İki Amerikan Asma Anacının Kuraklık Stresine Toleransının PEG Uygulaması ile Belirlenmesi

Abstract

Objective: This study was conducted to establish the in vivo protocol for the use of polyethylene glycol (PEG-6000) in 5BB (V. berlandieri x V. riparia) and 1103P (V. berlandieri x V. rupestris) American grapevine rootstocks, as well as to determine the plants' resilience to artificially induced drought stress. Materials and Methods: The experimental design of this study was planned as a randomized complete plot design with 3 replications, each consisting of 10 plants. Polyethylene glycol (PEG-6000) was administered to the plants in each irrigation at doses of 0%, 2%, 4%, 8%, and 16%, based on the percentage of irrigation water. The application lasted for a total of 3 weeks. The study investigated the responses of plants to drought in terms of shoot development parameters (shoot fresh weight, shoot dry weight, shoot length, node and leaf number, leaf area, shoot tolerance ratio), root development parameters (root fresh weight, root number, rooting rate, root tolerance ratio, root length), and physiological development parameters (plant vitality, damage degree, leaf turgor weight, chlorophyll content, ion flux, and cell membrane damage rate). Results: When examining the findings of the study, it was observed that polyethylene glycol material retained water, reducing the plant's water uptake and consequently creating artificial drought stress. The impact of drought induced by polyethylene glycol revealed that the 1103P rootstock exhibited higher resilience in shoot development parameters compared to the 5BB rootstock. On the contrary, the 5BB rootstock outperformed the 1103P rootstock in root development parameters. Concerning physiological development parameters, the severity of drought led to a significant decrease in plant vitality, chlorophyll content, and leaf turgor weight, while ion flux, cell membrane damage rate, and damage degree increased significantly to critical levels. Conclusion: As a result of the research, the 1103P rootstock was found to be more successful in terms of shoot and physiological development under drought conditions, while the 5BB rootstock was found to be more successful in terms of root development parameters. Compared to other cultivation environments (in vitro, hydroponics), it was determined that polyethylene glycol (PEG) had a less pronounced effect at lower doses due to the difficulty of binding PEG in the soil. However, when compared to control plants, statistically significant differences were observed in the examined traits. Regarding the parameters investigated in this study, the 16% PEG concentration used was identified as the most effective dose in triggering drought stress.