Interactive Effects of Intraspecific Competition and Drought on Stomatal Conductance and Hormone Concentrations in Different Tomato Genotypes

Plant physiological responses to various stresses are characterized by interaction and coupling, while the intrinsic mechanism remains unclear. The effects of intraspecific competition on plant growth, stomatal opening, hormone concentrations were investigated with three tomato genotypes (WT-wild type, Ailsa Craig; FL-a abscisic acid (ABA) deficient mutant, flacca; NR-a partially ethylene-insensitive genotype) under two water regimes (full irrigation, irrigation amount = daily transpiration; deficit 60% in full irrigation) this study. Three kinds competitions designed, i.e., root canopy competition, non-root non-canopy respectively. Intraspecific reduced leaf area conductance (gs) wild-type tomato, accompanied ABA accumulation ethylene evolution. competition-induced decrease gs was absent FL NR, indicating involved response competition. As soil becomes dry, decreased elevating accumulations. Under severe drought, decline covered drought-induced gs, as hydraulic signals most probably dominate. absence insignificantly influenced opening well-watered separation minimized neighbor sensing other signals. Whereas condition, significantly roots then conductance, belowground detection maybe enhanced drought. increased evolution, confirming importance environmental stress.