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101.
102.
Martella V Elia G Lucente MS Decaro N Lorusso E Banyai K Blixenkrone-Møller M Lan NT Yamaguchi R Cirone F Carmichael LE Buonavoglia C 《Veterinary microbiology》2007,122(1-2):32-42
CDV is a highly contagious viral pathogen causing a lethal systemic disease in dogs and other carnivores. Several lineages or genotypes of CDV exist that are variously distributed throughout several continents. Legal or uncontrolled trading of animals may modify the epidemiology of CDV, introducing novel strains in CDV-na?ve areas or accounting for the resurgence of CDV in areas where vaccine prophylaxis was effective and successful to control the disease. A hemi-nested PCR system was developed to genotype strains of the major CDV lineages, America-1, Europe, Asia-1, Asia-2 and Arctic. The assay was tested using a collection of 27 laboratory and vaccine strains and of 36 field CDV strains. Distinct lineages could be differentiated by specific primers targeted to the H gene. The method could be useful for molecular epidemiological studies of CDV, providing a tool for large-scale studies, and for the diagnosis of vaccine-related disease. 相似文献
103.
Kebebew Assefa Seyfu Ketema Hailu Tefera Henry T. Nguyen Abraham Blum Mulu Ayele Guihua Bai Belay Simane Tiruneh Kefyalew 《Euphytica》1999,106(1):87-97
Three hundred twenty germplasm lines of the major Ethiopian cereal, tef, [ Eragrostis tef (Zucc.) Trotter], were evaluated
for 20 morphological, phenological and agronomic characters in two-replicated randomized complete blocks at Debre Zeit and
Melkassa Agricultural Research Centers in Ethiopia during the 1995 main season. The objectives were to assess the diversity
of the lines, and to estimate the broad sense heritability (H) and genetic advance (GA) of the various characters. The mean
squares of genotypes were highly significant (p ≤ 0.001) for all the traits. The phenotypic and genotypic coefficients of
variation ranged in that order from about 6–40% and 3–23% for days to maturity and grain yield/plant, and days to maturity
and number of spikelets/main shoot panicle, respectively. The cluster analysis grouped the genotypes into 14 major complexes
consisting of one to 183 lines. Of the 19 principal components involved in explaining the entire variation among the genotypes
the first five which had eigenvalues of more than one explained about 73.8%. The first principal component which accounted
for about 34% of the total variance was due chiefly to plant height, culm and panicle length, diameters of the two basal culm
internodes, main shoot panicle mass and grain yield, number of main shoot panicle branches and spikelets, and days to panicle
emergence and maturity. Estimates of H varied from about 22% for length of the lowest main shoot stem internode to 74% for
number of main shoot panicle branches. Values of GA (expected from selection of the superior 5% of the lines and expressed
relative to the means) ranged from about 3% for days to maturity to 36% for number of spikelets/main shoot panicle. Overall,
the study indicated the existence of trait diversity in tef germplasm and this can be exploited in the genetic improvement
of the crop through hybridization and selection.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
104.
Heat tolerance in spring wheat. I. Estimating cellular thermotolerance and its heritability 总被引:1,自引:0,他引:1
High temperature is a major environmental stress factor limiting wheat (Triticum aestivum L.) productivity. Improvement of
heat tolerance in wheat is an important breeding objective. Genetic variation in cellular thermotolerance among 56 spring
wheat cultivars was evaluated at the seedling stage of growth by cell membrane thermostability (CMS) and triphenyl tetrazolium
chloride (TTC) assays. A subset of eight lines was also evaluated at the flowering stage using the same assays. With both
assays Average thermotolerance tended to decrease from the seedling to the flowering stages. However, thermotolerance was
well correlated between growth stages among the eight cultivars for both CMS (r = 0.92; p = 0.004) and TTC (r = 0.84; p =
0.050). The correlation between TTC and CMS among the eight cultivars tested at the seedling and the flowering growth stages
was significant (r = 0.74; p = 0.031 and r = 0.75; p = 0.029, respectively). The same correlation was less strong, though
still significant (r = 0.32; p = 0.014) across 56 cultivars at the seedling stage. In a study of the cross V747 (tolerant)/Barkaee
(susceptible), broad sense heritability was estimated at 89% for TTC. Most of the genetic variance was additive. CMS in seedlings
of 16 cultivars was positively and significantly (p ≤ 0.05) correlated with yields of these cultivars in each of four hot
environments in Mexico, Sudan, India, and Brazil. The same correlations for TTC were positive but nonsignificant.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
105.
Blood Polymorphism in West African Breeds of Sheep 总被引:1,自引:0,他引:1
This paper reports the blood groups and blood protein distribution in West African sheep breeds. About 100 animals of the Djallonke, Fulani and Touabire breeds were sampled for blood polymorphism analysis. Their blood groups were typed by haemolytic and agglutination reactions, and their blood proteins by starch gel electrophoresis. Almost all the loci analysed showed variability in the three breeds, with the Touabire and Fulani being closer to each other than to the Djallonke. 相似文献
106.
107.
