts are high. Extensive gene flow of Ptt between regions in Australia is suggested to maintain a panmictic population structure, with human-mediated dispersal aiding in virulence evolution of Ptt on barley
Data from: Matching symbiotic associations of an endangered orchid to habitat to improve conservation outcomes
Background and Aims: An understanding of mycorrhizal variation, orchid seed germination temperature and the effect of co-occurring plant species could be critical for optimising conservation translocation of endangered plants with specialised mycorrhizal associations. Methods: Focussing on the orchid Thelymitra epipactoides we isolated mycorrhizal fungi from ten plants within each of three sites; Shallow Sands Woodland (SSW), Damp Heathland (DH) and Coastal Heathland Scrub (CHS). Twenty-seven fungal isolates were tested for symbiotic germination under three temperature ranges: 12-16°C, 16-24°C or 27°C. Fungi were sequenced using the ITS, nLSU, 28S and mitochondrial regions. Orchids were grown to maturity and co-planted with each of ten associated plant species with tuber width measured at 12 months after co-planting. Key Results: Two Tulasnella fungal lineages were isolated and identified by phylogenetic analyses, OTU1 and “T. asymmetrica”. Fungal lineages were specific to sites and did not co-occur. OTU1 (from the SSW site), germinated seed predominately at 12-16°C (typical of autumn-winter temperature) whereas “T. asymmetrica” (from the DH and CHS sites), germinated seed across all three temperature ranges. There was no difference in the growth of adult orchids germinated with different OTUs. There was a significant reduction in tuber size of T. epipactoides when co-planted with six of the commonly co-occurring plant species. Conclusions: We found orchid fungal lineages and their germination temperature can change with habitat and established that translocation sites can be optimised with knowledge of co-occurring plant interactions. For conservation translocations, particularly under a changing climate, we recommend plants should be grown with mycorrhizal fungi tailored to the recipient site
Data from: Matching symbiotic associations of an endangered orchid to habitat to improve conservation outcomes
Background and Aims: An understanding of mycorrhizal variation, orchid seed germination temperature and the effect of co-occurring plant species could be critical for optimising conservation translocation of endangered plants with specialised mycorrhizal associations. Methods: Focussing on the orchid Thelymitra epipactoides we isolated mycorrhizal fungi from ten plants within each of three sites; Shallow Sands Woodland (SSW), Damp Heathland (DH) and Coastal Heathland Scrub (CHS). Twenty-seven fungal isolates were tested for symbiotic germination under three temperature ranges: 12-16°C, 16-24°C or 27°C. Fungi were sequenced using the ITS, nLSU, 28S and mitochondrial regions. Orchids were grown to maturity and co-planted with each of ten associated plant species with tuber width measured at 12 months after co-planting. Key Results: Two Tulasnella fungal lineages were isolated and identified by phylogenetic analyses, OTU1 and “T. asymmetrica”. Fungal lineages were specific to sites and did not co-occur. OTU1 (from the SSW site), germinated seed predominately at 12-16°C (typical of autumn-winter temperature) whereas “T. asymmetrica” (from the DH and CHS sites), germinated seed across all three temperature ranges. There was no difference in the growth of adult orchids germinated with different OTUs. There was a significant reduction in tuber size of T. epipactoides when co-planted with six of the commonly co-occurring plant species. Conclusions: We found orchid fungal lineages and their germination temperature can change with habitat and established that translocation sites can be optimised with knowledge of co-occurring plant interactions. For conservation translocations, particularly under a changing climate, we recommend plants should be grown with mycorrhizal fungi tailored to the recipient site
Sequence alignments
Zip file containing the sequence loci of the ITS region, nLSU1, nLSU2 and mtLSU from Tulasnella isolated from Thelymitra epipactoide
FUNECO_605_StarbeastXML
Starbeast XML files for four species delimitation hypotheses: T=2, T=3, T=7, and T=
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