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Somatic Embryogenesis

  • Sant Saran Bhojwani
  • Prem Kumar Dantu
Chapter

Abstract

Embryogenesis is a specialized mode of development by which a fertilized egg through a series of predetermined pattern of cell divisions and differentiation forms an embryo and the precursor of the next generation. In nature, embryogenesis is restricted to ovule and involves the fusion of male (sperm) and female (egg) gametes. Occasionally, as in some varieties of mango and citrus, the sporophytic cells of the nucellus form asexual or adventive embryos independent of fertilization. However, these embryos also mature only inside the embryo sac (female gametophyte). Fertilization-independent embryogenesis is also exhibited by some elements of the embryo sac (egg or synergid) in apomictic plants. Thus, in nature, sexual and asexual embryo formation is restricted to ovular cells and full development of the embryo occurs only inside the embryo sac. This led some scientists to suggest that the embryo formation requires a special environment available only inside the embryo sac. However, tissue culture studies during the past five decades have clearly demolished this myth and demonstrated that most plant cells, irrespective of their specialization and ploidy level, are capable of forming typical embryos that can germinate. The embryos formed by somatic cells are called somatic embryos, and the process by which a somatic cell differentiates into embryo is termed somatic embryogenesis. Since the first report of somatic embryogenesis in carrot in 1958, this phenomenon has been observed in over 500 plant species. The most potent explant to initiate embryogenic cultures is immature zygotic embryo. However, in plants such as alfalfa, buttercup and carrot almost all vegetative tissues have yielded embryogenic cultures. In vitro somatic embryogenesis has found wide applications in basic and applied areas of plant sciences. It is being used extensively to understand physiological, biochemical and molecular events underlying plant embryo development which is difficult to investigate using zygotic embryogenesis. Analysis of proteomes and transcriptomes has lead to the identification and characterization of genes involved in somatic embryogenesis. Scaling up the production of somatic embryogenesis in bioreactors has opened up the possibility of using it as an efficient system for rapid clonal propagation of plants.

Keywords

Somatic Embryo Somatic Embryogenesis Embryogenic Callus Zygotic Embryo Embryogenic Cell 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer India 2013

Authors and Affiliations

  1. 1.Department of BotanyDayalbagh Educational Institute (Deemed University)AgraIndia

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