Yusuf Yanar

Effect of Soil Saturation Duration and Soil Water Content on Root Rot of Maize Caused by Pythium arrhenomanes

ABSTRACT Three aggressive isolates of P. arrhenomanes (201-25, 7E, and 5E) were used to evaluate the effect of soil saturation duration and soil water content on maize root rot. Maize seedlings grown in infested and noninfested soil:sand mixtures were subjected to saturation durations of 0, 6, 12, 24, or 40 h. Four silty-clay loam soil:sand mixtures (100:0, 80:20, 50:50, and 0:100) were used to evaluate the effect of soil water content on disease development. Matric water potential was maintained at -1 J/kg during the experiment except for the saturation period. Multiple regression analysis was used to evaluate the effect of saturation duration and soil water content on root and shoot dry weight. Negative slope values were obtained for increasing saturation duration and reduced water content (increased proportion of sand to soil). Intercepts of regression lines for shoot and root dry weights were lower for the infested soil:sand treatments than the noninfested treatments. These results indicated that grow...

Vermicompost suppresses Rhizoctonia solani Kühn in cucumber seedlings

Disease suppressiveness of vermicompost produced from agricultural wastes consisting of cattle manure, tree bark (Salix spp.), potato culls, and apples was assayed on damping-off of two days-old cucumber (Cucumis sativus cv. Cevher) seedlings infected by Rhizoctonia solani Kühn (AG-4). Suppression effect was assessed at the rates of 0, 10, 20 and 30% (v/v) vermicompost, either blended with Trichoderma harzianum Rifai (KRL-AG2), amended with potting mixtures consisting of sand and garden soil (1:1, v/v). Effect of water extracts of vermicompost on growth of R. solani mycelium in Petri dishes was also analyzed. Disease suppression effect increased in proportion to the pot amendment rate of vermicompost. Vermicomposts not blended with T. h arz ian u m effectively controlled damping-off of cucumber by R. solani (AG-4) at the rate of 20% and 30%. Vermicompost not blended with T. harzianum improved plant growth as well as that blended with T. harzianum. Analysis of the effect of water extracts of vermicompost on growth of R. solani mycelium in Petri dishes revealed antagonistic activity of a putative bacterium. Heat sterilization eliminated the suppressive and antagonistic effect by vermicompost and its water extracts, respectively. Activity of an antagonistic bacterium, which expressed a strong inhibition of growth of the pathogen mycelium, indicated that the type of suppressiveness against Rhizoctonia disease by the vermicompost is specific.ZusammenfassungDie suppressive Wirkung von Wurmkompost aus Rinderdung, Baumrinde (Salix spp.) und nicht mehr verkaufsfähigen Kartoffeln und Äpfeln wurde gegenüber der durch Rhizoctonia solani Kühn (AG-4) verursachten Umfallkrankheit an infizierten, zwei Tage alten Gurkenkeimlingen (Cucumis sativus cv. Cevher) untersucht. Zu diesem Zweck wurde eine 1:1-Mischung von Sand und Gartenerde in Töpfen mit 0, 10, 20 oder 30% Wurmkompost gemischt und mit oder ohne Zugabe des Antagonisten Trichoderma harzianum Rifai (KRL-AG2) zur Anzucht der Keimlinge verwendet. Darüber hinaus wurde die Wirkung wässriger Kompostextrakte auf das Myzelwachstum von R. solani in Petrischalen untersucht. Die suppressive Wirkung des Komposts stieg mit zunehmendem Substratanteil. Kompost ohne Zugabe von T. harzianum besaß eine Wirkungseffizienz gegenüber der Umfallkrankheit an Gurkenkeimlingen von 20 bis 30%. Er förderte das Pflanzenwachstum genauso wie Kompost mit Zugabe von T. harzianum. Die wässrigen Kompostextrakte zeigten eine möglicherweise bakteriell bedingte antagonistische Wirkung auf das Myzelwachstum von R. solani. Eine Hitzesterilisation hob die suppressive und antagonistische Wirkung des Komposts bzw. seines wässrigen Extrakts vollständig auf. Eine deutliche antagonistische Wirkung eines Bakteriums auf das Myzelwachstum von R. solani bedeutete, dass die suppressive Wirkung des Komposts auf den Erreger spezifisch wäre.

