Zeki Kaya

Biodiversity and conservation of Turkish forests

The rapid human population growth of Turkey and associated demands on natural resources threaten the biodiversity of the nations natural ecosystems, including forests. Though limited to about 26% of the total land area of the country, maintaining healthy forests is vital to support sustainable development in Turkey. The purpose of this paper is to introduce the current status of Turkeys forests, present the national objectives for forest conservation and sustainable use, and describe the actions needed to protect forest biodiversity. While Turkey has numerous laws, regulations, and programmes that seek to promote biodiversity, implementation of these guidelines requires increased commitment and vigilance. Conservation programmes should be increased in number and effectiveness, particularly in light of increasing demand for forest products. Management plans for all conservation programmes require completion and implementation. Creating monitoring programs and building quantitative databases for conservation programs will be essential to assess future success in maintaining biodiversity. Conservation of natural resources requires public education and promoting awareness of the vital role of maintaining a healthy environment for sustainable development. Agroforestry endeavors can provide practical means of meeting both environmental protection and agricultural product production goals.

Doubled haploid plant production from unpollinated ovules of sugar beet (Beta vulgaris L)

Abstract The effects of cold pretreatment, AgNO3 and activated charcoal on haploid plant production from unpollinated sugar beet ovules were investigated. Both cold pretreatment and the addition of charcoal increased the frequency of embryo formation, whereas AgNO3 decreased or completely inhibited it. Colchicine (50, 100, 150 or 500 mg l–1) and trifluralin (1.7, 3.4 or 5.0 mg l–1) for 12, 24, 36 or 48 h were compared in agar-solidified, agarose-solidified or liquid media. Although colchicine gave a higher doubling rate (25.3%) than trifluralin (18.2%), the difference was not significant. Both agents were more effective when used in liquid (29.1%) than agarose-solidified medium (20.7%) and agar-solidified medium (15.4%). A treatment duration of 48 h was significantly more effective (27.5%) than 12 h (13.6%) but it was not different from 24 h (16.3%) or 36 h (18.6%).

Genetic Variation in Turkish Red Pine (Pinus brutia Ten.) Seed Stands as Determined by RAPD Markers

Summary Turkish red pine (Pinus brutia Ten.) is one of the important tree species in Turkey. The species has been heavily disturbed by anthropogenic factors and fire, making it important to understand the magnitude of the impact on genetic diversity of areas reserved for seed production. To explore the extent of genetic variation in Turkish red pine seed stands, a random amplified polymorphic DNA (RAPD) marker system was used in the study. The estimated genic diversity for seed stands was found to range from H =0.17 (P, %of polymorphic loci =%58.7) in Çameli-Göldağ to 0.29 (P =%81.7) in Bayramiç-Karaköy seed stand though the lowest polymorphism was observed in Fındıkpınarı seed stand (P =55.8%). The total gene diversity was calculated as HT=0.34, in Turkish red pine. About 65% of the total diversity was within seed stands. No distinct pattern of genetic diversity was found according to the geography, elevation or breeding zones. The highest genetic differentiation was found in the Western Mediterranean geographic region, however, within population genetic diversity was found to be similar among different geographic regions (HS=0.22-0.24). GST value calculated was high (0.35) indicating that genetic differentiation among the studied seed stands was substantial. Dendrogram constructed with genetic distance data did not yield a firm pattern with respect to geography, elevation and breeding zones. In fact, the most of the clusters in the dendrogram had very low bootstrap values, suggesting that the clusters could be refined if more populations and markers are included in the future studies. The implication of the results with respect to in situ conservation of genetic resources of the species was discussed.

Improved in vitro micropropagation method with adventitious corms and roots for endangered saffron

The objective of this study was to investigate development of an efficient in vitro tissue culture system for saffron (Crocus sativus L.) complete with roots and corms. In indirect organogenesis, Murashige and Skoog (MS) media with 3% (w/v) sucrose, 100 mg L−1 ascorbic acid, and the combination of 0.25 mg L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 1 mg L−1 6-benzylaminopurine (BAP) were best for callus initiation and growth while 1.5 mg L−1 BAP was excellent for high rate of adventitious shoot formation. 1 mg L−1 indole-3-butyric acid (IBA) was more preferable for adventitious corm and root initiation as well as growth. Overall, 64% rooting and 33% corm production rates were achieved in indirect organogenesis. In direct organogenesis, MS medium supplemented with 3 % sucrose, 100 mg L−1 ascorbic acid and 1 mg L−1 BAP was optimum for shoot growth. While 1 mg L−1 IBA was best for adventitious corm formation, 2 mg L−1 IBA promoted adventitious root initiation and growth. Overall, 36% and 57% of explants had corm and contractile root, respectively. The high rates suggest that efficient tissue culture system could be achieved for mass propagation and ex situ conservation of threatened saffron genetic resources.

