Effects of Rhododendron agastum Litter on Its Seed Germination

In order to ascertain the allelopathy and allelochemicals in litter of R. agastum,the allelopathic effects of litter aqueous extract on the seed germination,seedling growth and physiological indexes of R. agastum were studied by the way of indoor petri dish bioassay,by which produced a different treatment gradient. The results indicated that the allelopathic effects on seed germination and seedling growth varied with aqueous concentrations. The lowest aqueous at the concentration of 1 mg/m L promoted the seed germination,shoot and root elongation,which were increased 2. 67%,17. 71%,8. 64%. The highest aqueous at the concentration of 50 mg/m L led to the strong allelopathic effects,the germination rate,shoot and root length were decreased by 77. 88%,65. 82% and 78. 37%. In addition,at the concentration of 1 mg/m L,root activities and chlorophyll of seedling were increased,with the ascension of queous concentrations both the root activities and chlorophyll of seedling were reduced,these phenomena could be considered as a physiological reason for growth retards.