Yazar "Gokbayrak, Zeliha" seçeneğine göre listele
Listeleniyor 1 - 20 / 24
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Assessment of morphological changes and determination of best cane collection time for 140 RU and 5 BB(Elsevier Science Bv, 2007) Dardeniz, Alper; Muftuoglu, Nuray Muecellâ; Gokbayrak, Zeliha; Firat, MustafaThis study was carried out to assess morphological changes in the canes of 140 Ru and 5 BB and to determine best time for cane collection. The first part of the study included the morphological assessment of the rootstock canes during the winters of 2003-2004 and 2004-2005. Canes collected in the second part of the study in 2005-2006 were grown in pots to relate the changes with the vegetative growth characteristics. Cane collection commenced at leaf fall and they were collected three more times at 15-day intervals. Morphological changes were determined from the transverse internodal cuts and included: width of pith, xylem, phloem plus bark tissues, ratios of cane width/pith, cane width/ bark + phloem, xylem/pith and xylem/bark + phloem, and cane water content. Findings showed that lignification was best 30 and 45 days after leaf fall for 140 Ru and 15, 30 and 45 days after leaf fall for 5 BB. Canes collected in 2005-2006 were used to relate the changes observed in the previous 2 years with the vegetative development. Two-bud cuttings were grown in pots and viable plant and rooting ratios, root fresh weight, shoot number and length, and node number were determined. Data obtained were found in agreement with the morphological findings. A 140 Ru had the best vegetative growth 30 and 45 days after leaf fall, and 5 BB grew well at each collection period. Results showed that it is best not to collect canes from rootstock nurseries at or right after leaf fall due to poor lignification and subsequent poor growth. (C) 2007 Elsevier B.V. All rights reserved.Öğe Best duration for submersion of grapevine cuttings of rootstock 41B in water to increase root formation(Wfl Publ, 2010) Gokbayrak, Zeliha; Dardeniz, Alper; Arikan, Abdurrahman; Kaplan, UlasThis study was conducted to determine to find out how long the grapevine cuttings of rootstock 41B should be submerged in order to increase adventitious root formation. The cuttings were placed in a big container filled with tap water in an order of 72, 48, 24 and 12 hours. Data obtained showed that generally water soaking increases rooting of the cuttings. Auxin applied afterwards also has a positive effect on inducing rooting. Keeping the cuttings submerged in water at least 24 hours and applying IBA afterwards resulted in the best results. Water soaking and/or IBA, however, did not improve the top growth of the cuttings.Öğe Brassinosteroids and gibberellic acid: effects on in vitro pollen germination in grapevine(Vigne Et Vin Publications Int, 2017) Gokbayrak, Zeliha; Engin, HakanMany physiological processes related to plant growth and development are under the influence of growth regulators, which also have an impact on pollen germination. In this study, the effects of two brassinosteroid compounds, epibrassinolide and 22S,23S-homobrassinolide, and gibberellic acid (GA(3)) on in vitro pollen germination of two table grape cultivars, 'Italia' and 'Cardinal' (Vitis vinifera L.), were determined. A total of 28 treatments, alone and in combination, were applied to freshly collected pollens which were sown on a basic medium with 1% agar and 20% sucrose. Petri dishes were kept at 26 +/- 1 degrees C for 24 hours. Counting of the germinated pollens revealed that the effects of these plant hormones were cultivar- and substance specific. The cultivar 'Italia' was not influenced by the treatments (the highest germination ratio being 44.4% from 0.001 mg L-1 epibrassinolide) as opposed to the cultivar 'Cardinal'. The highest germination ratio in 'Cardinal' was about 50% in pollens treated with 25 mg L-1 GA(3) + 0.01 mg L-1 epibrassinolide. The control group resulted in 32.38% germination. Combining GA3 with epibrassinolide provided slightly higher germination ratios compared to combining GA3 with 22S,23S-homobrassinolide.