Selection Of Salt Tolerant Germplasm Resources And Identification Of Growth, Development And Agronomic Traits Of Millet

In order to study the effects of salt stress on the morphological structure,physiological characteristics,photosynthesis,main agronomic characters and yield components during harvest of different millet varieties from germination to growth and development,the optimal concentration of salt-tolerant screening for millet was determined by studying the effects of different Na Cl solution concentrations on the germination potential and germination rate of 5millet varieties.100 millet varieties were selected as materials for salt tolerance screening in germination period,and 30 materials were selected for pot test,to further identify and analyze the salt tolerance,in order to screen out the variety resources suitable for planting in areas with serious soil salinization,which are of high yield,strong stress resistance and excellent comprehensive characteristics,so as to provide necessary basic guarantee for breeding new varieties.The main findings are as follows:1.The differences of germination potential and germination rate of Gongai 5,Longgu 25,Longgu32,Jingu 29 and Nenxuan15 were different under 0(CK),50,100,150,200,250 mmol /L Na Cl solution treatment.When the concentration of Na Cl solution was lower than 100 mmol /L,there was no significant difference between the germination rate of different millet varieties and the control.With the increase of Na Cl concentration,the germination rate reached significant or extremely significant difference;when the Na Cl concentration reached 200 mmol / L,the germination rate decreased rapidly,even some seeds did not germinate.Therefore,150 mmol / L Na Cl was the best concentration for selecting salt tolerance of millet.2.Through 150 mmol / L Na Cl,100 different varieties of millet were screened for salt tolerance in germination period.Accorded to 8 indexes of germination potential,germination rate,germination index,vigor index,root length,bud length,root dry weight and bud dry weight,the test materials were divided into three salt resistance grades: salt resistance,moderate salt resistance and salt sensitivity.Salt stress had little effect on the germination potential and germination rate of salt tolerant cultivars,but had great effect on the germination potential and germination rate of salt sensitive cultivars.The varieties with strong comprehensive salt tolerance have larger relative root length,relative bud length,relative root dry weight and relative bud dry weight;the varieties with poor comprehensive salt tolerance have smallerrelative root length,relative bud length,relative root dry weight and relative bud dry weight.The inhibition of salt stress on the growth of millet bud was less than that of root.3.Salt stress significantly inhibited the growth,dry matter accumulation,and photosynthetic capacity of millet,dry matter accumulation in millet seedling stage is the most important.4.Under salt stress,the activities of SOD,POD,CAT and soluble protein content in millet leaves increased in different degrees compared with the control.The materials with strong salt tolerance has higher increase in protective enzyme activity and osmoregulants than those with weak salt tolerance.5.Germination potential,germination rate,germination index,vitality index,root dry weight and shoot dry weight can be used as the indexes of salt tolerance screening in germination stage of millet,dry matter and leaf area can be used as the indexes of salt tolerance in millet seedlings,ear length,single ear weight and single ear grain weight can be used as the indexes of salt tolerance screening in the plant growth stage.6.Jingu 25,Xiaobaigu,Chigu 8,Gong'ai 6,Longgu 35,and Heibei Xianggu are materials with strong comprehensive salt tolerance,which can be used as high-quality resources for further study.