NaCl对盐节木种子萌发和幼苗生长的影响及促进根尖生长的细胞学研究  

Effects of NaCl on seed germination and seedling growth of Halocnemum strobilaceum

作　　者：房娟娟[1] 武玉玲[1] 刘云[1] 宫慧芳[1] 马荣岗 胡灵芝[1] 陈惠[1] 

机构地区：[1]山西师范大学生命科学学院,山西临汾041004

出　　处：《草业学报》2015年第12期196-203,共8页Acta Prataculturae Sinica

基　　金：山西师范大学高等学校大学生创新性实验项目(SD2011CXSY-9;SD2012CXSY-38)资助

摘　　要：为了筛选基于MS培养基的盐节木种子萌发与幼苗生长的最佳NaCl浓度，及初步探讨NaCl渗透胁迫作用（使用MS盐消除了NaCl的离子毒害作用）促进根生长的机制，以MS为基本培养基研究了不同浓度的NaCI（0～700mmol／L）对贮存7年的盐节木种子在三角瓶中萌发及幼苗生长的影响，并用光学显微镜对适宜盐浓度促进盐节木根伸长的初步机制进行了根尖形态与细胞学观察。结果表明，1）储藏7年的种子仍有活力，对照组的活力指数和萌发率分别为3．36和74．46％，但萌发时间与前人比较有所延迟。2）盐节木种子的萌发具有不同步性，初始萌发天数为6～8d，萌发可持续到25～30d。3）基于MS培养基盐节木种子萌发最佳浓度为100～200mmol／L，与对照比可使萌发时间提早2d，且盐害率为负值。4）幼苗生长适宜的NaCl浓度范围为100～300mmol／L，最佳浓度为200mmol／L；盐对幼苗表型的影响是MSo和NaCI〉300mmol／L的MS培养基中生长的幼苗在1个月内能促进多数幼苗下胚轴变红，3～4个月后多数幼苗同化枝变红，而附加100～200mmol／LNaCl的培养基植株大多数呈绿色。5）根尖细胞学观察可知：MS附加100和200mmol／LNaCl促进根生长的原因是：NaCl促进了根尖分生组织细胞的分裂和伸长区与成熟区细胞的伸长，因而加速了根冠细胞的程序性细胞死亡，表现为根冠细胞脱落加快。本研究为盐节木耐盐机理的继续深入研究打下了一定的基础。In order to identify the optimal NaCl concentration in MS (Murashige and Skoog)medium for seed germination and growth of Halocnemum strobilaceum ,and to reveal the primary mechanism of salt osmotic stress (using MS salt medium)promotion of root growth in this species.We used MS medium as a basic medi-um and added different concentrations of NaCl (0-700 mmol/L)and measured the response of seed germina-tion and seedling growth by culturing seeds stored for 7 years.In addition seedling root tips were cultivated on media with optimum salt concentration to allow morphological and cytological observations under a light micro-scope.After 7 years of storage seed retained vigor;the seed vigor index and seed germination rate of the con-trol treatment was 3.36 and 74.46% respectively,but germination time appeared to be delayed.Seed germina-tion was not synchronized,beginning after 6-8 days and continued for 25-30 days.The optimum concentra-tion of NaCl in MS medium for seed germination ranged from 100 to 200 mmol/L and compared with the con-trol group,seeds germinated 2 days earlier.However,at NaCl concentrations over 400 mmol/L seed germina-tion was strongly inhibited.The most appropriate salt concentration range in MS medium for seedling growth was 100-300 mmol/L and the optimum concentration was 200 mmol/L.Observation of plant phenotype re-vealed that seedlings cultured on media with no or medium salt (>300 mmol/L)produced red hypocotyls and subsequently red pigmentation in most plant tissue (3-4 months growth).Root tips from seedlings cultured in medium salt conditions had accelerated root tip cell division and elongation and subsequently promoted root cap cell death and abscission.This investigation provided a good foundation for further study on the salt resistance mechanism of H .strobilaceum.

关 键 词：盐节木 NaCl浓度 种子萌发 幼苗生长 细胞学观察 组织培养法 

分 类 号：Q945[生物学—植物学]