甜瓜幼苗耐盐碱性及缓解盐碱胁迫γ-氨基丁酸浓度的筛选

The Screening of Melon(Cucumis melo L.)Seedling Cultivars for Salt-alkaline Tolerance and the Concentration of γ-aminobutyric Acid Alleviating Salt-alkaline Stress

以不同特性的20份甜瓜品种为试材，以50mmol／L盐碱溶液（NaCI：NazS04：NaHCO3：NazC03—9：1：1：9，pH10．80）模拟胁迫环境，对4叶1心的甜瓜幼苗进行7d的胁迫处理，研究了盐碱胁迫对其幼苗地上部鲜重（SFW）、根部鲜重（姗）、主根长（TL）、叶面积（I。A）、叶绿素总量（Chl）的影响，并利用聚类分析进行甜瓜品种耐盐碱性的评价；同时以筛选出的耐性差异显著的2个甜瓜品种为试材，叶面喷施不同浓度的7一氨基丁酸（GABA）（0、25、50、75mmol／L），通过测定甜瓜幼苗生长的变化，筛选缓解盐碱胁迫效果最佳的G心～浓度，为减轻盐碱胁迫提供调控依据。结果表明：利用聚类分析可以将20个甜瓜品种按耐盐碱性强弱分为三大类，耐盐碱品种为“凌甜一号”、“海蜜四号”、“白香蜜”、“陕甜一号”和“金辉一号”，盐碱敏感品种为“一品天下108”、“凌甜四号”与“一品天下208”，中等耐盐碱品种为“千玉一号”、“陕甜三号”、“雪莲”、“五台山三号”、“玉露”、“白玉香”、“天娇”、“贵妃雪蜜”、“瑞雪新早蜜”、“芝麻蜜”、“景甜208”和“凌甜三号”；当GABA喷施浓度在25-50mmol／L时，对盐碱胁迫下甜瓜幼苗生长有一定缓解作用，其中50mmol／L缓解盐碱胁迫效果最好，而75mmol／LGABA无有效缓解作用。

Taking 20 melon cultivars with different characters as materials, using the 50 mmol/L mixed salt-alkaline solution（NaC1 ： Na2SO4 ： NaHCO3 ： Na2COa =9 ： 1 ： 1 ： 9,pH 10.80）to simulate the typical salt-alkaline stress environment. The melon seedlings with four leaf were treated with salt-alkaline solution for 7 days, the changes of 20 melon cultivars seedling shoot fresh weight （SFW）, root fresh weight （RFW）, taproot length （TL）, leaf area （LA） and total chlorophyll content（Chl） were studied, and the salt-alkaline tolerance of melon cultivars were evaluated by the cluster analysis. Chosen two melon cultivars which had significantly different tolerance as test materials, foliar application of different concentrations of 7-aminobutyric acid（GABA）（0,25,50,75 mmol/L）, changes of melon seedling growth weremeasured,in order to find the appropriate concemration of salt-alkaline stress relief,thus providing basis of regulation to reduce salinity stress. The results showed that, the 20 kinds of melon could be divided into three categories using cluster analysis. ＇Lingtian No. 1 ’,‘ Haimi No. 4＇,‘Baixiangmi＇,‘ Shantian No. 1 ＇ and‘Jinhui No. 1 ’ were salt-alkaline tolerance cultivars, ＂Yipin Tianxia No. 108＇,‘ Lingtian No. 4 ＇ and ‘Yipin Tianxia No. 208 ’ were salt-alkaline sensitive cuhivars, ‘ Qianyu No. 1 ＇, ‘ Shantian No. 3 ’, ‘ Xuelian ’,‘ Wutaishan No. 3 ’,‘ Yulu ’, ‘ Baiyuxiang ’, ‘ Tianjiao ＇,‘ Guifeixuemi ’, ‘ Ruixuexinzaomi ＇, ‘Zhimami＇, ‘Jingtian No. 208 ＇,‘ Lingtian No. 3 ＇ were moderate salt-alkaline tolerance cultivars. When the GABA spraying concentration was 25-50 mmol/L, there was a certain role relief of the melon seedlings growth under salt-alkaline stress,and the 50 rnmol/L GABA was the best effect,while the 75 mmol/L GABA did not play an effective alleviating effects.