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Using isozyme analysis, we studied the genetic diversity among 316 Bromus hordeaceus (Poaceae) accessions of different geographic origin and belonging to five subspecies. Eight putative isozyme loci revealed remarkable allozyme va...
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Using isozyme analysis, we studied the genetic diversity among 316 Bromus hordeaceus (Poaceae) accessions of different geographic origin and belonging to five subspecies. Eight putative isozyme loci revealed remarkable allozyme variation. The isozyme variation occurred as different fixed homozygous and heterozygous phenotypes without segregation among the seed progeny. We detected no subspecies-specific allozymes. Two isozymes tend to differentiate among subspecies, indicating that subspecies of B. hordeaceus are still undergoing contemporary process of divergence. The differentiation into 65 multilocus isozyme lineages (MLILs) was not related to the geographic origin of B. hordeaceus accessions. Bromus hordeaceus did not lose genetic variation towards its range margins: we found 7.7% out of total MLILs in the northernmost part of a core distribution range and 7.7%-40% in the southern part. We recorded silencing of one homeoallelic isozyme gene in the allotetraploid genome of B. hordeaceus for accessions of different geographic origins.
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Wheat is the most important cereal in Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) and the Caucasus (Armenia, Azerbaijan and Georgia). Stripe rust, caused by Puccinia striiformis f. sp. tritici is...
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Wheat is the most important cereal in Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) and the Caucasus (Armenia, Azerbaijan and Georgia). Stripe rust, caused by Puccinia striiformis f. sp. tritici is considered the most important disease of wheat in Central Asia and the Caucasus (CAC). Although stripe rust has been present in the region for a long time, it has become a serious constraint to wheat production in the past 10 years. This is reflected by the occurrence of five epidemics of stripe rust in the CAC region since 1999, the most recent in 2010. Several wheat varieties occupying substantial areas are either susceptible to stripe rust or possess a low level of resistance. Information on the stripe rust pathogen in terms of prevalent races and epidemiology is not readily available. Furthermore, there is an insufficient understanding of effective stripe rust resistance genes in the region, and little is known about the resistance genes present in the commercial varieties and advanced breeding lines. The deployment of resistant varieties is further complicated by putative changes in virulence in the pathogen population in different parts of the CAC. Twenty four out of 49 improved wheat lines received through international nurseries or other exchange programs showed high levels of resistance to stripe rust to local pathogen populations in 2009. Fifteen of the 24 stripe rust resistant lines also possessed resistance to powdery mildew. It is anticipated that this germplasm will play an important role in developing stripe rust resistant wheat varieties either through direct adoption or using them as parents in breeding programs.
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Eucalypts were first introduced into China in 1890 and the first commercial eucalypt plantation was established in ZhanJiang, GuangDong province in 1954. Because natural ecosystems have been strictly protected from logging since 2...
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Eucalypts were first introduced into China in 1890 and the first commercial eucalypt plantation was established in ZhanJiang, GuangDong province in 1954. Because natural ecosystems have been strictly protected from logging since 2000, eucalypt plantations in South China have been substantially expanded to meet the needs of a rapidly growing local economy. Approximately 3.6 million ha of eucalypt plantations have now been established and half of these represent clones of Eucalyptus urophylla x E. grandis, and E. camaldulensis x E. grandis hybrids. However, the sustainable development of the eucalypt plantations is under increasing threat due to pathogens and pests. The fact that there has been very limited work on eucalypt pathology in China compounds this fact. During the course of past five years, a programme known as the CFEPP (http://www.fabinet.up.ac.za/cfepp/index) focusing on eucalypt health problems in China has been developed, and a large number of eucalypt disease surveys have been conducted in areas such as GuangXi, GuangDong, HaiNan, FuJian and Yunnan. This work has resulted in the collection of over 2000 fungal strains many of which are well-known eucalypt pathogens. A total of 30 fungal species (eight of them new to science) residing in 11genera such as Calonectria, Celoporthe, Chrysorporthe, Quambalaria and Teratosphaeria, have been characterized based on comparisons of morphology and DNA sequence data. Both glass-house and field trials have been conducted to test the pathogenicity of the most important of these fungi on commercially used eucalypt clones. Results have shown that there are significant differences in the susceptibility of these clones to fungal isolates/species, indicating that selection of resistant material for commercial planting in the future can be achieved.
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The bacterial 16S rRNA gene diversity of waterborne bacterial (WBB) communities was assessed using PCR/denaturing gradient gel electrophoresis (DGGE) techniques, along with sequence analysis of selected bands. 16S rRNA gene divers...
