2014 ASHS Annual Conference

Camellia oleifera Abel (oiltea) is an important woody plant for its edible oil production and has been utilized in South China for more than 2300 years. In these regions, the typical soil is red clay and soil P mainly presents in a form of aluminium-bound phosphate (Al-P) and whether or not the Al-P is uptaken by oiltea is unknown. Our study had found that phosphorus deficiency significantly induced the secretion of oxalic, formic, malic and citric acids from roots. Root exudates enhanced the mobilization of plant-unavailable phosphorus in red clay and Al-P. Simulation test of phosphorus activation showed that all induced organic acids could release phosphorus from Al-P effectively and citric acid was the highest. Applications of Al-P increased the available phosphorus in rhizosphere soil significantly as Ca-P did. The seedling height, diameter at ground level, and edible oil yield increased and root/shoot ratio decreased significantly by Ca-P and Al-P treatments.Ca-P and Al-P applications increased Fv/Fm, Fv’/Fm’, yield and qP.These results indicated that Al-P could be effectively utilized by oiltea plants and should be the source of available plant P under regular acidic red clay.