Chemical management of Fusarium wilt of watermelon

Watermelon yield loss due to Fusarium wilt is increasing in the U.S., due in part to the emergence of the virulent race 2 of Fusarium oxysporum f. sp. niveum, and to the shift in production to triploid cultivars, which generally have less host resistance than previously grown diploid cultivars. One potential management strategy is the use of soil-applied fungicides to reduce Fusarium wilt. The U.S. national program, interregional project 4 (IR-4) supported multistate trials of soil-applied chemicals to manage Fusarium wilt of watermelon. Greenhouse trials were conducted in Maryland, Indiana and Georgia to test the efficacy of 14 chemicals on Fusarium wilt. Based on the performance of these chemicals in the greenhouse, six in Maryland and Delaware and eight in Indiana were selected for subsequent field evaluations. These chemicals were applied once, as a drench at planting, in field trials in Maryland, Indiana, and Delaware in 2008. The fungicides prothioconazole, acibenzolar-S-methyl, and thiophanate-methyl resulted in the greatest reduction in Fusarium wilt, and caused no phytotoxicity. In Maryland and Indiana in 2009, these chemicals were applied through the drip irrigation line alone and in combination, at 0, 2 and 4 weeks after planting. The experiment was repeated in 2010 in Maryland. Prothioconazole alone and in combination with acibenzolar-S-methyl or/and thiophanate-methyl resulted in the greatest decrease in the area under the disease progress curve (AUDPC) of Fusarium wilt of watermelon in Maryland in 2009. The same trend was observed in 2010 in Maryland where three of the prothioconazole treatments ranked the lowest of all treatments and prothioconazole in combination with thiophanate-methyl had significantly lower Fusarium wilt AUDPC compared to the non-treated control. All chemical applications except for acibenzolar-S-methyl in combination with prothioconazole reduced Fusarium wilt AUDPC in Indiana in 2009. Prothioconazole alone and prothioconazole in combination with thiophanate-methyl ranked lowest in Fusarium wilt AUDPC, although not significantly lower than most other treatments. These studies are the first to demonstrate that the soil-applied fungicides prothioconazole and thiophanate-methyl may provide an additional field management option for Fusarium wilt of watermelon.     

Economics of foliar fungicides for hard red winter wheat in the USA southern Great Plains

Grain yields of winter wheat (Triticum aestivum L.) in the southern Great Plains are often reduced by the presence of foliar diseases. This study was conducted to determine whether the application of foliar fungicides is an economically optimal management strategy. The effects of fungicide treatment on commercially available hard red winter wheat varieties with differing levels of genetic resistance (i.e., resistant, intermediate, and susceptible) to foliar diseases were investigated at two locations, Apache and Lahoma, OK, USA, for the harvest years 2005–2012. Two fungicides were rotated between the two locations and applied at approximately Feekes growth stage 9–10.5. When averaged across years, plots to which fungicide was applied generated greater average net returns than plots that did not receive fungicide for susceptible varieties at Apache, and for resistant, intermediate, and susceptible varieties at Lahoma. However, foliar fungicide application was not economical in every year at either location suggesting fungicide use should be reassessed each year given that profitability depends on year specific yield potential, prices, and foliar disease conditions. At both locations high disease incidence occurred in all but one site-year when the average March through May relative humidity exceeded 65%. Additional research would be required to determine the relationship between weather, including relative humidity, and disease incidence, and to develop an economic threshold for treatment decision aid.     

延边地区烟草病毒病与气象因子关系的研究

为探明延边地区烟草病毒病的发病规律,为生产优质高产烟叶提供科学有效的病毒病预防措施,简要分析了延边地区2010和2011年病毒病与气象因子的关系.结果表明,延边地区进入6月份,当日平均温度高于16.0℃,烟草病毒病就可以发生.病毒病发病前10d的日平均温度高,日照时数大于6h的天数多,降雨量少的情况下,病毒病发生严重.     

Development of Nucleic Acid Lateral Flow Immunoassay Detection Method for Foot-and-mouth Disease Virus

In this article, through the combination of nucleic acid probes and immune chromatography, a simple, sensitive and specific detection system——nucleic acid lateral flow immunoassay (NALFIA) for amplifing foot-and-mouth disease virus (FMDV) 3D RT-PCR products was established.An ultrasensitive nucleic acid biosensor (NAB) based on streptavidin-labeled gold nanoparticles dual labels and lateral flow strip biosensor (LFSB) were used in this system.The biotinylated goat anti-rabbit IgG was marked to the NC membrane as the alleged strip and the anti-digoxin antibody was labeled to the NC membrane to capture the digoxin probe.After assemblying gold-labeled strip and detecting RT-PCR products, the detection limit of NALFIA was 0.3×10^-3 to 3×10^-3 μg/μL.The NALFIA was compared with agar gel electrophoresis analysis, the results showed that the sensitivity of NALFIA was higher than agar gel electrophoresis.There was an excellent agreement between the two methods.NALFIA was a method with high sensitive, low cost and short time.In conclusion, this method provided a good alternative to detect FMDV.     