Gene regulation network behind drought escape, avoidance and tolerance strategies in black poplar (Populus nigra L.)

Drought is the major environmental problem limiting the productivity and survival of plant species. Here, previously identified three black poplar genotypes having contrasting response to drought were subjected to gradual soil water depletion in a pot trial to identify their physiological, morphological and antioxidation related adaptations. We also performed a microarray based transcriptome analyses on the leaves of genotypes by using Affymetrix poplar Genome Array containing 56,000 transcripts. Phenotypic analyses of each genotype confirmed their differential adaptations to drought that could be classified as drought escape, avoidance and tolerance. Comparative transcriptomic analysis indicated highly divergent gene expression patterns among the genotypes in response to drought and post drought re-watering (PDR). We identified 10641, 3824 and 9411 transcripts exclusively regulated in drought escape, avoidance and tolerant genotypes, respectively. The key genes involved in metabolic pathways, such as carbohydrate metabolism, photosynthesis, lipid metabolism, generation of precursor metabolites/energy, protein folding, redox homeostasis, secondary metabolic process and cell wall component biogenesis, were affected by drought stresses in the leaves of these genotypes. Transcript isoforms showed increased expression specificity in the genes coding for bark storage proteins and small heat shock proteins in drought tolerant genotype. On the other hand, drought-avoiding genotype specifically induced the transcripts annotated to the genes functional in secondary metabolite production that linked to enhanced leaf water content and growth performance under drought stress. Transcriptome profiling of drought escape genotype indicated specific regulation of the genes functional in programmed cell death and leaf senescence. Specific upregulation of GTP cyclohydrolase II and transcription factors (WRKY and ERFs) in only this genotype were associated to ROS dependent signalling pathways and gene regulation network responsible in induction of many degrading enzymes acting on cell wall carbohydrates, fatty acids and proteins under drought stress. Our findings provide new insights into the transcriptome dynamics and components of regulatory network associated with drought adaptation strategies.

The effects of test environments on estimation of genetic parameters for seedling traits in 2‐year‐old Douglas‐fir

The effects of test environments (dry versus wet) on estimation of genetic parameters in seedling traits were studied in 160 open‐pollinated families of Douglas‐fir (Pseudotsuga menziesii (Mirb.) Franco) from southwestern Oregon. Seedlings from four populations were grown in two test environments for two growing seasons. Between test environments, ‐9 bars of water potential difference were created in both growing seasons. Estimated genetic variances in most growth and phenology traits were considerably higher for seedlings grown in the wet environment than for those in the dry. Estimated genetic correlations between the same traits measured in different test environments indicated that most seedling traits studied for two growing seasons are genetically stable in both environments—i.e., suggesting that genotype by environment interaction in these traits are weak. However, the effect of test environment on estimation of genetic parameters in seedling traits, especially in adaptive seedling traits, should b...

Genetic variability among Turkish pop, flint and dent corn (Zea mays L. spp. Mays) races: Enzyme polymorphism

To determine magnitude and pattern of genetic variation, 32 Turkish corn accessions available from the USDA/ARS North Central T-Regional Plant Introduction Station (NCRPIS) collections (Ames, Iowa), representing pop, flint and dent corn races, different climatic, geographic and topographic areas in Turkey, were identified and, 19 isozyme systems were studied. Thirty-nine alleles were detected by 19 isozyme loci in 32 accessions. The PGD-2, Mmm-1, GOT-3 and IDH-1 loci were found to be monomorphic in all accessions. Mean number of alleles per locus varied between 1.2 in Balıkesir-167949 accession to 1.7 in Ankara-177600, Trabzon-185062, Eskişehir-204822 and Samsun-239573 accessions. The proportion of polymorphic loci ranged from as low as 15.8% in Balıkesir-167949 to as high as 57.9% in Trabzon-185049 accession. Observed heterozygosity was the highest in Adana-183779 and the lowest in Ankara-204800 accession. Genetic identities ranged from 0.823 for 170881-Kocaeli and 167949-Balikesir pair to 0.997 for 182327-Iğdır and 168008-Kırklareli pair. Dendrogram constructed by using Neis genetic distances (1978) revealed three clustering groups, though one of the clusters included only 170881-Kocaeli accession. It is concluded that170881-Kocaeli accession must have experienced with intensive selection, inbreeding and/or bottleneck effects in the past. Corn germplasm managers and breeders could use the results of the present studies for monitoring genetic resources, accession identification, and sampling genetic diversity, but agronomic characteristics of these corn accessions are also needed for a better utlization of Turkish corn land races evolved over the years.

