Screening cereals for genotypic variation in efficiency of phosphorus uptake and utilisation

One hundred and six Australian cereal genotypes, including wheat, triticale, and rye, were screened for their ability to take up and utilise soluble phosphorus at different rates of P supply. Plants were screened in outdoor tanks irrigated at regular intervals with nutrient solution amended with 3 rates of P. Genotypes were ranked according to the following 3 criteria: shoot growth at deficient P supply, the relative shoot growth rate (dry weight at deficient P/dry weight at sufficient P), and phosphorus utilisation efficiency (amount of dry matter produced per unit of P accumulated in shoots corrected for seed P content). Considerable genotypic variation in growth and P utilisation efficiency was found in the cereal germplasm. Rye and triticale were generally more efficient in taking up and utilising P than wheat at low rates of P supply. Wheat genotypes Egret and Durati showed relatively high, and genotype Cadoux relatively low, P efficiency.