疣壶藓尖叶变种的芽胞形成及其生态意义  

Gemma Formation of Gymnostomiella vernicosa var.acuminata and Ecological Implications

作　　者：权玉萍 刘永英[1] 赵建成[2] QUAN Yuping;LIU Yongying;ZHAO Jiancheng(Department of Biology, Jiaozuo Teachers College, Jiaozuo, Henan 454001, China;2College of Life Science, Hebei Normal University, Shijiazhuang 050024, China)

机构地区：[1]焦作师范高等专科学校生物系,河南焦作454001 [2]河北师范大学生命科学学院,石家庄050024

出　　处：《西北植物学报》2020年第1期53-57,共5页Acta Botanica Boreali-Occidentalia Sinica

基　　金：国家自然科学基金(31370237);河南省高等学校重点科研项目(18A180021)。

摘　　要：该研究以疣壶藓尖叶变种(Gymnostomiella vernicosa var.acuminata)为实验材料,在人工培养条件下观察并记录其芽胞产生及脱落过程,以揭示该分类群及相关类群的芽胞形成过程和机制,为疣壶藓尖叶变种的分类提供参考性特征指标,明确苔藓植物芽胞的进化和生态学意义。结果显示,疣壶藓尖叶变种的芽胞形成过程划分为3个阶段:(1)茎表皮细胞的外切向壁局部向外隆起,外突的疣壶藓尖叶变种表皮细胞富含叶绿体,可进行光合作用。(2)芽胞起始细胞横向分裂,形成一个基细胞和一个顶细胞;基细胞经数次横向分裂,下部形成柄状结构,上部的细胞常呈喇叭形的“柄托”;顶细胞经多方向细胞分裂,形成椭球状至圆球状芽胞体,形成初期为富含叶绿体的厚壁细胞,成熟后叶绿体数目逐渐减少,最终变成深棕色至红棕色。(3)由薄壁的柄细胞随机破损使芽胞从母株上脱落。研究表明,在无法预测的多变栖息环境中,相对于有较高的能量、遗传和生态消耗的有性生殖,疣壶藓尖叶变种产生芽胞是一种风险分担策略,可以提高生存几率和有效利用资源,可视为一种扩大和维持种群的有效途径。In the research of the gemma in bryophyte,the bryologists mainly focus on the morphological traits and the uses in the classification.On the contrary,they virtually ignored the formation and liberation process of gemmae in the past.The present paper documented these process based on new observations on cultured materials,Gymnostomiella vernicosa var.acuminata.The aim of the study is to understand the formation pattern of gemma in this taxon and its related groups;to add classification characteristics for this variety;to understand the ecological and evolutionary significance of gemma in bryophytes.The results show that three stages can be divided roughly for occurrence process of the gemma:(1)the part of outer tangental wall in epidermis cell on the stem extrudes.These bulging epidermis cells have aboundant chloroplasts,reflects considerable photosynthetic autonomy.(2)The bulging cell divides transversely into one basal cell and one apical cell.The basal cell continues to divide transversely,and matures into a stalk structure with a trumpet-shaped distal cell.The apical cell subsequently divides for several times,and forms one ellipsoidal to sphere gemma.The thick walled cells of gemma have aboundant chloroplasts originally,and then number of chloroplasts drops lower gradually.The color of the gemma becomes generally into the thick brown to red brown after the gemma is mature.(3)The thin walled stalk cells break randomly that lead the gemma to liberation from the parent plant.In contrast to sexual reproduction,genetic,energetic and ecological cost of asexual reproduction is generally shown to be lower.In the inhabiting unpredictably varying environments,production of gemma for G.vernicosa var.acuminata can be interpreted as a risk spreading strategy,which effectively use of resources and enhances survival,and an effective way to maintain and enlarge populations.

关 键 词：疣壶藓尖叶变种 人工培养 芽胞形成 无性繁殖 生态意义 

分 类 号：Q945.51[生物学—植物学] Q949.35