Exploring the use of scions and rootstocks from xeric areas to improve drought tolerance in Castanea sativa Miller

•Grafting delays budbreak and reduces secondary growth in Castanea sativa.•Rootstocks and scions of xeric origin advance budbreak in Castanea sativa.•Rootstocks and scions of xeric origin increase drought tolerance of sensitive trees.•Jasmonates were involved in Castanea sativa response to drought.•Chestnuts from southern Spain could be a source of drought-tolerant rootstocks.