The Effect Of Drought Stress On Physiological Characteristics Of Seed Germination And Seedling Stage In Corn

This study evaluates the drought resistance of 10 different millet.In the seed germination stage,drought stress with high osmotic solution PEG-6000 of five different concentration level was simulated for measuring seed germination rate,radicle length,germ length,germination potential,radicle/germ value,and other relevant data such as index of germination to evaluate the drought resistance ability.In the corn seedling stage,through potted drought stress method,calculate below physiological and biochemical indexes(plant height,leaf relative water content,plasma membrane permeability,chlorophyll content,free proline,malondialdehyde content,soluble protein content,soluble sugar content)of 10 millets under different conditions of time and drought degree to comprehensively evaluate and screen drought resistance of the 10 varieties of foxtail millet.The specific research results are as follows:1.The influence of different concentration PEG-6000 solution on relative germination rate of corn seed with rising penetrating fluid concentration,seed germination rate is gradually declining,all the millet varieties tend to be same;Different concentrations of PEG-6000 solution influence millet seeds germinate relative potential more as the treatment concentration of PEG-6000 continues to increase.Only under the concentration of 10%,the lanzhou white grass seeds red valley relative germination potential rise,all the rest shows decreasing trend.Valley in concentration 20%,the no.3,huining big black valley,a valley of no.3,of out hair grass,three millet in relative germination potential rise;Ladder different concentrations of PEG-6000 solution radicle/germ of the corn seed value,the influence of the PEG-6000 concentration between 5%-15%,remove a miscellaneous valley 3,lanzhou red white grass valley,millet variety radicle/germ values are all showed a trend of rising.From the concentration of more than 15% and remove a miscellaneous valley 3,lanzhou red white grass valley,its ratio of all present a downward trend;Ladder different concentrations of PEG-6000 solution of millet seeds germination index,the influence of the concentration of PEG-6000 was5%,mixed valley valley of no.3 and jin zhang 28)(black rice germination index rose,the rest of the millet sprout index downward.With PEG-6000 concentration increasing,the processing of all varieties of foxtail millet radicle length trends are shown.2.At the same time,under the same concentration of PEG-6000,significant difference was found in 10 millet varieties between each measurement index.The comprehensive analysis of the whole test processing stage,the most suitable concentration of each measurement indexes are shown as follows: dealing with concentration of 25%,relative germination rate for the top three of out MAO grass valley of 50% 50%,huining big black red,lanzhou white grass valley,45%;In the treatment of the concentration of 20%,the relative germination potential of the highest in the first three delay valley 3 46%,huining big black valley of 44% 46%,of out hair grass;When the concentration of 25%,radicle/germ valley of the highest in the first three for the delay of 2.41 3(black rice),28,in the valley,valley delay 1,1.79 and 1.97,When concentration of 20%,the highest germination index in the first three of out MAO grass valley of 3,16.4,18.9,extending its big black valley of 16.3.3.In 20 days experiment of continuous drought,as for the influence of drought stress on leaf relative water content,millet leaf relative water content decreased significantly with the varying stress of continuous drought,all varieties show the same pattern;The influence of drought stress on leaf plasmalemma permeability,usually with the relative electrical conductivity value size is used to represent the size of plasma membrane permeability,millet leaf relative electrical conductivity with continuous drought stress time increasing,the first 10 varieties of foxtail millet leaf relative conductivity difference,along with the continuous drought stress,the difference increases gradually;As for the influence of drought stress on leaf chlorophyll content,in 0-10 days,millet leaf chlorophyll content under the stress of continuous drought shows a rising trend,and a declining trend in 10-20 days;The influence of drought stress on leaf malondialdehyde content,10 varieties of foxtail millet leaf malondialdehyde content of continuous drought stress increases with time and showed a trend of rise,deal with the stress of continuous drought,the maximum20 days,all millet variety show a consistent trend;The effects of drought stress on leaf free proline,10 millet all varieties of free proline content with the time increase of stress of continuous drought stress presents ascendant trend.In 5 ~ 20 days of drought treatment process,each millet leaf free proline content in the product are significant difference;The effects of drought stress on leaf soluble protein content,under the time of the stress of continuous drought,10 varieties of foxtail millet leaf soluble protein content were presented down,all millet variety trend is consistent;The influence of drought stress on leaf soluble sugar content in the test of 10 varieties of foxtail millet leaf soluble sugar content of time increases as the stress of continuous drought,present consistent trend of all varieties.4.In this 20 days experiment of continuous drought,the top three that grow most of the 10 strains of foxtail millet varieties respectively are delay valley No.3,huining big black valley,and Lanzhou red white grass valley;the top 3 of 10 varieties of foxtail millet with relative high water content in leaf are out of grass valley,huining big black valley,jin MAO valley 29;the top three of 10 varieties of foxtail millet plasma membrane permeability that change the slowest are of out MAO grass valley,lanzhou red white grass valley,huining big black valley;the top three of 10 varieties of foxtail millet leaf chlorophyll content are out of hair grass valley,huining red big black valley,lanzhou white grass valley;10 varieties of foxtail millet leaf malondialdehyde content is the lowest is in turn out MAO grass valley,huining big black valley,the valley of delay 1;10 varieties of foxtail millet leaf free proline content in the rose is the most slow and at least three hoeryong big black valley,long valley,1 of out MAO grass valley;10 varieties of foxtail millet leaf soluble protein content of the top three,respectively is out MAO grass valley,lanzhou red white grass valley,a miscellaneous valley 5;10 varieties of foxtail millet leaf soluble sugar content of the top three,respectively is out MAO grass valley,huining big black valley,the valley of the no.3.5.With comprehensive comparision of 10 millet seeds germination drought resistance related characteristics and physiological characteristics in seedling stage,the top two foxtail millet with best drought resistance in the test are screened out:MAO grass valley,and huining big black valley.