Öğe Cytological and Palynobiometric Investigation in Vitis vinifera L.: Case Study of Cultivar 'Cardinal'(Springer, 2022) Gokbayrak, Zeliha; Engin, HakanThis article describes pollen formation at various developmental stages, pollen morphology, pollen viability and in vitro germination in 'Cardinal' grapevine (Vitis vinifera L.). Various microscopy techniques were utilized in the study. Formation of pollen grain was observed under stereo zoom and light microscopy using anther squashes and acetocarmine staining. Size of the pollen grains and the development of the nuclei were observed with SEM. TTC test and the agar in petri dish method were employed for the assessment of pollen viability and germination, respectively. The pollen development in grapevine (Vitis vinifera L.) may be divided into four basic stages starting from mother cell formation as (1) formation of tetrad, (2) microspore release, (3) germination of microspore, followed by pollen tube growth and elongation, and (4) formation of vegetative and generative cells. The observations and tests showed that the formation of pollen occurred very close to the flowering. The tetrad stage was seen in Mid-May. The exine of the pollen had a striate pattern with long ridges. Pollen had similar size (approximate to 25 mu m) and an elliptical-oval shape. Although the highest pollen viability ratio was 81%, only 31% of the pollenwere germinated. Before germination, the pollen grain contained a nucleus. During pollen tube formation, a defined area in the pollen plasma membrane promoted a directional growth, and the tube cell elongated and formed its own pathway. Before entering the pathway, the generative cell formed two haploid generative cells.Öğe Effects of 22S, 23S-Homobrassinolide and Gibberellic Acid on Occurrence of Physiological Disorders and Fruit Quality of 'Summit' and 'Regina' Sweet Cherries(Springer, 2016) Engin, Hakan; Gokbayrak, Zeliha; Sakaldas, MustafaPlant growth regulators play a vital role in fruit growth and development. However, effects of compounds belonging to the group of brassinosteroids have not been fully investigated in sweet cherries. One relatively new and one commonly applied growth regulator, 22S, 23S-Homobrassinolide and GA(3), respectively, were tested on 'Summit' and 'Regina' sweet cherries to determine the effects on fruit quality and physiological disorders. The substances were applied with a handgun sprayer at full bloom and at the beginning of fruit development (shuck split) for a 2-year period. GA(3) was applied at the concentrations of 25, 50, 100 mgL(-1) and 22S, 23S-Homobrassinolide at 0.05, 0.1, 0.5 mgL(-1). A combined application of 100 mgL(-1) GA(3) + 0.1 mgL(-1) 22S, 23S-Homobrassinolide was also applied. Effects of GA(3) and 22S, 23S-Homobrassinolide on fruit weight and size were evident for the concentrations applied and between the seasons for both of the cultivars. Combination of the both growth regulators and 100 mgL(-1) GA(3) alone produced longer fruits compared to the control trees in 'Regina'. The 22S, 23S-Homobrassinolide applications increased the firmness of the flesh slightly, but not to a great degree, compared to the GA(3) applications alone. The brightness of the red color was better with GA(3) applications in 'Summit' and 'Regina'. Brassinosteroid caused the fruits to have comparably dull red color. Total soluble solid contents of the cultivars were influenced by the substances and the year of the application. Stem resistance to separation from the fruit was under the influence of both treatments and seasons. In general, 22S, 23S-Homobrassinolide provided better stem resistance than the GA(3) applications. There were no effects of the substances on the development of physiological disorders.Öğe EFFECTS OF CANE-GIRDLING AND CLUSTER AND BERRY THINNING ON BERRY ORGANIC ACIDS OF FOUR Vitis vinifera L. TABLE GRAPE CULTIVARS(Wydawnictwo Akad Rolniczej W Lublinie, 2013) Keskin, Nurhan; Isci, Burcak; Gokbayrak, ZelihaThe response of berry organic acids of four organically grown table grape cultivars to cane-girdling and cluster-berry thinning treatments were evaluated over two growing seasons. In addition pH, titratable acidity, soluble solids content and maturity index were also determined. Statistical analyses showed that individual organic acid content of the four grape cultivars were significantly affected by the treatments. Tartaric and malic acids of 'Red Globe' were mostly influenced by the cluster-berry thinning treatment. 'Alphonse Lavallee' accumulated the highest tartaric acid and malic acid in both the girdled/thinned and the cluster-berry thinned vines, respectively. The control and girdled 'Tralcya Ilkeren' vines had the most tartaric acid. Control vines also contained high malic acid amount. 