Genetic variability among Turkish pop, flint and dent corn (Zea mays L. spp. mays) races: Morphological and agronomic traits

Abstract32 Turkish corn accessions representing different climatic, geographic and topographic areas in Turkey were identified. Genetic variation and its pattern in three corn races (pop, flint and dent) included 32 accessions were investigated using 25 morphological and agronomic traits. Vegetative, ear and kernel related traits were significantly varied both among races and accessions within races. Variance component due to races and accessions within race were statistically significant, but the variance components due to accessions were generally made up large component of total variance and ranged from 17.17% in kernel length to 82.75% in tassel length. There were also strong and mostly positive correlations between studied agronomic traits as well as between agronomic traits and isoenzyme loci. These correlations were explained by the traditional farming practices and enzyme specificity with flint accessions since the enzyme systems such as Alcohol dehydrogenase (locus 1), Malate dehydrogenase enzyme (loci 2–3) and 6-phospho-gluconate dehydrogenase (locus-1) are generally considered to be the characteristics of flint corn race. Canonical discriminant function analysis with twenty-five morphological and agronomic traits revealed that first two canonical discriminant variables explained 68% of total variation among accessions. Two Canonical variables, in which kernel related traits were heavily weighted, correctly classify the three corn races – indicating that Turkish corn accessions maintained their racial characteristics with agronomic and morphological traits.

Parameters affecting shoot production and rooting of cuttings from lodgepole pine hedges

By propagating lodgepole pine (Pinus contorta) cuttings in vivo, we obtained after 7 growing cycles (ca 3.5 years) in a greenhouse, sufficient number of cuttings from most families to establish clonal progeny tests. Twenty-one full-sib families with approximately 20 clones per family were studied for five years. Years when cuttings were set, families within latitude and clones within families differed significantly in rooting percentages, with the variance components 4.2%, 8.2% and 9.5%, respectively. One way to get a frequent and uniform rooting is to take cuttings from non-leading shoots since they have higher rooting percentage than leading shoots. Neither total length of the cuttings nor length of the primary needles were significantly correlated to rooting percentage. With appropriate management of the ortets and the cuttings during rooting, most clones could be included in a cutting propagation program.

Genetic variation in cold hardiness and phenology between and within Turkish red pine (Pinus brutia Ten.) populations: implications for seed transfer.

Abstract Wind-pollinated seeds from 40 trees (half-sib families) were collected from each of six Turkish red pine (Pinus brutia Ten.) populations in southern Turkey. Two-year old seedlings were evaluated for growth, phenology and cold resistance in a common garden experiment established in Ankara, located outside the species’ natural range. Each family was represented with a six-tree row plot within each of the three replications. The below freezing temperatures (-15.2°C) observed in January and February of 2000 were sufficient to observe visually- assessable-cold damage to the seedlings. The populations significantly differed in all traits under investigation except for second flushing in 1999. Populations originating from more inland and higher elevation areas were more resistant to cold than coastal low elevation populations. Families within populations were significantly different as regards all traits except HT00. Family heritability for bud burst was 0.40, and ranged from 0.12 to 0.37 for height, and from 0.20 to 0.23 for bud set. Final height of cold damage prone seedlings was shorter than cold tolerant seedlings. Families with early bud-set, later bud-burst and shorter second flush shoots suffered less from cold damage. Considering the expected climate change in the eastern Mediterranean, there is a potential for using this species outside its natural range, especially in sites experiencing more continental climate since it will be possible to move the species 200-300 m in altitude and 2-3 degrees in latitude.