Contact and residual toxicities of 30 plant extracts to Colorado potato beetle larvae

Abstract Contact and residual toxicities of 30 plant extracts were investigated on third instar larvae of Colorado potato beetle, Leptinotarsa decemlineata. The plant samples were collected during the spring and summer of 2002 and were dried and ground. The plant samples were treated with methanol and the residue was eluted with distilled water containing 10% acetone, resulting in plant extracts. In contact bioassays, the beetle larvae were treated with 40% (w/w) plant extract using a Potter Spray Tower. The insects were incubated at 28±2°C under a 16 h: 8 h photo regime and the mortality was recorded at 24 h intervals for 7 days. The plant extracts exhibited varying toxicity to the larvae ranging from 0 – 91% after 24 h incubation and Artemisia vulgaris, Hedera helix, Humulus lupulus, Lolium temulentum, Rubia tinctoria, Salvia officinalis, Sambucus nigra, Urtica dioica, Verbascum songaricum, and Xanthium strumarium extracts resulted in significantly higher mortality than the control. Generally, prolonged incubation time did not result in an increase in mortality. After 48 h of incubation, 10 plant extracts yielded a significant mortality and H. lupulus extract, the most toxic extract among those tested, caused 99% mortality which is similar the mortality caused by the chemical standard, imidacloprid. In residual assays, potato leaflets were treated with 20% (w/w) plant-extract concentrations using a Potter Spray Tower. Third instar larvae were added to a glass jar to which treated leaflets were transferred before incubation at the temperature and photo regime described above. Mortality was recorded at 24 h intervals for 7 days. Five plant extracts, H. lupulus, L. temulentum, Reseda lutea and Solanum nigrum, induced significantly higher mortalities compared with controls. Chenopodium album extract was the most toxic, killing 34.9% of exposed larvae, followed by L. temulentum, H. lupulus and S. nigrum after 72 h incubation. The results exhibited that certain plant extracts were toxic to the beetle larvae and may have potential for controlling this destructive pest under field conditions.

Characterization ofRhizoctonia solani isolates from potatoes in turkey and screening potato cultivars for resistance to AG-3 isolates

A total of 304Rhizoctonia solani isolates and 60 binucleateRhizoctonia-like fungi were recovered from stems and tubers of infected potato plants over a 2-yr period in northeast Turkey.R. solani isolates were identified to 11 anastomosis groups (AGs): AG-1 (0.66%), AG-2-1 (5.6%), AG-2-2 (0.99%), AG-3 (83.9%), AG-5 (4.6%), AG-6 (0.66%), AG-8 (1.32%), AG-9 (0.33%), AG-10 (1.32%), AG-12 (0.33%), and AG-13 (0.33%). In the greenhouse tests, most of the AG-3 isolates were significantly more virulent than isolates belonging to other AGs on potato cv. Batum. Isolates of other anastomosis groups differed in their virulence. Results indicated that AG-3 is an important pathogen on potatoes grown in the study area. Five of 22 commercial and local potato cultivars evaluated for their reaction toR. solani AG-3 isolates (TP-2) under greenhouse conditions were highly resistant; the remaining cultivars exhibited different levels of susceptibility to the pathogen isolate.

Synthesis and characterization of two novel dicyanidoargentate(I) complexes containing N-(2-hydroxyethyl)ethylenediamine exhibiting significant biological activity

Two novel cyanido-bridged bimetallic polymeric complexes, [Ni(hydeten)2Ag(CN)2] [Ag(CN)2]·H2O (C1) and [Cd2(hydeten)2Ag4(CN)8]·H2O (C2) (hydeten: N-(2-hydroxyethyl)ethylenediamine) were synthesized and characterized by elemental, FT-IR, X-ray (C2), thermal and variable temperature magnetic measurement (C1) techniques. Their anticancer, antibacterial and antifungal effects were also investigated. The crystallographic analyses showed that C2 crystallizes in the monoclinic space group P21/c and shows a 3D 6,4 ladder-type polymeric chain in which the CdII centers are linked by [Ag(CN)2]− units. The Ag⋯Ag distance exhibits a short value of 3.1365(9) A. It features a rare linear pentameric unit of [Ag(CN)2]− ions assembled via d10–d10 interaction as building blocks. Both complexes exhibited outstanding antibacterial, antifungal and anticancer activities against ten different bacterial strains, two plant pathogenic fungi (Alternaria solani and Rhizoctonia solani) and four tumor cell lines (HT-29, HeLa, C6 and Vero), respectively.

