外源6-BA对盐胁迫下甘蓝种子萌发及幼苗生长的影响

Effects of exogenous 6-BA on seed germination and seedling growth of Brassica oleracea var.capitata under salt stress

【目的】研究外源激素6-BA对盐胁迫下甘蓝种子生活力和幼苗生长势及主要酶活性的影响,为提高盐渍地甘蓝的产量提供参考。【方法】以甘蓝‘秦甘68’为试验材料,研究盐胁迫下增施0(对照),50,100,200,400,600和800 mg/L 6-BA,对甘蓝种子萌发、幼苗生长及幼苗叶片丙二醛(MDA)含量和过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性的影响。【结果】增施100,200和400 mg/L 6-BA,能够提高盐胁迫下甘蓝种子的发芽势、发芽率、发芽指数,较对照分别提高了33.23%~44.63%,15.37%~18.74%和24.64%~37.42%;株高、茎粗、最大根长、根冠比(200 mg/L 6-BA除外)等较对照增大,分别增加22.79%~65.75%,7.30%~19.71%,5.94%~20.62%和10%~25%;幼苗叶片中CAT、POD和SOD活性提高,最高分别达269.33 U/(g·min)、45.07 U/(g·min)和1244.37 U/g;MDA含量较对照降低,最低为68.897μmol/g。增施50 mg/L 6-BA对盐胁迫下甘蓝种子萌发有极显著(P<0.01)促进作用,对幼苗叶片中MDA含量有极显著(P<0.01)抑制作用,对幼苗生长及3种酶活性的影响大多与对照相近。而增施600和800 mg/L 6-BA则会显著降低盐胁迫下甘蓝幼苗的上述指标值。【结论】综合比较认为,增施100 mg/L 6-BA能够显著提高盐胁迫下甘蓝种子的生活力,有效缓解盐胁迫对甘蓝种子萌发的影响,促进幼苗健壮生长,减轻盐胁迫对幼苗生长的伤害,效果相对最好。

【Objective】This study investigated the effects of exogenous hormone 6-BA on seed viability,seedling growth potential and main enzyme activities of Brassica oleracea var.capitata under salt stress to provide reference for improving the yield of brackish cabbage.【Method】‘Qin Gan 68’was treated with 6-BA at different concentrations of 0(CK),50,100,200,400,600 and 800 mg/L to investigate the effects on seed viability,seedling growth potential,content of MDA as well as activities of catalase(CAT),peroxidase(POD)and superoxide dismutase(SOD)in seedling leaves.【Result】The germination potential,germination rate and germination index were increased by 100,200 and 400 mg/L 6-BA under salt stress,with increases of 33.23%-44.63%,15.37%-18.74%and 24.64%-37.42%in comparison with the contrast.The plant height,stem diameter,maximum root length and root-shoot ratio were increased(except 200 mg/L 6-BA)by 22.79%-65.75%,7.30%-19.71%,5.94%-20.62%and 10%-25%,respectively.The activities of CAT,POD and SOD in leaves were increased with highest values of 269.33 U/(g·min),45.07 U/(g·min)and 1244.37 U/g,respectively.The MDA content was lower than the control with the minimum of 68.897μmol/g.The addition of 50 mg/L 6-BA had very significant effect(P<0.01)on germination of cabbage seeds under salt stress.MDA content in seedling leaves was very significantly(P<0.01)inhibited,and the effects on seedling growth and enzymes activities were similar to the control.The application of 600 and 800 mg/L 6-BA significantly reduced these indicators.【Conclusion】Adding 100 mg/L 6-BA significantly improved the viability of cabbage seeds under salt stress,effectively alleviated the impact of salt stress on germination of cabbage seeds,promoted the healthy growth of seedlings,and reduced the damage on the growth of seedlings.