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

CERRILLO TERESA; MONTEOLIVA, SILVIA; MOZO, IRINA; LUQUEZ VIRGINIA M.C.

Santa Fe

Congreso; XXXIII Reunión Argentina de Fisiología Vegetal; 2021

Sociedad Argentina de Fisiología Vegetal

Climate change will increasethe occurrence of flooding episodes in several areas of the world. Willow commercialgenotypes are usually propagated as unrooted cuttings. During the early stages,cuttings are still developing their root system and leaf area, being morevulnerable to the occurrence of stresses like flooding. In consequence, it isrelevant to identify traits correlating to flooding tolerance during the earlygrowth of willows.We evaluated the floodingtolerance of 29 willow genotypes from the breeding program of INTA. Two-monthsold plants growing in pots in a greenhouse underwent two treatments: watered tofield 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. Aflooding tolerance index for each genotype was estimated as the percent ratiobetween flooded and control total biomass. There was ample variation inflooding tolerance, with the index ranging from 39% to 117%. Most clones had a reducedbiomass accumulation under flooding conditions and only 4 genotypes had similaror higher biomass than control plants. Several traits had a positive andsignificant correlation (measured with the Pearson correlation coefficient) withflooding tolerance: height (r=0.69, p<0.01), collar diameter (r=0.71,p<0.01), plant dry biomass (r=0.71, p<0.01), plant leaf area (r=0.49,p<0.01) and basic wood density (r=0.53, p<0.01).These traits could be usefulto select for increased flooding tolerance in willows during the early stagesof growth.