滇鼠刺花的形态发生（鼠刺科）

在扫描电镜下 ,观察了滇鼠刺 (IteayunnanensisFranch .)花的形态发生。花 3朵一束 ,排成总状花序。花器官为轮状结构 ,向心发生 ;花萼以 2 /5螺旋式相继发生 ,5个花瓣原基几乎同步地在花萼内侧与其互生的位置发生。雄蕊单轮对萼。当雄蕊发生后 ,花顶中心的分生组织开始凹陷 ,成为浅锅状 ;在其周围出现一个环状的分生组织 ,随之 ,2心皮原基产生 ,进而发育为马蹄形。初期的心皮相互分离 ,随着进一步发育 ,心皮内卷 ,彼此靠近、紧贴 ,逐渐于腹面合生 ,形成 2室的中轴胎座 ;花柱的腹维管束通过薄壁组织连通 ;花期柱头融合 ,因此该种为合生心皮。对鼠刺属 (Itea)及相关类群花发育性状和花结构进行了比较 ,支持把鼠刺属提升为鼠刺科 (Iteaceae)的观点。     

西南美木滇鼠刺

滇鼠刺(Itea yunnanensis Franch.)为鼠刺科(也有学者主张将之归入虎耳草科)常绿灌木或小乔木,高1—10m,叶薄革质,卵形或椭圆形,长5—10cm,宽2.5—5cm,先端尖,边缘具锯齿;总状花序顶生,常俯弯至下垂,长达20cm。蒴果长约6mm,在每个菱形的蒴果内产有很多黑色的纺锤形细小种子。     

榛属 (桦木科) 花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4~6个雄蕊原基,形成4~6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中,出现雄蕊原基纵裂,并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

马兜铃属(马兜铃科)花的形态发生研究

对马兜铃属植物北马兜铃(Aristolochia contorta Bge.)花形态发生的扫描电镜观察表明:其花萼在发生时与苞片相似,6枚雄蕊呈4枚先发生、2枚后发生的方式,心皮的发生以6个胎座突出到子房室中为特征,由侵入的侧膜胎座合生为中轴胎座。在胎座发生发育过程中,在花药的腹面各产生一个突起,此突起后来与胎座上端相连,最终发育为合蕊柱裂片。结合文献资料,我们认为北马兜铃的花被与苞片是同源的,其合蕊柱裂片来自于雄蕊,中轴胎座是次生的。     

毛尾刺虫无性生殖周期中的形态和形态发生

利用蛋白银染色法研究了毛尾刺虫的形态及无性生殖周期中的形态发生,其过程为：（１）后仔虫口原基出现在左缘棘毛内侧深层,其内的毛基体组装成整齐排列的小膜并分化成新ＡＺＭ１,ＡＺＭ２和口侧膜,（２）前仔虫口原基出现在老仔虫ＡＺＭ２之前方深处,其随后发育成前仔虫的ＡＺＭ２口侧膜及ＡＺＭ１的一部分,并更新老结构的ＡＺＭ１中第７－１１片小膜,（３）额腹横棘毛原基为５列,分别以３：３：２：２：３方式分化最终产出     

黄连属(毛茛科)花的形态发生

本文运用扫锚电子显微镜(SEM)观察了黄连属(Coptis)植物花的形态发生和发育过程, 结果表明, 该属植物所有的花部器官均为螺旋状发生, 雄蕊为向心式发育, 花瓣原基有微弱的延迟发育, 心皮原基为对折型(即马蹄形), 子房为半封闭类型, 子房柄是在发育过程中形成的。通过与其它具T-型染色体类群在花形态发生上的比较, 认为黄连属表现出了某些原始的性状, 这一结果与分子系统学研究认为黄连属为毛茛科的基部类群的结论一致。     

黄连属(毛茛科)花的形态发生

本文运用扫锚电子显微镜（SEM）观察了黄连属（Coptis）植物花的形态发生和发育过程,结果表明,该属植物所有的花部器官均为螺旋状发生,雄蕊为向心式发育,花瓣原基有微弱的延迟发育,心皮原基为对折型（即马蹄形）,子房为半封闭类型,子房柄是在发育过程中形成的。通过与其它具T．型染色体类群在花形态发生上的比较,认为黄连属表现出了某些原始的性状,这一结果与分子系统学研究认为黄连属为毛莨科的基部类群的结论一致。     

华中五味子（五味子科）雄花和雌花的形态发生

通过扫描电镜观察了中国特有种华中五味子（ＳｃｈｉｓａｎｄｒａｓｐｈｅｎａｎｔｈｅｒａＲｅｈｄｅｔ．Ｗｉｌｓ）,雄花和雌花的形态发生过程,雄花：花被片和雄蕊连续向顶发生,未见有雌性结构的分化,花药的分化先花丝,雄蕊始终螺旋状排列在柱状花托上,雌花：花被片和心皮也为２／５序列连续地螺旋状向顶发生,未见有雄性结构的分化,心皮原基近轴面基部边缘的活动不明显,心皮为对折型：胚珠原基在心皮近轴面上近边缘处发生     

