Screening for waterlogging tolerance in strawberry clover and other perennial legumes

Soil waterlogging and salinity have negative impacts on the growth and productivity of perennial pasture systems. Commonly used perennial legume species such as white clover (Trifolium repens) and lucerne (Medicago sativa) are relatively salt and waterlogging sensitive, thus not suitable for areas prone to these conditions. Alternative species such as strawberry clover (Trifolium fragiferum) which are known to have high tolerance to waterlogging and salinity can be used to maintain productivity and persistence of legumes within affected pastures. Palestine is the major commercial strawberry clover cultivar currently used in Tasmania. Some Tasmanian breeding lines showed great potential of being commercialised. The aim of this experiment was to compare the waterlogging tolerance of these breeding lines with Palestine as well as Talish clover (Trifolium tumens), white clover (Trifolium repens), red clover (Trifolium pratense), Caucasian clover (Trifolium ambiguum) and a sensitive barley (Hordeum vulgare) variety. The experiment was conducted outside and the duration of the experiment from germination to harvest was 75 days with the waterlogging treatment imposed at day 54. The level of tolerance was assessed by observing the chlorophyll content, chlorophyll fluorescence and wet/dry weights of plants weekly. Three of the Tasmanian Institute of Agricultures advanced selections were observed to have the potential to have a higher tolerance to waterlogging than cv. Palestine.