Genotypic variation in the morphological and physiological response to boron toxicity in barley (Hordeum vulgare L.) and weed species / Eun-Young Choi.

"June 2004."Bibliography: leaves 135-159.xi, 159 leaves : ill. ; 30 cm.Studies the mechanism underlying the morphological responses of boron- tolerance in plants by observing root and shoot responses to varied levels of subsoil boron in 2 barley varieties and 3 weed species common to agricultural areas of South Australia. Hypothesises that 4 mechanisms of boron-tolerance exist: 1. a physical barrier at xylem loading that also, 2., may include an efflux system; 3. enhanced sugar levels in shoot and root and 4, maintaining or increasing root biomass in the upper soil depths where the concentrations of boron are not toxic.Thesis (Ph.D.)--University of Adelaide, School of Earth and Environmental Sciences, Discipline of Soil and Land Systems, 200