Reclassification of aster yellows group phytoplasmas in Korea     

Nang Kyu Kyu Win  Young-Hye Lee  Young-Hwan Kim  Chang-Gi Back  Heewon Chung  Hee-Young Jung 《Journal of General Plant Pathology》2012,78(4):264-268

Aster yellows group phytoplasmas were reclassified by analysis of the 16S rRNA gene sequence, their phylogeny and the presence of interoperon heterogeneity. Nine phytoplasmas were classified into subgroups 16SrI-B and 16SrI-D using the 16S rRNA gene sequence. Then, based on the presence of interoperon heterogeneity, subgroup 16SrI-B phytoplasmas were differentiated into three subunits as 16SrI-B(a): mulberry dwarf, sumac witches’ broom and porcelain vine witches’ broom; 16SrI-B(b): angustata ash witches’ broom and Japanese spurge yellows; and 16SrI-B(c): onion yellow dwarf, water dropwort witches’ broom and hare’s ear yellow dwarf phytoplasma.  相似文献   

Occurrence of bacterial rot of onion caused by Bacillus amyloliquefaciens in Korea     

Sun-Kyoung Hwang  Chang-Gi Back  Nang Kyu Kyu Win  Myung Kyum Kim  Hee-Dae Kim  In-Kyu Kang  Sang-Chul Lee  Hee-Young Jung 《Journal of General Plant Pathology》2012,78(3):227-232

In 2008, bacterial rot on onion bulbs (Allium cepa L.) was observed in several low-temperature warehouses in Changnyeong-gun, Korea. The causal pathogen was isolated and identified as Bacillus amyloliquefaciens based on morphological and biochemical characterization and sequence analysis of its genome. The isolated bacteria caused the same rot symptom on inoculated onion bulbs as found in naturally infected onions during storage and was reisolated from these bulbs. This is the first report of bacterial rot of onion caused by B. amyloliquefaciens in Korea.  相似文献   

A new localized sampling method to improve grape yield estimation of the current season using yield historical data     

Araya-Alman  M.  Leroux  C.  Acevedo-Opazo  C.  Guillaume  S.  Valdés-Gómez  H.  Verdugo-Vásquez  N.  Pañitrur-De la Fuente  C.  Tisseyre  B. 《Precision Agriculture》2019,20(2):445-459

Precision Agriculture - This paper proposes a methodology to improve grape yield sampling and yield estimation of the current season by using historical yield data. This approach is based on the...  相似文献   

Fractional excretion of electrolytes during pre- and postpartum periods in cows     

Ulutaş B  Ozlem MB  Ulutaş PA  Eren V  Paşa S 《Acta veterinaria Hungarica》2003,51(4):521-528

In this study, fractional excretions (Fe) of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), magnesium (Mg) and phosphorus (PO4) were examined with the aim to demonstrate interactions between fractional excretions of these electrolytes within each period and relate them to electrolyte metabolism in clinically normal cows at different stages of lactation and dry period. The material of this study consisted of 20 clinically healthy Holstein-Friesian cows of the same age and milk yield. Blood and urine samples were collected on 190-200th, 240-250th and 270-280th days of pregnancy and on days 1-7th, 35-45th and 75-85th after calving, altogether 6 times. An increase was observed in FeCa and FeMg during the transition from the lactation to the dry period (p < 0.05), and a decrease in FeCa (p < 0.05), FeMg (p < 0.01) in the 2nd month of the dry period. FePO4 and FeMg, respectively, increased on levels of p < 0.01 and p < 0.05, while FeCa decreased on a level of p < 0.05 after gestation compared to the level before gestation. FeNa and FeK showed a decrease of p < 0.001 and p < 0.01, respectively, between the 1st and 2nd months of the dry period, while after gestation this value showed an increase in FeNa (p < 0.05) and FeK (p < 0.01). FeCl increased significantly (p < 0.05) only from postpartum to the 1st month of lactation. There was a strong positive correlation between FeNa and FeCl in all of the periods. It was concluded that there were significant changes in the Fe of Na, K, Cl, Ca, PO4 and Mg before parturition and during lactation; these changes could have an important role in assessing renal function and electrolyte balance.  相似文献   

