Photosynthetic Physiological Response To Allelochemicals Of Phyllostachys Edulis In Seedlings Of Castanopsis Sclerophylla And Camelia Oleifera.

Phyllostachys edulis is a popular and useful plant that is not only for traditional shoot and culmharvesting but also an important biomass resource in southern China. Recently, this local species hasbeen shown to be a problematic tree with robust growth and strong rhizomes, capable of dominatingsome forest stands, devouring the forest plants, and threatening the biological diversity. However, littleinformation about the influences on regeneration of the main tree species in neighbor forests invaded byPh.edulis has been known. In order to explore the potential allelopathy in the invasion process ofPh.edulis, the effects of aqueous extracts from Ph.edulis on the seedlings growth of Castanopsissclerophylla （Lindl） Schott and Camellia oleifrea Abel. were assessed by pot experiment. The extractconcentration gradients were0.1g·mL^-1,0.05g·mL^-1, and0.02g·mL^-1, respectively. The chlorophyllrelative content, chlorophyll fluorescence and photosynthetic physiology of C.sclerophylla andC.oleifrea seedlings were measured under stem and leaf extracts, litter extracts, and soil extractstreatments. The conclusions of the study are as follow:1. Effects of the aqueous extracts of Ph.edulis on photosynthetic physiology of the seedlings of C.sclerophylla and C.oleifrea.Net photosynthesis rate and stomatal conductance of acceptor plant were inhibited at higherconcentration and enhanced at lower concentration of aqueous extracts of Ph.edulis. Allelomicals ofPh.edulis also had a certain effects on photosynthetic parameters.2. Effects of the aqueous extracts of Ph.edulis on chlorophyll relative content of the seedlings of C.sclerophylla and C.oleifrea.Effects of the aqueous extracts of Ph.edulis on chlorophyll relative content of acceptor plant wereinhibited at high concentration (0.1g·mL^-1), while increased at lower concentration (0.02g·mL^-1) andthe effects were differ at0.05g·mL^-1concentration.3. Effects of the aqueous extracts of Ph.edulis on chlorophyll fluorescence of the seedlings of C.sclerophylla and C.oleifrea.The effects of aqueous extracts of Ph.edulis on chlorophyll fluorescence of acceptor plant aredifferent. The litter aqueous extracts had a slight inhibitory on the chlorophyll fluorescence of theseedlings of C.sclerophylla and C.oleifrea. Under the lower concentration of stem and leaf extracts, the Fv/Fmof C.sclerophylla seedlings was notably lower than that under the higher concentration, while theFv/Fmand Fv/F0of C.oleifrea seedlings showed inhibitory effects under lower concentration of stem andleaf extracts. Under the effects of lower concentration of soil aqueous extracts, the Fv/Fmand Fv/F0ofC.oleifrea reduced.It shows that the aqueous extracts of Ph.edulis have significant effects on chlorophyll relativecontent, chlorophyll fluorescence and photosynthetic physiology of the seedlings of C.sclerophylla andC.oleifrea. The result is of great theoretical significance to explain the mechanism of Ph.edulis invadingto the surrounding stand. Moreover, it is valuable to direct the management of Ph.edulis stand.