榛属（桦木科）花序及花的形态发生

在扫描电镜下观察了桦木科榛属榛、毛榛和滇榛的花序和花的形态发生过程。榛属雌花序由多个小聚伞花序螺旋状排列组成;每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化形成2个花原基;每个花原基分化出2个心皮原基,形成二心皮雌蕊;雌蕊基部有2层花被原基,内层花被原基环状,外层花被发生于花原基近轴面和远轴面,近轴面和远轴面的花被不均等分化,外层花被发生早于内层花被。雄花序为柔荑状,由多个小聚伞花序螺旋状排列组成。每个小花序原基分化出1枚初级苞片和一团小花序原基分生组织,由小花序原基分生组织分化出2枚次级苞片和4。6个雄蕊原基,形成4—6枚雄蕊,每个雄蕊具4个药囊,在雄蕊原基分化形成4药囊雄蕊过程中．出现雄蕊原基纵裂。并且花丝纵裂至基部。为进一步全面探讨桦木科属间系统演化关系提供了证据。     

鼠刺科鼠刺属一新种

Itea tenuinervia S. Y. Liu,sp.nov.Affinis I. riperiae Coll. et Hemsl. quaeplantisad 6 m altis,foliis obovato-oblongis,ellipticis vellanceolatis,racemo pendulo,pedicellis(3～ 5 mmlongis) etpetalis(4 mm longis) omnine brevioribusdiffert;etiam species I. tho…     

Floral Ontogeny of Two Species in Magnolia L.

Floral ontogeny is described in two species of genus Magnolia （Magnollaceae）, Magnolia alboserlcea Chun et C. Tsoong, and M. amoena Cheng, representing subgenus Magnolia and subgenus Yulani In Magnolia, by using scanning electron microscope （SEM）. The sequence of Initiation of floral organs Is from proximal to distal. The three distinct outermost and middle organs are Initiated in sequence, but ultimately form a single whorl, thus their ontogeny Is consistent with a sepal Interpretation. The last three tepals （petals） alternate with the preceding tepal whorl. The members of androeclum and gynoeclum arise spirally, although the androecium shows some Intermedlacy between a spiral and whorled arrangement. The carpel prlmordia initiate in group of four to five. The order of stamen Initiation within each tier Is not determined. The floral ontogeny Is remarkably homogeneous between the subgenus Magnolia and subgenus Yulani that does not support the resuming of genus Yulani.     

数珠珊瑚(商陆科)的花器官发生

对数珠珊瑚的花器官发生和子房的发育过程进行了观察。结果表明：(1)数珠珊瑚花被呈2／5螺旋状发生,远轴侧的1枚先发生,其次为近轴侧的1枚发生,最后侧方的2枚花被几乎同时发生,第3枚花被在靠近第1枚的位置发生,第2枚和第3枚之间有1个空隙;(2)4枚雄蕊是同时发生的;(3)心皮发生于分生组织的远轴侧,心皮原基形成后,向上向轴生长,在子房成熟前在近轴侧非正中位形成1个孔,该孔为心皮最终愈合前的残迹,到子房成熟时．因子房的生长孔被挤压缩小,在进一步的生长过程中愈合。子房由1枚心皮构成;(4)从子房发育过程的切片看,该植物的胚珠是在子房发生后不久发生的,子房上的圆孔形成时,从近轴侧的分生组织发生胚珠原基,由胚珠原基分化出珠被与珠心。     

马先蒿属植物花冠分化与繁殖适应的研究进展

结合已有的研究报道和作者近年来的工作,对马先蒿属（Pedicularis）植物的花冠多样化成因与繁殖适应特性进行了总结和探讨。通过对该属4种进化花冠型的花器官发生和分化的研究发现,花部各器官在发生和发育初期基本一致,后期上唇形态的分化是导致成熟花形态结构产生较大差异的重要阶段。孢粉学研究认为,花冠类型与花粉萌发孔类型之间具有显著相关性;萌发沟的演化可能与繁殖适应有一定的关系。分子系统学研究表明,多样化的花冠类型在不同的谱系内经过若干次的独立进化而表现出了高度的平行演化（parallelism）。传粉生物学研究证实,该属植物花冠多样化与其主要传粉者熊蜂属（Bombus）昆虫的传粉行为存在较为密切的关系。具有相同（似）花冠类型的马先蒿可能被同种或不同种的熊蜂以相同的方式访问,但在花粉落置位置上存在显著差异,这可能有助于同域分布重叠的物种间在生殖上的机械隔离,而花冠的分化在一定程度上促进了新的物种形成。     

Floral development and vasculature in Eriocaulon (Eriocaulaceae) provide insights into the evolution of Poales

