Floral Organogenesis and Development of two Taxa in Tribe Hyoscyameae (Solanaceae)-Przewalskia tanguitca and Hyoscyamus niger

Floral organogenesis and development of Przeivalskia langutica Maxim, endemic to China and Hyoscyamus niger L. , which belong to the tribe Hyoscyameae (Solanaceae), were studied using scanning electron microscope. They have three common characters of floral organ initiation and development: 1) initia-tion of the floral organs in the two species follows Hofmeister's rule; 2) the mode of corolla tube development belongs to the "late sympetaly" type; 3) primordia of the floral appendages initiated in a pentameroua pattern and acropetal order. But initiation of the calyx-lobe primordia showed different modes in these two species. The calyx-lobe primordia of H, niger have simultaneously whorled initiation, while those of P, tangulica have helical initiation, but the five calyx-lobe primordia form a ring after all five calyx-lobe primordia occur. The systematic significance of the present results in the genera Hyoscyamus and Przeivalskia is discussed in this paper.

Genetic variation in the endangered Anisodus tanguticus (Solanaceae), an alpine perennial endemic to the Qinghai-Tibetan Plateau

We used random amplified polymorphic DNA markers (RAPDs) to assess genetic variation between- and within-populations of Anisodus tanguticus (Solanaceae), an endangered perennial endemic to the Qinghai-Tibetan Plateau with important medicinal value. We recorded a total of 92 amplified bands, using 12 RAPD primers, 76 of which (P = 82.61%) were polymorphic, and calculated values of H-t and H-sp of 0.3015 and 0.4459, respectively, suggesting a remarkably high rate of genetic variation at the species level. The average within-population diversity also appeared to be high, with P, H-e and H-pop values of 55.11%, 0.1948 and 0.2918, respectively. Analyses of molecular variance (AMOVA) showed that among- and between-population genetic variation accounted for 67.02% and 32.98% of the total genetic variation, respectively. In addition, Nei's coefficient of differentiation (G(ST)) was found to be high (0.35), confirming the relatively high level of genetic differentiation among the populations. These differentiation coefficients are higher than mean corresponding coefficients for outbreeding species, but lower than reported coefficients for some rare species from this region. The genetic structure of A. tanguticus has probably been shaped by its breeding attributes, biogeographic history and human impact due to collection for medicinal purposes. The observed genetic variations suggest that as many populations as possible should be considered in any planned in situ or ex situ conservation programs for this species.

Floral organogenesis and development of two taxa of the Solanaceae - Anisodus tanguticus and Atropa belladonna

Floral organogenesis and development of two Solanaceae species, Anisodus tanguticus and Atropa belladonna, were studied by using scanning electron microscopy (SEM) as part of a project on systematics and evolution in the tribe Hyoscyameae. These two species share the following common characters of floral organ initiation and development: (1) initiation of the floral organs in the two species follows Hofmeister's rule; (2) the mode of corolla tube development belongs to the "late sympetaly" type, namely, petals are initiated separately and later become joined by fusion of their basal meristem, then rise together and form a corolla tube; (3) primordia of the floral appendages are initiated in a pentamerous pattern and acropetal order: sepals are initiated first, followed by the petals and stamens, and finally the carpels. The whorl of five stamen primordia forms almost simultaneously and originates opposite the sepal primordia, but initiation of the sepal primordia shows different modes in the two species. The sepal primordia of Anisodus tanguticus have simultaneously whorled initiation, while those of Atropa belladonna have helical initiation. The systematic significance of the present results in the genera Anisodus and Atropa is discussed in this paper.

