紫梗籽银桂种子发育过程的超微结构观察  

Ultrastructure Observation in Seed Development of Osmanthus fragrans'Zigengziyin'

作　　者：朱永莉 沈永宝 ZHU Yongli;SHEN Yongbao(College of Humanities and Law,Shanghai Business School,Shanghai 201400,China;College of Forestry,Nanjing Forestry University,Nanjing 210037,China;Southern Tree Seed Inspection Center,National Forestry Administration,Nanjing 210037,China;Co-Innovation Center for the Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]上海商学院文法学院,上海201400 [2]南京林业大学林学院,南京210037 [3]国家林业局南方林木种子检验中心,南京210037 [4]南京林业大学南方现代林业协同创新中心,南京210037

出　　处：《种子》2025年第2期210-216,共7页Seed

基　　金：江苏省珍稀乡土树种种质资源离体保护长期科研基地项目(LYKJ[2021]03)。

摘　　要：为探讨桂花种胚发育过程及与种子休眠形成的内在联系,以紫梗籽银桂种子为材料,对其不同发育时期果皮、种皮、胚和胚乳进行扫描电镜和透射电镜观察。扫描电镜观察发现,在紫梗籽银桂种子发育初期,种子表皮细胞由鳞形和长方形的细胞交替组成,排列较为疏松;随着种子的发育,种子表皮细胞开始脱水,出现明显沟壑状,种皮结构更加致密;至种子发育成熟,种皮中部变得较为平坦,种皮表面出现较多长条状纹饰;果实在发育过程中果皮厚度明显增加,随着果实发育成熟,外果皮、中果皮逐渐变软,内果皮逐渐木质化变硬,形成种壳。透射电镜观察发现,紫梗籽银桂种子发育初期,在胚和胚乳细胞中液泡较多,细胞内有少量的嗜锇物质,细胞质较丰富,细胞体积较小;随着种子的成熟,胚和胚乳细胞内的脂滴和高电子致密物质不断增加,说明在紫梗籽银桂种子发育过程中,种子内大分子贮藏物质不断积累,种子逐渐进入休眠期。To investigate the developmental process of Osmanthus fragrans embryos and its intrinsic relationship with seed dormancy establishment,this study employed Osmanthus fragrans'Zigengziyin'seeds as experimental material,conducting systematic scanning electron microscopy(SEM)and transmission electron microscopy(TEM)observations on the pericarp,testa,embryo,and endosperm at distinct developmental stages.SEM analysis revealed that during early embryogenesis of Osmanthus fragrans'Zigengziyin',the seed epidermis exhibited an alternating arrangement of squamous and rectangular cells with loose intercellular connections.Progressive developmental stages manifested epidermal cell dehydration accompanied by pronounced furrow-like structures and enhanced testal compaction.At maturity,the median testal region displayed relative planarity with abundant linear ornamentations.Concurrently,pericarp thickness increased significantly throughout development,with the exocarp and mesocarp undergoing gradual softening,while the endocarp underwent lignification to form the protective seed shell.TEM observations demonstrated that initial embryonic and endospermic cells contained abundant vacuoles,sparse osmiophilic substances,dense cytoplasm,and diminutive cellular dimensions.As maturation progressed,these cells exhibited substantial accumulation of lipid droplets and high-electron-density substances.This cytological progression indicated continuous deposition of macromolecular storage materials during seed development of Osmanthus fragrans'Zigengziyin',ultimately culminating in physiological dormancy establishment.

关 键 词：紫梗籽银桂 种子发育 超微结构 扫描电镜 透射电镜 

分 类 号：S685.13[农业科学—观赏园艺]