Figen Eraslan

Interactive effects of salicylic acid and silicon on oxidative damage and antioxidant activity in spinach (Spinacia oleracea L. cv. Matador) grown under boron toxicity and salinity

We investigated individual and combined effects of salinity, soil boron (B), silicon (Si) and salicylic acid (SA) on the activities of major antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT and ascorbate peroxidase, APX) and non-enzymatic antioxidants (AA), proline, chlorophyll, anthocyanin, H2O2 concentration, stomatal resistance (SR), lipid peroxidation (MDA), membrane permeability (MP), and the uptake of sodium (Na), chloride (Cl), boron and Si of spinach plants. In general, salinity significantly increased H2O2 and proline concentrations, antioxidant activity, membrane permeability, lipid peroxidation and SR of the spinach plants, indicating that they were stressed, whereas application of B only increased proline concentration. However, plant fresh weights did not decline with either treatment. The application of Si decreased H2O2 and increased the activity of SOD and CAT. The application of SA increased SOD activity. Neither SA nor Si had any effect on the proline concentration, or MP. However, application of Si increased chlorophyll concentration and decreased lipid peroxidation (MDA concentration). Si treatment had no effect on SR. The concentration of B in the tissues, which was strongly increased by B treatment, was decreased by NaCl. As a result of salinity, concentrations of Na+ and Cl− ions were increased in the plant tissues, and application of Si slightly increased these concentrations. These results indicate that exogenous Si application increases stress tolerance of spinach, a plant that is naturally reasonably resistant to combined salinity and B toxicity, by the enhancement of antioxidant mechanisms that reduce membrane damage. Exogenous SA has a less obvious effect, although the levels of salinity and boron stress applied were not sufficient in this experiment to reduce plant fresh weight.

Boron Toxicity Alters Nitrate Reductase Activity, Proline Accumulation, Membrane Permeability, and Mineral Constituents of Tomato and Pepper Plants

ABSTRACT Boron (B) toxicity is an important disorder that can limit plant growth on soils of arid and semi arid environments throughout the world. Although of considerable agronomic importance, our understanding of B toxicity is rather fragmented and limited. The effects of increasing levels of B (0, 0.5, 5, 50 mg kg− 1) on plant growth, proline accumulation, membrane permeability, nitrate reductase activity (NRA), and mineral nutrient interactions of tomato and pepper plants were investigated in greenhouse conditions. Increasing levels of B increased the B contents of plants. Boron toxicity symptoms occurred at 5 and 50 mg kg− 1 levels. Fresh and dry weights of the plants clearly decreased with the application of the 50 mg kg− 1 level of B. Membrane permeability and proline accumulation were significantly increased by the 50 mg kg− 1 level of B. Nitrate reductase activity of tomato plants was increased with increasing levels of B. With the exception of potassium (K) and calcium (Ca) in pepper and magnesium (Mg) in tomato, B treatments significantly affected nutrient concentrations of tomato and pepper. Except for sulfur (S) and Ca in tomato, the highest rate of B applied increased the N, phosphorus (P), and K concentrations of tomato and N, P, Mg, and S concentrations of pepper.

Diagnosis of Sulfur Deficiency and Effects of Sulfur on Yield and Yield Components of Wheat Grown in Central Anatolia, Turkey

