Abstract:

A provenance-by-phosphorus-interaction trial of Pinus massoniana at age 5 was conducted to study genetic response of different provenances to phosphorus supply and their nutrient characteristics of rhizosphere soil under phosphorus stress.Significant phosphorus effect was found for both provenances of Cenxi GX and Gaozhou GD regarded as sensitive provenances to phosphorus supply,while Xinyi GD provenance and Wuping FJ provenance had higher tolerability to phosphorus stress or less sensitivity to phosphorus supply.For Chongyi JX provenance,the response to phosphorus was found to be marked only at age 2 or 3.There existed great differences in chemical characteristics of rhizosphere soil among 5 provenances. Percentages of organic matter,total N,hydrolytic N,and available P in rhizosphere soil were usually much higher than those in non-rhizosphere soil.Result indicated that P.massoniana roots of different provenances had an effect of soil phosphorus activation and available phosphorus enrichment,especially both provenances of Xinyi GD and Wuping FJ,which could preliminarily explain their genetic mechanism of adaptation to phosphorus stress.Marked acidification was not observed in their rhizosphere soil for provenances tested.

Key words: Pinus massoniana, Provenance, Phosphorus supply, Genetic response, Rhizophere, Phosphorus activation and enrichment