不同类型盐碱胁迫对棉花种子萌发的影响

Effects of different types of salt and alkali stress on cotton seed germination

【目的】研究不同类型盐碱胁迫对棉花种子萌发的影响并计算耐盐阈值。【方法】采用培养皿法,模拟设置4种类型盐碱胁迫和7个浓度处理,以新陆中84号、塔河2号、新陆中40号和酒棉18号棉花种子为研究对象,分析盐碱胁迫下棉花种子的发芽势、发芽率、发芽指数、种子活力指数、萌发后幼苗鲜重和干重变化,计算耐盐阈值和隶属函数值,并综合评价。【结果】(1)在4种盐碱胁迫下,棉花种子的发芽势、发芽率、发芽指数、活力指数、萌发后幼苗的鲜重和干重均呈显著下降趋势。盐碱浓度与各项指标均呈极显著负相关,其中与发芽率的相关性超过-0.90。(2)在4种盐碱胁迫条件下棉花萌发期的耐盐阈值存在差异,S_(1)胁迫下耐盐阈值为90.70~121.73 mmol/L;S_(2)胁迫下耐盐阈值为82.68~128.30 mmol/L;S3胁迫下耐盐阈值为51.97~84.62 mmol/L。S_(4)胁迫下耐盐阈值为73.49~98.21 mmol/L。(3)棉花种子耐盐性由强至弱的顺序在S_(1)胁迫下为新陆中84号>新陆中40号>塔河2号>酒棉18号,在S_(2)胁迫下为新陆中84号>塔河2号>新陆中40号>酒棉18号,在S_(3)胁迫下为塔河2号>新陆中40号>新陆中84号>酒棉18号,S_(4)胁迫下各品种棉花种子耐盐强弱顺序与S_(2)胁迫一致。【结论】4种盐碱胁迫下均降低了棉花种子的发芽势、发芽率、发芽指数和活力指数,随着浓度升高,幼苗的鲜重和干重均呈下降趋势。碱性盐对棉花种子萌发影响明显大于中性盐。

【Objective】This study aims to investigate the influence and threshold of different types of saline-alkali stress on the germination of cotton seeds.【Methods】Four types of saline-alkali stress and seven concentration levels were simulated by Petri dish method.Cotton seeds of Xinluzhong 84,Tahe 2,Xinluzhong 40 and Jiumian 18 were used as research objects.The germination potential,germination rate,germination index,seed vigor index,fresh weight and dry weight of seedlings after germination were analyzed,salt tolerance threshold and membership function values were calculated,and comprehensive evaluation was carried out.【Results】(1)The germination potential,germination rate,germination index,vitality index,fresh weight and dry weight of cotton seed after germination showed a significant downward trend under the four types of saline-alkali stress.There was a significant negative correlation between saline-alkali concentration and all indexes,and the correlation between saline-alkali concentration and germination rate was more than-0.90.(2)The salt tolerance thresholds of cotton at germination stage were different under the four types of saline-alkali stress conditions.The salt tolerance thresholds under S_(1)stress ranged from 90.70 to 121.73 mmol/L.The salt tolerance threshold under S_(2)stress ranged from 82.68 to 128.30 mmol/L.The salt tolerance threshold under S_(3)stress ranged from 51.97 to 84.62 mmol/L.The salt tolerance threshold under S_(4)stress ranged from 73.49 to 98.21 mmol/L.(3)The salt tolerance of cotton seeds under four kinds of saline-alkali stress was analyzed by membership function and its order was Xinluzhong 84>Xinluzhong 40>Tahe 2>Jiumian 18 under S_(1)stress,Xinluzhong 84>Tahe 2>Xinluzhong 40>Jiumian 18 under S_(2)stress,and Tahe 2>Xinluzhong 40>Xinluzhong 84>Jiumian 18 under S_(3)stress.It was found that the order of salt tolerance of cotton seeds under S_(4)stress was consistent with that under S_(2)stress.【Conclusion】The germination potential,germination rate,germination index and vigor index of cotton seeds are decreased under the four types of saline-alkali stress,and the fresh and dry weight of seedlings shows a downward trend with the increase of the concentration.The effect of alkaline salt on the germination of cotton seed is obviously greater than that of neutral salt.