刺五加、无梗五加花粉的亚显微形态学研究

用扫描电子显微镜观察了刺五加和无梗五加花粉的亚显微形态特征。花粉粒的赤道面观呈近圆形,极面观呈三裂圆形,具三孔沟。无梗五加、刺五加雄株的花粉表面纹饰为网状;刺五加两性株的花粉的表面纹饰亦呈网状,但有些花粉网脊不连续。无梗五加的花粉粒大小为26.5μm×27.4μm;刺五加雄株的花粉粒大小为21.1μm×22.1μm;刺五加两性株的花粉粒大小约为21.6μm×23.9μm。研究结果表明,无梗五加和刺五加雄株花粉的亚显微形态特征支持传统的属级和种级水平的分类;刺五加两性株某些花粉粒亚显微形态的独特表现可能与其发育不正常有关。     

Contrasting genetic patterns between two coexisting Eleutherococcus species in northern China

Climate oscillations are the key factors to understand the patterns in modern biodiversity. East Asia harbors the most diverse temperate flora, largely because an extensive terrestrial ice cap was absent during repeated Pleistocene glaciation–interglacial cycles. Comparing the demographic histories of species that are codistributed and are close relatives may provide insight into how the process of climate change influences species ranges. In this study, we compared the spatial genetic structure and demographic histories of two coexisting Eleutherococcus species, Eleutherococcus senticosus and E. sessiliflorus. Both species are distributed in northern China, regions that are generally considered to be sensitive to climatic fluctuations. These regions once hosted temperate forest, but this temperate forest was replaced by tundra and taiga forest during the Last Glacial Maximum (LGM), according to pollen records. Using three chloroplast DNA fragments, we assessed the genetic structure of 20 and 9 natural populations of E. senticosus and E. sessiliflorus, respectively. Extremely contrasting genetic patterns were found between the two species; E. sessiliflorus had little genetic variation, whereas E. senticosus had considerably higher levels of genetic variation (15 haplotypes). We speculated that a recent severe bottleneck may have resulted in the extremely low genetic diversity in E. sessiliflorus. In E. senticosus, populations in Northeast China (NEC) harbored all of the haplotypes found in this species and included private haplotypes. The populations in NEC had higher levels of genetic diversity than did those from North China (NC). Therefore, we suggest that both the NC and NEC regions can sustain LGM refugia and that lineage admixture from multiple refugia took place after the LGM elevated the local genetic diversity in NEC. In NEC, multiple genetic hot spots were found in the Changbai Mountains and the Xiaoxing'an Range, which implied that multiple locations in NEC may sustain LGM refugia, even in the Xiaoxing'an Range.     

刺五加、短梗五加的花蜜分泌节律、花蜜成分及访花者多样性的比较研究

野外定位观测刺五加（Eleutherococcus senticosus）、短梗五加（E.sessiliflorus）的花蜜分泌节律、访花者的多样性,室内分析其花蜜的主要成分。结果表明,刺五加雄株的花杂在开花1－3（4)d分泌花蜜,雌株在开花5－7,6－8或7－9d分泌花蜜;短梗五加以及刺五加两性株的部分花杂,在开花后有两次分泌花蜜的过程：第1次与花药开裂散粉时间一致,第2次与柱头具可授性的时间一致。而且,刺五加和短梗五加都由动物帮助传粉,花蜜分泌的时间与多数访花者的访花时间一致,在一天之中,散出花粉的花朵分泌花蜜的时间早于接受花粉的花杂,这种时间差异应该是植物控制该 花者流向并导致传粉成功的关键。短梗五加与刺五加之间以及刺五加不同性别的植株之间,花蜜的成分及相对含量各有特点,但都以果糖和葡萄糖为主。在刺五加、短梗五加花朵上记录到的访花昆明分别为50余种和40余种,多数隶属于膜翅目、鳞翅目、鞘翅目和半翅目。其中膜翅目的胡蜂、马蜂、熊蜂,双翅目的食蚜蝇、寄蝇等是刺五加、短梗五加的常见访花者。     

五加属学名考证及其一些新组合

本文考证了五加属学名,支持废弃不合法名称ＡｃａｎｔｈｏｐａｎａｘＭｉｑ．,强调应用合法名称ＥｌｅｕｔｈｅｒｏｃｏｃｃｕｓＭａｘｉｍ,在此基础上,将Ａｃａｎｔｌｈｏｐａｎａｘ属名下２种及１变种并入Ｅｌｅｕｔｈｅｒｏｃｏｃｃｕｓ属名,并对Ｅｌｅｕｔｈｅｒｏｃｏｃｃｕｓ属的４个异名作了订正。     

Influence of inoculum density and aeration volume on biomass and bioactive compound production in bulb-type bubble bioreactor cultures of Eleutherococcus koreanum Nakai

This study deals with the effects of initial inoculum density and aeration volume on biomass and bioactive compound production in adventitious roots of Eleutherococcus koreanum Nakai in bulb-type bubble bioreactors (3-L capacity). While the fresh and dry weights of the roots increased with increasing inoculum density, the highest percentage dry weight and accumulation of total target compounds (eleutheroside B and E, chlorogenic acid, total phenolics, and flavonoids) were noted at an inoculum density of 5.0 g L⁻¹. Poor aeration volume (0.05 vvm) stunted root growth, and high aeration volume (0.4 vvm) caused physiological disorders. Moreover, an inoculum density of 5.0 g L⁻¹ and an aeration volume of 0.1 vvm resulted in the highest concentration of total target compounds and least root death. Such optimization of culture conditions will be beneficial for the large-scale production of E. koreanum biomass and bioactive compounds.     

