We have obtained friable, non-mucilaginous embryogenic callus from cultured immature embryos of an elite maize inbred line derived from Iowa stiff stalk synthetic germplasm. This callus was used to generate embryogenic cell suspensions containing compact clumps of densely cytoplasmic cells. Plants were readily regenerated from the suspensions, which were also an excellent source of protoplasts. The suspension cultures maintained their plant regeneration capacity through many months. The cultures were cryopreserved in liquid nitrogen and embryogenic callus and suspension cultures were routinely recovered from cryopreserved cells. Protoplasts were isolated in large numbers from both primary and cryopreserved suspension cultures. Cultured protoplasts divided and formed embryogenic callus both when plated in agarose and on nurse cultures. Hundreds of plants were regenerated from protoplast-derived calli. Plants with viable progeny were obtained although many of the regenerates showed morphological and reproductive abnormalities.

Regeneration of fertile plants from protoplasts of elite inbred maize

1. Introduction. 2. Laboratory Organization and Equipment. 3. Media Preparation. 4. Collection, Sterilization, Excision and Culture. 5. Clonal Propagation. 6. Special Cultures. 7. Secondary Metabolite Production. 8. Pathology. 9. Nitrogen Fixation. 10. Storage of Cultures. 11. Genetic Modification. 12. Epilogue. 13. References. 14. Indices.

In Vitro Culture of Trees

Introduction. 1. Male Gametogenesis Development and Structure of Sperm D. Southworth, S.C. Russell. 2. Sperm and Generative Cell Isolation and Manipulation D. Southworth. 3. Pollen Germination and Pollen Tube Growth Tip Growth Mechanism in Sexual Plant Reproduction A. Moscatelli, M. Cresti. 4. Female Gametogenesis Ontogenesis of the Embryo Sac and Female Gametes S.D. Russell. 5. Embryo Sac Isolation and Manipulation D.D. Cass, J.D. Laurie. 6. In Vivo Fertilization T.B. Batygina, V.E. Vasilyeva. 7. In Vitro Fertilization E. Kranz. 8. Sexual Incompatibility F. Cruz-Garcia, B.A. MacClure. 9. Zygotic Embryogenesis Structural Aspects R. Czapik, R. Izmailow. 10. Zygotic Embryogenesis Hormonal Control of Embryo Development B. Fischer-Iglesias, G. Neuhaus. 11. Zygotic Embryogenesis: Developmental Genetics The Formation of an Embryo from a Fertilized Egg K. Schrick, T. Laux. 12. Somatic Embryogenesis T.A. Thorpe, C. Stasolla. 13. Synthetic Seeds of Asparagus officinalis L. K. Mamiya, et al. 14. Endosperm Development P.W. Becraft, et al. 15. Seed Maturation, Germination, and Dormancy A.B. Downie. 16. Gametophytic Apomixis A Successful Mutation of the Female Gametogenesis Y. Savidan. 17. Parthenocarpy State of the Art A. