The Phylogenetic Significance Of Plant Micromorphological And Anatomical Of Caryophyllaceae In Northeastern China

The trichome,leaf,fruit,and seed shape and anatomical structures of 55 Caryophyllaceae taxa(41 species,12 varieties and 2 forms)in northeastern China were deeply studied in the thesis,using morphological observation and GMA method.The results showed that the taxa studied could be divided into two subfamilies.Silenoideae: The capitate glandular trichomes are absent,the cell walls of fruit epidermis are flat.The fibers occur in the mesocarp a few taxa.The subfamily includes two groups.Group 1(Agrostemma,Cucubalus,Lychnis,Silene,Gypsophila,Saponaria,Vaccaria): The fruit epidermal cells are all lignified and cells in the mesocarp may be lignified and fibers are absent in most taxa.Group 2(Dianthus): The fruit epidermal cells may be lignified;seeds are round in shape and testas are with areolate.The mesocarp cells are slightly lignified or fibrous and fibers only occur in dorsal suture in some species.A few species of Silene and Saponaria have similar leaf micromorphology(e.g.,epidermal cell walls are wavy).Alsinoideae sensu lato(including Paronychioideae and Alsinoideae): The capitate glandular trichomes occur on the leaf epidermis in most taxa of the group,The out walls of fruit epidermis bulge outward and fibers are absent in the mesocarp.Group 1(Alsinoideae): The leaves are with pinnate veins.The group includs two subgroups.Subgroup 1(Subgen.Eremogone): The mesophyll is palisade and fibers are present next to the phloem and xylem of the vascular bundles.The seeds are triangle.Subgroup 2(Subgen.Arenaria,Moehringia,Cerastium,Minuartia,Stellaria,Sagina,Pseudostellaria): The mesophyll is composed of spongy,The fibers are present in phloem in a few species.Group 2(Spergula and Spergularia of Paronychioideae): The leaves are with veins and testas with papilaris.The Stellaria and Cerastium have similar leaf micromorphological features(e.g.,anomocytic stomata)and fruit structures(e.g.,lignified epidermal cells of fruits and thin walled mesocarpal cells).The study improved the morphology of Caryophyllaceae in northeastern China,provided the morphological evidence for the molecular systematics,e.g.,the Diantheae was not a natural group;Dianthus differs from Agrostemma,Cucubalus,Lychnis,Silene,Gypsophila,and Vaccaria and they should be placed in different groups.Both Silene and Arenaria are not monophyletic.The Stellaria and Cerastium are close related.Our study showed that the micromorphological and anatomical structures of the plants have important value for the systematical study of the family and provided the morphological bases for the further phylogenetic study of the family in China.