Physiological Index Determination Of Sorghum Head Smut Group And Molecular Markers Analysis Of Disease Resistance Genes

Sorghum,belonging to gramineous crops,is the fifth largest food crop in the world.Besides resistance to drought and temperature,sorghum has many other characteristics.Theexistence and occurrence of Head Smut has a serious impact on the quality and yield ofsorghum.The present study analyzed the related physiological indexes of the Head Smutresistance and susceptibility,and identified RAPD and SSR molecular markers linked tosorghum resistance gene to Head Smut.Combining the results of physiological indexesdetermination and the filter results of molecular markers to lay the theoretical foundation forbreeding the resistant plants and find a quick and easy way for identifying the resistantvarieties.1. This experiment determined the change of the activity of SOD,POD,CAT and thecontent of MDA in four growth periods of sorghum Head Smut resistance and susceptibility.The results showed that SOD,POD and CAT of Head Smut resistance were higher than HeadSmut susceptibility in four growth periods,which illustrated the Head Smut resistance hasstronger resistance.The activity of SOD was highest in heading stage,which can showed theability of SOD to scavenge effects on superoxide ions in this stage was the highest.Theactivity of POD and CAT in heading and jointing stage were higher than seedling and maturestage,which showed that the ability of sorghum to scavenge H2O2was stronger.The contentof MDA was higher in seedling stage,indicating that the plant were damaged least in thisstage,the extent of membrane lipid peroxidation was weak.2.70pairs of SSR primers were selected to analyse the sorghum Head Smutdisease-resistant restorer lines and susceptible-resistant restorer lines dwarf four, Head Smutresistance and susceptibility.Although the amplification results in the detection of agarose gelelectrophoresis appeared the band, but in the detection of subsequent non-denaturingpolyacrylamide gel electrophoresis were found no polymorphic bands,so the experimentdidn’t found SSR markers linked to head smut resistance gene.3.100RAPD primers were used to analyse the sorghum Head Smut disease-resistantrestorer lines and susceptible-resistant restorer lines dwarf four,Head Smut resistance andsusceptibility.Results showed that88of100pairs amplified products,so the amplification ratereached88%.The recombination rate of S405and resistance genes to Head Smut was11.7%.S405amplified polymorphic bands were recovered, cloned and sequenced,resultsshowed that length was32bp,according to the sequence to design SCAR primer,transferring the RAPD to SCAR molecular markers,the results showed that the chain was consistent withRAPD molecular markers.These may explain the SCAR molecular marker successfullytransferred.