盐胁迫对淡水浇灌互花米草种子的萌发及胚生长的效应  

Effects of Salt Stress on Seed Germination and Embryo Growth of Spartina alterniflora Cultivated with Fresh Water

作　　者：任丽娟[1,2] 仇乐[3] 王国祥[1,2] 毛志刚[1,2] 刘金娥[1,2] 

机构地区：[1]南京师范大学地理科学学院,南京210046 [2]江苏省环境演变与生态建设重点实验室,南京210046 [3]南京师范大学生命科学学院,南京210046

出　　处：《植物研究》2010年第3期305-310,共6页Bulletin of Botanical Research

基　　金：国家自然科学基金(40973053);江苏省近海资源专项调查与评价专项(JS-908-07-2);江苏省高校自然科学重大基础研究项目(08KJA180002)

摘　　要：盐度是影响互花米草在海滨湿地分布的重要生态因子,本文以淡水浇灌互花米草的种子为研究对象,通过对0～90g.L-1NaCl盐胁迫下种子萌发与胚的生长进行观测,结果表明:淡水浇灌互花米草种子具有萌发能力,萌发率最高达69%;盐胁迫对种子的萌发与胚的生长具有抑制作用,能够降低种子初始萌发率、种子萌发速率,并减缓胚的生长;高盐(盐浓度>30g.L-1)胁迫下,初始萌发率降低,同时种子萌发生成无胚根畸形胚;解除盐胁迫,移植到淡水培养后,胚在胚芽鞘基部长出不定根,而胚根未长出;种子在高盐条件下休眠,盐胁迫解除后,种子萌发率可以部分恢复,且种子的萌发恢复率与原胁迫盐浓度呈显著正相关关系;总萌发率与盐溶液浓度呈二次函数关系,在63g.L-1左右的盐溶液中,种子萌发力最低。盐胁迫下互花米草特殊的萌发与生长对策,可能是其适应并成功入侵海滨湿地的重要原因之一。Salinity is among the important ecological factors affecting the distribution of Spartina alterniflora in coastal wetland. In this study, we cultivated S.alterniflora in fresh water, and collected the seeds. Then the germination and embryo growth of the seeds in different NaCl salt solutions（salinity between 0~90g·L-1） were observed. It indicated that S.alterniflora cultivated with fresh water could germinate and the maximum germination rate was 69%; salt stress decreased seed initial germination rate, seed germination velocity and embryo growth; in high salt solution （salinity 30g·L-1）, seed initial germination rate decreased and the seed germinated embryo without radicle; after the stressed embryo was transplanted into fresh water, adventitious root of the embryo grew out in basal part of the coleoptile, but the radicle could not grow out; seed dormancy happened in high salinity, and when salt stress was relieved, the seed germination rate partially recovered; there was a significant positive correlation between the recovered seed germination rate and the salt stress it suffered before; the relationship between the total germination rate and the solution salinity was a secondary function; the seed in the solution of 63g·L^-1 NaCl showed the lowest germination rate. The special strategies of seed germination and embryo growth under salt stress were probably an important reason for S.alterniflora to cope with and successfully invade the coastal wetland.

关 键 词：互花米草 盐胁迫 种子萌发 胚的生长 

分 类 号：S727.26[农业科学—林木遗传育种]