Identification Of Salt Tolerance And Screening Of Differential Genes In Glutinous Sorghum Germplasm Resource

Soil salinization is one of the major abiotic stresses that reduce agricultural productivity and affect around the world,and waxy sorghums is a relatively salt-tolerant food crop.The screening of differential genes related to salinity tolerance of glutinous sorghums can lay a theoretical foundation for the improvement and breeding of salinity-tolerant glutinous sorghums,and accurately evaluate and screen salinity-tolerant glutinous sorghums,aiming to select high-yield,stress-resistant and comprehensive germplasm resources suitable for planting in areas with severe soil salinization,so as to provide a reference basis for the selection and breeding of new varieties,and also has important practical significance for the comprehensive utilization of saline-alkali land.In this study,150 parts of glutinous sorghums materials were germinated by saline solution of 175mmol·L^-1 Na Cl,salt tolerance related indexes were determined,and multivariate statistical analysis methods were used to comprehensively evaluate salt tolerance.Ten parts of glutinous sorghums materials were selected for potting tests to further identify and analyze the salt tolerance.At the same time,the salt tolerance and salt sensitivity of glutinous sorghums at the seedling stage were used as materials,and transcriptome sequencing was carried out to screen the different genes of salt tolerance in glutinous sorghums.The main findings are as follows:1.In this study,the salt tolerance index of 8 indexes（germinat ion potential,germination rate,bud length,root length,bud fresh w eight,root fresh weight,bud dry weight and root dry weight）of 150 waxy sorghums materials under salt stress was used for comprehe nsive correlation analysis,principal component analysis,membership function analysis and multivariate linear analysis to obtain a comple te equation Y=0.062+0.161×STI_GP+0.209×STI_GR+0.447×STI_SL+0.078×S TI_RL-0.530×STI_SFW+0.116×STI_RFW+0.305×STI_SDW+0.077×STI_RDW（P<0.01）.Since the salt tolerance index of bud length and bud dry weight can approximate the salt tolerance of glutinous sorghums,a simple r mathematical equation is constructed as Y=0.627×STI_SL+0.627×STI_{S DW}（P<0.01）,which can quickly and efficiently predict the salt toler ance of glutinous sorghums at the germination stage.This study suc cessfully divided 150 parts of glutinous sorghums materials into 6 t ypes:14 highly salt-tolerant,66 salt-tolerant,19 moderately salt-tole rant,34 low-salt-tolerant,9 salt-sensitive and 8 highly salt-sensitive.The results of the study can provide a reference for the identificati on and evaluation of salt tolerance of glutinous sorghums,and a ba tch of glutinous sorghums germplasm resources with strong salt tole rance can be screened.2.Under the conditions of salt stress,the agronomic and physiological indexes of different growth periods of glutinous sorghums were studied,and the comprehensive analysis showed that the number and size sequence of salt tolerance of different glutinous sorghums materials in the seedling,jointing and mature stages under salt stress was as follows:2>sticky sorghum-SX>glutinous sorghum-HB>485>229>565>36>82440>III.072>Combine 60.Through the analysis of salt tolerance of different growth periods of waxy sorghums,it can be seen that waxy sorghums material 2 shows strong salt tolerance at different growth stages,which can be used for variety selection in saline-alkali land.3.The most salt-tolerant glutinous sorghums material 2 and the most sensitive waxy sorghums material 82440 were screened by the salt tolerance screening test at the seedling stage at 175 mmol·L^-1 Na Cl conditions,transcriptome sequencing was performed under 0,24 and 48 h,respectively.After salt stress for 24 h and 48 h,the number of differentially expressed genes of the two types of waxy sorghums material increased with the extension of salt stress time,and the number of differentially expressed genes identified in different salt stress periods of glutinous sorghums 2 was higher than that of salt-sensitive material 82440.Salt-tolerant material 2 is subjected to salt stress to produce a large number of differentially expressed genes in response to salt stress.Pathways with significant enrichment of KEGG genes for salt-tolerant materials and sensitive materials include thiamine metabolism,circadian rhythm-plants,and DNA replication.The salt-tolerant genes in the thiamine metabolic pathway include THIC and THI1-2 and other genes with significant differences.The salt-tolerant genes of the DNA replication pathway include DNA replication licensing factor MCM2,DNA replication licensing factor MCM4,DNA replication licensing factor MCM6 and other genes with significant differences.The circadian rhythm of plants has genes with significant differences such as the protein CCA1.The results of this experiment can provide a theoretical basis for understanding the molecular mechanism of salt tolerance of glutinous sorghums and the selection and breeding of new salt-tolerant varieties of glutinous sorghums.