不同品种油葵对盐胁迫响应研究

RESPONSES OF DIFFERENT VARIETIES OF OIL SUNFLOWER TO SALT STRESS

通过盆栽试验,研究了盐胁迫对不同品种油葵出苗、生长、产量及植株Na+和K+吸收的影响,明确不同品种油葵对盐胁迫效应的差异。结果表明,随土壤盐浓度的升高,油葵的出苗率、株高、产量和生物量均有所下降,新葵杂6号受到的抑制作用更加明显;与全生育期的相比,各品种在出苗阶段的耐盐性远高于成苗至成熟期阶段,低盐胁迫对油葵的出苗和后期生长均有一定的促进作用。研究发现当盐胁迫对油葵苗期生长的相对抑制率超过40%时不能完成其生活史,超过50%时则不能生长至成熟期,在显蕾或花期枯死。随着盐胁迫程度的加剧植株中Na+的含量成倍增加,K+/Na+显著降低,而K+含量变化较小,适宜的盐浓度可促进植株对钾的吸收,但品种间存在较大的差异,在同一盐浓度下油葵植株中Na+含量陇葵杂1号<法A15<新葵杂6号,而K+含量与K+/Na+则刚好相反,各品种对盐胁迫的敏感性均为花期、显蕾期>苗期>成熟期;减少植株对Na+的吸收,维持K+的稳定性,保持较高K+/Na+是品种耐盐的重要机制之一,三个油葵品种中,陇葵杂1号耐盐性最强,其次为法A15,新葵杂6号耐盐性较差。

A pot experiment was conducted to study effects of salt stress on emergence,growth,yield and absorption of Na＋ and K＋ of oil sunflower in order to clarify differences in response to salt stress between different varieties of oil sunflower.Results show that increased soil salt concentration decreased emergence rate,plant height,yield and biomass of oil sunflower,regardless of varieties,and the inhibitory effects were more apparent with Variety XK-6 than with Varieties LK-1 and FA15.Oil sunflower was much more tolerant to salt stress at the germination stage than at any later stages,and lower salt stress was somewhat beneficial to emergence and growth of oil sunflower.It was found that when the relative inhibition rate of salt stress reached over 40% at the seedling stage,the plant could not complete its life cycle,and when over 50%,it could not survive the budding or flowering stage.Na＋ content in oil sunflower plants increased multiplied with increasing soil salt concentration,but K＋ content did not change much,thus lowering K＋/Na＋ ratio drastically.So,proper salt concentration may promote K＋ absorption by oil sunflower,but big differences exist between the varieties.The oil sunflower plants under the same salt stree followed an order of LK-1FA15XK-6 in Na＋ content,and a reverse order in K＋ content and K＋/Na＋ ratio.In terms of sensitivity of the plant at different stages to salt stress,a decreasing order of flowering stage and budding stageemergence stagematurity stage was worked out.Therefore,it seems to be a major mechanism of oil sunflower tolerating salt to reduce Na＋ absorption,keep K＋ stability and maintain higher K＋/Na＋ ratio in plants.The three varieties show a decreasing order of LK-1FA15XK-6 in salt tolerance.