不同盐胁迫对玉米种子萌发及幼苗生长的影响

Impact of Varying Salt Stress on Maize Seed Germination and Seedling Growth

本研究以华单86、鹏玉17、SK567、河农1号玉米品种为试验材料,采用5个NaCl浓度梯度(100、200、300、400、500mmol/L)处理种子,以蒸馏水作对照,对不同盐胁迫下玉米的发芽指标、幼苗形态指标及生理指标进行测定。结果表明:低浓度盐分对4个玉米品种的种子发芽率影响不大,高浓度NaCl条件显著降低品种河农1号种子的发芽率;随NaCl浓度的不断增加,发芽势、相对发芽指数和相对活力指数显著降低,株高、叶长和根长等形态生长受抑制,但河农1号受抑制程度相对较小。NaCl浓度越高,各品种与cK的脯氨酸含量差异越显著。在NaCl浓度为500mmol/L时脯氨酸含量均达到最大值,其中以河农1号的脯氨酸含量最高。随NaCl浓度的提高,各品种之间的MDA含量、相对电导率均升高,但增长幅度不一,SK567的MDA含量最高,河农1号的MDA含量最低;鹏玉17、华单86的相对电导率增加较迅速,而SK567、河农1号则相对缓慢。综合不同盐胁迫下对4个玉米品种的萌发、幼苗生长以及生理指标的影响,4个玉米品种中耐盐性最强的品种为河农1号,其次为SK567,次之为鹏玉17和华单86。

To provide a theoretical basis for selecting salt-tolerant maize varieties for seed production and saline-alkali soil cultivation in Zhangye City,this study used maize varieties Huadan 86,Pengyu 17,SK567,and Henong No.1 as test materials.The seeds were treated with varying concentrations of NaCl(100,200,300,400,and 500 mmol/L)with distilled water as the control.The germination indices,seedling morphological characteristics,and physiological indices of maize were measured.The results showed that low salt concentrations had minimal impact on the germination rate of the four maize varieties,while high NaCl concentrations significantly reduced the germination rate of Henong No.1.As NaCl concentration increased,the germination potential,relative germination index,and relative seed vigor index significantly decreased.Morphological growth,including plant height,leaf length,and root length,was inhibited,though Henong No.1 showed slower inhibition.The higher the NaCl concentration,the more pronounced the differences in proline content between the varieties and the control group.At 500 mmol/L NaCl,proline content reached its peak,with Henong No.1 having the highest level.As NaCl concentration increased,MDA content and relative conductivity also rose across all varieties.SK567 had the highest MDA content,while Henong No.1 had the lowest.The relative conductivity of Pengyu 17 and Huadan 86 increased rapidly,while SK567 and Henong No.1 showed slower increases.Based on the effects of salt stress on germination,seedling growth,and physiological indices,Henong No.1 was identified as the most salt-tolerant variety,followed by SK567,Pengyu 17,and Huadan 86.