盐胁迫对不同基因型黄秋葵苗期生长及生理生态特征的影响

摘要

为揭示盐害下不同黄秋葵品种苗期生长的差异,以2个黄秋葵品种皇星五角(HXWJ,耐盐型)和绿新五角(LXWJ,盐敏感型)为试验材料,采用盆栽法研究不同浓度NaCl(0,80,160 mmol/L)、不同胁迫时间(25,50 d)对黄秋葵植株苗期生长及生理生态指标的影响.结果表明:随着NaCl浓度的提高、胁迫天数的增加,黄秋葵幼苗的株高、根长、植株鲜干质量、细胞膜稳定指数(CMSI)、K+含量,K+/Na+比呈下降的趋势;而叶片丙二醛(MDA)含量,Na+含量逐步升高;盐胁迫下黄秋葵幼苗鲜质量下降的幅度大于干质量,茎叶下降的幅度大于根系;胁迫至25 d,黄秋葵叶片和根中SOD、POD活性随NaCl浓度增加逐步升高,胁迫至50 d,2个酶活性随NaCl浓度增加先升高后降低;整个胁迫过程中,幼苗的株高、根长、植株鲜干质量、CMSI、K+含量,K+/Na+比含量的降幅及MDA含量的增幅均为HXWJ＜LXWJ,表明苗期较高的干物质积累、细胞膜稳定性及K+含量是耐盐性黄秋葵品种的基本特征.%In order to clarify the difference response of okra growth under salt stress at seedling stage,Two okra cultivars (genotypes:HXWJ salt tolerant and LXWJ salt sensitive) were subjected to different NaCl concentrations (0,80,160 mmol/L) for various periods of time to determine the effects on seedling growth and physiological and ecological index in soil pot culture.The results showed that plant length,root length,leaf,cell membrane stability index (CMSI),K + content,K +/Na + of okra were reduced,while malondialdehyde (MDA) content,Na + content was enhanced with NaCl concentration increasing.Fresh weight of okra seedlings was more sensitive to salt stress as compared to dry weight,shoots were more sensitive as compared to roots.The activities of superoxide dismutase (SOD)and peroxidase (POD) increased with the increase of NaCl concentrations at the 25th day,which increased firstly and then decreased at the 50th day.High plant height,root length,plant fresh weight,K + content,the decrease range of K +/Na + ratio and the increase range of MDA content was observed in HXWJ as compared to LXWJ during NaClstressed period,which suggested that greater biomass,higher cell membrane stability and higher tissue K + accumulation at seedling stage could be considered as the physiological characteristics in NaCl tolerant genotypes of okra.