Sporogenesis, gametogenesis and pollen morphology of Solanum japonense and S. septemlobum (Solanaceae)

Yanshuang Liu,Lei Gu,Jiaxi Liu

doi:10.2298/abs170724048l

Abstract

Solanum japonense Nakai and S. septemlobum Bunge are medicinal plants used chaotically in traditional Chinese medicine because they have the same Chinese name, Shuyangquan. In this study, anther wall development, microsporogenesis, male gametophyte development, megasporogenesis and female gametophyte development of S. japonense and S. septemlobum were studied using traditional paraffin section technology for the first time, and their pollen morphologies were compared using scanning electron microscopy. The results showed that both species exhibit dicotyledonous anther wall development, dual tapetum origination, secretory tapetum development, simultaneous microsporocyte cytokinesis, tetrahedral tetrad, coexistent 2-celled and 3-celled mature spheroidal pollen grains that are circular along the equatorial view and have tricolporate groves, 2 locules per ovary, axial placenta, anatropous, unitegmic and tenuinucellate ovule, linear megaspore tetrad, as well as monosporic Polygonum type of embryo sac, where the chalazal megaspore develops into the functional megaspore and the other three megaspores degenerate. However, the pollen grains of S. japonense are circular along the polar view, while those of S. septemlobum are triangular; the pollen surface ornamentation of S. japonense is granulate-verrucate-punctate, while that of S. septemlobum is granulate-punctate-fossula. These results enrich the embryological data of Solanum and provide palynological bases for the classification of these two species. https://doi.org/10.2298/ABS170724048L Received: July 24, 2017; Revised: October 20, 2017; Accepted: November 9, 2017; Published online: November 22, 2017 How to cite this article: Liu Y, Gu L, Liu J. Sporogenesis, gametogenesis and pollen morphology of Solanum japonense and S. septemlobum (Solanaceae). Arch Biol Sci. 2018;70(2):313-20.

Highlights

Solanum belongs to the family Solanaceae [1] and is the largest genus in the family [2]
We studied anther wall development, microsporogenesis, male gametophyte development, megasporogenesis and female gametophyte development of S. japonense and S. septemlobum for the first time, with the aim of enriching the embryological data about Solanum
Inflorescences of both S. japonense and S. septemlobum are conical, bearing flowers with purple corolla and green spots on the base, reflexed petals, yellow, oblong, basal anthers and green capitate stigma located higher than the anthers (Fig. 1A, Fig. 2A-B)

Summary

INTRODUCTION

Solanum belongs to the family Solanaceae [1] and is the largest genus in the family [2]. It comprises approximately 1200 species, of which 41 are found in China [3]. S. japonense Nakai is a medicinal plant of the section Dulcamara of the genus [7]. S. japonense and S. septemlobum are misidentified Sporogenesis, gametogenesis and pollen morphology of Solanum japonense and S. septemlobum (Solanaceae). Our work is an attempt toward a better understanding of the taxonomic relationships of these two species using palynological characteristics

MATERIALS AND METHODS

Methods

RESULTS AND DISCUSSION

CONCLUSIONS