Salih Ülger

Determination of endogenous hormones, sugars and mineral nutrition levels during the induction, initiation and differentiation stage and their effects on flower formation in olive

Olive (Olea europaea L.) is one of the most important crop plants grown in the Mediterranean region. Varying levels of hormones, sugars and mineral nutrient are thought to influence flower bud formation. The objective of this study was to evaluate the changes in endogenous sugar, mineral nutrition and hormone levels in leaf, node and fruit samples of ‘Memecik’ olive during the induction, initiation and differentiation periods in on (bearing) and off (non-bearing) years. Leaf, node and fruit samples of mature 15-year-old Memecik olive were used. The samples were taken during the induction, initiation and differentiation periods of olive in on (2000) and off (2001) years. Sugar (glucose, fructose and sucrose), mineral nutrient (N, P, K, Ca, Mg, Fe, Zn, Mn and Cu) and hormone [abscisic acid (ABA), indole acetic acid (IAA), gibberellic acid (GA3, GA4) and zeatin (Z)] levels were determined in on and off years. Hormone and sugar levels were measured by gas chromatography and high-performance liquid chromatography. The K, Ca, Mg, Fe, Mn, Zn and Cu levels were quantified by an atomic absorption spectrophotometry. Nitrogen was determined by the Kjeldahl procedure, and P by a spectrophotometric method. The differences in any of the sugar concentrations, with the exception of fructose, were not significant in on and off years. Hormone levels, however, were significantly different in on and off years. Glucose had the highest concentrations in both years, followed by sucrose and fructose, respectively. The highest macro and micro element concentrations were found to be Ca and Fe, respectively. Thus, the results suggest that carbohydrates and mineral nutrients may not have a direct effect to induce flower initiation. However, high GA3 level exhibited an inhibitory effect on floral formation during the induction and initiation periods. On the other hand, the high concentrations of GA4, ABA and certain cytokinin levels may have a positive effect on flower formation in olive during the induction and initiation periods.

Endogenous Hormone Variations in Annual Wild Cicer Species

All processes that regulate of growth, differentiation and development and also stomatal movement are influenced by endogenous hormones in plants. Research related with endogenous hormones is known for cultivated chickpea (Cicer arietinum L.), while in wild chickpeas no data existed. In this study, C. bijugum K.H. Rech.; C. chorassanicum (Bge) M. Pop.; C. cuneatum Hochst. ex Rich.; C. echinospermum P.H. Davis; C. judaicum Boiss.; C. pinnatifidum Jaub. et Sp.; C. reticulatum Ladiz.; and C. yamashitae Kitamura were evaluated for variations in endogenous plant hormone concentrations; indole-3-acetic acid, zeatin, gibberellic acid, and abscisic acid in both leaf and pod. It was concluded that there was a great variation on endogenous plant hormones among the annual wild Cicer species. The data may support selection for various attributes.

Comparison of some endogenous hormone levels in different parts of chickpea (Cicer arietinum L.)

The objective of this study was to detect plant hormone levels in different plant parts of chickpea, and to compare cultivars with different characteristics such as simple leaf vs. normal leaves, simple leaf vs. bipinnate leaf, kabuli type vs. desi types, double-podded vs. single-podded. It was found that there was a great variation in basic plant hormone levels among genotypes, and plant hormone concentrations varied according to leaf type, pod and seed characteristics in these genotypes. IAA level in leaves was the highest in ICC 6119 (bipinnate leaf) and followed by ICC 552 (double-pod) and Kusmen 99 (simple leaf), while it was highest level in pods of ICC 552 (double-pod). Zeatin concentration in leaves and pods was the highest level in ICC 6119 (bipinnate leaf). GA3 concentration was the highest in leaves of ICC 6119 (bipinnate leaf). ICC 552 (double-pod) has the highest GA3 in leaves. It was postulated that leaf type and pod characteristics may be related to hormones induced growth and development.