Mélodie Schmitz Sébastien Baekelandt Lam Khoa Tran Thi Syaghalirwa N. M. Mandiki Jessica Douxfils Thinh Quoc Nguyen Huong Do Thi Thanh Patrick Kestemont 《Fish physiology and biochemistry》2017,43(1):39-49
In Vietnam, the production of striped catfish Pangasianodon hypophthalmus S. reached more than 1.2 millions of tons in 2014 and is mainly gathered in the Mekong Delta (South Vietnam). A survey was carried out during the dry season 2013 (March–April) and rainy season 2014 (July–August) in 12 fish farms of the lower (Tra Vinh Province) and higher (Can Tho Province) Mekong River Delta. This study allowed drawing up current key osmoregulatory and innate immune parameters of striped catfish in aquaculture depending on the geographical location, particularly the proximity to the River Mekong Estuary and the seasonal surface runoff. In the dry season, plasma osmolality was positively correlated with salinity. Gill Na+K+ ATPase dropped in the rainy season, while kidney Na+K+ ATPase remained stable. Abundance of immune blood cells, especially thrombocytes and monocytes, tended to increase in farms located in tidal area. Production of reactive oxygen species in the spleen, kidney lysozyme activity and plasma complement activity did not vary whatever the season or the proximity to the estuary. Plasma lysozyme activity was 50-fold higher than in kidney and increased in the rainy season as well as in tidal sites. Kidney complement activity decreased in the dry season, especially in tidal sites. In conclusion, regarding key osmoregulatory and immune factors, striped catfish farms located in the Mekong Delta may be affected by seasonal and regional salinity and runoff fluctuations. 相似文献
108.
Thi Nhu Thuong Nguyen Timothy Chataway Ricardo Araujo Munish Puri Christopher Milton Mathew Franco 《Marine drugs》2021,19(11)
Alginate, a natural polysaccharide derived from brown seaweed, is finding multiple applications in biomedicine via its transformation through chemical, physical, and, increasingly, enzymatic processes. In this study a novel alginate lyase, AlyDS44, was purified and characterized from a marine actinobacterium, Streptomyces luridiscabiei, which was isolated from decomposing seaweed. The purified enzyme had a specific activity of 108.6 U/mg, with a molecular weight of 28.6 kDa, and was composed of 260 amino acid residues. AlyDS44 is a bifunctional alginate lyase, active on both polyguluronate and polymannuronate, though it preferentially degrades polyguluronate. The optimal pH of this enzyme is 8.5 and the optimal temperature is 45 °C. It is a salt-tolerant alginate lyase with an optimal activity at 0.6 M NaCl. Metal ions Mn2+, Co2+, and Fe2+ increased the alginate degrading activity, but it was inhibited in the presence of Zn2+ and Cu2+. The highly conserved regions of its amino acid sequences indicated that AlyDS44 belongs to the polysaccharide lyase family 7. The main breakdown products of the enzyme on alginate were disaccharides, trisaccharides, and tetrasaccharides, which demonstrated that this enzyme acted as an endo-type alginate lyase. AlyDS44 is a novel enzyme, with the potential for efficient production of alginate oligosaccharides with low degrees of polymerization. 相似文献
109.
A bacterial infectivity challenge model of Edwardsiella ictaluri in striped catfish was developed. All experiments were conducted using a bacterial isolate of E. ictaluri that had been recovered during a natural outbreak of bacillary necrosis of Pangasianodon (BNP) in farmed striped catfish Pangasianodon hypophthalmus in Vietnam. Time of immersion in 107 CFU.ml−1 had a significant effect on mortality. The immersion bacterial dose of 107 CFU/ml for 30 s resulted in a cumulative percentage mortality of 63%. Three to four days post-bacterial challenge, fish showed gross clinical signs of natural BNP and E. ictaluri was recovered and identified from these fish. Moreover, a cohabitation challenge was evaluated as an alternative challenge method, although the mortalities among the infected fish were lower at around 15%–40%. This study confirmed the horizontal transmission of E. ictaluri in striped catfish and elucidated that cohabitation challenge could be used in reproducing the disease under controlled conditions. 相似文献
110.
Partho Pratim Debnath Jerome Delamare-Deboutteville Mona Dverdal Jansen Kornsunee Phiwsaiya Afsana Dalia Md. Abir Hasan Saengchan Senapin Chadag Vishnumurthy Mohan Ha Thanh Dong Channarong Rodkhum 《Journal of fish diseases》2020,43(11):1381-1389
Tilapia lake virus (TiLV) is an emerging pathogen in aquaculture, reportedly affecting farmed tilapia in 16 countries across multiple continents. Following an early warning in 2017 that TiLV might be widespread, we executed a surveillance programme on tilapia grow-out farms and hatcheries from 10 districts of Bangladesh in 2017 and 2019. Among farms experiencing unusual mortality, eight out of 11 farms tested positive for TiLV in 2017, and two out of seven tested positive in 2019. Investigation of asymptomatic broodstock collected from 16 tilapia hatcheries revealed that six hatcheries tested positive for TiLV. Representative samples subjected to histopathology confirmed pathognomonic lesions of syncytial hepatitis. We recovered three complete genomes of TiLV from infected fish, one from 2017 and two from 2019. Phylogenetic analyses based on both the concatenated coding sequences of 10 segments and only segment 1 consistently revealed that Bangladeshi TiLV isolates formed a unique cluster within Thai clade, suggesting a close genetic relation. In summary, this study revealed the circulation of TiLV in 10 farms and six hatcheries located in eight districts of Bangladesh. We recommend continuing TiLV-targeted surveillance efforts to identify contaminated sources to minimize the countrywide spread and severity of TiLV infection. 相似文献