Wasim Mohsen^(1)* and Khzama AL-kountar⁽¹⁾ , and Maysa Amer⁽¹⁾

(1) Department of Biotechnology, Al Suwayda Scientific Agricultural Research Center General Commission for Scientific Agricultural Research, Syria.

(*Corresponding author: Dr.  Wasim Mohsen, E-Mail: wasimmo6@yahoo.com)

 Abstract

This study was carried out in the 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 their 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(  andadded 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, then the resistance plants were acclimated. 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 concentrationincreased compared with control. 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. Using the in-vitro screening was an effective technique and a quick method to evaluate the variability between grape rootstocks and its resilience to water stress.        

Keywords: American grapevine rootstocks, water stress, in-vitro culture_.

Full paper in Arabic: pdf