Uygun Aksoy

AFLP reveals structural details of genetic diversity within cultivated olive germplasm from the Eastern Mediterranean

Amplified fragment length polymorphism (AFLP) analysis was used to assess genetic inter-relationships among olive varieties cultivated in the Eastern Mediterranean Basin. The genotypes sampled included most of the important cultivars from Turkey, Greece and the Middle East and selected genotypes from the Western Mediterranean area. A total of 119 polymorphic markers were generated from five selective primer-pair combinations. The combined data sets generated by just two primer-pairs were adequate to discriminate between all 65 genotypes, while each primer-pair could individually identify up to 64 genotypes. A factorial correspondence analysis (FCA) plot indicated that the cultivars clustered into two relatively modestly defined groups. The first broad group was dominated by cultivars from Turkey but also included genotypes originating from the Middle East (Syria and Lebanon) that collectively formed a tight subcluster. The second group comprised Greek cultivars and those originating from the Western Mediterranean. A significant genetic distance value between Greek and Turkish cultivars was provided by an analysis of molecular variance (amova). There was also evidence of substructure here, with an apparent separation of most Spanish and Italian clones. These findings are in general accordance to previous suggestions of an East-West divergence of olive cultivars, although the dichotomy is less extensive than reported previously and complicated by regional variation within each group.

Suitability of isozyme, RAPD and AFLP markers to assess genetic differences and relatedness among fig (Ficus carica L.) clones

Sarilop is the main and standard cultivar for commercial dried fig (Ficus carica L.) production in Turkey. Eleven of the most promising Sarilop clones and one clone of Sarizeybek, all selected from a former agronomic evaluation, were analysed by three molecular marker techniques, isozymes, RAPDs and AFLPs. The resolution power and the accuracy of these three analytical techniques, in distinguishing among fig clones, were determined. The analysis of five isozyme systems permitted the discrimination between the two cultivars, Sarilop and Sarizeybek. Besides the discrimination between the two fig cultivars, the use of 31 10-mer primers in RAPD analysis allowed splitting the 11 Sarilop clones into two groups of genetic similarity, but not to distinguish between all the clones. The AFLP™ technology showed a much higher multiplex ratio than the RAPD technique (42.4 vs. 6.1) and eight combinations of EcoRI/MseI primers were enough to clearly distinguish between all the Sarilop clones.

Five-year survey of ochratoxin A in processed sultanas from Turkey

The results of surveillance for ochratoxin A (OTA) in 1885 samples of sultanas taken during five crop years between 1999 and 2003 are reported. The analytical method was based on extraction with methanol + sodium bicarbonate and clean-up by immunoaffinity column chromatography followed by high-performance liquid chromatography with fluorescence detection. The limit of detection for OTA was 0.3 µg kg−1. The results show that 9.3% of the samples contained no detectable levels of OTA, whereas 0.6% had concentrations exceeding 10 µg kg−1; the remaining 90.3% had levels within the range 0.3–10 µg kg−1. The overall mean OTA concentration in the total number of 1885 samples taken was 1.36 ± 2.91 µg kg−1; the overall median was calculated as 0.90 µg kg−1.

Ochratoxin A in sultanas from Turkey I : Survey of unprocessed sultanas from vineyards and packing-houses

A method for the determination of ochratoxin A (OTA) in sultanas from Turkey using extraction with a sodium bicarbonate solution (2% NaHCO3) followed by immunoaffinity clean-up and liquid chromatography with fluorescence detection was used to assess the frequency of occurrence and level of OTA. In-house validation was carried out with spiked samples at levels of 0.15, 1.5, 5.0 and 10 µg kg−1 and average recoveries were 91, 93, 87 and 89%, respectively. The limits of detection and limit of quantification in Turkish sultanas were 0.026 and 0.09 µg kg−1, respectively. A survey for the presence of OTA was carried out on 264 unprocessed sultana samples during the production seasons between 1998 and 2000 collected annually from vineyards and from packing-houses. The analyses of unprocessed sultanas showed that 32.2% of the total number of samples contained no detectable OTA, whereas 9.8% of sultana samples had OTA concentrations above 10 µg kg−1, and the remaining 58% had levels within the range 0.026–10 µg kg−1. There were big differences in median concentrations between years. Considering the year of production, it appears that sultanas produced in 1998 and 2000 showed the lowest incidence of OTA contamination (median < 0.02 µg kg−1), whereas 2002 showed the highest incidence (median = 4.3 µg kg−1). The overall mean OTA concentration was calculated as 3.4 µg kg−1, and the overall median as 0.9 µg kg−1. Among the samples analysed, the highest detected level of OTA was 54 µg kg−1.

Propagation of Ficus carica L. clones by in vitro culture

This experiment is designed to determine the most suitable conditions and media for propagating three selected fig (Ficus carica L.) clones through tissue culture. The clone 37 displayed a higher performance than clones 50 and 82. As the multiplication medium, the Murashige and Skoog (MS) medium containing 1 mg dm−3 α-indole-3-butyric acid (IBA), 1 mg dm−3 gibberellic acid and 5 mg dm−3 6-benzyladenine were the best, whereas, MS medium complemented with 1.2 and 2.5 μM IBA or 1-naphthalene acetic acid (NAA) were better in respect to rooting. Peat followed by volcanic tuff gave the best performance for acclimatization to outdoor conditions.

