外源γ-氨基丁酸对干旱胁迫下甜瓜幼苗生长的影响

Effects of exogenous γ-aminobutyric acid on growth of melon seedlings under drought stress

以薄皮甜瓜品种‘白沙蜜'为试材,研究了喷施不同浓度的γ-氨基丁酸(GABA)溶液对干旱胁迫下甜瓜幼苗生长的影响。结果表明,干旱胁迫显著降低了甜瓜幼苗株高、茎粗、叶面积、干鲜重、根总长、根表面积等生长指标,在重度及轻度干旱胁迫下,脯氨酸含量分别升高了137.41%和87.04%,丙二醛含量分别升高了207.5%和102.4%,质膜伤害度升高至46.2和24.58。重度及轻度干旱胁迫下,外源喷施20mmol/L的GABA溶液显著提高了甜瓜幼苗株高、茎粗、叶面积、地上及地下部干鲜重、根系总长、根表面积等指标;经20mmol/L GABA处理的幼苗相较于未处理幼苗,脯氨酸含量分别降低了26.46%和11.58%,丙二醛含量分别降低了30.08%和49.38%,质膜伤害度降低至26.26和2.16,表明GABA有效促进了干旱胁迫下幼苗的生长,缓解了胁迫造成的生长抑制和伤害。

Foliar-sprayingγ-aminobutyric acid（GABA）was conducted to evaluate its effects on the growth of melon cultivar ‘Baishami＇under drought stress.The results showed that drought stress significantly reduced plant height,stem diameter,fresh and dry mass,root length,etc.Meanwhile,severe and mild stress increased Pro（proline）by 137.41%and 87.04%,MDA（malonic dialdehyde）by 207.5%and 102.4%and cell damage degree to 46.2 and 24.58,respectively.However,treatment with 20 mmol/L GABA remarkably alleviated the inhibition of severe and mild stress on plant height,stem diameter,leaf area,fresh and dry weight,root length,root superficial area and decreased Pro by 26.46% and 11.58%,MDA by 30.08% and49.38%,cell damage degree to 26.26 and 2.16,respectively.In conclusion,GABA can play an important role in plant resistance against drought stress and be beneficial in melon seedling production.