Root growth characteristics of Festuca, Lolium and Festulolium in relation to stress tolerance

Abstract

Linear root growth of meadow fescue (Festuca pratensis Huds.), Italian ryegrass (Lolium multiflorum Lam.) and their hybrid Festulolium braunii was studied under a hardening temperature of +4 °C. It was defined, that the root growth rate of Festuca pratensis was considerably lower than that of Lolium multiflorum (vF .<< vL.). The cytological growth analysis suggests that the main reason for the lower root growth rate of Festuca pratensis, compared to Lolium multiflorum, was a low cell production rate (VF.< VFl.< VL.). Festulolium braunii took the intermediate but closer to Lolium multiflorum position within these parameters. An exceptionally short root elongation zone L of Festuca pratensis was the result of a low cell production rate. We sugest that the low cell production rate V as a consequence of low meristem activity is a cytological expression of growth slowdown and a stress state into which plants transit and in such a way express stress tolerance. Thus, a short root elongation zone L can be a marker of a stress state and cold resistance. Keywords: Festuca pratensis, Lolium multiflorum, Festulolium braunii, root linear growth, cell production rate, stress tolerance, stress state, rounded cells