Changes in K, Ca and Mg contents in different parts of the fig fruit during development

Changes in the K, Ca and Mg contents and K/Ca ratios within the fig fruit were determined during the fruit development period. The trial was performed with the Bursa Black, Goklop and Sarilop (syn = Calimyrna) varieties in Erbeyli-Aydin, the main fig-producing province of Turkey. The K, Ca and Mg analyses were carried out on whole intact fruits and on the skin, meat and pedicel of the fruit. It was found that in the Goklop and Sarilop varieties, there was a rapid decline in the Ca content of the fruit prior to ripening, as opposed to an increase in Bursa Black. Significant differences were determined among varieties with respect to fruit K, Ca and Mg content. The results are discussed in terms of fruit cracking.

Quality and nutritional property changes in stored dried apricots fumigated by sulfur dioxide

Apricots are grown in many countries and are marketed as dried or fresh. Sulfur fumigation is preferred as a low-cost pre-treatment to maintain apricot color. This study aims to determine the effect of sulfur dioxide (SO2) concentration on quality and nutritional properties of dried apricot fruits during storage. Apricot fruits were treated with different concentrations of SO2 (1,250, 2,000, and 3,500 mg·kg−1) and then stored at 20°C under 50–65% relative humidity conditions for 18 months. Fruit SO2 concentration decreased rapidly during the initial stage and then decreased at a slower rate. Fruit color darkening became more pronounced after 12 months, especially in the fruit treated with 1,250 and 2,000 mg·kg−1 SO2. After 18 months of storage, total phenolic content (839–890 mg GAE 100 g−1 dry weight), antioxidant activity (9.4–11.6 μmol TE g−1 dry weight), and β-carotene levels (42.7–47.6 mg·kg−1) of all treatments varied only slightly, despite lower values overall. Therefore, SO2 levels must be chosen based on the expected storage conditions and length of the storage period.

Fumonisin B1 and B2 occurrence in dried fig fruits (Ficus carica L.) under Meander Valley's climatic conditions and relationship with fruit quality

Fusarium is the agent causing endosepsis (internal rot) in fig fruits and it is widespread in fig orchards in the Aegean region. This research was conducted to determine the natural occurrence of fumonisin B1 (FB1) and B2 (FB2) on dried fig fruits of Sarilop (syn. Calimyrna) variety which are mainly grown in the Big and Small Meander Basins in the Aegean region, representing 60% of world dried fig production. A total of 262 samples belonging to two quality classes, Class A and Class cull, were collected from 12 different locations during the two crop years in 2004 and 2005. The fumonisin detection method is based on extraction with methanol–acetonitrile–water, derivatization with o-phthaldehyde and quantification by reversed-phase high-performance liquid chromatography with fluorescence detection. The mean concentrations of FB1 and FB2 in fumonisin-positive samples were 0.080 ± 0.047 µg g−1 and 0.055 ± 0.031 µg g−1 and ranged from LOD to 0.332 µg g−1 and from LOD to 0.198 µg g−1, respectively. The incidence of fumonisins significantly differed between the two crop years. This difference can be attributed to the alteration in the rainfall regime from mid-May to mid-August (7.2 mm in 2004, 90.9 mm in 2005) and number of humid wind currents from a westerly direction (183 in 2004, 492 in 2005) from the end of July and mid-August that may have triggered a higher incidence of Fusarium spp. and thus fumonisin production.

Elucidating genetic relationships, diversity and population structure among the Turkish female figs.

A collection of 96 female Turkish fig (Ficus carica L.) accessions was studied to elucidate genetic structure and estimate diversity and genetic similarity distribution among the female figs present in Turkish genetic resources, using 157 molecular genome markers including 129 sequence-related amplified polymorphisms, 21 random amplified polymorphic DNAs, and 7 simple-sequence repeats. The plant samples mainly included Turkish fig collections selected throughout the country over the course of a half-century. Neighbor-joining analysis revealed continuous dissimilarity range, and it was difficult to classify figs into distinct groups. The principle component analysis produced similar results. The analysis of molecular variance indicated that 95 and 93% of genetic variation were explained by within geographic origins and similar fruit rind color, respectively. Sub-structuring Bayesian analysis assigned the 96 female figs into four sub-populations, and indicated that they were highly related. The corrected allelic pairwise distances among the six geographic origins were less than 5%. This study suggests that geography- and color-based groups were not genetically distinct among the Turkish figs.

Seasonal and diurnal photosynthetic behaviour of fig (Ficus carica L.) under semi-arid climatic conditions

Abstract Diurnal and seasonal variations in net photosynthetic (PN) and transpiration (E) rates and water use efficiency (WUE) of the fig tree (Ficus carica L.) were investigated under semi-arid climatic conditions. The two types of leaves from southern and northern parts of trees experienced natural air temperature and irradiance conditions, but differ particularly in water use efficiency. The obtained data reveal that leaf temperature, because of decrease in stomatal conductance, is the major factor limiting the gas exchange capacity of fig trees grown under rain-fed conditions. Stomatal conductance is the major control mechanism, particularly in the northern parts of the trees; however, PN was most probably decreased by both stomatal and non-stomatal resistance mechanisms such as photoinhibition under severe drought and high irradiance conditions in the southern parts of the trees.