ECONOMIC SIGNIFICANCE IN GYMNOSPERMS -A REVIEW

Gymnosperms and angiosperms are two groups of seed plants. The former are naked seeded plants in which ovules are not enclosed by the ovary wall, born freely on open. whereas later, ovules are born in the closed. K.R. (Reprint 2020). Due to this reason (protected seed), angiosperms are more advanced than Gymnosperms. In Gymnosperms, ovules are either borne naked or on the surface of megasporophylls, often arranged in cones. These plants evolved approximately 300 million years ago from non-seed-producing ancestors of the extinct division. which had a fern-like appearance and acted as a bridge between pteridophytes and Angiosperms. During the Jurassic and Cretaceous periods of the Mesozoic era, Gymnosperms were the dominant plants on Earth's surface. S.P., and Moitra, A. (1996). As Gymnosperms do not possess an ovary, hence. they don't produce fruits, whereas angiosperms possess ovaries and produce fruits. Today, approximately 83 genera and around 790 species of living Gymnosperms are distributed across temperate, tropical, and arctic regions worldwide Biswas Chhaya and Johri, B.M. (1997) & Vashishta, P.C. (1990). General characters of gymnosperms 1. They are slow growers and lack vegetative means of propagation such as by cuttings, layering, etc. 2. They are unable to grow under varied habitats as they can grow in some specific habitats and conditions. 3. They have limited means of dispersal of seeds and can be dispersed only by wind, animals or human beings. 4. Most of the Gymnosperms are terrestrial and unable to grow in aquatic habitats, except a few. 5. They lack vessels in the xylem (with few exceptions) and companion cells in the phloem. 6. Most of the Gymnosperms are unisexual; thus due to the absence of bisexuality, the chances of Self-pollination are reduced. Chamberlain, C.J. (2009) & Christenhusz et al. (2011).

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