Andrea Maas1, Richard Layton1, and Benjamin G. Mullinix2. (1) USDA-ARS, PO Box 748, Tifton, GA 31793, (2) University of Georgia, UGA-CAES Tifton Campus, Tifton, GA 31793
Identification of improved salt tolerant grass germplasm is needed due to the increased use of low quality secondary water sources for turfgrass, and the need for low cost disposal of drainage water on forage land. Typically, studies have focused on several species of grasses and a limited number of genotypes within species, however, significant differences among cultivars within species have been demonstrated. The objective of this study was to identify bermudagrass [ Cynodon dactylon (L.) Pers.] germplasm with improved salinity tolerance for development of new cultivars. One hundred eight tetraploid germplasm lines taken from the USDA-ARS core collection maintained at Tifton, Georgia, along with ‘Tifton 10', ‘Tifton 86', as well as four seashore paspalum (Paspalum vaginatum Swartz); ‘Adalayd', ‘Sea Isle 1', ‘Sea Isle Supreme', and advanced University of Georgia line 03.5.278 were tested. Plants were greenhouse established in 6 inch pots, two pots per table of each entry were grown on three tables. Fourteen day growth clipped shoot weights were taken twice prior to treatment to establish untreated standards for each pot. Water applied through an overhead misting system was increased in salinity over 6 wk until a level of 300m Ì NaCl (17.5g •l -1) was reached. Three additional fourteen day growth clipped shoot weights were taken, and data were analyzed using ordinary least squares procedure with SAS software. Several accessions including PI 290899, PI 315904, PI 255457, PI 224148, and PI291189 demonstrated higher levels of salinity tolerance than previously reported for bermudagrass.