'Bum Razakisi', on the other hand, had the most prominent tartaric and malic acid levels in the girdled/thinned and thinned vines, respectively. Quality parameters also showed significant differences among the cultivars in response to the treatments.Öğe Effects of Foliar-Applied Brassinosteroid on Viability and In Vitro Germination of Pollen Collected from Bisexual and Functional Male Flowers of Pomegranate(Taylor & Francis Inc, 2018) Gokbayrak, Zeliha; Engin, HakanEvaluation of pollen viability and its germination capacity are essential criteria for pollinator's characterization. Hormones have been used to increase yield and quality of pomegranates without any reference to effects on pollen viability or germination. With this point of view, effects of field-applied 22S, 23S-homobrassinolide (HBR) after bud break at concentrations of 0.001, 0.01, and 0.1 mg L-1 were evaluated on pollen quality of Mayhos-8 pomegranate cultivar. After collection of the flowers of both sexual morphs (bisexual and functionally male), colori-metric test of 2,3,5-triphenyl tetrazolium chloride (1%) were used to estimate pollen viability. Later, pollen germination was determined in vitro on a medium containing 1% agar and 20% sucrose. Results showed that pollen viability was under the influence of both the types of the flower and the concentration of the HBR. The highest pollen viability (96%) was obtained from both functional male and bisexual flowers treated with 0.1 mg L-1 HBR. Germination ratio, on the other hand, was only affected by the hormone concentrations, and it increased significantly as the concentration was higher.Öğe EFFECTS OF HYDROGEN CYANAMIDE ON THE FLORAL MORPHOGENESIS OF KIWIFRUIT BUDS(Inst Investigaciones Agropecuarias, 2010) Engin, Hakan; Gokbayrak, Zeliha; Dardeniz, AlperThe influence of hydrogen cyanamide (HC) on the flower bud development of kiwifruit (Actinidia deliciosa (A. Chev.) C. F. Liang & A. R. Ferguson). 'Hayward' was studied. The bud samples were taken every 5-10 d starting from dormant season (March) and fixed in FAA (10% formalin, 50% ethanol, 5% glacial acetic acid). Flower bud development was compared in three HC concentrations and the control. 1%, 2%, and 3% of HC was applied 35 d before the expected natural bud break. During the onset of bud break, only 57.6% of control buds had sepal primordia developed. On the other hand, HC treated buds had almost completed their stamen formation and started stigma primordia. When the control vines were in advanced bud break, gynoecial plateau already began to form in the vines treated with 2 and 3% HC. Vines treated with 1% HC lagged a little behind and had not started developing the gynoecial plateau. As the bud developed from the open cluster to the tight bud stage, the differences between the control and HC treated plants were more distinct. However, there were no differences between HC treatments as the ovule initiation took place in the buds.Öğe Effects of Melatonin and IAA on Adventitious Root Formation in Rootstock 5BB and cv. Cabernet Sauvignon (Vitis vinifera L.)(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2020) Gokbayrak, Zeliha; Engin, Hakan; Kiraz, HaticeBoth derived from tryptophan, melatonin (MEL) and indole acetic acid (IAA) were tested for their influence on rooting in the cuttings of two Vitis species, the 5BB rootstock and the cultivar Cabernet Sauvignon. The 2-bud cuttings were grown in a growth chamber after the basal ends were dipped in the following treatments; for 5 seconds in IAA solutions at 0 (the control), 5.7, 11.4 and 16.1 mu M concentrations, and for 10 minutes in the melatonin solutions at 0 (the control), 0.1, 0.5 and 1.0 mu M. The results indicated that percentages of rooting, shooting and healthy plants in both species were not statistically significant under the influence of the treatments. However, increasing concentrations of IAA resulted in increasing rooting percentages in 5BB rootstock. On the other hand, 0.1 and 0.5 mu M MEL also induced rooting. In the cuttings of Cabernet Sauvignon, 11.4 mu M IAA provided the highest percentage (100%). Melatonin caused a relative decrease in rooting compared to the IAA. The action of melatonin on rooting seems to be independent of IAA. Hormone treatments caused significant differences in the root number per cutting and fresh root weight in 5BB. Effects of the hormones were important on all the rooting features, including root number, root length, root distribution pattern, and weight of fresh and dry roots in Cabernet Sauvignon. Results indicate that extensive research is needed to extrapolate the influence of melatonin on rooting in grapevine with a possibility in practical use since it is inexpensive and easy to obtain in pure form.