【作者】 鲁松；

【导师】 杨德奎； 李法曾；

【作者基本信息】 山东师范大学 ， 植物学， 2006， 硕士

【摘要】 中华结缕草(Zoysia sinica Hance)是我国濒危的国家二级野生保护植物。具有耐践踏、抗高温干旱、耐贫瘠、抗病虫、抗盐碱等优点,是非常珍贵的草坪植物。本文通过对中华结缕草进行不同浓度的NaCl处理,利用石蜡切片技术、光学显微技术和扫描电镜技术等,研究了中华结缕草在盐胁迫下叶片的适应性结构,并着重研究了中华结缕草的泌盐结构-盐腺的发育过程以及泌盐过程。研究结果表明,中华结缕草在盐胁迫下叶片发生以下变化。气孔器面积和气孔器的长宽比与NaCl浓度变化呈负相关。盐胁迫下,中华结缕草是通过角质层厚度的增加,导管直径的减小和导管数目的增加相互协调来渡过不良的环境的。但是叶肉细胞的低环数比例升高;泡状细胞失水,所占叶横切面整体面积的比例减小,泡状细胞的数目增加,但是最大泡状细胞的体积减小。维管柱的面积减小。盐浓度进一步升高时,叶片枯萎,甚至植株死亡。因此整体说明中华结缕草的耐盐性并不是很强。中华结缕草盐腺的发育过程是盐腺原始细胞起源于叶原基和茎尖、幼叶的原表皮。有的原表皮细胞突出生长,原生质变浓,细胞核变大,形成盐腺原始细胞。后经过平周分裂(不均等分裂)形成两个子细胞,其中一个子细胞发育成帽细胞,细胞核大且明显,另一子细胞发育成为基细胞,最终形成盐腺。盐腺基细胞肩部和底部与表皮细胞和叶肉细胞之间没有角质层隔开。角质层向外延伸越过帽状细胞,在角质层和帽细胞之间形成一空腔。泌盐时顶部先形成突起,随后突起伸长,形成顶端具小孔的具膜小管。小管中含有浓盐液,随后小管破裂在盐腺帽细胞处形成盐结晶。更多还原

【Abstract】 Zoysia sinica Hance is in severe danger in china.It is a twostage wild protectiveplant.It can resist salt stress,alkali stress,hot stress,drought and so on.Themorphological structure in leaves of Zoysia sinica Hance was studied under lightmicroscopy and scanning electron microscope, and the development of salt glands wasemphasized at different NaCl concentration. The results showed the countermeasuresagainst salt stress as follows. Growth of palisade tissue increased with the stimulationof NaCl, just as the vessel of the mid rib. Leaves became smaller with the increase ofNaCl concentrations. In the same process, the cuticle become thicker while stomabecome less in number and smaller in area. There were crystalliferous cells inmesophyllous tissue too.The structure and development about salt glands were studied.The results showed that a salt gland was composed of one stalk cell and one ball cellwith thicker cuticle covered. The salt gland originated from the epidermal cells in theyoung lamina and stems. The initial cell with large vacuole and dense cytoplasmdivided into two daughter cells. Then they formed stalk cell and ball cell. Zoysiasinica Hance possesses many useful characteristics and has become an ideal materialin halophytes filtrating. The research also represents an important part of basic plantbiology, contributing to understanding the mechanism of plant salt tolerance. That willlead to effective means to breed or genetically engineer salt tolerant plants.更多还原