Abstract Deficiency of sulfur (S) has been recognized as a limiting factor for crop production in many regions of the world. A survey study was initiated to determine the current S nutritional status of wheat plants in Ankara, Turkey in the cropping season of 1999–2000. Owing to the results of the survey study signing soil and plant S deficiency, a greenhouse and field study were conducted during 2000–2001 on the effect of S on yield and yield components of bread (Triticum aestivum L. cv. Bezostaja) and durum (Triticum durum L. cv. Kiziltan) wheat cultivars. According to the survey study results, more than 50% of the soil, plant straw, and grain samples contained lower S than the critical limits. Significant positive correlations were observed between total and extractable soil‐S (r = 0.4799), and also between both the total and extractable soil‐S and grain‐S (r = 0.3097 and r = 0.4162). Additionally significant positive correlation was observed between straw and grain‐S (r = 0.4500). Yield and some of the yield components in both wheat cultivars were significantly responded to the application of S fertilizer in the greenhouse and field experiments, which conducted with a soil containing 12.78 mg extractable S kg−1 soil. Dry weights of Bezostaja and Kiziltan increased from 4.38 to 4.72 g pot−1 and 3.03 to 3.26 g pot−1 respectively, at the minimal dose of S (10 mg S kg−1) application in the greenhouse study. In the field study, grain yield increased from 3472 to 4869 kg ha−1 in Bezostaja and 4787 to 5804 kg ha−1 in Kiziltan at the minimal dose of applied S (20 kg S ha−1). After these levels of S application, the differences among the S levels with respect to yield were found not to be significant both in the greenhouse and field study. Concentration of S in plant, grain yield per spike and harvest index for both cultivars, and spike number m−2, spike length, fertile and sterile spikelet number per spike for Bezostaja, and thousand kernel weight for Kiziltan were responded positively to S fertilization in field conditions. On the other hand, the ratio of N/S in the grain and shoots of both cultivars decreased by S fertilization.

Role of Phosphatases, Iron Reducing, and Solubilizing Activity on the Nutrient Acquisition in Mixed Cropped Peanut and Barley

ABSTRACT The effect of interspecific complementary and competitive root interactions and rhizosphere effects on primarily phosphorus (P) and iron (Fe) but also nitrogen (N), potassium (K), calcium (Ca), zinc (Zn), and manganese (Mn) nutrition between mixed cropped peanut (Arachis hypogaea L.) and barley (Hordeum vulgare L.). In order to provide more physiological evidence on the mechanisms of interspecific facilitation, phosphatase activities in plant and rhizosphere, root ferric reducing capacity (FR), Fe-solubilizing activity (Fe-SA), and rhizosphere pH were determined. The results of the experiment revealed that biomass yield of peanut and barley was decreased by associated plant species as compared to their monoculture. Rhizosphere chemistry was strongly and differentially modified by the roots of peanut and barley and their mixed culture. In the mixed cropping of peanut/barley, intracellular alkaline and acid phosphatases (AlPase and APase), root secreted acid phosphatases (S-APase), acid phosphatases activity in rhizosphere (RS-APase), and bulk soil (BS-APase) were higher than that of monocultured barley. Regardless of plant species and cropping system, the rhizosphere pH was acidified and concomitantly to this available P and Fe concentrations in the rhizosphere were also increased. The secretion Fe-solubilizing activity (Fe-SA) and ferric reducing (FR) capacity of the roots were generally higher in mixed culture relative to that in monoculture treatments which may improve Fe and Zn nutrition of peanut. Furthermore, mixed cropping improved N and K nutrition of peanut plants, while Ca nutrition was negatively affected by mixed cropping.

Variations in essential and non-essential element composition and yield of silage corn fertilized with sulfur

Abstract The effect of sulfur fertilization on the silage yield and essential and non-essential element composition of silage corn was investigated at the Experimental Field of Research and Experiment Station of the Ankara University during the years 2002 and 2003. The experimental design was a randomized complete block with five replications. Sulfur was applied at 1000 (S1) and 1500 (S2) kg ha−1 as gypsum. Element concentration of the plants was measured by polarized energy dispersive X-ray fluorescence (PEDXRF). Sulfur fertilization increased S concentrations and improved silage corn yield for both years. Applied S reduced P and Mo concentrations, increased Fe and Mn concentrations, and had no significant effect on the K, Ca, Mg, Zn and Cl concentrations of silage corn. Non-essential element composition of silage corn was also influenced by S fertilization. Applied S significantly increased Sr and Pb, reduced Si, Ba and U, while had no effect on Na, Ti, Ni, Br and Rb concentrations of silage corn. In the current work, essential and non-essential element concentrations of silage corn in 2002 and 2003 years under our experimental conditions were as follows; 1.58–1.89 S, 1.07–1.046 P, 14.3–15.9 K, 8.35–9.20 Ca, 3.34–4.28 Mg, 0.26–0.53 Na, 1.36–2.46 Cl, 38.4–42.1 Si as g kg−1, and 2.06–3.13 Mo, 140–144 Fe, 6.08–17.69 Zn, 104–116 Mn, 9.37–12.2 Cu, 23.9–22.6 Ti, 2.10–2.31 Ni, 6.54–6.71 Br, 7.04–8.74 Rb, 94.8–118.8 Sr, 24.0–31.51 Ba, 1.20–2.22 Pb and 3.17–4.07 U as mg kg−1.