Background and AimsFloral developmental studies are crucial for understanding the evolution of floral structures and sexual systems in angiosperms. Within the monocot order Poales, both subfamilies of Eriocaulaceae have unisexual flowers bearing unusual nectaries. Few previous studies have investigated floral development in subfamily Eriocauloideae, which includes the large, diverse and widespread genus Eriocaulon. To understand floral variation and the evolution of the androecium, gynoecium and floral nectaries of Eriocaulaceae, we analysed floral development and vasculature in Eriocaulon and compared it with that of subfamily Paepalanthoideae and the related family Xyridaceae in a phylogenetic context.MethodsThirteen species of Eriocaulon were studied. Developmental analysis was carried out using scanning electron microscopy, and vasculature analysis was carried out using light microscopy. Fresh material was also analysed using scanning electron microscopy with a cryo function. Character evolution was reconstructed over well-resolved phylogenies.Key ResultsPerianth reductions can occur due to delayed development that can also result in loss of the vascular bundles of the median sepals. Nectariferous petal glands cease development and remain vestigial in some species. In staminate flowers, the inner stamens can emerge before the outer ones, and carpels are transformed into nectariferous carpellodes. In pistillate flowers, stamens are reduced to staminodes and the gynoecium has dorsal stigmas.ConclusionsFloral morphology is highly diverse in Eriocaulon, as a result of fusion, reduction or loss of perianth parts. The nectariferous carpellodes of staminate flowers originated first in the ancestor of Eriocaulaceae; petal glands and nectariferous branches of pistillate flowers originated independently in Eriocaulaceae through transfer of function. We present a hypothesis of floral evolution for the family, illustrating a shift from bisexuality to unisexuality and the evolution of nectaries in a complex monocot family, which can contribute to future studies on reproductive biology and floral evolution in other groups.     

云南切梢小蠹对云南松树的蛀干危害及致死机理

蛀干危害是云南切梢小蠹致死云南松树的关键环节。通过控制云南切梢小蠹蛀干密度,对云南切梢小蠹在自然条件下蛀干行为与危害进行了首次探讨。结果表明,云南切梢小蠹蛀干密度与云南松存活率呈负相关,蛀干密度直接决定云南松死亡或存活。研究发现,蛀干密度115坑/m2是云南松树的最低致死密度阈值,云南松树在蛀干密度低于26.4坑/m2情况下存活,在26.4-115坑/m2有部分存活,超过115坑/m2以后将被害致死。云南切梢小蠹对树干攻击形成有卵和无卵两类坑道。形成无卵坑道的蛀干攻击可导致树势衰弱,形成有卵坑道的蛀干危害严重破坏了韧皮组织,是导致云南松死亡的直接原因。     

Floral morphogenesis in Euptelea (Eupteleaceae, Ranunculales)

BACKGROUND AND AIMS: Based on molecular phylogenetic studies, the unigeneric family Eupteleaceae has a prominent phylogenetic position at or near the base of Ranunculales, which, in turn, appear at the base of eudicots. The aim of the present paper is to reveal developmental features of the flowers and to put the genus in a morphological context with other basal eudicots. METHODS: Flowers in all developmental stages of Euptelea pleiosperma were collected in the wild at intervals of 7-10 d in the critical stages and studied with a scanning electron microscope. KEY RESULTS: Remnants of a perianth are lacking throughout flower development. Floral symmetry changes from monosymmetric to asymmetric to disymmetric during development. Asymmetry is expressed in that the sequence of stamen initiation is from the centre to both lateral sides on the adaxial side of the flower but starting from one lateral side and proceeding to the other on the abaxial side. Despite the pronounced floral disymmetry, a dimerous pattern of floral organs was not found. The carpel primordia arise between the already large stamens and alternate with them. Stamens and carpels each form a somewhat irregular whorl. The carpels are ascidiate from the beginning. The stigma differentiates as two crests along the ventral slit of the ovary. The few lateral ovules alternate with each other. CONCLUSIONS: Although the flowers have some unusual autapomorphies (wind pollination, lack of a perianth, pronounced disymmetry of the floral base, long connective protrusion, long temporal gap between androecium and gynoecium initiation, small space for carpel initiation), they show some plesiomorphies at the level of basal eudicots (free carpels, basifixed anthers, whorled phyllotaxis), and thus fit well in Ranunculales.     

Chaotic Floral Phyllotaxis and Reduced Perianth in Achlys (Berberidaceae)

Among the 16 genera of the Berberidaceae Achlys is the only one with a reduced perianth, an irregular floral phyllotaxis, and variable stamen number. Early floral stages show an unstable (chaotic) arrangement of the organ primordia. Only the single carpel of the gynoecium has a more fixed position in that the placenta is formed in the adaxial half of the flower. The irregularities in the androecium may be caused by the lack of influence of a perianth on floral symmetry. On the other hand, the regular orientation of the carpel is perhaps due to the early polarity of the flower, whereby the abaxial half of the flower is larger (with further developed stamen primordia) at the time when carpel polarity is established.