Öğe Effects of Plant Growth Regulators on Sex Expression and Flower Development in Pomegranates(Springer, 2019) Engin, Hakan; Gokbayrak, ZelihaThe effects of external treatments with gibberellin, brassinosteroid and auxin on sexual determination and flower development in pomegranate (Punica granatum L. cv. Cekirdeksiz) were investigated. Eigth treatments with three growth regulators, viz., epibrassinolide at 0.01 and 0.1ppm, homobrassinolide at 0.01 and 0.1ppm, GA3 at 10 and 25ppm, NAA at 5 and 15ppm and control (water spray) were sprayed at the time of initiation of new sprouts. Effects of the plant growth regulators on the percent of the flowers types were not clear. Plants produced considerably more male flowers. Although no statistical importance was detected, it was clear that all growth regulators decreased bisexual flowers and increased male flowers. There were no significant effects of growth regulators on the formation of bisexual flowers at different positions in the plants. The percentage of single bisexual flower was significantly higher than terminal or lateral bisexual flower in acluster in the control plants. Effects of the plant growth regulators on the size of the parts of the bisexual pistils were, however, found important. The smallest ovaries were obtained from 0.1ppm HBr, base to sepal notch was the only characteristic which was not influenced by the treatments and stayed between 15 and 18mm. Total pistil length of the bisexual flowers was greatest with EBr applications and the shortest with the HBr treatments (about 27.5mm). Length of the style and stigma was mostly shorter, but 0.1ppm EBr boosted it up comparably more than the rest of the applications including the control. Stigma, on the other hand, was widest in the control flowers, closely followed by all except 0.1ppm EBr application.Öğe Establishing Genetic Relation between a Marker Locus and Fungal Disease in Grapevine Using Multidimensional Scaling Analysis(Univ Agr Sci & Veterinary Med Cluj-Napoca, 2010) Gokbayrak, Zeliha; Isci, Burcak; Ozer, Cengiz; Soylemezoglu, Gokhan; Altindisli, AhmetIn a hybrid population of Italia (female) and Mercan (male) grape cultivars with their 60 offsprings a classical two point linkage analysis was attempted with 300 RAPD 20 SSR and 24 AFLP primers using Mapmaker/Exp 30 Linkage groups of 12 in Italia and 4 in Mercan were attained with 25 and 8 marker loci respectively Resistance phenotypes and segregating characteristics were scored as quantitative traits in two growing seasons MDS analysis was performed to examine the relationship between the marker loci and the fungal diseases powdery and downy mildew both of which developed naturally on the progenies Results of the MDS showed that five and eight marker loci were in close relationship with the powdery and downy mildew respectively The R-2 was 62 12% which considered as acceptable fit and the stress coefficient was 026Öğe Floral Development Stages in Vitis vinifera L. and Association With Phenological Stages(Kahramanmaras Sutcu Imam Univ Rektorlugu, 2019) Gokbayrak, Zeliha; Engin, HakanAfter the development of inflorescence primordia in the first season in Vitis, flower and floral organ differentiation take place in the second season. Aim of this study was to describe the differentiation events which occur in the compound buds and flowers during and after budbreak, and to associate these events with the phenological stages in Merlot (Vitis vinifera L.) grape cultivar. In addition, size of the floral organs was determined using microscopy, after careful examination of samples collected as buds and flowers under microscope at every 5 to 10 days. Between March 10 and May 10 in 2016, five interval stages (complete shaping of stamen and pistil primordia following petal primordia formation) were added. According to the results, differentiation of inflorescence and flower primordia occurred after bud swelling in the spring. Approximately 3 weeks after the appearance of inflorescence primordia, stamen and pistil were visible. The development was complete in the following 3 weeks. Flower primordium was sighted on April 1 and increased its size more than 900% in 5-6 weeks. Primordia of reproductive organ was seen when the 2-4 leaves separated from the shoot. By the time of pistil taking its final shape, there were 6-8 full leaves grown from the shoot and inflorescences were easily distinguishable by the naked eye.