Relations among Boron Status and Some Soil Properties of Isparta Region Apple Orchards

This study was conducted to determine the boron (B) status of apple orchards and examine the relations among B nutrition and some soil properties in Isparta province. For this purpose 250 gardens from the seven districts of the region were determined and soil and leaf samples were collected. In order to determine soil and leaf B status and relations among these some soil properties were determined. Similarly, other leaf nutrient concentrations were analyzed. According to the soil analysis it was seen that most of the soils are B-sufficient. If soil B concentrations were evaluated depending on the district, the lowest soil B (0.26 mg kg -1 ) was measured from the gardens of Senirkent, the highest B concentration (3.44 mg kg -1 ) was determined in Atabey. Looking at the individual districts, all apple orchards in Gonen and Keciborlu have sufficient (0.5-2 mg kg -1 ) soil B. Also in Yalvac, Atabey, Gelendost and Egirdir 71%, 95%, 96% and 97% of the soils had higher B concentration than B deficiency level (0.5 mg kg -1 ). The most soil B deficiency problem was observed in Senirkent and Yalvac. Average soil B levels for Atabey, Egirdir, Gelendost, Gonen, Keciborlu, Senirkent and Yalvac orchards were calculated as 1.32, 0.96, 0.87, 0.67, 0.91, 0.49 and 0.62, mg kg -1 respectively and general average were determined as 0.84 mg kg -1 . Depending on leaf analyze results, it was seen that 94.8% of the trees had sufficient B and only 5.2 percent of trees had B deficiency. According to the results, there is not B deficiency in 85 % of the soils. And this reflects the leaf analysis as well. Although this result, there was not seen any correlation between soil and leaf B concentrations. But, there were negative correlations among available soil B and soil pH and Ca. Positive correlations were determined among soil B concentrations and other micro nutrients. While a negative correlation between leaf B concentration and leaf P was found, there was a positive correlation between B and Mn.

Effect of Different Nitrogen Doses on Plant Growth, Quality Characteristics and Nutrient Concentrations of Lavandin (Lavandula × intermedia Emeric ex Loisel. var. Super A)

Abstract This research was conducted to determine the effect of nitrogen fertilization on the yield, yield components and nutrient concentrations of lavandin (Lavandula×intermedia Emeric ex Loisel. var. Super A). Experiment was designed as randomized block design with three replications. Nitrogen fertilization increased yields and some quality parameters such as plant height, branch height, length of flower, essential oil content and affected essential oil components (such as: linalool, linalyl acetate and camphor). Nitrogen fertilization also led to increase nutrient concentrations, generally. Results obtained from two years of the study showed that the most effective level of N on lavandin yielding and plant nutrient concentrations appeared to be 100 kg n ha-1.

MERCİMEK VE NOHUT BİTKİLERİNDE KURAKLIĞA BAĞLI OKSİDATİF STRES VE FİZYOLOJİK TOLERANS MEKANİZMALARININ BELİRLENMESİ

Kurak ve yari kurak kosullarda yetistirilen nohut ve mercimek bitkisinde kuraklik verimliligi kisitlayan en onemli etkendir. Nohut ve mercimek cesitlerinin kuraga toleranslari ile ilgili bilinenler cok azdir. Bu calismada Turkiyede yaygin olarak yetistirilen 11 nohut (Cicer arietinum L.) (Menemen-92, Akcin, Aydin-92, Izmir-92, Kusmen, Canitez-87, Gokce, Sari, Uzunlu-99, Er-99 ve ILC-195) ve 6 mercimek (Malazgirt 89, Ozbek, Firat 87, Sazak 91, Emre 20 ve Kayi 91) cesitinin kurakliga tolerans mekanizmalari arastirilmistir. Bu amacla sulu ve kuru kosullarda yetistirilen cesitlerinin kuraklik stabilite indeksleri (KHI) belirlenmistir. Bitkilerin KHI ile kurakliga (oksidadif strese) gostermis olduklari tepkiler veya tolerans mekanizmalari, H2O2 olusumu, lipid peroksidasyonu ve buna bagli olarak membranlarinda olusan zararlanmalar ve prolin ve askorbik asit akumulasyonu ile aciklanmistir. Ayrica kurakliga toleransli cesitlerin seciminde kullanilan veya kullanilma potansiyeli olan stoma direnci, bitki sicakligi, nisbi klorofil, nisbi nem icerigi, yaprak su tutma kapasitesi gibi fizyolojik parametreler belirlenmistir. Ayrica bu fizyolojik parametreler ile bitkide olusan biyokimyasal degisimler arasindaki iliskiler ve kurakligin nohut cesitler uzerinde mineral beslenme performanslarinda meydana getirdigi degisimler de ortaya konulmustur. Bu calismada ayrica kuraga dayanikli cesitlerin beslenme (N, P, K, Ca, Mg, Fe, Zn, Mn and B) performanslari da belirlenmis ve besin maddesi kullanim etkinligi ile kurakliga tolerans arasinda onemli iliskiler belirlenmistir.