Resistance of Pepper Cultivars and Accessions of Capsicum spp. to Sclerotinia sclerotiorum

Sclerotinia stem and fruit rot, caused by Sclerotinia sclerotiorum (Lib.) de Bary, is a potentially serious disease of bell peppers (Capsicum annuum L.), affecting both seedlings and mature plants. Management options for the disease are limited and information is not available on resistance in Capsicum spp. to this pathogen. The level of resistance of 12 commercial pepper cultivars and 110 Capsicum spp. accessions to Sclerotinia sclerotiorum was determined by using limited-term and ascospore inoculation methods. None of the commercial cultivars tested were resistant to Sclerotinia stem rot. Stem rot incidence among the Capsicum spp. accessions tested by ascospore inoculation ranged from 0 to 100%. Fifty-eight accessions had significantly less stem disease than the susceptible commercial cultivar Marengo. There was no correlation between results of the limited-term and ascospore inoculation tests. These results demonstrate for the first time that a high level of Sclerotinia stem rot resistance exists among the Capsicum spp. accessions. Several accessions may be suitable for use in breeding programs to increase resistance in commercial pepper cultivars.

Five novel dicyanidoaurate(I)-based complexes exhibiting significant biological activities: synthesis, characterization and three crystal structures

Five new cyanido-bridged coordination polymers having closed formulae [Ni(hydeten)Au2(CN)4] (C1), [Ni(hydeten)2Au2(CN)4]·H2O (C2), [Cu(hydeten)2Au2(CN)4]·CH3OH (C3), [Zn(hydeten)2 Au2(CN)4]·H2O (C4), and [Cd(hydeten)2Au2(CN)4]·H2O (C5) (hydeten: N-(2-hydroxyethyl)-ethylenediamine) have been prepared and characterized by elemental, thermal, FT-IR and XRD (C3, C4 and C5) measurement techniques. The anticancer, antibacterial and antifungal activities of the complexes are also investigated. The C3, C4 and C5 units according to XRD analyses are linked to each other via –CN–M(hydeten)–NC–Au(1)–CN–M(hydeten)–CN– chains (MII = Cu, Zn and Cd) and aurophilic interacted –Au(1)(CN)2–Au(2)(CN)2–Au(1)(CN)2–Au(2)(CN)2– zig-zag shaped chains along the a axis. C1, C2 and C4 show significant antifungal effects against several plant pathogenic fungi, while surprisingly C3 exhibits a considerable antibacterial effect against Gram negative E. coli. The studies of the antiproliferative activity on Hela, HT29 and C6 tumor cell lines indicated the anticancer potential of these complexes even at low doses.

In vitro biological properties and predicted DNA–BSA interaction of three new dicyanidoargentate(I)-based complexes: synthesis and characterization

The reaction of certain metal salts with N,N′-bis(2-hydroxyethyl)ethylenediamine (bishydeten) and [Ag(CN)2]− resulted in [Ni(bishydeten)2][Ag(CN)2]2·H2O (C1), [Cu(bishydeten)2Ag2(CN)4] (C2) and [Cd(bishydeten)0.5]2[Ag(CN)2]4·3H2O (C3), characterized by elemental, magnetic (C1 and C2), FT-IR, EPR (C2), ESI-MS, thermal, spectroscopic (C1, C2 or C3), and X-ray diffraction (C3) techniques. A detailed study of the antiproliferative and apoptotic properties of all the compounds and [Ag(CN)2]− was carried out using the BrdU Cell Proliferation Assay (BCPA), DNA laddering assay and TUNEL method on HT29, HeLa, C6, and Vero cell lines. These compounds exhibiting a very strong antiproliferative effect even at low micromolar concentrations were found to have cytostatic activity, whereas [Ag(CN)2]− had cytotoxic activity. The cells exposed to the compounds showed DNA laddering formations and the appearance of apoptotic bodies. Also, application of the test compounds at low concentrations was associated with a pronounced loss of the adhesive, migratory, and topoisomerase I activity of the treated tumor cell lines. Immunohistochemical staining analysis demonstrated that these complexes significantly reduced the level of Bcl-2 while causing the accumulation of P53 in HeLa and HT29 cells. Absorbance and emission spectral data reveal that the complexes interact with the DNA via a groove binding mode of interaction.

