Anther and ovule development of Clematis serratifolia (Ranunculaceae)-with new formation types in megaspore and nucellus.

Yi Yang,Qinghua Liu,Kuiling Wang,Qingchao Liu,Xiao Guo,Jie Sun

doi:10.1371/journal.pone.0240432

Abstract

Morphological indices of vegetative organs or reproductive organs, which are often used to analyze the evolution and classify Clematis, indicate that Clematis serratifolia and C. glauca could be related members at similar evolutionary levels. However, this assumption differs with phylogenetic studies based on genetics. Embryonic characteristics, which are more stable, are commonly used to estimate the phylogeny and evolution of angiosperms. We studied the microsporogenesis, microgametogenesis, megasporogenesis and macrogametogenesis development of C. serratifolia, and compared the early embryological characteristics among C. serratifolia, C. serratifolia and other Clematis species reported to provide a reference for the taxonomy of the genus Clematis. Our results showed that C. serratifolia and C. glauca differ in megaspore formation and nucellus types suggesting that they have originated from different ancestors. The differences among Clematis were mainly found in the type of the anther wall development, tapetum, pollen grains, megaspore formation and nucellus types.

Highlights

The genus Clematis belongs to the Ranunculaceae family, which is one of the ancestral groups of angiosperms, the eudicots [1]
C. serratifolia plants were grown from seed at Qingdao Agricultural University (36 ̊200N, 120 ̊120E, Qingdao city, Shandong, China) in April 2015
We observed that the microspore and microgametophyte development of C. serratifolia and C. glauca were with only minor differences in the structure of the mature anther wall (Table 3)

Summary

Introduction

The genus Clematis belongs to the Ranunculaceae family, which is one of the ancestral groups of angiosperms, the eudicots [1] It is a diverse genus of about 355 species with highly variable morphology and a wide distribution. The morphological indices of vegetative organs or reproductive organs of Clematis [2,3,4,5] have long been used as the basis for classifying Clematis These indices have proved unstable in different environments. The results are affected by the equipment and methods employed [7,8,9,14], and can be contradictory [11,12,13] It is, necessary to find relatively stable morphological characteristics that can reflect the phylogeny and evolution to assist with the taxonomic study of Clematis

Methods

Results

Discussion

Conclusion