مشخصات پژوهش

Drought stress threatens human food security by reducing product yields and by limiting the practice of crop cultivation. Roots are the first to detect water deficiencies and send signals to aerial parts. The current study evaluates several responses of the roots to drought stress by considering measurable features such as the architecture and anatomy of ‘Chandler’ walnut seedlings. Here, 18 seedlings were divided into two groups: the first group of seedlings was exposed to drought stress by withholding irrigation, and the second group was maintained under normal irrigation conditions. The roots of seedlings in both groups were harvested thirty days after the experiment had begun. Eight of the sampled roots in the two groups were significantly different when considering twenty parameters pertaining to the architectural appearance of roots. Most of these parameters were related to the root thickness and root volume. Also, anatomical studies showed that the suberization of roots increased in seedlings under drought stress, compared to the roots of the control group. Finally, the nutritional analyses of roots showed that K+ and Ca+2 increased in the roots of seedlings under drought stress. These findings suggest that breeders can focus on the responses of roots to improve drought tolerance when breeding walnut rootstocks.