Drought Differentially Affects Root System Size and Architecture of Potato Cultivars with Differing Drought Tolerance

Potato plants are often exposed to soil drought, which results in crop losses, because potato root system is shallow. The aim of our study was to examine the relationship between root system architecture and drought tolerance. We measured rooting depth, total length, surface area, average diameter, and dry weight of the root system every 20 cm of soil depth. We examined four potato cultivars, two that were more tolerant to drought (Gwiazda and Tajfun), and two that were more sensitive (Oberon and Cekin). Our results showed different responses by the tested cultivars to drought. The root dry mass decreased in response to drought and this decrease was smaller in the more drought-tolerant cultivars. In response to drought, the more drought-tolerant cultivars developed elongated roots, but the roots of the less-tolerant cultivars remained the same length. The decrease in root diameter was also smaller in the more drought-tolerant cultivars.