Polyploid Induction And Biological Characteristics Research On Salvia Miltiorrhiza Bge.

Growing in Fangcheng County of Nanyang,Salvia miltiorrhiza Bge.is the famous genuine regional drug,whose quality is excellent and effect is significant.But it vegetatively propagated by root breeding for a long time,which resulted in species degeneration,stress-tolerance weakened,decline of yield and quality.In order to obtain polyploid strains whose growth is vigorous,resistance is strong,yield and quality is satisfactory,this experiment induced polyploidy of Salvia miltiorrhiza Bge..The results are as follows:1.Established the aseptic system.Taking the apical bud of Salvia miltiorrhiza Bge.growing in the field as explants,we got sterile plantlets by the method of 75% alcohol immersion combined with 0.1% mercuric chloride solution immersion.The number of sterile plantlets was the largest when the immersion time of mercuric chloride solution was 7 min.2.Established a rapid propagation system.Taking MS as the basic medium,we prepared the medium containing plant growth substances of different types and concentration,and then transferred stem fragment with bud to it.We found the best rapid propagation medium was MS+GA 0.5 mg/L+NAA 0.005 mg/ L+6-BA 0.04 mg/L according to the height,reproductive coefficient and growth status of test-tube plantlets.In this medium,propagation coefficient was 5.11 and propagation cycle was 30 d,thus theoretical propagation capacity per year was more than 310 million.3.Induction and identification of polyploid.Taking the stem fragment with bud of Salvia as explants,we induced polyploid by the method of adding colchicines to the medium.Four polyploid strains were obtained by identification and the treatment combination by colchicines of which induction ratio was the highest was the concentration of 200 mg/L for 12 days.Compared with the control,the mutated plants grew more vigorously;leaves were bigger and thicker;leaves' color was darker;stem was thicker.The number of stomata in the single visual field of abaxial surface of the mutated plants' leaves was reduced by 61.54%,and the stomatal length and width were increased by 116.2% and 63.8% respectively.The number of chromosomes of the mutated plants doubled(32,and the control was 16).The DNA content of the mutated plants doubled.4.The SOD and POD isozymes of different ploidy plants were compared.After separating isozyme by the method of PAGE and then dyeing,the results showed that POD isoenzyme of the polyploid had one more band than diploid,whose color was darker,and SOD isoenzyme of the polyploid also had one more band,which was brighter.5.The low temperature tolerance of different ploidy test-tube plantlets was compared.Under low temperature treatment,the activity of SOD,POD,CAT,APX,GR and the contents of free proline,soluble protein and chlorophyll in the leaves of polyploid test-tube plantlets were always higher than those of diploid,and MDA content was always lower,indicating that the low temperature tolerance of the polyploid was stronger.6.The field adaptability of different ploidy plants was compared.After growing in the field for a period of time,the plant height,crown width,maximum leaf length and width,stem diameter of polyploid plants were larger than those of diploid control,and leaf index was less than or close to control;The contents of soluble protein,soluble sugar,chlorophyll and the activity of SOD and POD of polyploid plants were higher than those of control;The dry weight yield per 667m2 of the two polyploid strains were increased by 15.48% and 18.72% respectively compared with corresponding control;The contents of soluble sugar,soluble protein and starch of polyploid plants' roots were higher than those of control;The content of tanshinone?A of the two polyploid strains' roots were increased by 162.85% and 87.41% respectively,and the content of salvianolic acid B were increased by 24.93% and 41.65% respectively compared with corresponding control.