Sreening And SSR Analysis Of Drought-resistant Mutants Of Wheat Radiated By⁶⁰Co-γ

M3and M4progenies of wheat GUO9722and Heke2irradiated by⁶⁰C o-γ ray were used for the material.The drought resistance variation was analyzed. The experimentions of germination and seedling growth of lines were carried out by drought stress in PEG-6000solution，the traits of germination，seedling growth and physiology were tested.The germination potentiality，germination rate，ge rmination index，p lant height，leaf number， root number，main root length，root dry weight，shoot dry weight,root/shoot ratio，root moisture content，shoot moisture content，proline content，soluble sugar content and chlorophyll content were tested. The complex drought resistance coefficient was used to identify drought resistance of mutant，SSR identification were also analyzed. The result showed as follows：1. GUO9722and Heke2generation group differences of each index have reached0.05significant level or0.01significant level. In M3generation of GUO9722，germination potential，g ermination rate，g ermination index，se edling height，le af number，ro ot number， root dry weight，shoot dry weight，root/shoot ratio，root moisture content，shoot moisture content，chlorophyll content were less than parents，another traits were higher than parent In M4generation，g ermination potential，g ermination rate，g ermination index，le af number， root number，root dry weight，shoot dry weight，ro ot/shoot ratio，ro ot moisture content， shoot moisture content，chlorophyll content group were less than parent and seedling height，another traits were higher than parent. In M3generation of Heke2，germination potential，germination index，leaf number，root dry weight，root moisture content is less than parent and germination rate，another traits were higher than parent In M4group， germination potential，germination index，root number，leaf number，root dry weight， root/shoot ratio，root moisture content，chlorophyll content group is less than parent and another traits were higher than parent. For GUO9722，the coefficient of variation of physiological indexes were high，m orphological index is low For Heke2，the coefficient of variation of germination index were high，morphological index were low.2. Correlation analysis of drought resistant coefficient for two generations showed that GUO9722，th e main root length，sh oot dry weight，root moisture water have positive correlation，seedling height，root dry weight，root/shoot ratio，soluble sugar content， chlorophyll content and total drought resistant coefficient behaved very significant positive correlation. Heke2showed that seedling height，shoot moisture content of shoot dry weight behaved positive correlation level，b ut the root number，ro ot moisture content，the content of soluble sugar and chlorophyll content and total drought resistant coefficient behaved significant positive correlation.3. The complex drought resistance coefficient was used to identify the drought resistance of these lines，according to the mean±2×standard deviation of complex drought resistance coefficient，In M3genertion of GUO9722，positive variation occurred in9lines，the positive mutation rates for3.96%，In M4genertion，positive variation occurred in14lines the positive mutation rates for6.16%.In M3genertion of Heke2，positive variation occurred in9lines，the positive mutation rates for4.64%，In M4genertion， positive variation occurred in10lines，the positive mutation rates for5.15%.Depended on comprehensive performance between two generations，7drought resistance mutants was selected in M4of GUO9722group，5drought resistance mutants was selected in M4of Heke2group.4. For GUO9722，Cluster analysis showed that the group of M3can be divided into6groups when genetic distance was1.59，th e group of M4can be divided into6groups when genetic distance was1.96ï¼›F or Heke2，C luster analysis showed that the group of M3can be divided into6groups when genetic distance was3.45，the group of M4can be divided into6groups when genetic distance was2.54.5. According to SSR identification indicated，th ere were7and8lines of Guo9722and Heke2whose genetic locus mutated. In M4progenies of Guo9722，mutation occurred in genome2A、3A、3B、3D、7D. There were8SSR locus which mutated （26.7%） in genome A，7SSR locus which mutated （23.3%） in genome B，15SSR locus which mutated （50%） in genome D. In M4progenies of Heke2，mutation occurred in genome2A、3B、3D、5D、7D. There were1SSR locus which mutated （5.6%） in genome A，6SSR locus which mutated （33.3%） in genome B，11SSR locus which mutated （61.1%） in genome D.