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.