Study On Tetraploid Induction And Character Analysis Of Chilopsis Linearis Based On Rapid Propagation Technology

Chilopsis linearis belongs to Bignoniaceae as deciduous shrub.It is the masculine sun species produced originally in North America.It has many characteristics such as growing quickly,artistic, drought- resistant,thermostable and so on.It can adapt to different types soil circumstance,and can resist the wind-drift sand and seasonal flood silting alluviation.It has good ability to salty resistant, and grow well in the soil with pH 8.32 and 0.2%salt content.It is the ideal botanical garden afforestation tree and bonsai flower.The desert willow can resist bacteria and refrigerate,with chemical substance tecomin(Lapachol) that the derivativeβ-1apachol may intervene the HIV-1 virus'duplication as to postpone AIDS advancement.C.linearis was fistly introduced from the US by the research institute of Gansu Province in 2000.There were few reports in our country,just as introduction domestication,cultivation breeding and drought-resistant aspects.The overseas researches mainly concentrated in physiology,ecology,pharmacology and dissection characteristic.We used the C.linearis seeds as experiment material to tissue culture and polyploid induction. Firstly,established rapid propagation system,that might provide precious experimental materials to protect or improve and provide theory support for its factorization production.Secondary,used colchicine to induce tetraploid,and tried to find out the most suitable induction condition and obtain the tetraploid.This could establish the foundation for good variety selection especially which had better ornamental ability or stonger resistant ability.The main results were as follows:(1) The proper method to seeds sterilization was:clear water soaked for 30 min,0.5%HCl soaked fro 20 min,75%alcohol soaked for 20 s,sterilized water cleaned 2 times,then used 0.1% mercuric chloride(to add 1-2 drop of Twain-80) to soak 6 min,sterilized water cleans 4 times,at last turned on the MS culture medium,and the germination rate was 86.7%.The proper method to cotyledon and stem was:detergent soaked for 10 min,running water flushed 30 min,75%alcohol soaked for 20 s,0.1%mercuric chloride processed 6 min..Used stem as esplants were better than cotyledon.The appropriate medium for stem explant was MS+6-BA2.0 mg/L,that the bud coefficient was 4.7 and the ratio was 100%.The most suitable differentiation medium was MS+6-BA0.5 mg/L+IBA0.02 mg/L,and the proliferation rate was 7.5.The highest differentiation medium was MS+6-BA1.0 mg/L+IBA0.02 mg/L,and the proliferation rate could reach 9.0.The best rooting medium was 1/2MS+IBA0.2 mg/L+2%sugar,and the rooting rate was 96.7%.(2) We used two methods to induce tetraploid of C.linearis by colchicines base on tissue culture.The way of immersion law had more effectively inducing rate and higher homozygous tetraploid inducing rate than the way of mixed culture method.The most effectively induced of immersion law was in 0.2%colchicine solution for 43 h,which had 46.7%mutagenesis rate and 40%homozygous tetraploid.(3) We contrasted the exterior shape characteristic,blowhole density,guard-cell size and chlorophyll content in tetraploid and diploid of C.linearis.The results indicated that:The leaves of tetraploid plants were longer,wider,thicker,deepener color,and smaller foliate index than diploid plants.The leaves length,width,thickness,foliate index of tetraploid were 121.6%,145%,189.7% and 76.6%to diploid respectively.The tetraploid has larger guard-cell,more chloroplast number and higher blowhole density than the diploid.The guard-cell length,width,chloroplast number among and blowhole density of tetraploid were 167%,158%,185%,60%to diploid respectively.The leaf chlorophyl content of tetraploid increased than diploid.So,leaf length,the width,thickness, blowhole density,guard-cell size and chloroplast number among guard-cell,leaf blade chlorophyl content could be taken to identify the tetraploid and the diploid of C.linearis.(4) The resistance was contrasted between tetraploid and dipoid of C.linearis.The results were as follows.The electrolyte exosmosis rate of tetraploid was lower than diploid under the same temperature.It indicated that the cold resistant ability of the tetraploid was better than diploid.The tetraploid leaves preserve water ability was 169%to the diploid.The cell damage rate was 34.67%to diploid by using the Sullivan law.Two methods simultaneously indicated the tetraploid drought resistance enhancement.The tetraploid'diosmosis rate was 79.2%to the diploid by the hot stable survey of Cell membrane.(5) Analysis was conducted on diploid and auto-tetraploid of C.linearis by using AFLP molecular marker.20 pairs primer have amlificated 1058 bands.Polymorphism position loci were 59 and the rate was 5.57%.Compared with the diploid,the auto-tetraploid had special fragment added and lost.It was showed that the tetraploid genome occurred certain adjustment.