Male and Female Gametophyte Development in Artemisia aucheri B. (Asteraceae)

The genus Artemisia belonging to the Asteraceae family and is the largest genus of the Anthemideae tribe, which is widely used in medicine due to Artemisinin. The Asteraceae family has been used for various studies due to their interesting evolutionary and developmental characteristics, some of which have been very limited studies. For this purpose, to study the growth stages of male and female gametophytes, flowers and buds were prepared at different growth stages and after stabilization with ۷۰% FAA, the samples are stored in ۷۰% ethanol. Then, to prepare for histological studies, they were placed in paraffin wax and stained with hematoxylin-eosin, and sectioned with a microtome. Histological analysis showed that the anther is tetrasporangiate and also the anther wall is composed of ۴ layers including epidermis, endothelium, middle layer, and tapetum. Tetrahedral microspore tetrad was observed in this genus. Besides, pollen grains are tricolporate with have a spherical shape in equatorial view and a three-lobed in polar view. Accordingly, pollen and anther development follow the standard pattern of dicotyledonous plants. Other results demonstrated that anther tapetum is of the secretory type with polyploidy cells. Based on the results of this study, the ovule is anatropous. The largest megaspore at the chalazal pole becomes the functional megaspore. Meiosis cause to form T-shaped or linear tetrads. Embryo sac development is of Polygonum type.

Keywords:

Asteraceae family , Artemisia , Male and Female gametophyte , Developmental biology