珍稀濒危植物裸果木生物学特性研究

Study on Biological Characteristics of Rare Endangered Plant Gymnocarpos Przewalskii

裸果木属国家一级重点保护野生植物,具有重要的科研价值。在分析裸果木研究现状的基础上,测定了裸果木的结籽率、种子萌发的最适温度和裸果木的染色体数目,并运用形态解剖学的方法,研究和探讨了裸果木对干旱环境的适应性结构特征。结果表明,裸果木的结籽率非常低,不到1%;裸果木种子萌发的最适温度为25℃,木体细胞染色体数目为2n=40。由于裸果木长期生活在干旱的荒漠环境中,形成了一整套对干旱和低温的适应性结构。即叶片线形、气孔下陷、表皮角质化程度高且附有蜡质层,栅栏组织发达,几乎没有海绵组织,贮水组织发达;茎部次生木质部发达,髓腔较大;根茎比率高,根皮层具有发达的贮水薄壁组织。分析了裸果木濒危的主要原因,并提出了保护措施。

Gymnocarpos przewalskii was the first national protection species, it had important research value. Based on the summarizing of its current research condtions, tiffs article determined the seedling rote of Gymnocarpos przewalskii, conformed the optimum temperature of seed germination, took count of chromosome number and with merphologieal anatomy, discussed the adaptability chacteristies on arid environment of environment. The results showed that： The seeding rate was 1%, the optimum temperature of seed germination was 25 ℃, the chromosome numbers were 2n = 40. Because of always leading a dry and desert life, Gymnocarpos przewalskii were formed a series of adaptive stretures： Slender leaves, thick cuticle, sunday stomata, waxy layer, well - developed palisade tissue, degenerated spony tissue, the ratio of palisade tissue to spony tissue, well - developed water storing tissue, well - developed leilgewebe and faserbard, well - developed sckundares of stem, bigger markgewebe, high ratio of root to stem and so on. At last the authors analyzed the endangered reasons of Comnocarpos przewalskii and proposed several advice to protect it.