| Wheat is one of the most important food crops in China,and its output affects national food security.Soil salinization has become one of the main factors affecting wheat yield.Therefore,cultivating and screening wheat varieties(lines)with strong salt tolerance are of great practical significance for making full use of saline-alkali soils and solving current food problems.The germination and seedling stages are the most sensitive and vulnerable periods in the growth period of wheat.With the extension of the growth period,the stress resistance will gradually increase.Therefore,the germination and seedling stages are the best time for salt stress in the early stages of wheat.Therefore,this study used the collected 157 wheat germplasms as materials and set different salt concentrations and carry out the screening and identification of the salt tolerance of wheat at the bud and seedling stage under hydroponic conditions;Comprehensive evaluation of the salt tolerance of germplasm materials by measuring the phenotypic and physiological indicators of wheat materials at the bud and seedling stage under different salt concentration stresses,screening and identifying materials with strong salt tolerance,and crossing them with current popularized varieties Utilization,laying the material foundation for the cultivation of new varieties of salt-tolerant wheat.The main results are as follows:1.Under salt stress,the proportion of germinating materials at the bud stage and the biomass at the bud stage and seedling stage of the test materials were significantly inhibited,and decreased with the increase of salt concentration.The analysis showed that the salt concentration of 100mmol/L was the best for subsequent identification of salt tolerance at seedling stage;2.The maximum value,minimum value,average value and coefficient of variation of the 18 indicators at the seedling stage were significantly lower than the control,indicating that the tested wheat germplasm was severely affected under salt stress,among them,the MDA,SNC,SKC and SNKR is very sensitive to salt stress and has great potential for improvement;3.Correlation analysis shows that the traits are either positively correlated or negatively correlated,or reach significant or extremely significant levels;among them,the SNC and SKC are significantly negatively correlated,and the SKC is positively correlated with the dry and fresh weight of the above-ground parts.The SNKR has a very significant negative correlation with the dry and fresh weight of the above-ground;the RNKR in the underground have a very significant positive correlation and a very significant negative correlation with the RNKR,and the RNKR has a significant negative correlation with The fresh weight of the above-ground part shows a very significant positive correlation,although the correlation with the dry weight of the above-ground part is not significant,it is positively correlated,etc.;4.Principal component analysis combined 18 relevant indicators(germination rate of wheat bud stage,fresh weight above ground,dry weight above ground,fresh weight below ground,dry weight below ground,seedling height,maximum root length,water content,MDA,root Crown ratio,sodium-potassium ratio,etc.)are divided into 6 types of comprehensive indicators,namely: dry and fresh weight main component,root-to-shoot ratio main component,main component of water content,main component of seedling height,main component of sodium and potassium ion,and germination rate main ingredient.5.Through systematic clustering analysis and comprehensive evaluation of the comprehensive value of the membership function(D value)of each material of wheat,the 157 test materials were divided into five categories,namely: the first category is high salt tolerant materials(D value)The range is 0.5464-0.6351),a total of 17 copies,accounting for 10.83%of the tested materials;the second category is salt-tolerant materials(D value range is0.4722-0.5360),a total of 39 copies,accounting for 24.84% of the tested materials;third The category is moderate salt-tolerant materials(D value range is 0.4534-0.4653),a total of 13 copies,accounting for 8.28% of the tested materials;the fourth category of salt-sensitive materials(D value range is 0.3779-0.4528),a total of 53 copies,accounting for 33.76% of the tested materials;the fifth category is high salt sensitive materials(D value range is0.2663-0.3778),a total of 35 copies,accounting for 22.29% of the tested materials.Among them,the germplasm material G69 has the highest D value with a value of 0.6351;G83 has the lowest D value with a value of 0.2663.6.The two highly salt-tolerant germplasm materials G69 and G79 were crossed with high-yield and high-quality wheat materials Shannong 116,Xinong 979 and GJP18,respectively,and a total of 6 new hybrid combinations were obtained. |
