Investigating seasonal changes of morphological, physiological and biochemical content in european hophornbeam seedlings exposed to drought stress

Drought stress caused by drought causes many changes in plants as morphological, physiological and biochemical. In this study, three different water stresses (irrigation twice in a week, once in a week, 1 time in two weeks) was applied to 1+0 year old seedlings grown from seeds which were obtained from some O. carpinifolia Scop. populations naturally occurring in Turkey (Antalya Finike, Erzurum- İspir, Düzce-Yığılca, Adana-Saimbeyli, Antalya-Akseki Sinop-Duvarsöküğü and Kastamonu-Şehdağ). In addition, changes in the content of proline related to the populations were examined seasonally (5 times in each June, July, August, September and October) to determine more durable populations against drought. In the repeated measurements (once a month), 63 seedlings were used for each treatment by using 3 randomly selected seedlings from 3 different irrigation regimes and 7 different populations. In this study morphological (sapling length, diameter of seedlings, and total biomass), physiological (water potential and stoma conductivity), biochemical (total soluble sugar and proline) parameters measured. When the morphological result was examined, it was observed that between populations watering twice a week, the populations of Adana-Saimbeyli and Antalya-Finike's growth is less than in other populations. When the effects of water stress on total biomass were observed, the least measured populations were highest in the Adana-Saimbeyli and Antalya-Finike populations in the irrigated group compared to other irrigated groups. When the water potentials were measured, the highest plant water tension was measured Adana-Saimbeyli and Antalya-Akseki populations in the irrigated group every two weeks. According to results of the study, it was determined that the populations with northern locality were stressed more quickly and the populations with southern locality were more resistant.