Studies On The Taxonomical Problems Of Tulipa L.from China

In this paper, the taxonomical problems of Tulipa L. from China were studied based on the results of both the field observation and the examination of herbarium specimens,and the analysis of leaf epidermis morphology, pollen morphology, seed coats micromorphology and comparative embryology. The main results are as follows:(1) Tulipa L. from China is taxonomically revised .There are 16 species distrubuted in China and Tulipa kuocangshanica D.Y.Tan,X.R.Li et D.Y.Hong is described as new.(2) The morphological characteristics of leaf epidermis of 16 species were studied. The results show that the morphological characteristics of leaf epidermis have not obvious differences among sections except Sect. Amana, but there are some differences between species , and indicate that the morphological characteristics of leaf epidermis have some value for the interspecific classification . (3)The pollen morphology of 19 species was investigated under SEM . The results show that the morphological characteristics and exine ornamentation are not similar among species and sections. the morphological characteristics are recognized as 3 types: nearly globe,nearly boat shape and nearly shield shape .The exine ornamentation can be divided into 5 types : reticulate, steiate-veticulate, tuberculate,verrucate and rugose-sinuate. The morphological characteristics show some vaviations among sections and species in terms of the shape of pollen and the exine ornamentation.and thus can be used as one of characters in the consideration of the classification of this genus. (4) The micromorphology of the seed coats were observed in 13 species. The results show that the surface structure of the seeds have obvious differences and can be divided into 3 types including reticulate,areolate and rugose-sinuate. Features of the micromorphology of the seed coats can be used as evidences to classify clearly this genus. (5) There are 6 types of embryo sac in 16 species from China , such as Eriostemones type, Fritillaria type, Adoxa type, Drusa type ,T. illiensis type and T. tetraphylla type. There are more than one types of embryo sac in 3 species ,sush as T. illiensis,T.heteropetala and T. heterophylla.According to the analysis of comparative embryology, we think that the types of the embryo sac are of some systematical significances.