Öğe Graft formation in some spur and vigorous apple varieties grafted on Ottawa 3 rootstock: A histological investigation(Wfl Publ, 2010) Yildirim, Adnan N.; Polat, Mehmet; Dolgun, Oguz; Askin, M. Atilla; Gokbayrak, Zeliha; San, BekirThis research was designed to observe the stages of graft union in relation to different growth rate between the rootstock Ottawa 3 and three apple varieties, Smoothee, Summerred and Braeburn. Three to five graft samples of each rootstock/scion combinations were taken at 30 days interval until 12 months passed after from grafting. Samples were fixed in ethanol (70%). Transverse sections in 20-30 mu m thickness were cut with a rotary microtome. Five base stages of graft formation were examined on samples: (1) development and positions of necrotic layers, (2) proliferation of callus cells, (3) formation of callus bridge at the graft interface, (4) cambial continuity and (5) formation of vascular tissues. In the sections prepared from subsequent samples of graft combinations were seen as a good union. Necrotic layers were eliminated in the callus, except for the outer cortex. In outer cortex region, necrotic layers were transformed to bark. Callus filled the gaps between interface of the stock and the scion. Cambial continuity occurred successfully and vascular tissues were connected. Thus, no evidences for tissue incompatibility were found in this study. Histological observations showed a compatible graft union between the graft partners which have different growing characteristics in relation to tissue formation.Öğe Graft union formation of spur apple varieties grafted on different rootstocks(Wfl Publ, 2010) Polat, Mehmet; Dolgun, Oguz; Yildirim, Adnan; Askin, M. Atilla; Gokbayrak, ZelihaThe aim of this research was to observe histological developments during the early stages of graft formation between some spur apple varieties and apple rootstocks in order to assess compatibility/incompatibility related to different growing rate of the plants used. As rootstocks, one year-old clonally propagated A2, B118, M111 (vigorous) and M7, MI6, Pj80 (semi-dwarfing) were used. Scions were taken from one-year-old shoots of Scarlet Spur, Red Spur and Redchief spur apple varieties. Rootstocks were planted in the field in winter 2007 and whip-grafted in April 2008. An evident incompatibility was not observed in the combinations. Sufficient callus proliferation was visible in all the combinations. Successful cambial and vascular connection was apparent in the 90-day sections. In the 120(th) and following sections, it was observed that callus usually filled all the gaps between the rootstock and the scion. Xylem and phloem strands successively bridged the union. However, especially Pj80/Redchief and M16/Red Spur should be followed up in subsequent years in the field conditions because of the excessive callus formation between the stock and the scion.Öğe Influence of 24-Epibrassinolide on Physiological Characteristics of Tomato Seedlings Infested with Root-knot Nematode Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae) br(Ankara Univ, Fac Agr, 2022) Gozel, Cigdem; Gokbayrak, ZelihaThe aim of this research is to determine the physiological responses of tomato seedlings treated with 24-epibrassinolide (EBL), given via different methods such as immersion, irrigation, and foliar spray, followed by inoculation of root-knot nematode Meloidogyne incognita (Kofoid & White 1919) Chitwood, 1949 (Tylenchida: Meloidogynidae). Physiological measurements (chlorophyll, flavonols, nitrogen balance index, and anthocyanins) were carried out non-destructively with a portable chlorophyll meter at the end of the 56th days post inoculation. Results showed that chlorophyll contents of the tomato leaves were affected by both the EBL applications and the methods. Chlorophyll contents were better protected with the irrigation method. Flavonols and nitrogen balance index were inversely related with the application method. Leaf anthocyanin index was affected just by the EBL applications. Depending on the physiological aspect under observation, the method (immersion against irrigation, for instance) might present a challenging status in terms of providing protection against root-knot nematode when tomato plants are treated with EBL.