茄科天仙子族：结构、分化和系统关系

本文研究了茄科天仙子族7属以及有亲缘关系的颠茄属、茄参属和枸杞属的形态学、解剖学、孢粉学、种子形态学、胚胎学、花器官发生、分子系统学和分支系统学;论述了它们的结构、分化和系统关系。主要内容包括： 1．解剖学 在光学显微镜和扫描电镜下，观察了茄科天仙子族(Hyoscyameae)7属21种及邻近4属4种共25种植物的叶表皮特征，结果表明：气孔器在各种植物的上、下的表皮均有分布，多为无规则型，也有不等细胞型;叶表皮细胞形状有不规则形、十字形、近长圆形和不规则多边形，垂周壁较平直或各种波状。叶表皮气孔器外拱盖内缘近平滑、浅波状或波状;角质膜多为具条纹，也有同时具条纹和颗粒或鳞片，偶尔仅具颗粒和鳞片或光滑。气孔器类型可以作为区分部分属的依据之一。颠茄叶表皮细胞形状和垂周壁式样在一些属和种中有一定的规律性，并与外部形态、孢粉学性状或地理分布相关;叶片表面角质膜的特征对属和种的划分也有一定意义。 2．种子形态学 在扫描电子显微镜下首次全面研究了天仙子族及颠茄属和茄参属等共10属25种植物的种子形态学特征，结果表明： 该族植物种子表面纹饰有脑纹状或近脑纹状和网状两大类，除了山莨菪属Anisodus和Hyoscyamus.pusillus 外，其余类群均为网状。外种皮细胞形状和周壁式样有两大类，一类为多边形至近圆形，等径，周壁近平直，另一类为形状不规则，常不等径，周壁为各式波状;外种皮细胞周壁内侧有皱波状、瘤状、小颗粒、片状或小刺等各式附属物。各属植物的种子大小、形状及种脐着生位置的系统学意义不大。但是，种脐突出与否、种子外种皮细胞形状和周壁式样，尤其是周壁内侧附属物等性状具有较大的分类学意义。 3．孢粉学 在扫描电镜下研究了该族7属及其它3属共10属23种植物的花粉形态学特征。结果表明：天仙子族的花粉粒形状为球形、近球形、扁球形和长球形;萌发孔类型有无萌发孔、不规则的拟孔、3沟、4 沟、3- 4沟、散沟和3孔沟;外壁纹饰为小刺状、瘤状、各式条纹状、条纹-穴状、条纹-网状、皱波状、细网状和网状。沟膜近光滑、具小颗粒、具小刺状突起或具瘤状突起。各属植物的花粉形态在萌发孔的有无、萌发孔的类型和外壁纹饰等方面有较大的差异，可以作为探讨属间分类和系统关系的重要依据。天仙子族植物花粉萌发孔的演化趋势为：无萌发孔→ 3、4沟→3孔沟。无萌发孔的山莨菪属是原始类群，三孔沟的马尿泡和天仙子等属是进化类群。 4．胚胎学 本论文首次研究了天仙子族山莨菪Anisodus tanguticus的胚胎学特征，结果表明：山莨菪的小孢子形成为同时型，腺质绒毡层;胚珠半倒生，单珠被，薄珠心;蓼型胚囊;其胚胎发生类型可能为茄型;胚乳形成为细胞型。山莨菪的胚胎学性状与马尿泡十分相似。胚胎学证据支持山莨菪属与马尿泡属关系密切的观点。 5．花器官发生 首次全面研究了天仙子族的山莨菪属（山莨菪）、马尿泡属（马尿泡）、天仙子属（天仙子）及其邻近2属共5种植物的花器官发生特征，结果表明：山莨菪和天仙子的5个花萼裂片原基突起最早发生，且几乎是近同时环状发生，其排列方式从花发育早期直至花成熟后始终为轮状排列。而马尿泡和颠茄首先是5个花萼裂片原基突起依次螺旋状发生，但在其5个花萼裂片原基都出现后，其排列方式仍为轮状排列。不同之处是：马尿泡的花萼裂片原基在其花冠裂片原基刚刚不明显地发生时，就已经在基部联合并形成了一个环，而颠茄的花萼裂片原基直到雄蕊原基突起开始发生并较明显时，花萼裂片原基仍然是分离的，当花顶的中央开始出现很不明显的雌蕊原基的凹陷时，花萼裂片原基才开始联合。青海茄参与其它4种植物的不同之处在于柱头2裂或3裂，而后4者的柱头均为2裂。花器官发生的特征表明马尿泡与天仙子和山莨菪的关系较近。 6．基于叶绿体DNA trnL-F序列和核糖体DNA ITS序列的初步分析 以宁夏枸杞作为外类群，对代表天仙子族及其邻近3属的10种植物的ITS区和trnL-F序列进行了测定，将这两个序列结合构建系统树。将gaps作为fifth base处理时，马尿泡属和茄参属构成最基部的一支，赛莨菪属和天仙子属构成一支然后与泡囊草属构成姐妹群，另外一支由天蓬子属、颠茄属和山莨菪属组成，其中天蓬子属与颠茄属构成一支后与山莨菪属构成姐妹群。分子证据只是一个尝试，还不足以说明天仙子族各属的系统关系。 7．分支分析 以枸杞属为外类群，基于形态学、叶表皮、种子形态学、孢粉学等特征对天仙子族7属及颠茄属和茄参属进行了分支分析。结果表明：目前公认的天仙子族7属构成一个单系类群，而颠茄属和茄参属并没有包括在内，它们两者构成一支，并与天仙子族形成姐妹群的关系。这与该族传统的分类结果相一致。 8．天仙子族的分化和系统关系 基于上述研究结果，结合天仙子族各属的现代地理分布，讨论了各属的分化和系统关系。认为根据传统分类包括有7个属的天仙子族是一个自然的单系类群，目前还没有足够的证据说明是否应该将颠茄属和茄参属放在天仙子族中。