Evaluation of Turf-Type Intergeneric Hybrids of Lolium perenne with Festuca pratensis for Improved Stress Tolerance

Recurrent selection for drought and heat tolerance among hybrids of perennial ryegrass (Lolium perenne L.) with meadow fescue ( Festuca pratensis Huds.), was used to develop turf-type populations with a marked increase in stress tolerance. Increased tolerance was associated with the presence of an introgression of F. pratensis chromatin on chromosome 3 of L. perenne. To determine if root characteristics were responsible for the improved stress tolerance, a greenhouse study was conducted to compare sister lines of Festulolium both with or without the introgression; the recurrent backcross parent; a representative F. pratensis; and turf-type tall fescue (Festuca arundinacea Schreb.) grown under well-watered conditions in 5.1-cm diam. x 160-cm long tubes containing sand. Two separate 120-day experiments revealed that F. pratensis produced deeper roots, more root biomass, and a higher root:shoot, while the industry standard, F. arundinacea, ranked at or near the lowest value. For the hybrids and ryegrass, the root parameters were intermediate between the 2 fescues, with no statistically significant difference among the 3 lines tested. The results indicate that in the tested Festulolium turf, drought and heat tolerance were not a consequence of increased root depth or root biomass as reported in previous reports for forage-type intergeneric hybrids of ryegrass and fescue.