Öğe Influence of plant growth regulators on sex differentiation and floral characteristics of pomegranate flowers: a case of brassinosteroids(Polskie Towarzystwo Botaniczne, 2018) Gokbayrak, Zeliha; Engin, HakanThe objective of the present study was to determine the effects of brassinosteroid application on the sex determination and floral growth of pomegranate flowers. Whole tress of Punica granatum 'Mayhos-8' were sprayed with 0.001, 0.01, and 0.1 mg L-1 28-homobrassinolide (Hbr) at bud break. The selection of flowers was based on the appearance of a visible pistil/stigma and shape of the ovary of intact flowers. Grouping of bisexual flowers was based on their flower position, i.e., single, terminal, and lateral flowers, during the first flush of flowering in mid-June. Approximately 20 days and 40 days after spraying, 100 randomly chosen bisexual flowers per collection time were collected and measurements of floral parts were immediately taken. The differences between bisexual and functional male flowers were not distinct enough to assert any significant effects from the different Hbr treatments. Irrespective of treatments, the percentage of male flowers was higher than that of bisexual flowers. Hbr treatments applied at the bud break period had significant effects only on bisexual flowers that developed as single flowers. Applying 0.01 mg L-1 Hbr produced comparably lower percentages of single bisexual flowers (53.4%). Although the 0.1 and 0.001 mg L-1 Hbr treatments resulted in increased percentages of bisexual flowers, the difference was not significant. For the first collection time (mid-June), the effects of Hbr concentration on the size of the floral parts for bisexual flowers were only significant in ovary width and stigma diameter. As the concentration decreased, smaller ovaries were obtained. During the second flowering, application of 0.01 mg L-1 Hbr considerably increased the overall sizes of floral parts in bisexual flowers. Hbr might affect the ratio of flower formation in certain positions on a branch and could influence the growth of floral parts in bisexual flowers. Further elucidation of these effects would help to better understand floral organ development in plants.Öğe Influence of Postharvest Application of 28-Homobrassinolide onStorage Quality of Medlar Fruit(Springer, 2019) Ekinci, Neslihan; Gokbayrak, Zeliha; Cavusoglu, Seyda; Akcay, Mehmet EminThis study was conducted to determine the effects of 28-homobrassinolide (Hbl) applied postharvest on the storage quality of medlar fruit (Mespilus germanicaL.). Fruits were submerged into the solutions containing 3 and 5 mu M Hbl for 5min. Control fruits were submerged into distilled water for the same duration. Treated and control fruits were stored at 0 degrees C and 95% relative humidity conditions for 60days. Samples were taken at 15, 30, 45 and 60th day of storage. On the sampling dates, soluble solid content (SSC), pH, titratable acidity (TA) in malic acid, fruit firmness, weight loss, taste, browning, and color of the skin and pulp were analyzed. Results showed that these properties of the fruits changed over time in the storage and depended on the concentration of the homobrassinolide. 3 mu M Hbl treated fruits kept their firmness and initial weight longer. Fruits with 5 mu M Hbl application resulted in high TA and low SSC and provided best browning in the fruit skin. Taste was better attained and protected over alonger time with 5 mu M Hbl treatment. In conclusion, 28-homobrassinolide exerted some effects on quality of medlar fruits.