关键词: 丛枝菌根真菌, 西瓜, 嫁接, 防御性酶, 连作

Abstract: A factorial combination pot experiment was designed to study the growth response and foraging behavior of three South China forestation species Pinus massoniana, Schima superba and Liriodendron chinense under heterogenous nutrient envionment and different light conditions. The results demonstrated that under full light, the plant height and biomass of P. massoniana and S. superba were enhanced in heterogenous nutrient environment, with the root biomass increased by 99.5% and 66.7%, respectively, compared with that in homogenous environment; while L. chinense exhibited singnificant growth benefits in homogenous environment. The root scale, foraging precision, and nutrient uptake of S. superba reduced markedly under shading, which in turn decreased the growth benefits in heterogenous nutrient environment. The influence of shading was weaker on P. massoniana than on S. superba, still with some growth benefits for P. massoniana due to its root proliferation and enhanced nutrient uptake in nutrient rich patch. There was a slight influence of shading on the foraging precision and sensitivity of L. chinense root, with no growth response pattern change to heterogenous nutient environment occurred. It was concluded that three tree species not only differed in the inheritance of root foraging mechanism and behavior, but also varied in the response pattern to light condition. Therefore, different measures should be adopted in forestation with the three tree species to enhance the forest productivity.

Key words: arbuscular mycorrhizal fungus, watermelon, graft, defensive enzyme, continuous cropping.