【作者】 齐伟辰；

【导师】 陆静梅；

【作者基本信息】 东北师范大学 ， 植物学， 2006， 硕士

【摘要】 本文采用光学显微技术和石蜡切片技术,对生长在白城地区和长春地区的四种裸子植物,即:欧洲赤松Pinus sylvestris Linn、红皮云杉Picea koraiensis Nakai、侧柏Platycladus orientalis (linn) Franco、铺地柏Sabina procumbens(Endl.)Iwata et Kusaka进行比较结构研究。实验结果表明:在盐碱环境胁迫下,四种裸子植物都不同程度的演化出了颉颃逆境的抗旱、抗盐的结构特征。在盐生环境中生长的四种裸子植物角质层明显比中生环境的厚。四种裸子植物中除红皮云杉叶的气孔数目盐生环境的明显少于中生环境的以外,其他植物的气孔数目差距不大。盐生环境的植物气孔多数关闭或为树脂所堵塞,中生环境的植物气孔则有开放的也有关闭的。不同生态环境的四种裸子植物都表现出气孔下陷并都具有孔下室,其中盐生环境的侧柏孔下室较大,有时两个或多个孔下室连通,形成通气组织,而中生环境的孔下室小或没有。通过对盐生环境和中生环境中四种植物叶显微结构研究,结果表明盐生环境中的欧洲赤松、红皮云杉和侧柏叶片明显比中生环境的厚,这是因其处在干旱、盐碱的环境中,通过增厚叶片来减少水分散失,是受盐胁迫的结果。两种生境下欧洲赤松叶肉不同,白城市的赤松叶肉细胞小,为3-4层,有利于光合作用。长春市的赤松叶肉细胞大,为2层,光合作用不如白城市的赤松叶肉细胞强。但是,它们的细胞壁都向内皱褶,呈梅花型。中生环境叶肉细胞多为长圆柱形。细胞壁向内凹陷,就形成了壁内突的结构,有利于细胞吸收和分泌某些物质;质膜紧贴细胞壁生长,增加了质膜的表面积,大大地扩大了原生质体表面积与体积之比,叶绿体沿褶皱而分布,这些褶皱增加了叶绿体在细胞内排列的面积。本实验结果发现,在盐碱环境胁迫下的四种裸子植物都演化出了发达的通气组织。通气组织形成低压空腔可以增强对氧气吸收能力,保证了盐碱生态环境下植物体的正常呼吸及代谢;还可以减少光子扩散阻力,从而提高植物光合效能,增强抗盐性。欧洲赤松和红皮云杉针叶都具发达的转输组织,白城地区赤松和云杉针叶转输组织细胞多为长圆柱形,稀不规则多边形,长春赤松和云杉针叶转输组织细胞为不规则多边形。转输组织是裸子植物叶子特有的一种结构,有助于叶肉组织与维管束之间的物质交流。转输管胞次生壁上有具缘纹孔,为原始的转输组织,它是由管胞分子演化而来。欧洲赤松针叶的维管束,在盐生环境的木质部所占维管束的比例比中生环境的小,盐生环境的红皮云杉针叶的维管束木质部管胞小。针叶内木质管胞小和细胞数量增加是一种旱生适应特征。更多还原

【Abstract】 Anatomic structures of Pinus sylvestris Linn,Picea koraiensis Nakai,Platycladus orientalis (linn) Franco and Sabina procumbens(Endl.)Iwata et Kusaka growing in Baicheng and Changchun were studied by the methods of paraffin and two-dimensional microtechnique.The study showed that the four gymnosperms evolved structures of drought-and salt-resistance to divergent extents under the saline environment. The cuticles of these four gymnosperms growing in saline environment were significantly thicker than those that growing in mesophytic habitat。The number of stoma was similar between P. sylvestris Linn、P. orientalis (linn) Franco and S.procumbens growing in different habitats, but that of P. koraiensis was different. Most of the stoma of plants growing in saline were closed or were jammed by resin, whereas those of plants growing in mesophytic habitat were open or closed sometimes. There were cryptopores and substomatal chamber in the four gymnosperms growing in two habitats. And substomatal chamber of P. orientalis growing in saline habitat was bigger and there were ventilating tissues formed by two or more substomatal chamber, but there were not or smaller substomatal chamber in P. orientalis growing in mesophytic habitat.The needles of P. sylvestris ,P.koraiensis,P. orientalis and S.procumbens growing in saline habitat were significantly thicker than those growing in mesophytic habitat, probablely because the thicker leaves can decrease water loss in saline and droughty environment which was the result of salt stress.The mesophylls of P. sylvestris growing in two habitats were different. There were smaller and 3-4 layers of mesophylls in P. sylvestris growing in Baicheng, which in favor of photosynthesis. There were larger and two layers of mesophylls in P. sylvestris growing in Changchun which showed weaker photosynthesis. But their methophylls were both cinquefoil-shaped and the cell walls had inner plications which can absorb and secrete materials efficiently. Inner plications increase the ratio of surface area to volume of mesophyll, that is to say, the distribution area of chloroplast.The study also found that the four gymnosperms all evolved ventilating tissues under saline environment. Ventilating tissues can form chamber with low pressure which can strengthen the ability of absorbing oxygen, guarantee the normal respiration and metabolism of plants under saline habitat, decrease the diffusion resistance of photons and so can increase the photosynthetic efficiency and salt resistance.Transfusion tissues of P.sylvestris and P. koraiensis were both developed and belong to更多还原