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Mixed Salinity Stress On Sorghum

Posted on:2003-11-10Degree:MasterType:Thesis
Country:ChinaCandidate:Y M LiFull Text:PDF
GTID:2190360062985807Subject:Botany
Abstract/Summary:PDF Full Text Request
The formation of salt-alkaline soil included salinization and alkalinization. The increase of salinity was the character of salinization, and the increase of pH was the character of alkalinization. The aim of this experiment was to show the characters that salt-alkaline mixed stress on plant and the correlativity between saline stress and alkaline stress. Seedlings of sorghum (Changbang 128) were stressed with 28 kinds of mixed salt which were composed of NaCl, Na2SO4, NaHCO3 and Na2CO3 at various proportions and were different in salinity and alkalinity each other (the range of total salt concentration 50-300mmol/L and pH 7.12-11.43). Twelve strain indexes, such as survival rate; were determined. The relationships between the all stress acting factors and each strain index were mathematically analyzed.The results showed as follows. (1) All the strain indexes were changed regularly with the increasing strength of mixed salt-alkaline stress. Survival rate, relative growth rate, water content, root vitality, chlorophyll content decreased; Leakage rate of electrolyte, leakage rate of K+, proline content increased; oxygen free radical content decreased then increased, meanwhile superoxide dismutase activity increased first then decreased. (2) There was a combined effect of salinity and alkalinity in mixed salt-alkaline stress, and this effect was more great than either simple saline stress or alkaline stress. (3) According to the changes of water content, oxygen free radical content and surperoxide dismutase activity, seedlings of sorghum showed some adaptability to lower stress of salinity and alkalinity. (4) According as the result of correlativity analysis between every strain index and stressing factors, three factors salinity, buffercapacity and pH can represent all of stress acting factors. The multiple regression between every strain index and the three-factor were analyzed. It showed that buffer capacity and salinity were dominant factors for all the strain indexes; pH was obviously less important factor and even can be neglected in some cases.Mixed salt-alkaline stress was different from simple saline stress, such as NaCl stress, or simple alkaline stress in damaging to crops .The composition of mixed salt-alkaline was more closed to natural salt-alkaline soil, so that this research can contribute to improve the salt-alkaline soil.
Keywords/Search Tags:Sorghum bicolor L., Mixed salt-alkaline stress, Salinity, pH, Buffer capacity
PDF Full Text Request
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