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The bacterial 16S rRNA gene diversity of waterborne bacterial (WBB) communities was assessed using PCR/denaturing gradient gel electrophoresis (DGGE) techniques, along with sequence analysis of selected bands. 16S rRNA gene diversity varied between seasons, and significant differences were recorded between night and day. However, there were no significant differences detected between low, ebb, flood and high tides when the water body sampled would have originated from completely different areas including those off-reef. These results suggest that changes in productivity and/or vertical diurnal migrations of plankton may have greater effects than large-scale water movements effected by tidal flows. These results do not demonstrate a strong link between WBB communities and their underlying benthos. This either suggests a lack of coupling between the benthos and the water column (benthic-pelagic coupling) or that the processes are extremely rapid and efficient with strong mixing. Previous studies at this site have shown cycling between coral reef and lagoon sediments via coral mucus release and tidal transport, supporting the latter. We found a strong seasonality in the abundance and composition of WBB communities, with Alphaproteobacteria being more prevalent during winter and Gammaproteobacteria during summer, but quantitative PCR (qPCR) showed no significant differences in vibrios between seasons.
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Anglerfish from the genus Lophius are a globally important commercial fishery. The microsporidian Spraguea infects the nervous system of these fish resulting in the formation of large, visible parasitic xenomas. Lophius litulon fr...
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Anglerfish from the genus Lophius are a globally important commercial fishery. The microsporidian Spraguea infects the nervous system of these fish resulting in the formation of large, visible parasitic xenomas. Lophius litulon from Japan were investigated to evaluate the intensity and distribution of Spraguea xenomas throughout the nervous system and to assess pathogenicity to the host and possible transmission routes of the parasite. Spraguea infections in L. litulon had a high prevalence; all fish over 403 mm in standard length being infected, with larger fish usually more heavily infected than smaller fish. Seventy percent of all fish examined had some gross visible sign of infection. The initial site of development is the supramedullary cells on the dorsal surface of the medulla oblongata, where all infected fish have parasitic xenomas. As the disease progresses, a number of secondary sites typically become infected such as the spinal, trigeminal and vagus nerves. Fish with infection in the vagus nerve bundles often have simultaneous sites of infection, in particular the spinal nerves and along the ventral nerve towards the urinary bladder. Advanced vagus nerve infections sometimes form xenomas adjacent to kidney tissue. Spraguea DNA was amplified from the contents of the urinary bladders of two fish, suggesting that microsporidian spores may be excreted in the urine. We conclude that supramedullary cells on the hindbrain are the primary site of infection, which is probably initiated at the cutaneous mucous glands where supramedullary cells are known to extend their peripheral axons. The prevalence of Spraguea infections in L. litulon was very high, and infections often extremely heavy; however, no associated pathogenicity was observed, and heavily infected fish were otherwise normal.
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Previous studies have shown that ragweed pollen arrives in Poland from sources in the south, in Slovakia, the Czech Republic, Hungary and Austria. It is likely that ragweed pollen also arrives from sources in the southeast (e.g. U...
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Previous studies have shown that ragweed pollen arrives in Poland from sources in the south, in Slovakia, the Czech Republic, Hungary and Austria. It is likely that ragweed pollen also arrives from sources in the southeast (e.g. Ukraine). This hypothesis was investigated using 13 years of pollen data and back-trajectory analysis. Ambrosia pollen data were collected at three sites in Poland, Rzeszw, Krakw and PoznaA". The amount of ragweed pollen recorded at Rzeszw was significantly higher than in PoznaA" and Krakw. This can be related to either a higher abundance of local populations of Ambrosia in south-east Poland or the proximity of Rzeszw to foreign sources of ragweed pollen. The combined results of pollen measurements and air mass trajectory calculations identified plumes of Ambrosia pollen that were recorded at Rzeszw, Krakw and PoznaA" on 4 and 5 September 1999 and 3 September 2002. These plumes arrived at the pollen-monitoring sites from an easterly direction, indicating sources of Ambrosia pollen in eastern Poland or Ukraine. This identifies Ukraine as a possible new source of ragweed pollen for Poland and therefore an important source area of Ambrosia pollen on the European Continent.
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Common names: Weatherfish (Eng). Conservation status: IUCN Red List of Threatened Species Least Concern (2008); Rare and Vulnerable (Lelek 1987); Endangered, Red List in the Czech Republic (Lusk et al. 2004); Danger of extinction,...
