Protection Strategies For Minimal Population And Wild Plants Loropetalum Subcordatum

As a minimal-wild population plant,Loropetalum subcordatum is national secondary protection specie and endemic relic specie of China.It is special and important for the study of the system evolution of Hamamelidoideae Subfamily.In addition,because of the graceful shapes and long florescence,L.subcordatuma is an excellent indigenous garden plant.However,there are only four natural populations survived,which have degenerated seriously.So,it is urgent to take protective measures.This study chooses conservation of endangered plants as breakthrough point and carries out research on seedlings cultivation and population rejuvenation by the way of tissue culture and rapid propagation,fertilization and cultivation,Inoculating AMF to improve drought resistance,Ex-situ habitation adaptability of different populations,monitor for Ex situ conservation and reintroduction.The purpose is to lay a practice foundation of population protection for L.subcordatum.There are five main results of this study:1.The research of tissue culture showed that,using 0.1%HgCl₂ to sterilize for 10minutes was the best treatment.The best enrichment medium was 1/4 MS+6-BA 2.0mg·L^-1+KT 2.0mg·L^-1+IBA 0.2mg·L^-1+AC 0.3 g·L^-1,the best rooting medium was WPM+IBA 1.0 mg·L^-1,the best transplant medium was humus soil.By this way we could get a large number of seedlings in a short time and it provide the basis to protect L.subcordatum.2.The research of fertilization experiment showed that,L.subcordatum had high requirement of fertilizer ratio,and the range of optimum fertilization ratio was narrow.The better fertilization treatment could significantly increase the seedling height,crown width,ground diameter,leaf area,root growth and biomass of the four herbs.The analysis used fuzzy mathematical membership function shows that:the best threatment was phosphate fertilizer 3.33g/pot in the first time,and nitrogenous fertilizer 0.13g/pot,potash fertilizer0.03g/pot or nitrogenous fertilizer 0.13g/pot,potash fertilizer 0.07g/pot every month,nitrogen fertilizer and potassium fertilizer were dissolved in 50mL water to spray 1 pot plant.3.Fertilizating and inoculating AMF had a significant promoting effect on the root length,average of root diameter,ERT,F_v/F_m,F_v/F_o,Soluble protein content,chlorophyll content,plant nutrient content and so on,by these to improve drought resistance.Fertilization was better for growth to provide normal water,however,it was better to inoculate AMF for enhancing the drought resistance during drought stress.The best treatment was SJ.4.The research of anatomic structure showed that,the suitable environment of four populations was different.The habitats of GX and ZS were more cloudy with curved periocular wall on leaf epidermis,larger stomata epidermis.GZ were more sunny with polygonal or curved perimeter wall in upper epidermis,smaller vents in lower epidermis.Adaptability of light of XG maybe between them.GX and GZ were more drought tolerant because of the thicker skin stratum corneum and leaves,howerver,ZS and XG not.Loropetalum subcordatum with low plasticity and low ecological adaptability,it maybe the one of main reasons for narrow distribution.Photosynthetic characteristics results showed that,photosynthetic rate of ZS was the highest,GZ was the lowest,population of GZ,GX,XG were all inappropriate,Their photosynthetic parameters are low.5.Monitoring results of Ex situ protection?Zhongshan arboretum?and regressive introduction?Wu Guishan?showed that,the seedlings height,ground diameter and crown growth characteristics and chlorophyll content of L.subcordatum near the water and under shade were significant higher than which far away from water and not under shade.The adaptability of reintroduction was better than Ex situ protection,it was easier to adapt to water and light environment.This research came up with a complete strategy of tissue culture and rapid propagation technology,high efficiency fertilization management technology,formula for improving drought resistance,adaptability of different populations,adaptive characteristics of regression introduction and ex situ conservation for protection of L.subcordatum.