叶施和根灌ALA对香蕉幼苗冷害的缓解效应(英文)

Mitigative Effects of Foliage Spraying and Root Irrigation of ALA on Banana Plantlets Exposed to Cold Stress

[目的]通过研究了解叶施和根灌ALA对低温胁迫下香蕉幼苗的影响。[方法]用4种不同浓度ALA分别叶施和根灌巴西蕉幼苗后置于人工气候箱中7℃下模拟低温胁迫,研究ALA不同处理方式对巴西蕉幼苗冷害的影响。[结果]结果表明,无论叶施或根灌,ALA均可提高低温胁迫下香蕉幼苗叶片超氧化物歧化酶（SOD）、过氧化物酶（POD）活性,降低超氧阴离子产生速率、MDA含量及相对电导率,同时还可增加脯氨酸、可溶性蛋白含量及相对含水量（RWC）,维持叶绿素的稳定性。以叶施0.50~5.00mg/LALA效果最好,与同浓度根灌相比,叶施处理的叶绿素含量均显著增加,相对电导率、丙二醛含量均显著降低,5mg/LALA叶施比根灌SOD和POD活性提高了64.5%、12.3%,RWC提高了12.1%,差异均达显著水平。[结论]由此表明,ALA叶面喷施可更好地减缓低温胁迫对香蕉造成的冷害。

[Objective] This study aimed to investigate the effect of ALA applied by foliage spraying and root irrigation on banana plantlets exposed to cold stress. [Method] After applied by foliage spraying and root irrigation with 5-aminolevulinic acid （ALA） at four different concentrations, ＂Brazil banana＂ plantlets were placed in artificial climate boxes at 7 ℃ to imitate low-temperature stress. [Result] The results showed that ALA application by both foliage spraying and root application can significantly increase SOD and POD activities, and reduce O2- generation rate, MDA content and relative conductivity in leaves of banana plantlets, as well as raising proline content, soluble protein content and relative water content, and maintaining the stability of chlorophyll. Foliage application of ALA within concentration range of 0.505.00 mg/L had best effect, which increased the chlorophyll content and reduced the relative conductivity and MDA content significantly compared to root irrigation at the same concentration, and raised SOD and POD activities by 64.5% and 12.3% respectively at 5 mg/L compared to their counterparts by root irrigation. [Conclusion] Foliage spraying of ALA can better mitigate the injuries to banana plantlets caused by low-temperature stress.