Abstract: To probe into the morphological and physiological responses of Cucurbita ficifolia B.in response to phosphorus deficiency,the biomass,root morphological characters,P absorption characters and root exudates were determined by using nutrient solution approach in greenhouse.Based on the studies,we expected to lay some theoretical foundations for the improvements of P efficiency and provide materials for such studies.The results showed that on the 21st days after phosphorus deficiency,the shoot biomass of C.ficifolia was significant decreased,root/shoot ratio,root lengths and root surface areas increased,no significant differences were found in root biomass,root tips,root average diameter and root volume between phosphorus deficiency and normal phosphorus status.P uptake rate and P reallocation rate decreased,root P uptake/plant P uptake ratio and P utilization rate increased.The results demonstrated that root lengths and root surface areas increased might be responsible for the efficient P acquisition in C.ficifolia in the phosphorus deficiency environment.On the 21st days after phosphorus deficiency,root exudates of C.ficifolia contained similar chemical compounds as those of normal phosphorus status,which were mainly phenol,aromatic,ester,amine,olefin and alkanes.The components of root exudates of C.ficifolia under phosphorus deficiencywere more than that in normal phosphorus status.The autotoxicosis of C.ficifolia was enhanced in phosphorus deficiency.

Key words: Phosphorus deficiency, Cucurbita ficifolia, Root growth, Root exudates

CLC Number: 

• S642.1