Studies On Characteristics Of Seed Germination And Seedling Growth Dynamics Of Bupleurum Smithii Var. Parvifolium

Bupleurum smithii var.parvifolium was perennial herbaceous plant of Umbelliferae with dry root medicine,it is wild at present.With the cognition of medicinal value of Bupleurum smithii var.parvifolium deepened constantly,its market requirement was escalation.However,the wild resources decreased year after year because of excessive excavation of Bupleurum smithii var.parvifolium.Therefore,the domestication and cultivation of Bupleurum smithii var.parvifolium was urgent.In the long-term cultivation process,the germination rate of Bupleurum seed was low,the germination time was long,and the germination was out of order.The studies on seed breeding technique,growth and development law of seedling of Bupleurum smithii var.parvifolium had great significance to its introduction,domestication and cultivation.The characteristics of seed germination and the growth and development dynamics state of seedling of Bupleurum smithii var.parvifolium was studied,the main results were as follows:1.Bupleurum smithii var.parvifolium was distributed in elevation 2700³500 m Gannan forests,Minshan mountains,Taizi mountains（Hezheng,Zhuoni,Lintan,Hezuo,Xiahe）and Hexi region（Wuwei and Zhangye）and Xinglong Mountain in Lanzhou.The population type is alpine meadow,grassland,alpine scrub and forest edge zone,the main slope was sunny slope and half-sunny slope.2.The preference temperature of seed germination for Bupleurum smithii var.parvifolium was 20℃,the optimum germination medium was sand;KMnO₄、GA₃、NAA and IAA could promote seed germination in different extent,the optimal concentration of KMnO₄、GA₃、NAA and IAA was 0.4%,50 mg/L,20 mg/L and 30 mg/L,respectively.The method of soaking seeds in warm water also could markedly promote seed germination,the seed should be soaked at constant temperature of 40℃for 4 h or at varying temperature 20℃for 2 h and 40℃for 2 h.3.In the stage of seedling development,compared with Bupleurum scorzoneri folium Willd.,whether the morphological index of Bupleurum smithii var.parvifolium such as plant height,root diameter,root length and leaf number or the biomass index of Bupleurum smithii var.parvifolium such as root fresh weight and stem-leaf fresh weight was lower.This phenomenon was caused by the genetic factor rather than environmental factor.4.In the same environment condition,the comparison of physiological index indicated that the SOD,POD,CAT and APX activity of Bupleurum smithii var.parvifolium was lower than Bupleurum scorzoneri folium Willd.,the MDA content of Bupleurum smithii var.parvifolium was higher than Bupleurum scorzoneri folium Willd.,it indicated that the resistance of Bupleurum smithii var.parvifolium was weak relatively,Bupleurum scorzoneri folium Willd.had stronger adaptation after artificial domestication in the same cultivation condition.