Retracted: Risks of Avian Influenza (H5) in Duck Farms in the Ayeyarwaddy Delta Region,Myanmar     

H. H. Win  C. C. Su Mon  K. M. Aung  K. N. Oo  K. Sunn  T. Htun  T. Tiensin  M. Maclean  W. Kalpravidh  A. Amonsin 《Zoonoses and public health》2014,61(5):317-323

The Ayeyarwaddy delta region in the south‐west of Myanmar is the main agricultural and rice‐growing area. The region has a high density of duck and backyard chicken populations with low biosecurity. The objective of this study was to analyse risk factors for avian influenza (H5) in the Ayeyarwaddy delta region, Myanmar. A case–control risk factor study was conducted from April to June 2010 by individual interviews including risk factor questionnaires given to duck farmers (n = 50) in five townships in the Ayeyarwaddy delta region, Myanmar. Risk factor analyses were conducted using univariate analysis and multivariate logistic regression model with backward stepwise (wald) method. The results showed significant risk factors for AI (H5) sero‐positivity in ducks were wooden egg box containers (OR = 52.7, 95% CI = 2.34–1188, P = 0.013) and water sourced from wetlands (OR = 30.7, 95% CI = 1.96–481.6, P = 0.015). Conversely, the cleaning of reusable egg containers was determined as a protective factor (OR = 0.03, 95% CI = 0.00–0.42, P = 0.01). In conclusion, this study identified risk factors for AI (H5) in duck farms and the importance of avian influenza prevention and control.  相似文献   

Río de la Plata voyagers: Deciphering the migration ecology of a vulnerable marine catfish (Genidens barbus) in a large subtropical river (lower Uruguay River)     

Nicolás Vidal  Alejandro D'Anatro  Iván González-Bergonzoni  Ivana Silva  Patricia Correa  Joaquín País  Giancarlo Tesitore  Franco Teixeira de Mello 《水产资源保护:海洋与淡水生态系统》2021,31(6):1367-1378

1. Genidens barbus is a vulnerable marine migrant catfish with low fecundity, a complex life cycle (i.e. mouth breeding), and is the target of industrial and artisanal fisheries of several countries. This species regularly migrates from marine to freshwater environments of the south-western Atlantic.
2. The aim of this work was to delve deeper into the migration ecology of G. barbus, characterizing both its timing and potential environmental drivers. Furthermore, aspects of the population structure and reproduction of migrants in the lower Uruguay River were studied and the presence of juveniles in the adjacent estuarine recruitment area was evaluated.
3. Data from 11 years (2008–2018) of records of adult G. barbus captured by artisanal fisheries were used alongside relevant environmental variables that were recorded monthly. Reproductive biology (i.e. sex ratio, gonadosomatic index, fecundity, and oocyte size) was analysed for a period of 3 years (2016–2018). The juvenile abundance in the Río de la Plata estuary was evaluated seasonally.
4. A total of 935 adult individuals of G. barbus were captured, representing a total biomass of 3,123 kg. The migration timing was from early spring to early summer. The abundance of migrants strongly increased with river discharge, suggesting that this variable regulates the upriver migration. Furthermore, pre- and post-spawn females and males displaying mouth breeding were recorded during the study period, confirming G. barbus reproduction in the lower Uruguay River.
5. The results obtained suggest that G. barbus ascend to spawn in the freshwater environments upstream from the mouth of the Uruguay River. Then, adult males incubate and carry the embryos downstream, releasing juveniles in the Río de la Plata estuary.
6. This relevant information will help with the implementation of effective management polices (e.g. fishing restrictions during the reproductive period) for the presently unregulated fishery of this vulnerable species in the lower Uruguay River.