DOMATES VE BİBER BİTKİSİNDE GÜBRELERDEN KAYNAKLANAN TUZLULUĞUN İYONİK VE OZMOTİK ETKİSİNİN FİZYOLOJİK PARAMETRELER İLE BELİRLENMESİ

Gubrelerden kaynaklanan tuzlulukta diger toksik iyonlardan (Na, Cl vb) kaynaklanan tuzluluk gibi iyonik ve ozmotik etki yaratarak bitki gelisimini olumsuz etkilemektedir. Gubrelerden kaynaklanan tuzluluk ile ilgili yapilan calisma sayisinin sinirliligi nedeniyle bu konuda bilgi azdir. Bu calismada gubreden kaynaklanan tuzlulugun iyonik ve ozmotik etkisinin domates ve biber bitkisinde fizyolojik parametrelerle belirlenmesi amaciyla bitkiler perlit, bahce topragi, sera ici ve disi topraginda kontrol (normal gubrelenen), NaCl tuzlulugu ve gubre tuzlulugu (normal dozun 3 kati) konularinda yetistirilmistir. Ayrica seralardan toplanan toprak orneklerinin de verimlilik analizleri yapilarak tuz stresi ile uygulamadaki durum arasinda iliski kurulmustur.Tuz stresi altinda yetistirilen domates ve biber bitkilerinin yas ve kuru agirliklarini NaCl tuzluluguna benzer sekilde gubreden kaynaklanan tuzluluk ta onemli oranda azaltmistir. Fizyolojik stress parametrelerinden; membran permeabilitesi genellikle NaCl tuzlulugundan daha cok etkilenirken sera ici ve sera disi topraginda gubre tuzlulugundan da etkilenmistir. Domates bitkisinin nisbi nem icerigi sera ici ve disi topraginda gubre tuzlulugu tarafindan onemli derecede azaltilmistir. Yaprak su tutma kapasitesi, biber bitkisinde tum ortamlarda, domates bitkisinde ise sera ici ve disi topraginda NaCl ve gubre tuzlulugunun etkisiyle onemli derecede azalmistir. Tuzluluk bitkilerdeki prolin ve H2O2 akumulasyonu ile stoma direncinde de onemli artislara neden olmustur. Domates ve biber bitkilerinin klorofil (toplam, klorofil a ve b) icerigi hem NaCl hem de gubre tuzlulugu nedeniyle azalmistir. Gubre ve NaCl tuzlulugu nedeniyle bitkilerin besin maddesi (N, P, K, Ca, Mg, Na, Fe, Zn, Mn) iceriklerinde de onemli degisiklikler olmustur. Gubre ve NaCl tuzlulugu bitkilerin gelisme, beslenme durumlari ve fizyolojik proseslere iyonik ve ozmotik acidan benzer etki yapmislardir. Bu etkiler genellikle sera topraklarinda daha belirgin olmustur.Sera topraklarinin analiz sonuclari da bitkilerin stresli kosullar altinda yetistiklerini dogrulamistir. Sera topraklarinda genellikle besin maddesi (gubre) fazlaligi, tuzluluk sorunu (EC yuksekligi), pH yuksekligi, OM yetersizligi gibi sorunlar oldugu tespit edilmistir.