Comparison On Salt Tolerance Of Different Lines Fraxinus Velutina Torr And RAPD Analysis Of Fraxinus Velutina Torr36After Space Mutation

Fraxinus velutina Torr is the most salt-resistance tree species in north China. Thestudy observed the growth condition and determined the various physiological andbiochemical indexes, analyse the growth conditions and physiological andbiochemical indexes of ten strains of Fraxinus velutina Torr under different salttolerance, make analysis and comparison about the salt tolerance of ten strains ofFraxinus velutina Torr., through the different concentrations of salt treatment to it.Furthermore, use the space mutation of Fraxinus velutina Torr36seedling asexperiment material, observe the growth conditions and determine the morphologicalindexes, analyse its genomic DNA used RAPD molecular marker technology, exploreand research the mutation of Fraxinus velutina Torr36genomic DNA after spaceradiation.It provides theory basis for the screening and breeding the salt tolerancestrain, Salt resistance research of Fraxinus velutina Torr and the improvement andutilization of saline and alkaline land.The main research results as follows:1. Observe the influence of different concentrations of salt stress on the ten strainsof the Fraxinus velutina Torr, determine the plant height, leaf relative water content,relative electric conductivity, chlorophyll content, enzyme activity and other indexesof ten strains of Fraxinus velutina Torr, and make analysis and comparison the salttolerance of ten strains of Fraxinus velutina Torr, take all indexes into consideration,reach the order of salt tolerance is R36＞R21＞R48＞R37-1＞R29＞R30＞R23＞R41＞R26＞R12. Determined the most suitable RAPD reaction system for Fraxinus velutina Torris: The10×PCR Buffer is2.5μL, the Mg2+（25mmol/L）is2.0μL, primers（20μmol/L）is2.0μL, dNTPs（2.5mmol/L）is1.8μL, the template DNA template（49.5μg/mL）is2.0μL, Taq DNA polymeras（e5U/μL）is0.3μL, other supplemented with the doubledistilled water. Determined the most suitable amplification program of RAPD-PCRfor Fraxinus velutina Torr is: Pre-denatured94℃for5minutes,44circulations(denatured94℃for30seconds, annealing at36℃for30seconds, extends72℃for2minutes),72℃extends for10minutes, hold at4℃. The PCR amplification productsdetected with the1.2%agarose gel electrophoresis.3. The genomic DNA of Fraxinus velutina Torr was extracted following the CTAB method, selected the12random primers which have good polymorphism andgood repeatability, clear and stable bands from the fifty（S150-S199）primers by usingthe optimized reaction system, and used these primers to analysis fifty-eight seedlingplants of the space mutation Fraxinus velutina Torr36strain for RAPD, the resultsshowed that twelve primers produced sixty-five bands in all, and fifty-eight bandswere polymorphism of them, the polymorphic rate is89.23%. According to the resultsof amplification RAPD, used UPGMA system clustering method to analyse, theresults showed that, when similarity coefficient was0.72，fifty-eight Fraxinusvelutina Torr could be classified into for two groups,1-5were clusterd for a group,6-58were clusterd for a group.