Effects Of Salt Stress On Seed Germination,Seedling Growth And Yield Of Maize Varieties With Different Salt Tolerance

To study the salt tolerance characteristics and salt tolerance mechanisms of different salt-tolerant maize varieties.In this paper,through the indoor sand culture experiment and field test with salt tolerance.The response mechanism of NaCl to salt stress of growth and yield components of 6 different salt tolerant maize varieties was studied.Salt-tolerant maize variety traitswere preliminarily known.Identification these salt tolerancetraits include salt injury index,relative germination potential,salt tolerance vitality index,biomass in seedling stage,organic permeate,field biomsaa,plant height,ear height,LAI.The results were as followed:1.Effects of NaCl stress on seed germination characteristics of different salt tolerant maize varietiesMaize germination is a critical period for the identification of salt tolerance.Relative germination potential,relative germination rate and SVI decreases with increasing salt concentration.When the stress concentration is less than 160 mmol·L^-1.The growth trend of salt damage index of salt tolerant varieties is low.When the stress concentration reached 160mmol·L^-1.The salt injury index of different varieties was different.Salt tolerance index of salt tolerant varieties is lower.Relative germination potential,relative germination rate and SVI of salt tolerant varieties is higher.When the stress concentration increased to 220 mmol·L^-1.Salt tolerance index of tolerant varieties was lower than that of in-tolerant varieties.The difference between different varieties is significant.Salt tolerant varieties of Denghai 605 were more seriously affected by salt at this concentration.The salt damage index of other salt tolerant varieties under this concentration is lower than that of in tolerant varieties.Relative germination potential,relative germination rate and SVI higher than in tolerant varieties.Different varieties had died when the stress concentration was greater than 280 mmol·L^-1.Identify appropriate concentrations of salt tolerance of different varieties concentration at160-220 mmol·L^-1.When stress greater than 220 mmol·L^-1 salt concentration is Denghai 605upper concentrations.When stress less than 160 mmol·L^-1 salt concentration is Xundan 20lower concentrations.Tolerant varieties have a higher accumulation of radicle and germ dry matter than in-tolerant varieties when the stress concentration was 160 mmol·L^-1.Prolonged germination of in-tolerant varieties.The elongation of embryos of different varieties was significantly inhibited when the stress concentration was 220 mmol·L^-1.2.Effects of NaCl stress on seedling growth and development of different salt tolerant maize varietiesWith the increase of NaCl stress concentration.The weight of underground and ground decreased significantly.The ground dry weight reduction trend is more significant than the underground dry weight.The dry matter accumulation in the aboveground and underground parts of salt-tolerant cultivars is more severely affected by NaCl stress.With the increase of salt stress concentration.The elongation of the main root of different varieties was significantly inhibited.Different varieties net photosynthetic rate and transpiration rate showed a significant decreasing tendency with increasing stress concentration.Tolerant varieties significant decreasing tendency more than in-tolerant varieties.Different varieties chlorophyll relative content increase first and then decrease.Different varieties H₂O₂ and MDA showed a significant increasing trend with increasing stress concentration.But Oxygen free radical scavenging-effectto the opposite.The Oxygen free radical increase of the content will affect the photosynthesis of the plant.The osmotic substance in cell showed increase first and then decrease with increasing stress concentration.The organic permeate improving intracellular osmotic to ensure no loss of water in cells.Different salt tolerance stronger maize varieties higher the osmotic substance content with low salinity stress concentration.3.Relationship between characters and yield in different periods of Maizeunder saline and alkali land environmentThe yield,spike numbers,thousand kernel weight,grain number per spike,spike lengthof tolerant varieties is higher than that of in-tolerant varieties in saline land.The LAI,plant height tolerant varieties is higher than that of in-tolerant varieties during grain-filling period.Dry matter accumulation in leaves and grains of tolerant varieties is higher than that of in-tolerant varieties during maturity.Tolerant varieties have larger leaf area,higher plant height,and more dry matter accumulation.So,tolerant varieties has higher germination energy.The plant high is higher than in-tolerant during filling stage.Tolerant transpiration rate,net photosynthetic and organic osmatics rate is higher than in-tolerant.Tolerant varieties higher plant height.Therefore accumulate more dry matter.When selecting salt-tolerant cultivars.Should choose stronger germination energy,higher plant height at seedling stage,bigger leaves in the field,higher plant height and higher ear position.