In Vitro Evaluation of Shoot Regeneration and Biomass Traits in Tobacco Genotypes Under Polyethylene Glycol Simulated Drought Stress
Türk Tarım - Gıda Bilim ve Teknoloji dergisi, cilt.14, sa.2, ss.575-581, 2026 (TRDizin)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 14 Sayı: 2
- Basım Tarihi: 2026
- Doi Numarası: 10.24925/turjaf.v14i2.575-581.8343
- Dergi Adı: Türk Tarım - Gıda Bilim ve Teknoloji dergisi
- Derginin Tarandığı İndeksler: CAB Abstracts, Central & Eastern European Academic Source (CEEAS), Directory of Open Access Journals, TR DİZİN (ULAKBİM)
- Sayfa Sayıları: ss.575-581
- Çukurova Üniversitesi Adresli: Evet
Özet
This study aimed to evaluate the morphological responses of three tobacco genotypes Birlik 124, Birlik 128, and İzmir Özbaş to Polyethylene glycol (PEG) mediated in vitro drought stress using a multivariate approach. PEG concentrations of 0% - 2% - 4% and 6% were applied to simulate osmotic stress, and five morphological parameters; plant height, leaf number, multiplication rate, fresh weight, and dry weight were assessed. Principal Component Analysis was additionally performed to evaluate genotype-level variation across treatments. PEG concentration and genotype significantly affected all traits, with genotype × PEG interaction being significant for leaf number and dry weight. Multiplication rate and plant height declined progressively with increasing PEG levels, while İzmir Özbaş consistently maintained superior values, indicating enhanced drought tolerance. Leaf number was highest in İzmir Özbaş (42.9) and lowest in Birlik 124 under 4% PEG (20.1), reflecting genotype-specific stress sensitivity. Multiplication rate decreased across all genotypes under stress, yet İzmir Özbaş retained higher rates under 4% and 6% PEG, suggesting resilience in shoot proliferation. Fresh weight showed a genotype-dependent decline, with Birlik 124 exhibiting gradual reduction and İzmir Özbaş displaying partial recovery at 6% PEG. Remarkably, dry weight increased with PEG concentration, particularly in Birlik 124, which reached 0.53 g at 6% PEG the highest among all genotype × PEG combinations highlighting a compensatory biomass accumulation mechanism under stress. Principal Component Analysis (PCA) revealed distinct genotype clustering across PEG levels, with the first two components explaining 79.7% of the total variance. İzmir Özbaş and Birlik 128 showed broader dispersion, indicating morphological plasticity, while Birlik 124 remained tightly clustered, suggesting a stable growth strategy. Overall, the findings demonstrate that PEG-induced osmotic stress elicits genotype-specific morphological responses, İzmir Özbaş exhibiting complementary drought adaptation traits. These results provide valuable insights for genotype screening and in vitro drought tolerance assessment in tobacco.