The impact of climate change on the yield and quality of Saaz hops in the Czech Republic     

Martin Mozny  Radim Tolasz  Jiri Nekovar  Tim Sparks  Mirek Trnka  Zdenek Zalud 《Agricultural and Forest Meteorology》2009,149(6-7):913-919

The impact of climate change on the production and quality of hops Humulus lupulus will depend on future weather conditions in the growing season. Our simulations suggest that hops will be particularly vulnerable to a change in climate. Even with the modest warming so far experienced yields have stagnated and quality declined. Recorded observations show an increase in air temperature which is associated with an earlier onset of hop phenological phases and a shortening of the vegetation period. Simulations using future climate predict a decline in both yields, of up to 7–10%, and α-acid content, of up to 13–32%, the latter a major determinant of quality. The concentration of hop cultivation in a comparatively small region in the Czech Republic makes it more vulnerable than if the crop were grown in more areas with different climates. Thus climate change may gradually lead to changes in the regionalization of hop production. Policy assistance may be necessary for the adaptation of the Czech hop growing industry to changed climatic conditions.  相似文献   

Invasive Asian <Emphasis Type="Italic">Fusarium</Emphasis> – <Emphasis Type="Italic">Euwallacea</Emphasis> ambrosia beetle mutualists pose a serious threat to forests,urban landscapes and the avocado industry     

Kerry O’Donnell  Ran Libeskind-Hadas  Jiri Hulcr  Craig Bateman  Matthew T. Kasson  Randy C. Ploetz  Joshua L. Konkol  Jill N. Ploetz  Daniel Carrillo  Alina Campbell  Rita E. Duncan  Pradeepa N. H. Liyanage  Akif Eskalen  Shannon C. Lynch  David M. Geiser  Stanley Freeman  Zvi Mendel  Michal Sharon  Takayuki Aoki  Allard A. Cossé  Alejandro P. Rooney 《Phytoparasitica》2016,44(4):435-442

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SIRT1-dependent modulation of methylation and acetylation of histone H3 on lysine 9 (H3K9) in the zygotic pronuclei improves porcine embryo development     

Katerina Adamkova  Young-Joo Yi  Jaroslav Petr  Tereza Zalmanova  Kristyna Hoskova  Pavla Jelinkova  Jiri Moravec  Milena Kralickova  Miriam Sutovsky  Peter Sutovsky  Jan Nevoral 《畜牧与生物技术杂志(英文版)》2018,(2)

Background: The histone code is an established epigenetic regulator of early embryonic development in mammals.The lysine residue K9 of histone H3(H3 K9) is a prime target of SIRT1, a member of NAD+-dependent histone deacetylase family of enzymes targeting both histone and non-histone substrates. At present, little is known about SIRT1-modulation of H3 K9 in zygotic pronuclei and its association with the success of preimplantation embryo development. Therefore, we evaluated the effect of SIRT1 activity on H3 K9 methylation and acetylation in porcine zygotes and the significance of H3 K9 modifications for early embryonic development.Results: Our results show that SIRT1 activators resveratrol and BML-278 increased H3 K9 methylation and suppressed H3 K9 acetylation in both the paternal and maternal pronucleus. Inversely, SIRT1 inhibitors nicotinamide and sirtinol suppressed methylation and increased acetylation of pronuclear H3 K9. Evaluation of early embryonic development confirmed positive effect of selective SIRT1 activation on blastocyst formation rate(5.2 ± 2.9% versus 32.9 ± 8.1% in vehicle control and BML-278 group, respectively; P ≤ 0.05). Stimulation of SIRT1 activity coincided with fluorometric signal intensity of ooplasmic ubiquitin ligase MDM2, a known substrate of SIRT1 and known limiting factor of epigenome remodeling.Conclusions: We conclude that SIRT1 modulates zygotic histone code, obviously through direct deacetylation and via non-histone targets resulting in increased H3 K9 me3. These changes in zygotes lead to more successful pre-implantation embryonic development and, indeed, the specific SIRT1 activation due to BML-278 is beneficial for in vitro embryo production and blastocyst achievement.  相似文献   

