Study On Polyploid Induction And Physiologic Characteristics Of Salt Resistance Of Miscanthus Sinensis (Poaceae)

Miscanthus sinensis is a species of Miscanthus Andress,which is a new kind of lignocellulosic biomass for the production of biofuels. They have high biomass productivity, strong adversity resistance, high cellulose content, burning suffciently and relatively low ash content, etc.In order to improve the biomass production and resistance of Miscanthus sinensis,the polyploid induction have been researched. The results showed as follows:1.The range of phytohormone concentration has been determined.Seed as explant to induce embryonic callus in different schemes. Through the experiment on three kinds of seeds material, analysed the test data, deduced appropriate concentration of phytohormone in the range of2,4-D4.021～4.339mg/L,6-BA0.846～1.032mg/L, KT0.281～0.311mg/L.2. Find out the best polyploid induction treatment combinations of experiment.Using three different mutagens in different combinations to induce polyploid. Checking DNA content of selected plants by flow cytometry instrument to detect the DNA content of suspected tetraploid plant’s leaf is approximately twice of the contrast.Through chromosome technique to identifice chromosome is2n=4x=76. Analysing callus survival rate, rate of callus differentiation, the number of plants, the results showed that the best method for polyploidy induction was soaking callus in1.02mmol/L. Oryzalin for about15minute at5℃and Ca2+concentration of1.02mmol/L in a high number of tetraploid plants (35.19%). Miscanthus sinensis mutagenized by nocodazole density of5μM with Ca2+concentration1.02mM for20minute at15℃, the induction ratio were26.92%. Colchicum density of4.96mM with Ca2+concentration2.99mM for20minute at5℃are more easily to be mutagenize, the induction ratio were28.57%.3. Comparison the botany traits related to production of diploid to tetraploid Miscanthus sinensis, it is concluded that the tetraploids have production advantage than the diploids. Comparing stomatal guard cells of tetraploid and diploid, found that stomatal density and stomatal guard cell diameter of tetraploids has significant differences between the diploids’. Designed0%,0.3%,0%,0.3%,1.2%,1.5%six different gradients of soil salinity levels and measurant after1week,tested cell membrane permeability, chlorophyll content, MDA content, SOD activity of leaves, it is concluded that tetraploid have more salt tolerance ability than diploid plants.