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Common names: Weatherfish (Eng). Conservation status: IUCN Red List of Threatened Species Least Concern (2008); Rare and Vulnerable (Lelek 1987); Endangered, Red List in the Czech Republic (Lusk et al. 2004); Danger of extinction, category 1, Austria (Spindler 1997); Vulnerable, Croatia (Mrakovaia et al. 2008); Near Threatened, Slovakia (Kocao and Holík 2008); Vulnerable, Poland (Witkowski et al. 2009). Identification: DII–IV 5–7, A III–V 5–6, Lateral line scales 135–175. Ten whiskerlike barbels around its mouth, without a movable spine near its eye, dark brown body, with fine specks. Distribution: Misgurnus fossilis is native to Europe (Kottelat and Freyhof 2007). Found in Europe in patches dispersed from the Seina River to the Volga River. Introduced into Spain and Italy (Hanel and Lusk 2005). Abundance: The numbers are rapidly decreasing (Hanel and Lusk 2005), particularly in central Europe where the distribution of M. fossilis has recently been reduced. Habitat and ecology: Demersal, potamodromous freshwater species that inhabits muddy still and moderately flowing waters with pools. All size groups avoid open substrate without vegetation (Meyer and Hinrichs 2000). Reproduction: Spawns April through June; 5–35 thousand eggs are laid on plants. Free swimming larvae emerg from eggs that have typical outer fibrillae (Hol?ík 1998). Threats: Stream regulation and agrarian use of former floodplains, and use of pesticides in agriculture have caused population reductions (Spindler 1997). Conservation action: Protection of suitable habitats. Recovery of watercourses, renewal of extinct wetlands, and building new artificial wetlands, are appropriate measures to take to support this species (Hala?ka et al. 1998). Remarks: The species has relatively low level genetic diversity within the whole area of its spread (Bohlen et al. 2007; Mendel et al. 2008), which may increase its vulnerability to habitat changes.
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This study presents the initial results of a collaborative project aimed at the evaluation of Toxoplasma seroprevalence in a population of Kosovar pregnant women. The serum samples of 334 pregnant women were tested to detect IgG, ...
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This study presents the initial results of a collaborative project aimed at the evaluation of Toxoplasma seroprevalence in a population of Kosovar pregnant women. The serum samples of 334 pregnant women were tested to detect IgG, IgM, IgG avidity for toxoplasmosis. Data regarding age, occupation, area of origin and education were also obtained for the pregnant women examined; 97/334 (29.4%) resulted positive for IgG antibodies, four of whom (4.1%) were also positive for IgM, (1.2% of the total population examined). All four IgM-positive pregnant women also demonstrated low avidity tests.The rate of IgG seroprevalence found in our study was lower than that observed in various European countries, especially those of western Europe. Conversely, the percentage of recent infections was higher than expected. The higher rate of infections could be the result of a recent toxoplasmosis epidemic in Kosovo, most likely due to the altered hygienic conditions caused by the forced transfer of the ethnic-Albanian population from an area of low (Serbia) to high (Kosovo) toxoplasmosis prevalence.
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We present a revised and updated synoptic list of 44 Arabian Monomorium species, including two new species of the M. salomonis species-group: M. heggyi sp. n., and M. khalidi sp. n. We propose the following new synonyms: M. abeill...
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We present a revised and updated synoptic list of 44 Arabian Monomorium species, including two new species of the M. salomonis species-group: M. heggyi sp. n., and M. khalidi sp. n. We propose the following new synonyms: M. abeillei André (= M. wahibiense Collingwood & Agosti syn. n.); M. areniphilum Santschi (= M. fezzanense Collingwood & Agosti syn. n., = M. hemame Collingwood & Agosti syn. n. = M. marmule Collingwood & Agosti syn. n.); M. bicolor Emery (= M. phoenicum Santschi syn. n.); M. harithe Collingwood & Agosti (= M. najrane Collingwood & Agosti syn. n.); M. niloticum Emery (= M. matame Collingwood & Agosti syn. n.); and M. nitidiventre Emery (= M. yemene Collingwood & Agosti syn. n.). An illustrated key and distribution maps are presented for the treated species. Ecological and biological notes are given when available. The majority of Arabian Monomorium species (24) are endemic to the peninsula. All except one of the remaining species are more broadly ranging Afrotropical and Palearctic species, supporting the view of Arabia as a biogeographical crossroads between these two regions. Monomorium floricola (Jerdon), the sole species of Indomalayan origin, is recorded for the first time from the Arabian Peninsula.
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