VESICULAR‐ARBUSCULAR INFECTION AND SOIL PHOSPHORUS UTILIZATION IN <i>LUPINUS</i> SPP.

Abstract

SUMMARY Lupinus angustifolius, L. cosentinii and L. luteus were weakly infected (&lt;10% of root length) with vesicular‐arbuscular endophytes and hence VA mycorrhizas were not considered of any value in their phosphorus uptake on the nutritionally poor sandy soils of Western Australia. Vesicles were present in approximately 30% of field plants and less often in the glasshouse. Arbuscules were observed on only one specimen of L. cosentinii in a restricted section of one lateral root. Infection was reduced further when soil moisture was high and by small additions of phosphorus to the soil. Under certain conditions, VA mycorrhizal infection in L. cosentinii was stimulated by the growth of red clover. ‘Proteoid’ ‐like rootlets were observed on lupins and these had specialized root‐soil surface properties that may be responsible for improved phosphorus uptake.