Use of triple-labelled nutrient solution to study the effects of root-infecting fungi on uptake of potassium, calcium and phosphorus by wheat

Triple-labelled nutrient solution was used to compare the effects of seven root-infecting fungi on uptake of K, Ca and P by wheat. Plants grown in sand or hydroponic culture were transferred to solutions that contained42K,45Ca and32P for 24 h, then dried, ashed and digested in 6M HCl. To distinguish radiation emitted by42K,45Ca and32P plant digests were counted on two channels of a liquid scintillation counter immediately and 7 days later, after the decay of42K radiation. Plants infected byGaeumannomyces graminis took up and translocated less K, Ca and P to their shoots than uninfected plants. Other root-infecting fungi had little effect on uptake of these ions.