Mohsen*⁽¹⁾, Kh. AL-kountar⁽¹⁾, M.Amer⁽¹⁾ and O. Aljbaii⁽²⁾

(1). General Commission for Scientific Agricultural research, Al- Suwayda Scientific Agricultural Research Center

 (2). Damascus University

 (*Corresponding author: Wasim Mohsen, email: wasimmo6@yahoo.com )

            Received:   22/11/2024                   Accepted:  6/4/2025

Abstract: 

The research was carried out in Al-Suwayda research center during the period 2016-2019, seven American rootstocks of grapevine which is resistant to Phylloxera insect have been studied in vitro for its response to drought stress treatments, these rootstocks are775P VGVA 12, 140Ruggeri UBA05, 161 49 VGVA5, 157 11C UBA01 1103 Paulsen UBA01, Kober 5BB  UBA01, 779P UBA04. polyethylene glycol ( PEG₆₀₀₀ ) has been used for drought stress treatments, explants between 2-3 cm with two leaves have been planted in WPM liquid medium with ( 1mg/L Kin + 0.2 mg/L IBA + 0.2 mg/L GA3(  and added to it ( PEG₆₀₀₀ ) in this concentrations 0,2,4,6, and 8%, with paper bridges used to carry explants, the results were taken 60 days after planting for the rate of survival plants, shoot length, shoots number, leaves number, roots length, roots number and the extent of drought damage,   The results show a difference in rootstocks response to water stress based on the studied parameters. Progressive reduction in the studied parameters occurred as PEG₆₀₀₀ concentration increased compared with control., where each of the rootstocks, 140 Ruggeri, 775/p, 157/11C and Kober 5BB is the lowest decrease in most of the studied indicators. This indicates their good tolerance of the applied drought stress, while the rootstocks, 779/P 161/49 could not tolerant the drought stress well compared to the rest of the studied rootstocks, as the studied indicators decreased significantly.  The highest percentage of plants in plants was 8% PEG6000. Kober 5BB rootstock record a high level in shoots length reaching 6.78 cm on 2% PEG₆₀₀₀, treatment, it also recorded the average number of leaves was 7.2 leaf on the same one, while it did not register any significant difference between the control 2% PEG₆₀₀₀ treatment for shoots number, but for roots length it has recorded an average 9.7 cm. while 140Ruggeri did not register any significant difference between the control and the treatments for roots number excluding the treatment containing 8% PEG₆₀₀₀ which has recorded an average 1.01 root. drought injury varied depending on the rootstock and PEG₆₀₀₀ concentration, the deadest plants were observed on 8% PEG₆₀₀₀, the results show that Kober 5BB rootstock has the lowest level of injury degree reaching 1.3, while 161 49 rootstock has the highest level of injury degree reaching 1.8.

Keywords: American grape origins, dry stress, plant tissue transplantation.

 Full paper in Arabic: PDF