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1.
Daniela Moyankova Aneta Lyubenova Slavtcho Slavov Dimitar Djilianov 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(1):149-155
The Phytophthora pathogens are among the most important pests in the modern agriculture and forestry. This makes them a subject of intensive studies, including laboratory experiments with in vitro culture on various plant-derived media. Here we show that leaf extracts from the resurrection endemic plant Haberlea rhodopensis stimulates significantly the in vitro growth of various isolates from several Phytophthora species. The extracts stimulate the formation of oospores in some heterothallic species. In this respect, the idea to propose Haberlea extracts as a potential ingredient of culture media for Phytophthora spp. maintenance under controlled conditions or as a component of detection systems for Phytophthora presence in nature seems quite attractive and promising. 相似文献
2.
DimitarDomozetov 《烟台果树》2005,(1):47-48
种苗砧木的苹果树由于生物学因素,具有比较稳定的苹果产量,因为它们具有较好的生物可塑性。然而,与矮化砧木相比,种苗砧木促进栽培品种枝条的旺长,果树进入结果期较晚,但具有较长久的生命力和结果期。为了避免种子砧木的这些不足,我们决定寻找降低枝条旺长的树,并在幼树期间,利用宽大的行间距栽植密植树,这样可使广大果园的苹果产量猛增。我们的研究目标是使建立种子砧木树的密植园成为可能,矮化和半矮化无性繁殖砧木也是我们报告结果的一部分。1材料与方法试验果园是1998年春天定植的,栽培品种是Florina和Freedom,嫁接在两个种苗砧木上,即… 相似文献
3.
保加利亚气候条件非常适宜苹果生长.1968年保加利亚苹果种植面积为3.04万hm2,但近年由于土地改革,苹果种植面积持续减少,现仅存5393hm2.笔者介绍了目前保加利亚苹果的种植面积、产量、主栽品种、砧木、树形及研究状况. 相似文献
4.
Popmintchev T Chen MC Popmintchev D Arpin P Brown S Alisauskas S Andriukaitis G Balciunas T Mücke OD Pugzlys A Baltuska A Shim B Schrauth SE Gaeta A Hernández-García C Plaja L Becker A Jaron-Becker A Murnane MM Kapteyn HC 《Science (New York, N.Y.)》2012,336(6086):1287-1291
High-harmonic generation (HHG) traditionally combines ~100 near-infrared laser photons to generate bright, phase-matched, extreme ultraviolet beams when the emission from many atoms adds constructively. Here, we show that by guiding a mid-infrared femtosecond laser in a high-pressure gas, ultrahigh harmonics can be generated, up to orders greater than 5000, that emerge as a bright supercontinuum that spans the entire electromagnetic spectrum from the ultraviolet to more than 1.6 kilo-electron volts, allowing, in principle, the generation of pulses as short as 2.5 attoseconds. The multiatmosphere gas pressures required for bright, phase-matched emission also support laser beam self-confinement, further enhancing the x-ray yield. Finally, the x-ray beam exhibits high spatial coherence, even though at high gas density the recolliding electrons responsible for HHG encounter other atoms during the emission process. 相似文献
5.
Kamen L. Stefanov Dimitar L. Djilianov Zarka Y. Vassileva Rositsa B. Batchvarova Atanas I. Atanassov Liliana V. Kuleva Simeon S. Popov 《Pest management science》1996,46(4):369-374
After a one-step selection procedure with glyphosate added to the callus medium, tobacco regenerants were obtained from calluses surviving on field doses of the herbicide. The lipid and sterol compositions of potted plants from the two original cultivars which underwent the selection procedure but without glyphosate, and the selected regenerants were investigated. Controls were derived from micropropagation and not from seeds. They served as appropriate controls for comparison with glyphosate regenerants, i.e. they underwent exactly the same experimental conditions except for the glyphosate treatment. Plant regeneration was strongly (at one-step selection) or fully (at stepwise selection) inhibited. Only a few glyphosate-tolerant plants (seven of Nevrokop A24 and five of Zlatna arda) were obtained which were cloned and potted. At least 10 plants of one clone per genotype were used for the further biochemical analyses. The spraying of the tobacco plants from the cultivars with glyphosate led to a decrease of monogalactosyl diacylglycerol content and increase of the saturated fatty acids in all glycolipid classes. The concentration of stigmasterol increased and that of sitosterol decreased only in Zl.arda variety. In the regenerants there were different changes in lipid composition, concerning mainly a decrease of monogalactosyl diacylglycerols (MGDG) and an increase of digalactosyl diacylglycerols (DGDG) in Zl.arda-derived regenerants and increase of the amounts of neutral lipids and decrease of phospholipids (PL) in the Nevrokop A24-derived regenerants. Surprisingly, after treatment of the regenerants with glyphosate, the MGDG amounts in these regenerants were higher than in the controls, which could mean a lesser ability to control ion permeability. 相似文献
6.