Molecular, Morphological and Oil Composition Variability within Olive (Olea europaea L.) at Semi-Arid Conditions

ABSTRACT Genetic diversity studies using Random Amplified Polymorphic DNA (RAPD) technique were carried out on olive (for oil) ecotypes of Olea europeae L. for semi-arid region. Analysis of PCR products was achieved by using the simple matching coefficient and UPGMA clustering. Primers were identified and used in order to discriminate within the Ayvalik cultivar, which is moderate drought resistant. The diversity of RAPD patterns demonstrated the biodiversity among samples. The genetic variability was further subjected to pomological and biochemical analyses to support and determine the genetic variability.

Endogenous organic acid variations in different chickpea (Cicer arietinum L.) genotypes

Five chickpea genotypes were sown in the last week of February 2002 and harvested in the second week of May 2002 at Antalya, Turkey. The highest seed organic acid content was succinic acid, followed by malic, quinic, oxalic and citric acids. The highly pigmented cultivars ICC 6119, ICC 4951 and ICC 4949 recorded high levels of short-chained organic acids (citric, malic and oxalic acids), but did not contain quinic acid. On the other hand, the non-pigmented cultivar Kusmen 999 recorded the highest quinic acid content, but contained low values of the short-chained organic acids. The low-pigmented cultivar ICC 12422 recorded the highest succinic acid content, followed by the highly pigmented cultivars ICC 6119 and ICC 4951.

Production of Common Sour Orange × Carrizo Citrange Hybrids Using Embryo Rescue

Citrus rootstock breeding is important in improving resistance to diseases, insect pests, and adverse environmental conditions. The majority of citrus species and cultivars have nuceller embryony, which causes some problems for breeding programs. This disadvantage can be eliminated by using embryo rescue. In this research, Common sour orange × Carrizo citrange were crossed in order to produce new rootstocks and immature embryos. The embryos were gathered from the crossed plants 80, 100, and 120 days after pollination. The immature embryos were transferred to 0, 0.5, and 1 mg/L GA3 containing medium to germinate them. In general, the later after pollination that the embryos were harvested, the higher the germination rate. Those harvested at 80 days averaged 32% over all treatments, while those harvested at 100 days averaged 77%, and those harvested at 120 days averaged 98% germination. Embryos on control media averaged 67% germination over all treatments, while those with 0.5 mg/L GA3 averaged 62%, and those with 1 mg/L GA3 in the media averaged 78% germination. The percentage of embryos developing trifoliate leaves for those harvested at 80 days averaged 51% over all treatments, while those harvested at 100 days averaged 24%, and those harvested at 120 days averaged 41%. Embryos on control media averaged 36% trifoliate leaf development over all treatments, while those with 0.5 mg/L GA3 averaged 35%, and those with 1 mg/L GA3 in the media averaged 44% germination.

Effects of endogenous phenolic compounds and hormones on in vitro shoot tip culture of grapevine

Summary We have examined changes in endogenous hormones [indole-acetic acid (IAA), gibberellic acid (GA3), zeatin (Z) and abscisic acid (ABA)], total phenolic contents and seven major phenolic compounds (gallic acid, +(-) catechin, catechol, chlorogenic acid, o-coumaric acid, rutin and quercetin) in shoot tips of two grapevine cultivars (‘Çavus’ and ‘Hafızali’) collected during different months, to determine the effects of these endogenous compounds on the survival and subsequent growth of explants in vitro. Shoot tips of grapevine cv. ‘Çavus’ showed higher explant survival rates than those of ‘Hafızali’ from all months. Hormone and phenolic compound concentrations also varied depending on cultivar and harvest month. Endogenous compounds showed various correlation coefficients with the survival and subsequent growth of explants. According to our results, the survival and subsequent growth of explants were affected by phenolics and endogenous hormones to various extents. In both grapevine cultivars, shoot tips collected in May exhibited the highest survival rate and growth during the culture period, compared to shoot tips collected in all other months. It may therefore be possible to increase the success of grapevine shoot tip culture by selecting the most suitable collection time.