Effects Of Continuous Cropping On Leaf Photosynthetic Characteristics And Quality Of Salvia Miltiorrhiza Bunge.

Objective:The effect of continuous cropping on photosynthesis and medicinal material quality were explored in order to provide the references for high yield and good quality for danshen medicinal material.Methods: Salvia miltiorrhiza Bunge.were used as trial material and rhizosphere soil(CK,one years,two years,three years,five years)in differnent growth years have a pot experiment and the index of photosyntetic like Pn and Tr were detected by LI-6400,the biomass of morphological characteristics like seeding height ? root length ? fresh weigh of root were detected in the different growth periods(growing period,full-blossomperiod and harvest time)of danshen.The content of Active substance like phenolic acid B and tanshinone ?A were detected by HPLC.Results:(1)Continuous cropping of danshen caused a significant inhibition on the morphology parameters and biomass.Compared to CK Danshen,seeding height were biggest decreased 35.88%(P<0.05),crown breadth were biggest decreased46.27%(P<0.05),the root diamter were biggest decreased 36.66%(P<0.05),root length were biggest decreased 37.25%(P<0.05),fresh weigh of root were biggest decreased 53.75%(P<0.05).(2)With the increase of the growth years,daily variation trend of photosynthetic parameters like Pn ? Cond ? Tr ? Ci and WUE bring into line,but compared to CK Danshen,they were reduced at a different level.At the same time,chlorophyll content gradually decreased obviously,there are significant differences between different continuous cropping years(P<0.05).(3)With the increase of the growth years,the contents of lithospermic acid,cryptotanshinone,tanshinone?and tanshinone ?A gradually decreased and have a significant different(P<0.05).The contents of Salvianolic acid B is increased until the content of2 years Danshen present the highest.Then with the increase of the growth years,The content of salvianolic acid B is gradually decreased(P<0.05).Conciusion: With the increase of the growth years,the index of photosynthesis?biomass and the content of active substance were significantly decreased.In order to achieve the purpose of the production of the medicinal materials and quality,it is competent to adopt reasonable cultivation system and to avoid the continuous cropping and continuous cropping,...