Parthenogenesis is formed from the Greek word parthenos meaning virgin or unfertilized and genesis meaning origin. The process by which ovules develop into embryos and ovules into seeds without fertilization is called parthenogenesis. Parthenocarpy is the process of producing seedless fruit with the application of hormones. In 1908, scientist Winkler first observed the process of embryo production without fertilization. Parthenogenesis occurs in plants like lemon, orange etc.
Natural parthenogenesis is mainly of two types. These are-
1. Haploid parthenogenesis: If the haploid egg produced by meiosis develops into an embryo without fertilization, it is called haploid parthenogenesis. The organisms produced in this process are haploid and sterile. For example – bee, bolata, tobacco, bitter gourd (Solanum nigrum), purple orchid (Orchis maculata) etc.
2. Diploid parthenogenesis: If the diploid egg produced by the process of mitosis develops into an embryo without fertilization, it is called diploid parthenogenesis. The organisms produced in this process are diploid. Such as Parthenium (Parthenium argentatum), Tobacco (Nicotiana tabacum), Taraxacum (Taraxacum albidum) etc.