Comparative Study On Morphological Characteristics Of Caltha And Trollius

This paper choose Trollius buddae Schipcz., Trollius farreri Stapf andCaltha palustris Linn as the main subjects, and choose Adonis sutchuenensis Franchand Callianthemum taipaicum W. T. Wang as outgroups. The features of anatomy,floral morphogenesis and embryology of Trollius buddae Schipcz and Calthapalustris Linn were described. The features of anatomy of Adonis sutchuenensisFranch and Callianthemurn taipaicum W. T. Wang were described. We attempted tosupply some new feature on the determination of the systematic position of Calthaand Trollius in Ranunculaceae.1. AnatomyThe primary structre of root is tetrarch and pentarch in Caltha, xylem of Vascularbundles show V-shaped appearance, the vascular bundles of the primary structure instem are irregular, the node of leaves is multilacunarly and multi-traced, the node ofbract is trilacunar and 3-traced, the node of sepals is uniacunar and 3-traced. Theprimary structre of root is diarch and triarch in Trollius, xylem of Vascular bundlesdoesn't show V-shaped appearance, the vascular bundles of the primary structure instem and petiole are ring arranged, the node of sepals is trilacunar and 3-traced.Xylem of Vascular bundles doesn't show V-shaped appearance in Adonissutchuenensis Franch, the vascular bundles of the primary structure in stem are ringarranged, the node of leaves is trilacunar and 3-traced, the node of sepals is trilacunarand 3-traced. Xylem of Vascular bundles doesn't show V-shaped appearance inCallianthemum taipaicum W. T. Wang, the vascular bundles of the primary structurein stem are ring arranged, the node of leaves is trilacunar and 3-traced, the node ofsepals is trilacunar and 3-traced. We observed the receptacular bundles doesn't endwith carpellary traces, they sometimes continue a slight distance upwards afterproducing the last carpellary traces in Caltha. we considered that Caltha is not closelyrelated to TrolIius and these two genera should not be treated in the same tribe.2. Floral morphogenesisThe floral morphogenesis of Caltha palustris L. and Trollius buddae Schipcz.was observed under a scanning electron microscope (SEM). The result showed that the primordia of all floral organs initiate spirally and centripetally and thedevelopment of all floral organs is also centripetal. The floral organs initiate spirallymay be a basic pattern in Ranunculaceae. The primordia shape of bracts, sepal, andother floral organs are different: the bract primordia are triangle in shape, the sepalprimordia are crescented, and the primordia of petals (in Trollius), the stamens, andthe carpels are hemispheric. This may indicate that the bracts, the sepals and otherfloral organs are different phylogenetically. The petals are retarded in earlydevelopmental stages in Trollius buddae Schipcz. and have purses at the base. Theretarded petals are very common in Ranunculaceae and the purse of the petal issimilar to that of some Aquilegia species. The development of the microspores in alongitudinal series of stamens is centripetal in both Caltha and Trollius, this may be abasic pattern in Ranunculaceae. The carpel primordia are plicate. In thedevelopmental process of the carpels, the stigmatic tissue forms at the top and alongthe ventral suture in Caltha, but there is no obvious stigmatic tissue formed in Trollius.Based on floral morphogenesis characteristics and combined with the evidences frommolecular systematics, comparative morphology, and palynology, we considered thatCaltha is not closely related to Trollius and these two genera should not be treated inthe same tribe.3. EmbryologyThe development of anther walls conforms to the monocotyledonous type inCaltha palustris Linn. The cytokinesis is simultaneous, pollen tetrads are tetrahedral,pollen with 2-celled at the shedding stage. The microphylardyad remains undividedfemale gametes develop from. the chalazal megasorogenesis.The development of wall layers is of the Basic type, The cytokinesis issimultaneous, pollen tetrads are tetrahedral, pollen with 2-celled at the shedding stage.The ovule of Trollius buddae Schipcz is anatropous and crassinucellate. The chalazalfunctional megaspore developed into polygonum type of embryo sac.