Studies on the formation adDevelopmen of Tangerine’s Embryos

Abstract

Tangerine flowers arise from terminal as well as ateralbuds. The flowers are of perfect and solitary types. The inflorescences arrange cymosely from the terminal branchwith 4-6 petals, 5 sepals, 16-24 stamens and 10-14 carpels. Each carelconsists of 4-5 ovule arranged in the way of axil placentation. The anther consists of two lobes, with two locules in each lobe. The moicrospore tetrad has tetrahedral arrangement and appears as binucleated pollen. The megaspore tetrad has linear arrangement. The mbryo sac develops normally or as the polygonum type in the ovule. The receptive time for stigma is 2-3 days before blooming, and double fertilization occurs 4 days after pollination. The zygote divides 45 days after fertilization and develops into gametic embryo at about the same tim s nucellar embryo development which takn place near the micropylar end. The endosperm develops as the nuclear type. The largest embryo may be either nucellar or gametic embryos. If the nucellar embryo quickly develops and becomes large the gametic embryo may degenerate. The reasons of polymbryo formation in tangerine are:- a) Cleavage of zygote or fission of gametic embryo. b) There are two embryo sac in one ovule and both embryo sacs develop into gametic embryo. c) Nucellus cell divides into nucellar mbryo. d) Budding of nuclear embryo.