Effects Of Saline-alkaloid Stress On The Seed Germination And Physiological Characteristics Of Seven Grass Seeds

Soil salinization has seriously affected to the ecological environment.Songnenplain is the important natural pasture and livestock production base in China, but it isalso one of the most serious soil salinization area.Use saline resistance strong grassvarieties in the salinization soil improvement and recovery has very important practicalsignificance.In this paper, in accordance with the songnen plains salinization soil saltcomposition characteristics, according to1:9:9:1proportion of in the mixed saltsolution of intimidation with NaCl、Na2S04、NaHC03and Na2C03,study of Leymuschinensis Nongjing11,Leymus chinensis,Elytrigia and other7cold resistance strongperennial gramineous forage varieties of seed germination, seedling growth andphysiological indicators under saline-alkaloid stress,and the comprehensive evaluationof saline-alkaloid stress, so as to provide reference for practical application.The resultsshow that:1)Germination rate, germination index,root length,shoot height of Leymuschinensis Nongjing11,Leymus chinensis,Elytrigia in low concentration (≤20mmol·L^-1)treatment was higher than control,with the increase of treatment concentration aboveindex dropped significantly,when the concentration of more than60mmol·L^-1is lowerthan the control significantly（P＜0.05）,show that low concentration of stress canpromote seed germination,and the high concentration inhibited germination;germinationrate, germination index of Bromus inermis,Nongjing6,Roegneria nutans Keng andElymus dahuricus in stress decreases gradually after processing.When the concentrationof mixed solution120mmol·L^-1,the seven forage varieties of grass roots for an averageof only0.1cm long,almost stop growing.Either promote or inhibit are effects onseedling root;2)Seven forage varieties chlorophyll content changes in different undersaline-alkaloid stress,it is increases after the first drop of Leymus chinensis Nongjing11and Elytrigia,there is an extremely significant negative correlation between chlorophyllcontent and stress concentration of Bromus inermis,Nongjing6,Roegneria nutans Kengand Elymus dahuricus. Free proline content increased with the increase of the mixed solution concentration of seven forage varieties,it is the largest in Elytrigia.Malondialdehyde content with the change rule of the free proline.POD content changesshow the typical single-peak curve of Leymus chinensis Nongjing11,T4is the max,andall the other six varieties of bimodal curve.3) Membership function method can commendable evaluation of saline-alkaloid offorage varieties,it has strong scientific and rationality.The comprehensive evaluationshow that the saline-alkaloid tolerance from strong to weak of seven forage varieties isElytrigia>Leymus chinensis Nongjing11>Elymus dahuricus>Leymus chinensis>Bromus inermis>Roegneria nutans Keng>Bromus inermis Nongjing6.