中文摘要：

用溶液培养的方法研究了缺磷胁迫下不同种源马尾松和杉木苗木根系有机酸的分泌。结果表明：缺磷胁迫下杉木和马尾松苗木根系有机酸的分泌量显著增加，在P。，（KH2PO4，0 mmol／L）、P·（KH2PO4，0．03mmol／L）和P2（KH2PO4，0．09mmol／L）3种缺磷水平下，马尾松根系有机酸的平均分泌量分别比正常供磷P3（KH2PO4，0．5mmol／L）时提高328．6％、267．9％和126．4％，其中浙江马尾松根系分泌有机酸最多；浙江杉木根系有机酸分泌量分别比正常供磷时提高325．0％、150．0％和50．0％。缺磷胁迫下，不同种源的杉木和马尾松增加分泌有机酸的种类不同。浙江马尾松主要增加分泌草酸、酒石酸、柠檬酸和苹果酸，广西马尾松主要增加分泌草酸和酒石酸，贵州马尾松主要增加分泌酒石酸、草酸和苹果酸；杉木主要增加分泌草酸和酒石酸。

英文摘要：

Organic acids exudation from the roots of Chinese fir （Cunningharnia lanceolata ） and Masson pine （Pinus rnassoniana） seedlings under low phosphorus stress was studied with solution culture method. The results revealed that organic acids exudation from the roots of Chinese fir and Masson pine seedlings under low phosphorus stress increased. Compared with P3 （KH2PO4,0.5 mmol/L）, the average organic acids exudation from the root of Masson pine seedling under Po （KH2PO4,0 mmol/L）, P; （KH2PO4,0.03 mmol/L） and P2 （KH2PO4 ,0. 09 mmol/L）increased 328. 6%, 267.9% and 126.4% respectively. Masson pine from Zhejiang province had the highest organic acids exudation. Under the low phosphorus stress, the kinds of increased organic acids exudation from the different provinces of Chinese fir and Masson pine were different. Masson pine from Zhejiang province mainly increased oxalic acid, tartaric acid, citric acid and malic acid exudation, from Guangxi Province mainly increased oxalic acid and tartaric acid exudation, from the Guizhou Province mainly increased oxalic acid, tartaric acid and malic acid exudation. Chinese fir mainly increased oxalic acid and tartaric acid exudation.