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In this study, it was aimed to test the seed viability of Alkanna orientalis and endemic Alkanna sieheana species rich in Alkannin/Shikonin (A/S) and to determine the germination percentage and callus regeneration suitable for in vitro A/S production. The viability rates of seeds collected from nature were determined by the tetrazolium method. The germination rates of the seeds of both species were tested with three different applications (on filter paper, MS nutrient medium with agar, in peat). The seed coats of both species were removed, and their embryos were cultivated in Murashige and Skoog (MS) media containing plant growth regulators in various proportions. The viability rates of the seeds were found at 98.3% for A. orientalis and 96.0% for A. sieheana. Germination rates were determined only on filter paper as 8.3% for A. orientalis and 5.0% for A. sieheana, no germination was observed in other applications. The highest zygotic shoot and root formation rate were obtained from A. orientalis with 91.6% and 40.3%, respectively. But, the highest callus formation rate was observed on A. siehenea with 75.0%. As a result, it was determined that although the viability rates were high in both species, the germination rates were low, but in vitro reproducibility was possible.

ABSTRACT Salinity is one of the abiotic stresses that lead to an imbalance in the physiological processes of the plants and also affects potato growth and productivity in maınly semi-arid and growing areas. The accumulation of Na+ and Cl- ions in the cells is very toxic can influence all mechanisms and the enzymatic actions of the plants. In vitro screening of plant genotypes for osmotic stress represents a valuable tool as an alternative to field trials and can be applied based on osmotic stress tolerance. The main goal of this study was to reveal variability in salinity stress tolerance of potato varieties using in vitro screening. Stem cuttings consisting of a single node of different varieties were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of sodium chloride (NaCl) (0, 50, 100 and 150 mM). The differences among the plantlet length, number of branches, number of nodes, number of the leaflet, leaflet width, leaflet length, root length, number of the root, fresh plantlet weight, dry plantlet weight of all varieties were negatively influenced by all NaCl concentrations tested. Microtuberization and stolon growth of the varieties were also completely inhibited at high concentrations (100-150 mM). The Principal components analysis (PCA) was applied to the data matrix (15 morphological characteristics x 12 potato varieties) of the potato varieties. Also, a hierarchical cluster analysis (HCA) was used to identify the possible nearest and similarity of all morphological characteristics analyzed of the potato varieties. In grouping potato varieties, HCA and PCA results were found to be similar. We can speculate about the responses of morphological similarities of the potato varieties against salt stress. We concluded that Innovator and Kennebec are respectively the most salt-tolerant varieties. Hermes was moderately salt-tolerant and microtuberization capacity of Slaney was also high under salt stress conditions.

The aeroponic production system is one of the new applications in soilless agriculture. This system is also an alternative seed production system for mini-tuber production of potato in terms of providing optimum growth conditions, enabling potato production to be free from diseases and pests and to make economic use of agricultural inputs. This system, which is independent of climatic conditions, has the advantage of improving the vegetative growth, delaying tuber formation, prolonging the vegetative period, increasing the tuber yield per plant and total tuber yield while decreasing the tuber weight. Due to the problems experienced in potato seedling tuber production in recent years, it emerged as an alternative production system for our country.

10 aspir genotipi pas hastal ığı na karşı tepkileri bak ı mı ndan tarla koşulları nda değerlendirilmişlerdir. Puccinia carthami test edilen bütün genotiplerin yapraklar ı nda hastal ı k oluşturmuştur. En yüksek hastal ı k Syrian 1 genotipinde, en düş ük hastal ı k Afyon genotipinde görülmü ştür. Afyon genotipinde Syrian 1, Sivas, Syrian Hama, Cyprebregon, PI 537598, PI 251982 ve Gila genotiplerine oranla daha az hastal ı k görülmü ştür.

Peach (Prunus persica L.) is one of the most important worldwide fresh fruits. Since fruit growth largely depends on adequate water supply, drought stress is considered as the most important abiotic stress limiting fleshy fruit production and quality in peach. Plant responses to drought stress are regulated both at transcriptional and post-transcriptional level. As post-transcriptional gene regulators, miRNAs (miRNAs) are small (19-25 nucleotides in length), endogenous, non-coding RNAs. Recent studies indicate that miRNAs are involved in plant responses to drought. Therefore, Illumina deep sequencing technology was used for genome-wide identification of miRNAs and their expression profile in response to drought in peach. In this study, four sRNA libraries were constructed from leaf control (LC), leaf stress (LS), root control (RC) and root stress (RS) samples. We identified a total of 531, 471, 535 and 487 known mature miRNAs in LC, LS, RC and RS libraries, respectively. The expression level of 262 (104 up-regulated, 158 down-regulated) of the 453 miRNAs changed significantly in leaf tissue, whereas 368 (221 up-regulated, 147 down-regulated) of the 465 miRNAs had expression levels that changed significantly in root tissue upon drought stress. Additionally, a total of 197, 221, 238 and 265 novel miRNA precursor candidates were identified from LC, LS, RC and RS libraries, respectively. Target transcripts (137 for LC, 133 for LS, 148 for RC and 153 for RS) generated significant Gene Ontology (GO) terms related to DNA binding and catalytic activities. Genome-wide miRNA expression analysis of peach by deep sequencing approach helped to expand our understanding of miRNA function in response to drought stress in peach and Rosaceae. A set of differentially expressed miRNAs could pave the way for developing new strategies to alleviate the adverse effects of drought stress on plant growth and development.