Tuesday, November 6, 2007 - 11:30 AM
167-10

Identification of Turf Grasses with Improved Salt Tolerance.

Sanalkumar Krishnan, UNIVERSITY OF RHODE ISLAND, DEPARTMENT OF PLANT SCIENCES, WOODWARD HALL, KINGSTON, RI 02881 and Rebecca Nelson Brown, Plant sciences, University of Rhode Island, 210 Woodward Hall, Kingston, RI 02881.

Turf grasses are often irrigated with effluent and recycled water with high salt content due to the non-availability of potable water. Also deicing salt is applied during winter to roadside grasses. The objective of this study was to identify salt tolerant genotypes of cool season grasses, which are adapted for the soil and climate in Rhode Island and the Northeast. An experiment was conducted in the greenhouse to evaluate the salt tolerance levels of 48 Festuca accessions (F. ovina, F. rubra, F. idahoensis, F. arizonica, F. longifolia, F. rubra.spp.fallax, F. arundinaceae and F. filiformis) and 52 Lolium accessions (L. perenne). Potted tillered plants were treated in an ebb-and-flow water bath filled with half strength Hoagland solution and NaCl. Concentration of NaCl was raised from 0 to 15,000ppm with an increase of 2500ppm every two weeks.

Digital photography and SigmaScan software were used to measure leaf firing. The grasses were also scored for foliar salt injury symptoms on a scale ranging from 1 to 9. The data was collected at each NaCl concentration level. After 15000 ppm, three F. rubra and one F. arundinaceae accession showed significantly better salt tolerance with 20-39 percent green tissue remaining in the F. rubra accessions and 47 percent remaining in the F. arundinaceae accession. The relative salinity tolerance of Festuca species at 15,000ppm NaCl were F. arundinacea> F. rubra>F. rubra.spp.fallax>F. ovina>F. filiformis>F. idahoensis= F. arizonica. Six Lolium accessions were found to have significant salinity tolerance with 22-28% green tissue remaining after two weeks at 15,000ppm. Regression analysis showed good correlation between the visual observation and the green pixels obtained through the SigmaScan analysis at all the salt concentration levels for Festuca and Lolium accessions.