Developmental Features of Reproductive Organs in Viburnum tinus L.

Abstract

Viburnum tinus, which belongs to Adoxaceae family, is a plant that commonly used in pharmacy and landscape architecture. Flowers located in corymb-type of the inflorescence are white, fragrant, hermaphrodite. The development of the flower buds begins with the differentiation of the apical meristem as a small bulge. Afterwards, the apical apex is expanded, flattened and transforms into a floral meristem. Floral meristem cells have large volume and abundant cytoplasm. Concomitant with the development, firstly five stamen primordia and then three carpel primordia differentiate from the floral meristem. Anthers are tetrasporangiate. Anther wall is formed by epidermis, endothecium with fibrous thickening, ephemeral middle layer and, plasmodial tapetum. Tapetal cells degenerate at the young pollen stage. Pollen grains are discharged by the opening of stomium. Carpel primordial cells lengthen upwards, merge and form a style above the ovary. An ovule differentiates into each ovarian loculi. But the development continues only in one them and transforms into the mature embryo sac. Ovules are unitegmic and tenuinucellate. The style has a transmitting channel. Stigma is three-lobed and wet typed. The transmitting tissue and stigmatic papillae start to degenerate after pollination.