Öğe Pollen of Arbutus unedo: Effects of plant growth regulators(Univ Belgrade, Inst Botany & Botanical Garden, 2020) Gokbayrak, Zeliha; Engin, Hakan; Akcal, Arda; Kiraz, HaticeArbutus unedo is a species mainly used for landscaping purposes and lately for honey production. Its antioxidant characteristics have also been a subject of of research interest. The germination of pollen grains freshly collected from flowers was tested in vitro, and 30% sucrose gave the highest pollen germination. Subsequently, three growth regulators belonging to the categories of gibberellins and brassinosteroids [24-epibrassinolide (Ebl) and 22S,23S-homobrassinolide (Hbl)] were added to the growth medium singly or in double combinations (gibberellin + brassinosteroid), and the petri dishes were kept for 24 hours at 26 +/- 1 degrees C. The results showed that the highest germination rates were obtained from treatments with 0.01 ppm Hbl (45.47%) and 0.001 ppm Hbl (26.74%). They were followed by treatments with 0.001 ppm Ebl, 25 ppm GA(3) and 0.1 ppm Ebl. As the concentration of GA(3) increased, the germination rate declined considerably. Statistical analysis of the combined treatments showed that combinations of growth regulators lowered the germination rates compared to their individual application. Moreover, action of the lowest GA(3) concentration (25 ppm) best matched the effects of brassinosteroids, and increasing the GA(3) concentration in combined treatments did not improve germination. The highest germination was obtained with 0.1 ppm Hbl, followed by all Ebl treatments. Brassinosteroids might be an inducer of pollen germination in plants depending on their type and concentrations. When individually included in the growth medium, the extent of this induction was greater with the homobrassinolide than with the epibrassinolide. Their interactions with gibberellins are shown to be mostly dependent on the concentration of gibberellic acid used. The tested epibrassinolide was more consistent than the homobrassinolide in maintaining higher germination levels. The findings of this study indicate that gathering more information from studies involving other plant species is needed to clarify the role of brassinosteroids in in vitro and in vivo germination.Öğe Research on the physiological disorders and fruit quality of Cardinal peach(Taylor & Francis Ltd, 2010) Engin, Hakan; Sen, Fatih; Pamuk, Guelay; Gokbayrak, ZelihaThis study was carried out on 'Cardinal' peach (Prunus persica L. Batsch) between 2003 and 2005 in Bornova, in Izmir, Turkey to study the effects of irrigation, gibberellic acid (GA(3)) and nitrogen (urea) on the physiological disorders split or shattered pit, double fruit and fruit quality. Irrigation treatments that were tested included 100% (no water stress) and 20% (water stress) replenishment of water depleted from the 100% replenishment treatment at 60 cm soil profile at 10-day intervals. GA(3) and nitrogen (urea) were applied to trees during the flower bud differentiation period at doses of 100 mg L-1 and 900 mg L-1, respectively. Irrigation, nitrogen and gibberellic acid exerted a significant influence on fruit disorders and quality of peach cv. 'Cardinal'. Although the rate of double fruit was increased by water stress, GA(3) and nitrogen application decreased it. Irrigation (100%) during the final swell phase of fruit development accelerated the occurrence of split and shattered pit. Application of nitrogen and gibberellic acid or both to the trees with no water stress resulted in the lowest number of fruits with physiological disorders. Fruit quality characteristics, except for titratable acidity, were not significantly altered by the treatments.Öğe RESPONSE OF VITIS VINIFERA L. SEEDS TO 22(S), 23(S)-HOMOBRASSINOLIDE(Pakistan Botanical Soc, 2014) Gokbayrak, Zeliha; Cakir, Atilla; Sirin, AndomerIn order to determine effects of brassinosteroid on germination, seeds of var. Karasakiz (Vitis vinifera L.) were soaked in different concentrations of 22(S), 23(S)- homobrassinolide solutions (0.025, 0.010, and 0.005 mgL(-1)) followed by stratification for 30, 45, 60 and 90 days at 4 degrees C in perlite. In comparison, seeds were also treated with gibberellic acid concentrations (0, 500, 1000, and 1500 mgL(-1)). Seeds were sown in plastic cell containers containing perlite:peat moss: cocopeat (1:1:1 v/v) and the containers were placed under glasshouse conditions. Germination was not influenced by the brassinosteroid application. As the stratification time prolonged the germination increased. Effect of brassinosteroid on germination was not statistically important. However, it seemed that treatment with low concentration of the brassinosteroid resulted in similar germination percentage with the seeds stratified at least for 60 days.