Miroslav Zorić Sreten Terzić Vladimir Sikora Milka Brdar-Jokanović Dimitar Vassilev 《Euphytica》2017,213(1):23
Tuber yield, together with tuber number and size are the basic agronomic and breeding traits in Jerusalem artichoke and can be significantly affected by environmental factors. We report the results of a long term trial on the performance of 20 Jerusalem artichoke cultivars. The random model for means with restricted maximum likelihood (REML) procedure was used to estimate the overall effects of the genotype, environment and genotype by environment interaction on traits. The partial least square regression (PLSR) model was used for modeling genotype by environment interaction variance components with a set of available correlated environmental variables. The REML variance component estimates model revealed that tuber number and yield are more dependent on GE interaction which allowed identification of best genotypes for specific environments. The PLSR model revealed that the most important climatic variables for optimal emergence, canopy development, high tuber number and yield are adequate soil and air temperatures in April. For larger tuber mass, precipitation variables and even distribution of rainfall were the most important factor, together with soil and air temperature in June when tuber growth is initiated. The knowledge obtained in this study is valuable for the identification and understanding of key environmental factors that contribute to the performance of Jerusalem artichoke. 相似文献
7.
2005年3~7月在新疆卡拉麦里山地区和北塔山地区的猎隼(Falco cherrug)食性研究中发现鼠类是其主要食物.调查中收集到猎隼食团342个,其中有鼠毛出现的食团是287个,占到83.9%.有鼠骨出现的食团是117个,占到34.2%.在鉴定出来的117个残留物种类中,大沙鼠出现次数超过15次.根据目击的结果分析,鼠类在食物种类中占绝对优势.由于繁殖季节对鼠类大量捕食,猛禽类能在生物防治鼠害中起到积极的作用. 相似文献
8.
European corn borer (Ostrinia nubilalis Hbn., Lepidoptera: Crambidae): comparing the performance of a new bisexual lure with that of synthetic sex pheromone in five countries
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9.
The temperature induced changes in chlorophyll fluorescence induction parameters (F0, Fm, Fv and their ratios) measured by a PEA analyzer were used to screen for heat-tolerance 12 cultivars and lines of common bean (Phaseolus vulgaris L.) available in the germplasm collections of Maritsa Vegetable Crops Research Institute, Plovdiv, and Institute of Plant Genetic Resources, Sadovo, Bulgaria. The experiments were carried out in a selection field of Maritsa Institute. The measurements were made on six different dates during the bean reproductive period (in June–July) when the temperatures were approximately 26 °C in the morning to and 42 °C at noon. Two lines, known earlier as heat-tolerant were used as controls. 相似文献
10.
Diana Svetleva Graca Pereira Jorge Carlier Luis Cabrita José Leitão Dimitar Genchev 《Scientia Horticulturae》2006
Seventy-eight (33 Bulgarian and 45 foreign) common bean (Phaseolus vulgaris L.) genotypes included in Bulgarian collection were screened for ISSR (Inter Simple Sequence Repeats) and AFLP™ (Amplified Fragment Length Polymorphism) markers. ISSR analysis was performed with 13 primers, and 55 (36.7 %) out of the 150 bands observed were polymorphic. One hundred and sixty-four AFLP™ fragments were obtained with three primer combinations, of which 54 (32.9%) were polymorphic. UPGMA (Unweighted Pair Group Method Arithmetic Averages) analysis was performed using DICE coefficient and dendrograms were constructed using either the data from each method (ISSR and AFLP™) separately or combined in a single joint matrix. Despite some genetic heterogeneity observed in both pools (Middle American origin: M and Andean origin: A) the genotypes were separated in to main groups: one gathering genotypes mainly from pool M and the other more genotypes from pool A. Moreover, Bulgarian genotypes were spread over the two groups suggesting that they are not subject to genetic erosion and that the Phaseolus genetic diversity is conserved. 相似文献