Effects of Priming and Drought in the Andean Desert Wild Potato Solanum kurtzianum

Abstract

Priming is a phenomenon that has received special interest in recent years to better understand plant acclimation to environmental cues and its potential use in improving the drought response in susceptible crops. Crop wild relatives (CWR) play a role in natural ecosystems, are part of agrobiodiversity, and represent essential genetic resources for crop breeding. Although priming to drought has been demonstrated in the cultivated potato (Solanum tuberosum), it has been overlooked in potato CWR. Solanum kurtzianum is an Argentinian wild potato species adapted to arid conditions and represents a promissory model to study drought memory. The aim of the study was to evaluate the priming effect in two genotypes of S. kurtzianum of contrasting drought tolerance (G1 and G2). We obtained plants from tubers of a previous experiment, where plants were subjected to well-watered (non-primed) and moderate water-deficit (primed) conditions. Primed and non-primed plants were then grown under three irrigation treatments: i) well watered (WW), ii) moderate water deficit (MWD), and iii) severe water deficit (SWD). Morphological, physiological, biochemical, and yield traits were evaluated. Both genotypes presented higher biomass when they were exposed to a previous water deficit. G1 primed plants showed major above-ground biomass in MWD, whereas G2 primed plants showed major stolon biomass in SWD. According to drought tolerance indices, primed plants were more tolerant to water deficit than the non-primed ones. These results suggest that there are different priming effects to drought that would favour sexual or asexual modes of reproduction in the Andean desert potato S. kurtzianum.