Effect of the Period of Maceration on the Content of Antioxidant Substances in Grape Juice     

Mojmir Baron  Michal Kumsta  Daniela Sumczynski  Jiri Mlcek  Tunde Jurikova  Jiri Sochor 《Erwerbs-Obstbau》2018,60(1):37-45

The study deals with the monitoring of the content of antioxidant components in grape juice in the course of cold maceration of grapevine varieties ‘Italian Riesling’ and ‘Cabernet Sauvignon’, vintages 2011 and 2012. For analyses, grape juice was sampled after the maceration intervals of 0; 2; 4; 6; 8; 12 and 24?h. Spectrophotometry was used to estimate antioxidant activity (by the DPPH test), total flavanols, contents of anthocyans and contents of hydroxycinnamic acids. The content of total acidity and pH were estimated as well. Obtained results indicated that contents of aforementioned compounds increased with the increasing time of mush maceration.  相似文献   

Separation, characterization, and quantitation of phenolic acids in a little-known blueberry (Vaccinium arctostaphylos L.) fruit by HPLC-MS     

Ayaz FA  Hayirlioglu-Ayaz S  Gruz J  Novak O  Strnad M 《Journal of agricultural and food chemistry》2005,53(21):8116-8122

The aim of this study was the qualitative and quantitative determination of free, ester, glycoside, and ester-bound phenolic acids in the blueberry (Vaccinium arctostaphylos L.) fruit. A method for the determination of the profile of phenolic acids of four different phenolic fractions in the fruit was developed using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Thirteen compounds (gallic, protocatechuic, p-hydroxybenzoic, m-hydroxybenzoic, gentisic, chlorogenic, p-coumaric, caffeic, ferulic, syringic, sinapic, salicylic, and trans-cinnamic acids) were identified and quantified in the berry. These experimental results showed that the predominant phenolic acid in the fruit of V. arctostaphylos is caffeic acid in free and insoluble ester-bound forms and p-coumaric acid in soluble ester and glycoside forms. Seven phenolic acids were identified as hydroxybenzoic acid derivatives (HBAs) and four as hydroxycinnamic acid derivatives (HCAs). Total content of HBAs and HCAs in the four phenolic fractions constituted 30.1 and 69.9% of the free, 27.9 and 72.1% of the ester, 24.7 and 75.3% of the glycoside, and 51.7 and 48.3% of the ester-bound forms, respectively. Total phenolics as the sum of individual phenolic acids identified is 698.5 ng/g of fresh weight (fw) for the free, 3399.2 ng/g of fw for the ester, 3522.1 ng/g of fw for the glycoside, and 3671.6 ng/g of fw for the ester-bound phenolic fractions. The present results were compared with reported levels of phenolic acids in the fruits of different Vaccinium species. These data suggest that the fruit can be considered as a potentially good dietary source of phenolic acids.  相似文献   

Reservoirs' siltation measurments and sediment transport assessment in the Czech Republic, the Vrchlice catchment study     

Josef Krasa  Tomas Dostal  Anton Van Rompaey  Jiri Vaska  Karel Vrana 《CATENA》2005,64(2-3):348

