Abstract: The phenotypes of floral organs, female and male gametophytes and seeds vary in various degrees because of the genome reduplication for autotetraploid plants. Compared with original diploid plants, the variations focus on the following aspects. The form and inserted site of inflorescences are diverse. The floral organs generally increase in size. The transmitting tissue in style is not well developed. The content of nucleic acid increases whereas the numerical value of RNA/DNA decreases in buds. Parts of egg apparatus, centrocytes and antipodal cells in sac degenerate or grow abnormally of morphology and location, which result in embryo sac abortion. Male gametophytes (pollen) are bigger than original diploid in size, diversiform and infertile. Seeds of autotetraploid plants have an increasing trend of size, weight, content of protein and tolerability to salt, but few of the seeds can germinate. The abnormal development of endosperm negatively affects the supply of nutrition to embryo, so that a lot of embryos degenerate or develop abnormally.

Key words: autotetraploid, floral organ, female and male gametophyte, seed