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脐腹小蠹伴生菌致病性测定     

沙依拉.帕那西  朱晓梅徐 阳等 《安徽农业科学》2014,(10):2949-2951

[目的]了解茄病镰刀菌对白榆的致病性及致病程度。[方法]通过在白榆细枝接种脐腹小蠹虫伴生真菌镰刀菌和在粗枝上接种镰刀菌等8株坑道真菌进行接种试验,测定脐腹小蠹虫的致病性。[结果]镰刀菌有伤接种可导致白榆粗枝条和细枝条韧皮组织变褐色坏死,从接种变褐色的组织中可重新分离到相同的真菌,说明脐腹小蠹虫的伴生菌镰刀菌可从伤口侵入,对榆树有一定的致病性,但致病性不强。[结论]通过形态学和分子生物学鉴定,确定该镰刀菌为茄病镰刀菌。  相似文献   

温度对微晶氧化铁形成与性质的影响   总被引：2，自引：0，他引：2  

顾新运  李淑秋  徐拔和 《土壤学报》1989,26(1):9-15

稀释0.5mol/L Fe(NO₃)₃母液,制成二组0.001mol/L Fe(NO₃)₃,溶液,每组分成5等份,于每份溶液中分别加入不同量的NaOH,使溶液的NaOH/Fe,分子比为0、1.0、1.8、2.7、3.1,然后在70℃烘箱中水解。制备二组试样的主要区别是母液稀释水的最初温度不同,但其最终形成的氧化铁在颗粒大小,结晶度以及显微形貌等方面有明显差别。Ⅰ组试样是用70℃水稀释制备而成,1天后其反应产物呈无定形的非晶物质,在70℃老化很短时间后,便转变成结晶好的针铁矿和赤铁矿。Ⅱ组试样是用室温水(25℃)制备。在整个实验期间,其水解产物具有轮廓明显的小圆球状微晶氧化铁,即使在老化248天后仍属结晶差的针铁矿和赤铁矿,只能用高功率转靶的X射线衍射仪才能反映其特征衍射峰,鉴定其组成。试验结果表明:制备试样时,水的温度对最初水解产物的性质起关键作用,而最初产物的特性对溶液中再溶解再结晶的速率起着重要作用。  相似文献   

Identification of main factors affecting the within-field spatial variability of grapevine phenology and total soluble solids accumulation: towards the vineyard zoning using auxiliary information     

Verdugo-Vásquez  N.  Acevedo-Opazo  C.  Valdés-Gómez  H.  Pañitrur-De la Fuente  C.  Ingram  B.  García de Cortázar-Atauri  I.  Tisseyre  B. 《Precision Agriculture》2022,23(1):253-277

Precision Agriculture - Grapevine phenology and total soluble solids (TSS) accumulation are important information to plan agricultural operation in the vineyards over the season. The study aims at...  相似文献   

Evidence of potential vertical transmission of tilapia lake virus     

Jidapa Yamkasem  Puntanat Tattiyapong  Attapon Kamlangdee  Win Surachetpong 《Journal of fish diseases》2019,42(9):1293-1300

Tilapia lake virus disease (TiLVD) is an emerging viral disease in tilapia with worldwide distribution. Although the horizontal transmission of TiLV has been demonstrated through the cohabitation of infected fish with susceptible fish, no direct experiment showed the potential of vertical transmission from broodstock to progeny. In this study, natural outbreaks of TiLV in broodstock and fry in two tilapia hatcheries were confirmed. The TiLV genomic RNA was detected in liver and reproductive organs of infected broodstock, while infective virus was isolated in susceptible cell line. In situ hybridization assay confirmed the presence of TiLV in the ovary and testis of naturally infected fish and experimentally challenged fish. Moreover, early detection of TiLV in 2‐day‐old fry and the presence of TiLV genomic RNA and viable virus in the testis and ovary suggested the possible transfer of this virus from infected broodstock to progenies. As infective virus was present in gonads and fry in natural outbreak and experimental fish, the importance of biosecurity and prevention of the virus to establish in the hatchery should be emphasized. Hence, the development of TiLV‐free broodstock and the maintenance of high biosecurity standards in the hatcheries are essential for any attempt of virus eradication.  相似文献