2018年进口奶牛检疫情况分析

随着十多年的超速发展,我国奶牛业已由单一品种的散养方式逐步转变为高产品种的规模化、集约化养殖方式。然而,我国奶牛整体遗传素质不高,多为进口高产奶牛与地方奶牛的低代次改良品种,以致原奶质量参差不齐,严重制约了我国奶业的健康发展。因此,大规模引进高品质的奶牛品种,已成为我国优化奶牛基因、推动畜牧业产业化发展的重要抓手,但同时也为检疫工作带来了挑战。本文通过分析2018年我国进口奶牛数量、来源国、疫病检出、进境口岸及隔离检疫场分布等数据,结合各来源国的疫病防控特点,有针对性地提出检疫要点,为我国全面提升进口奶牛的检疫水平、切实做好奶牛群体遗传改良计划、加快推进畜牧业转型升级提供参考。     

口蹄疫疫苗对牛的应用效果调查

牛口蹄疫是传染性疾病,为研究青海省峰堆乡口蹄疫疫苗的免疫效果,于2018—2019年对该乡的7个村开展牛口蹄疫疫苗免疫效果调查,共调查牛634头,7个村总体的口蹄疫合格率为100.00%和97.56%,最低合格率为81.63%和88.63%。为更好地控制该类疾病发生流行,提升免疫效果,该文探讨口蹄疫疫苗免疫失败原因,并制定了相应的预防措施。     

高致病性猪蓝耳病防控

随着人们生活方式的变化,养猪户也变得越来越多,不仅能为其带来更多的经济收入,也可提高其生活质量和水平。调查数据显示,很多养殖户在养猪中通常会因很多因素致使猪群感染疾病,倘若不能及时处理,势必会对自身带来较为严重的经济损失,甚至会加大疫病的扩散。该文主要对高致病性猪蓝耳病防控新理念展开分析,并提出一些可行的对策。     

Study on Antiviral Effect of Polysaccharides from Lagenaria siceraria (Molina) Standl.on NDV in vitro

To research on polysaccharides from Lagenaria siceraria (Molina) Standl.against Newcastle disease virus (NDV).Total polysaccharide and four different solvent extractions of Lagenaria siceraria (Molina) Standl.were extracted by the methods of hot water extraction and ethanol precipition in this study.The content of polysaccharide was measured by phenol-sulfuric acid method and infrared spectroscopy method.The safe concentration and growth of chick embryo fibroblast (CEF) were assayed by MTT method,in order to facilitated the comparison under the same level,the safe concentration was united as 78.125 μg/mL.Under the safety range of concentration,detected the block-virus activity,anti-virus activity and virus-killing activity of polysaccharides through the ways of pre-adding polysaccharides,post-adding polysaccharides and adding polysaccharides with NDV.The results showed that the direct inactivation and propagation inhibition activity of total polysaccharide and four different solvent extractions were stronger than anti-absorption function.Anti-virus inhibition rate of 70%,80% gradient alcohol precipitation of polysaccharides from Lagenaria siceraria (Molina) Standl.(LSP₇₀,LSP₈₀) and total polysaccharide (LSP_t)were 40.41%,44.54% and 61.85%,virus-killing inhibition rate were 44.74%,58.76% and 59.38%.LSP₈₀ had the highest virus inhibition rate as 37.14% in the block-virus activity of those five polysaccharides.In summary,70%,80% gradient alcohol precipitation and total polysaccharide in polysaccharides possessed better activity and would be as the materials for further research.     

Dysbiotic gut microbiome: A key element of Crohn's disease

Since the first publication on “regional ileitis”, the relevance of this chronic inflammatory disease condition termed finally as Crohn's disease is continuously increasing. Although we are beginning to comprehend certain aspects of its pathogenesis, many facets remain unexplored. Host's gut microbiota is involved in a wide range of physiological and pathological processes including immune system development, and pathogen regulation. Further, the microbiome is thought to play a key role in Crohn's disease. The presence of Crohn's-associated variants of NOD2 and ATG16L genes appears to be associated not only with alterations of mucosal barrier functions, and bacterial killing, but the gut microbiota, as well, reflecting a potential relationship between the host's genotype and intestinal dysbiosis, involved in disease etiology. This review aims to characterize some exciting new aspect of Crohn's disease pathology, focusing mainly on the role of intestinal microbes, and their interplay with the immune system of the host.     

浅议保护性耕作技术推广过程中存在的问题及解决途径

土地采用保护性耕作方法,可有效的防止水土流失,增加土壤蓄水能力,提高雨水利用率,培肥地利,增加土壤有机质,减少耕作次数,降低生产成本,各种农作物增产明显。