The Phylogenetic Significance Of The Morphological Structure Of The Taxa In The Famiy Ranunculaceae Of China

The seedlings, vegetative organs, stamens, pollens and fruits of the family Ranunculaceae taxa in China were studied in this research using GMA method, and the phylogeny value of the structures were discussed.Seedling:The seedlings of Ranunculaceae could be divided into three types according to that the cotyledon is epigaeous or hypogaeous. if the primary root is with root collar. (?) Hypogaeous germination, without root collar, cotyledon petioles separate, euphylla alternate; (?) Epigaeous germination, with overground root-cotyledon node transition region, cotyledonary petioles separate:A. with root collar, B. without root collar; (?) Epigaeous germination, without overground root-cotyledon node transition region and root collar:A. Cotyledon petioles symphysis, B. Cotyledon petioles separate, euphyllas (the first and second) alternate, C. Cotyledon petioles separate, euphyllas (the first and second) opposite. The tissue from root to cotyledon node zone (including cotyledon) is continious, the vascular system didn't connect to the epicotyl shoot zone at the beginning of the seedling growth. The seedlings of Ranunculaceae maybe do not have the transitional "hypocotyl"Root:The roots could be divided into four types according to that the secondary xylem and pith exist or not:(?) The cortex is developed, without secondary xylem and pith; (?) The root is without secondary xylem, but with pith:A. the cortex is undeveloped, B. the cortex is developed or highly developed; (?) The root is with secondary xylem, but without pith:A. the cortex is undeveloped or fall off, B. the cortex is developed or highly developed; (?) The root is with secondary xylem and pith:A. the cortex is undeveloped, B. the cortex is developed. According to secondary xylem and pith existing or not, it can be speculated that the type ? may be the more evolved root type in Ranunculaceae and the type ? may be more original.Stem and leaf:The study shows that some characteristics can be as a basis for the taxonomical study of the species or above, such as the trichome type (glandular, nonglandular) and cortex tissue (aerenchyma, collenchyma, sclerenchyma), the distribution of fiber close to the vascular bundle, and interfascicular cambium and pith cavity existing or not. The leaf petioles could be divided into three types based on the distribution of vascular bundle:radiation, bending and dispersion. The epidermal cells of leaves are deeply, internediate, or slightly wave, the position of stomata could be the character of classification of the genus.The cluster analysis about the structures of vegetative organs:two branches of Group I in the structure of vegetative organs clustering tree are the same with Ranunculeae and Anemoneae in the molecular system. Although Group 2 is different from the conclusion of the existing molecular systematics, but Eranthis-Thalictrum branch is similar with Trib. Isopyreae in the molecular system, Delphinium-Aconitum branch is similar with Trib. Delphinieae.Stamen:The filaments vary in shape, filiform, strip, clavate, long triangular or short columnar. The anthers are oo shape, ellipse, near round, or strip in lateral view. The young anthers are V shape, A shape, ellipse, square, oo shape, or butterfly in transverse sections. The parenchyma cells between pollen sac are arranged in V shape, A shape, or a line. The young anthers which are V shape, A shape, ellipse has no obvious change when they are mature. When the anthers mature, young anthers in oo shape develop into ellipse usually, and butterfly and square develop into oo shape. The features of the stamens could provide the taxonomic evidence for the most genera position in Ranunculaceae.Pollen:The pollens of most species in Ranunculaceae are tricolpate, a few species are stephanocolpate, pantocolpate or pantoporate. The pollen grain of the most species are granular or spiny except Trollius in which the pollen has striped grain. The pollen shape usually could be used for the identification of species in Ranunculaceae for the pollens differ in the species of the genus, but the pollens of Thalictrum and Trollius are similar in shapes, which could be used as classification of the genus. The pollen features provide the supporting for that Thalictrum formed a subfamily.The cluster analysis about the fruit structures:The fruit surface and anatomy features (e.g., vascular bundle distribution mode, the cell types of mesocarp and endocarp) can be used as basis to distinguish the genera of Ranunculaceae. The dendrogram (include 27 genera) was formed base on the fruit and relevant characteristics. The taxa of the Ranunculaceae was divided into four groups and seven groups. Group 1:follicle or achene, mesocarp consists of parenchyma cells, branching or branching and anastomosing vascular bundles, and endocarp is lignified (including 20 genera); Group 2:achene, mesocarp lignified, vascular bundle branching, endocarp with one layer of irregular and partly lignified cells(Thalictrum only); Group 3: including 3 genera, e.g. Adonis, achene, branching or unbranching vascular bundles, endocarp with multilayered thick-walled cells; Group 4:achene, two non-branching vascular bundles, and endocarp with one layer of fibers (including 3 genera, e.g. Pulsatilla). Helleboroideae and Thalictroideae of Classical classification system is supported by Group 1 and 2 respectively, Sub-group 1 is the same with Delphineae in the molecular system. Sub-group 2 and Sub-group 5 are similar with Isopyreae and Ranunculeae respectively.This research shows that anatomical structure of vegetative organs and reproductive organs (quality traits) in Ranunculaceae can be taken as the basis for judging the Relationships between species, and can provide new morphological evidence for Ranunculaceae molecular system. The results show that the systematics value of anatomical structure of the reproductive organs is higher than vegetative organ. This study is provides some new morphological basis for establish a natural Ranunculaceae system.