海水胁迫对海稻86种子萌发和幼苗生长的影响

Effects of seawater stress on seed germination and seedling growth of Sea rice 86

【目的】探讨盐胁迫对耐盐水稻新品种海水稻(海稻86)芽苗期生长发育的影响,为耐盐水稻的推广应用及构建河口低盐池塘渔稻生态共作模式提供参考。【方法】分别在海稻86种子萌发和幼苗生长阶段进行水培试验,以蒸馏水(盐度0)为对照,模拟不同盐度海水胁迫(3‰、6‰、9‰、12‰、15‰和20‰)处理后,测定种子发芽状况(发芽率、发芽势、发芽指数和活力指数)和幼苗表观形态特征(根长、茎长、叶长及各器官生物量分配),分析海水稻对盐胁迫的响应及其对海水盐度的生长适应范围。【结果】不同盐度海水溶液对海稻86的种子活力表现出低促高抑作用,当海水溶液盐度为3‰时,种子的发芽率、发芽势、发芽指数和活力指数均达最大值,随海水溶液盐度的继续升高,种子活力呈下降趋势。随海水营养液盐度升高,海稻86种子胚芽和幼苗生长均受到不同程度的抑制,胚芽长、苗高、叶长、主根长、生物量及冠跟比等指标总体上均呈下降趋势,但低盐海水(3‰)对海水稻根系的生长有一定促进作用;海稻86种子萌发的最佳盐度和最大盐度分别约为3‰和15‰,幼苗生长适盐范围为0~9‰,当在盐度超过9‰时,幼苗生长缓慢(15‰),甚至停止生长逐渐枯黄(20‰)。【结论】海稻86在苗芽期具有较强的耐盐性,适盐范围较广,适合在河口低盐或半咸水养殖池塘推广种植。

【Objective】The effects of salt stress on seedling growth of a new salt-tolerant rice variety(Sea rice 86)at seedling stage were explored,which provided scientific basis for the development and application of salt-tolerant rice and for the construction of fish-rice farming mode in low-salinity ponds.【Method】Water culture experiment was conducted on Sea rice 86 during seed germination and seedling stages.Distilled water(0 salinity)was as control,and a series of seawater stress treatments(3‰,6‰,9‰,12‰,15‰and 20‰)were simulated.Then the seed germination status(germination rate,germination potential,germination index and vigor index)and the morphological characters of seedlings(root length,stem length,leaf length and biomass allocation of plant organs)were investigated to analyze the response of sea rice to salt stress and its adaptation range to the salinity of seawater.【Result】Seed activity of Sea rice 86 were promoted in lowsalinity treatments but inhibited in high-salinity treatments.Seed germination rate,germination potential,germination index and vigor index reached its highest level in 3‰treatments,then gradually declined as the salinity increased.With the increase of salinity in seawater nutrient solution,the seed germination and seedling growth of Sea rice 86 were adversely affected,growth indicators such as shoot length,seedling height,length of leaf and root,biomass,shoot to root ratio decreased,but the root growth of Sea rice 86 were promoted in low-salinity treatments(3‰).The optimum salinity and the maximum salinity for seed germination of Sea rice 86 were about 3‰and 15‰respectively.The suitable salinity range for seedling growth was between 0 and 9‰.When the salinity was above 9‰,the seedlings grew slowly(15‰),even stopped and gradually withered(20‰).【Conclusion】Sea rice 86 has strong salt tolerance at seedling stage and a wide range of adaptive salinity.It is suitable for planting in low-salt estuary areas or brackish water aquaculture pond.