Flooding tolerance during the early stages of growth in 29 willow genotypes (Salix spp.)

MOZZO IRINA; MONTEOLIVA S; CERRILLO T; LUQUEZ V

Congreso; XXXII Reunión Argentina de Fisiología Vegetal RAFV 2021; 2021

RAFV

Climate change will increase the occurrence of flooding episodes in several areas of the world. Willow commercial genotypes are usually propagated as unrooted cuttings. During the early stages, cuttings are still developing their root system and leaf area, being more vulnerable to the occurrence of stresses like flooding. In consequence, it is relevant to identify traits correlating to flooding tolerance during the early growth of willows. We evaluated the flooding tolerance of 29 willow genotypes from the breeding program of INTA. Two-months old plants growing in pots in a greenhouse underwent two treatments: watered to field capacity (control) and flooded (80% of the stem covered by still water) for 41 days. At the end of the stress episode, different traits were measured: height, collar diameter, basic wood density, plant dry biomass and leaf area. A flooding tolerance index for each genotype was estimated as the percent ratio between flooded and control total biomass. There was ample variation in flooding tolerance, with the index ranging from 39% to 117%. Most clones had a reduced biomass accumulation under flooding conditions and only 4 genotypes had similar or higher biomass than control plants. Several traits had a positive and significant correlation (measured with the Pearson correlation coefficient) with flooding tolerance: height (r=0.69, p