Sediment transport from agricultural land into rivers and reservoirs is a problem within the Czech Republic. This problem was highly accelerated almost 50 years ago during the communist period. At that time strong collectivization was undertaken leading to destruction of traditional landscape patterns, surface outflow, erosion processes intensification and surface water quality deterioration. Thirteen years after political changes erosion problems remain.At the Department of Irrigation, Drainage and Landscape Engineering at the CTU Prague there has been continuous research undertaken in the field of erosion and sediment transport assessment. There are several modelling tools available for this purpose. One of them—USLE (Universal Soil Loss Equation) is commonly used in the Czech Republic for many years at a plot-scale but modern GIS (geographical information systems) tools in computer science allow using it at larger scales. Very important is the validation of this model for two-dimensional topography and GIS routines. Moreover USLE produces only local erosion amount values and has to be completed by another tool to get sediment amounts. For this purpose SDR (sediment delivery ratio) is usually used, applying a lumped approach—total erosion of every watershed is reduced by SDR and by pond’s trapping efficiency. Another available approach is using the Watem/SEDEM model that puts together RUSLE (Revised USLE) and a distributive approach to sediment transport modelling. This has already been used for estimating sediment amount in several catchments of the Czech Republic, but has to be validated as well.At the Dept. of Drainage, Irrigation and Landscape Engineering there are datasets of sediment amount from different reservoirs available and other reservoirs are to be measured soon. As the dataset of various watersheds is expanded, a methodology for sediment amount measurements is needed. The main objective of this paper is to propose a simple methodology to measure the sediment amount within reservoirs as well as to present a review of available methods. The application of the methodology at Vrchlice Catchments (97 km²) case study is presented. Total sediment amounts between 125 000140 000 m³ were measured in Vrchlice reservoir and values of 110 976 m³ (using USLE), resp. 105833 m³ (using Watem/SEDEM) were predicted by the erosion models. For catchments of this scale it is a sufficient validation.  相似文献   

Canopy reduction as a possible measure for adaptation of young Scots pine stand to insufficient precipitation in Central Europe     

Marian Slodicak Jiri Novak  David Dusek 《Forest Ecology and Management》2011,262(10):1913-1918

Climate change towards a warmer and dryer vegetation period may negatively impact growing conditions for Scots pine monocultures situated on dry, sandy soils in Central Europe. The purpose of the study was to evaluate the effect of thinning on precipitation throughfall in young Scots pine stands on typical pine sites. In 1992, observation of precipitation and throughfall started at the Tyniště research site (lowland of Eastern Bohemia) in a 7-year-old pine stand planted in rows at a stocking of ca 10,000 trees ha⁻¹. Throughfall was measured at weekly intervals during the growing season (April-September) by gauges randomly located in two treatments - variant 1C - Control without thinning and variant 2T - Thinned - and compared to precipitation at an open space outside of the canopy. The results demonstrated the positive effects of heavy low thinning (removal of 47% of the total number of trees and 31% of total pre-treatment basal area) on the water supply of young Scots pine stands. On the Thinned treatment, throughfall increased by 2-8% compared to Control plot. This positive effect persisted for six years after the first canopy reduction and the differences were significant for the first four years after thinning. After the second treatment (high thinning), throughfall on the Thinned treatment showed a nominal, but statistically insignificant increase. The likely reason for this result is that the application of a different type of thinning increased the variability of the canopy and, consequently, the effect of released crowns could not be detected.  相似文献   

灰色关联度分析在紫苏高产中的应用初探     

吴松权  吴明根  王立平  吴基日 《中国林副特产》2006,66(4):10-11

应用灰色关联度分析方法,对6个农户中影响产量因素的6个主要性状进行了分析,结果表明小坚果数/株、分枝数/株对产量的高低起主要作用。  相似文献   

麦类赤霉病菌子囊壳形成所需环境条件的研究     

吴基日  刘宪虎 《延边大学农学学报》1997,19(2):69-73

本文主要探讨了麦类赤霉病菌的子囊壳形成能力的菌株间差异、子囊壳形成所需要的主要环境条件及子囊壳形成的培养方法。结果表明：供试的248个菌株之间的子囊壳形成能力有很大的差异；子囊壳形成所需要的光源是紫外光（波长：300～400nm），每天光照时间为2小时以上，培养温度为21℃左右。  相似文献   

大麦品种对赤霉病的抗性鉴定     

吴基日  刘宪虎  许明子  李艳茹 《延边大学农学学报》1996,(1)

用“切穗鉴定法”分别对大麦１６６８个品种（二棱大麦４３５个品种、六棱大麦１２３３个品种）、４１３个品种和３４６个品种进行了大麦抗赤霉病鉴定，结果表明：二棱大麦的赤霉病抗性比六棱大麦强；来自温带湿润地区（日本、中国、朝鲜等国）的大麦品种比来自干旱地区（土耳其、非洲等地）的大麦品种赤霉病抗性强；用方差分析法估算的大麦赤霉病抗性的广义遗传力分别为０．５９和０．５２．  相似文献