ECO-TURF: WATER USE EFFICIENT TURFGRASSES FROM AUSTRALIAN BIODIVERSITY

Water use in both urban and rural communities has become an enormous environmental and social issue, and over 30% of domestic water consumption is applied outdoors. To use Australia's unique biodiversity to select turfgrasses that maintain quality with reduced inputs of water and nutrients, we have collected about 500 indigenous couch grass genotypes and have begun to characterise them using physiological and genomics tools. Here we report on experiments that aim to develop the methodologies for screening a large number of genotypes for water use efficiency. Eight Cynodon grasses were grown in 40-cm-long PVC tubes with two soil types, two cutting heights, and four replications. The plants were grown at field capacity for several weeks prior to applying a terminal water stress. A survival period was estimated based on the time from the last watering to the time that all green leaf was lost. Large genotypic differences in survival period of up to 14 days were observed. Two genotypes, '81-1' and 'CT2', outperformed the other genotypes for survival period, possibly due to lower rates of evapotranspiration either through lower stomatal conductance and/or lower leaf area.