γ-氨基丁酸浸种对不同温度胁迫下黄瓜种子萌发和幼苗生长的影响

以清白黄瓜为材料,研究外源γ-氨基丁酸(GABA)浸种对不同温度胁迫下黄瓜种子萌发、幼苗生长及光合特性的影响。研究结果表明,次低温(20℃/10℃)、次高温(35℃/28℃)、高温(40℃/35℃)显著抑制了黄瓜种子的萌发和胚根的生长,同时使黄瓜幼苗的株高、壮苗指数、根冠比以及根系活力显著降低,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)呈现下降趋势。外源GABA浸种能够显著提高温度胁迫下黄瓜种子的萌发和胚根生长速率,并能促进黄瓜幼苗的生长,提高黄瓜叶片的光合特性,其中以10 mmol/L GABA浸种处理效果最好。

Effects of GABA Soaking on Cucumber Seed Germination and Seedling Growth under Different Temperature Stress

We studied the effects of exogenousγ-aminobutyric acid （GABA） soaking on seed germination, seedling growth and photosynthetic characteristics of Qingbai cucumber under different temperature stress. The results showed that, under sub-low temperature （20℃/10℃）, sub-high temperature （35℃/28℃）, high temperature （40℃/35℃） conditions, the seed germination and radicle growth of cucumber were inhibited, and the plant height, sound seedling index, root-top ratio and root activity of cucumber seedlings were significantly decreased, in addition, the net photosynthetic rate （Pn）, stomatal conductance （Gs）, transpiration rate （Tr）, intercellular CO2 concentration （Ci） all showed downward trends. In conclusion, exogenous GABA soaking could significantly increase seed germination and radicle growth of cucumber seeds, and also promote the growth of cucumber seedlings and enhance photosynthetic characteristics of cucumber leaves, while the best seed soaking concentration of GABA was 10 mmol/L for cucumber.