[Effects of phosphorus stress on the growth and nitrogen and phosphorus absorption of different Formosan sweet gum provenances].

Aiming at the ecological value of Formosan sweet gum (Liquidambar formosana) as a pioneer species and the status of red soil phosphorus (P) deficiency, a sand culture experiment of split design was conducted to study the responses of three-leaf stage seedlings of seven Formosan sweet gum provenances from Yixing of Jiangsu, Jingxian of Anhui, Yongkang of Zhejiang, Nanchang of Jiangxi, Shaowu of Fujian, Yanping of Fujian, and Nandan of Guangxi to four levels of P (P0, P1/2, P1, P2). With increasing P stress, the biomass and the N and P absorption of test provenances decreased, whereas the utilization efficiency increased. In higher P treatments, the provenances from Nanchang and Yixing had higher biomass and higher N and P absorption but lower utilization efficiency, while the provenance from Nandan had lower N and P absorption but higher utilization efficiency. In lower P treatments, the biomass and the P absorption and utilization efficiency of the provenances from Nanchang and Nandan were all higher. All the results illustrated that the provenances with high biomass had high P absorption at high P level, and had both high P absorption and high utilization efficiency at low P level. The provenance from Nanchang could be considered to be an excellent P stress-resistant provenance, followed by that from Nandan. Phosphorus was not a limiting nutritional factor of Formosan sweet gum, biomass, leaf delta (N/P) ratio and P efficiency could be used as the indicators of P stress-tolerance of Formosan sweet gum provenances.