Identification And Analysis Of Agronomic And Physiological Characters Of Germplasm Resources In Sorghum (Sorghum Bicolor Moench)

Sorghum（Sorghum bicolor Moench）belongs to monocotyledonous gramineous family（Poaceae）millet subfamily（Andropogoneae）sorghum subfamily（Sorghinea）sorghum.It is a C₄ photosynthesis and has strong resistance to drought,waterlogging,salt and alkali,barren and high temperature.Sorghum is mainly planted in arid and semi-arid regions around the world,after wheat,rice,corn and barley,in area,and is the fifth largest crop in the world and one of the oldest grain cereal crops in the history of cultivation.How to reasonably develop and utilize sorghum germplasm resources on the basis of the existing cultivated land area,and breed high-yield,high-quality and disease-resistance hybrids is an important goal of sorghum breeding.Core sorghum germplasm collection group has been established internationally to explore key genes that control important traits.A total of 104 local varieties,imported germplasm and improved strains of sorghum were planted in two different planting areas in Shanxi province: spring sowing area（Taigu district of Jinzhong）and summer sowing area（Yaodu district of Linfen）.The agronomic character value,leaf green value（SPAD）and photosynthetic parameters of different sorghum varieties were measured.The effects of varieties and test points on the expression of physiological characters such as agronomic characters,chlorophyll value and photosynthetic parameters were analyzed.The correlation between agronomic character value and physiological characters was studied.Clustering analysis of phenotypic trait values of the two test sites was carried out,and genetic diversity analysis of 104 sorghum germplasm resources was studied,which laid a foundation for the establishment of association analysis population of sorghum trait heredity.The main findings are as follows:（1）The tested sorghum germplasm has abundant genetic diversity.The genetic diversity index is between 1.27-2.02,the highest is flag leaf length,the lowest is flag leaf width,the coefficient of variation is between 14.51-29.81%,the highest is leaf area and the lowest is plant height.It can be concluded that the performance of the two is not the same,indicating that the diversity of sorghum can be evaluated from many aspects.（2）Test sites and varieties affect both the agronomic and physiological traits of sorghum.For the two characters of sorghum plant height and ear length,the test point had a greater effect on the leaf length,flag leaf width,SPAD value and yield of sorghum flag.（3）The agronomic traits of 104 sorghum materials from two test sites were clustered by SPSS.The results showed that at the genetic distance of 10,the tested materials could be divided into four groups at Taigu test site.The tested materials can be divided into seven groups at Yaodu test site.（4）By correlation analysis,the agricultural characteristics,yield,SPAD and photosynthesis parameters of sorghum were analyzed.The results showed significant positive correlation between the leaf area and the SPAD value,the net photosynthesis rate,transpiration rate,and porosity,the yield,the higher the yield,the higher the yield,and other traits showed significant or no significant correlation.Therefore,in the selection of breeding,multiple characteristics should be taken into account,with high strains and ear length as the direct index to assist the efficiency of SPAD,photosynthesis to obtain excellent products.（5）According to the analysis of yield of two experiments,the varieties with germplasm number YZ011、YZ027、YZ047、YZ057、YZ066、YZ067、YZ068、YZ077、YZ082 have high yield and stable yield in different environments,which is expected to be applied in breeding.The number of varieties with long ears and high single ear grain weight at Taigu test point is YZ010、YZ057、YZ077、YZ083、YZ091、YZ097.The number of varieties with long ears and high single ear grain weight is YZ003、YZ057、YZ077、YZ092、YZ093;at Yodu test point.The number of varieties with long ears and high single ear grain weight is YZ025、YZ034、YZ038、YZ057、YZ093 respectively.（6）The natural population of sorghum germplasm is representative and rich in genetic variation,which can be used as a key material for genetic analysis and gene mining.