نمو تخمك، گامتوفيت ماده، رويان و اندوسپرم در گل اطلسي(Petunia x hybrida Juss)

Development of Ovule, Female Gametophyte, Embryo and Endosperm in Petunia Hybrid Grandiflora

The life cycle of flowering plants is divided into two phases, a dominant diploid sporophyte phase and a transient haploid gametophyte phase. During the complex process of plant sexual reproduction, the male gametophyte or pollen grain and female gametophyte are formed. Female gametophyte or embryo sac is formed in the ovule and consists of seven cells. Double fertilization of egg cell and central cell initiates development of the diploid embryo and of the triploid endosperm, respectively. Flower bud and fruits of Petunia x hybrid were collectd, fixed and studied. Gynocium is sessile and contains two syncarpous carpels. Ovary has two locules and several anatropous ovules. The female gametophyte, also referred to as the embryo sac or megagametophyte, develops within the ovule. It is the polygonum type female gametophyte. After fertilization, the stages of development of embryo are as stages of globular, cell differentiation, heart-shaped and cotyledonary (mature). The endosperm persists in the mature emabryo and functions as storage tissue for germinating seedlings. So these seeds are termed albuminous.