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[目的]研究卷柏管状分子的类型和特点。[方法]用扫描电子显微镜对经离析法处理的4种卷柏属植物的茎进行观察。[结果]中华卷柏和蔓出卷柏中具有管胞,其中蔓出卷柏中还可见梯状穿孔的管状分子,推测可能为导管;圆枝卷柏、垫状卷柏仅观察到导管,有梯状穿孔以及网状-梯状混合型穿孔2种类型。这4种卷柏中,圆枝卷柏和垫状卷柏的管状分子最为进化,蔓出卷柏次之,中华卷柏最原始。垫状卷柏、蔓出卷柏和中华卷柏的管状分子类型为首次报道。卷柏管状分子类型的不同可能与其生境有关。[结论]该研究为验证同形叶和异形叶类型卷柏管状分子的差别以及探讨卷柏管状分子的演化问题奠定了基础。 相似文献
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Trochodendron aralioides Sieb. et Zucc. and Chloranthus glaber (Thunb.) Makino [Sarcandra globra (Thunb.) Nakai] belong to primitive angiosperms, and are characterized by the absence of vessels. Ephedra sinica Stapf, which is classified in the gymnosperms, contains vessel elements and fiber together with tracheids. Podocarpus macrophyllus (Thunb. Ex Murray) D. Don var. macrophyllus is reported to give a weak positive Mäule test, although it is classified as a gymnosperm. Podocarpus macrophyllus gave only vanillin on alkaline nitrobenzene oxidation, while E. sinica, T. aralioides, and C. glaber gave both vanillin and syringaldehyde. The molar ratio of syringyl to guaiacyl nuclei (S/V ratio) of C. glaber was significantly low (S/V = 0.08) in comparison with the value for T. aralioides (S/V = 1.56). The erythro form is the predominant diasteromeric form of β-O-4 intermonomer linkages of T. aralioides and E. sinica [molar ratio of erythro to threo forms (E/T ratio): 1.93 and 1.67, respectively]; however, P. macrophyllus and C. glaber lignins, of which S/V ratios were 0 and 0.08, gave approximately equal amounts of erythro and threo forms (E/T ratio: 1.01 and 1.14). Results from 1H NMR spectroscopy agree well with S/V ratios of alkaline nitrobenzene oxidation and E/T ratios of ozonation products. In conclusion differences in guaiacyl lignin and guaiacyl-syringyl lignin do not exactly reflect taxonomical differences, as reported in previous articles. It was found that guaiacyl-syringyl lignin is not necessarily linked to the presence of vessels. 相似文献
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中国裸子植物木材管胞瘤状层的电镜观察 总被引:4,自引:2,他引:4
本文对中国裸子植物11科、41属、99种木材管胞瘤状层进行了系统观察。瘤状层的有无及形态特征是区分裸子植物材的重要标志。此外并对5种针叶树材在一个年轮内,瘤状层从早材到晚材大小、分布密度的变化做了观察;12种针叶树材的切片,用0.5%次氯酸钠溶液处理后,瘤状物减小、以至消失;在另6个树种的管胞内,观察到瘤状层被白腐菌或软腐菌溶解。 相似文献
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