Wednesday, August 1, 2012
Grand Ballroom
Salinity and waterlogging are two major abiotic stresses commonly associated with irrigated soils. In this study, four low-inputs turfgrass species (tall fescue, Kentucky bluegrass, blue grama, and buffalograss) were germinated under well-drained (control), waterlogged (i.e. flooded), saline (NaCl 5 g·L-1), or saline-waterlogged conditions in the greenhouse. Flooding with tap water did not inhibit seed germination or seedling growth although a low salt accumulation in the soil (soil salinity = 2.5 dS/m) was observed. Seedling number (SN), shoot fresh weight (SFW), root fresh weight (RFW), and the longest root length (LRL) were significantly decreased under saline and saline-waterlogged conditions with reductions ranging from 20.3% of the control in LRL to 70.0% of the control in RFW. Higher reductions in germination and seedling growth were observed in the salinity treatment, compared to the combined stresses, although soil salinity levels were similar between these two treatments (soil salinity = 29.9 dS/m in the salinity treatment and 31.9 dS/m in the combined saline-water-logged treatment). Tall fescue was the most tolerant of saline and waterlogging stresses, followed by blue grama and Kentucky bluegrass; buffalograss showed the lowest tolerance.