短柄五加种子结构、后熟作用及其细胞化学研究

短柄五加Eleutherococcus brachypus Harms种子为扁肾形,种皮由一层细胞构成。种子脱落时,胚 为心形胚期,胚周围的胚乳细胞解体形成液样囊腔,并包裹胚,胚细胞中存在较多蛋白质,胚乳细胞贮 存大量蛋白质颗粒和脂类,但两者均未见多糖颗粒。有萌发潜能的种子只占全部种子的9.27％。在试 验地种植条件下饱满种子经18～19个月后萌发,出苗率为1．67％,该过程细胞化学特点是胚细胞中蛋 白质含量逐渐减少,并逐渐积累少量多糖颗粒。种子经变温层积处理6个月即可完成后熟过程,其细胞 化学特点是胚细胞中蛋白质含量逐渐减少,但在心形胚后期即已积累大量多糖颗粒,并一直保持至胚 完全发育成熟。经比较短柄五加与刺五加的种子结构、后熟作用及其细胞化学特点,认为短柄五加种子质量差、自然状态下后熟时间长和出苗率低是短柄五加致濒的重要生殖因素,并提出了相应保护方法。     

刺五加开花后雌蕊的发育状态与受精作用

刺五加Eleutherococcus senticosus(Rupr． et Maxim．)Maxim．植株在开花后雌配子体的发育状态与 一般植物不同在于:雌配子体在开花当天均末成熟,在开花后经4-5天才发育成熟。开花第6天,雌株 和两性株的成熟胚囊百分率各为82．25％和67．25％,其余为未育、败育、退化或未成熟胚囊,未观察到 已受精的胚囊;而此时,雄株的雌配子体退化、花朵全部脱落。伴随着胚囊的分化,刺五加雌株和两性株 的花柱逐渐延长,蜜腺渐趋成熟。开花后4～6天,乳突细胞发育,柱头开始外翻;此后,蜜腺分泌花蜜, 柱头进入可授期。开花第7天,胚囊开始受精。开花后9～10天,雌株已受精的胚囊占胚囊总数的40～ 65％,两性株已受精的胚囊占胚囊总数的25～41％。刺五加花粉萌发至雌雄性核融合的间隔期约为2 ～3天。刺五加的双受精过程与一般被子植物基本相同。其受精作用属于有丝分裂前配子融合类型。 此外,还观察了成熟胚囊退化的类型,观察到多余花粉管进入胚囊以及两个精子与卵受精、两个精子与次生核融合的图象。     

短柄五加开花后雌蕊的发育状态与受精作用的研究

短柄五加（ＥｌｅｕｔｈｅｒｏｃｏｃｕｓｂｒａｃｈｙｐｕｓＨａｒｍｓ．）开花当天,花药散粉,而雌配子体需经４～５ｄ才发育成熟。证实短柄五加为雄蕊先熟植物。开花第５天,成熟胚囊的比率为５７６９％,其余为退化和不育胚囊。开花第６天,胚囊开始受精。开花第１０天,受精胚囊占胚囊总数的５３５７％。柱头的可授期自开花后第４～５天开始,自花粉萌发至雌雄性核融合大约有２～３ｄ的间隔期。短柄五加受精过程与一般被子植物相同,其受精作用属于有丝分裂前配子融合类型。观察并统计了合子中雌性核仁的数目、存在状态,指出短柄五加合子中从雄性核仁出现到与雌雄性核仁融合为一个大核仁需经历３ｄ左右;如果以胚乳游离核数目为对照,大部分合子中雌雄性核仁的融合发生在３２～１２８个胚乳游离核时期。大多数合子是以雌雄性核仁融合为一个大核仁后进入合子分裂期;少数合子的雌雄性核仁不经融合也进入合子分裂期。观察到多精入胚囊、多精入卵以及成熟胚囊退化的现象。讨论了被子植物受精过程中有关受精终结的标志等问题。     

刺五加(Eleutherococcus sentincosus)会成为濒危种吗?

刺五加是阔叶红松林及其次生林下的重要灌木。因其优良的药用功能和疗效,自７０年代末进行工业生产以来,资源消耗与日俱增,１９９２年出版的《中国植物红皮书———稀有濒危植物》中,被列为渐危植物。本文通过野外调查、长期定位观测和实验生态学的试验,对影响刺五加种群持续和发展的内外因素进行了研究。认为造成刺五加种群迅速缩小的主要外因是不合理采挖。刺五加结实的植丛少,种子产量低、质量差、传播动力弱,并具有先天性休眠及自毒现象等一系列种群过程,是制约刺五加种群持续和扩展的内在因素。无性繁殖是维持现有种群的主要途径。长期无性繁殖可能导致遗传多样性下降,从而减弱了它对多变环境的抗逆性,若在外因的作用下可能使种群进一步缩小,进而增加其濒危的程度。