Patateste Farklı Ortam ve Dönemlerde Yapılan Melezleme ve Melez Tohum Elde Edilmesini Etkileyen Faktörler

Bu arastirmada, ustun ozelliklere sahip ileri patates klonlari ile bazi yerel patates cesitleri ve ticari cesitler arasinda melezlemeler yapilarak, melez tohumlarin elde edilmesi amaclanmistir. Calisma, Tokat sartlarinda 2014 yili ilkbahar doneminde baslayip, 2015 yili kis doneminde de devam ettirilerek, 2014 ve 2015 yillarinda yurutulmustur. Patateste melezleme islemleri 2014 yilinda cam ve tul sera ile dusuk (650 m) ve yuksek rakimli (1200 m) acik alanlarda yapilmistir. Arastirmanin 2014-2015 kis donemi polikarbon sera ortaminda yurutulmustur. Elde edilen sonuclara gore 2014 yili yaz donemi acik alan ve tul sera sartlarinda 15 kombinasyonun 14’unde 1260 cicek melezlenmis, bunlardan 65’i meyve olusturabilmis ve 1831 adet melez tohum elde edilmistir. 2014 yili yaz doneminde zaman zaman asiri yagis ve ozellikle yuksek sicakliklardan dolayi melezleme basarisi olumsuz etkilenmis, bu yuzden melezleme calismalarina kis doneminde polikarbon serada devam edilmistir. Bu donemde yapilan melezleme calismalarinda 15 kombinasyonda yaklasik 1602 cicekte melezleme yapilmis ve halen 203 meyveden 13302 adet melez tohum elde edilmistir. Yaz doneminde melezlenen ciceklerin %5.2’ si meyve baglamis iken, kis doneminde bu oran %12.7 olmustur. Benzer sekilde yaz doneminde meyve basina 28.2 adet tohum elde edilmis iken, kis donemi melezlemelerinde bu sayi 65.5’e yukselmistir. Diger taraftan, yaz doneminde yuksek rakimli acik alan ve tul sera sartlarinda yapilan melezlemelerden daha iyi sonuclarin alindigi da belirlenmistir.

Trabzon İli ve İlçelerindeki Mera Alanlarındaki Önemli Yabancı Ot Türleri ile Bunların Dağılımları ve Yoğunluklarının Belirlenmesi

This study was carried out to determination important weed species, the available frequency, common covering and density of weeds in grasslands of Trabzon province in 2008-2009. Surveys were conducted in 214 sampling areas belong to 80 grasslands of Trabzon province (central district, Akcaabat, Arakli, Caykara, Dernekpazari, Hayrat, Koprubasi, Macka, Surmene, Tonya, Vakfikebir and Yomra). The random sampling was made according to representing at least 1% of the areas of grassland. 1/4 m2 were taken in a sampling area at least 20 times. The weeds within the frame were counted, the frequency, common covering and density of weeds were determinated. Sixty weed species and forty eight genus belong to Twenty four families (1 Pteridophyta, 4 Monocotyledonae, 19 Dicotyledonae) were identified in the grasslands surveyed. The most commonly found families were Asteraceae (10 species), Apiaceae (6 species), Lamiaceae (6 species), Scrophulariaceae (5 species), Liliaceae (4 species) ve Polygonaceae (3 species). The most common weed species were Alchemilla pseudocartalinica Juz., Pteridium aquilinum (L.) Kuhn, Euphorbia oblongifolia C. Koch, Veratrum album L., Silene vulgaris (Moench) Garcke, Digitalis ferruginea L., Hypericum perforatum L., Conium maculatum L. and Alchemilla orduensis B . Pawl. in pasture areas surveyed.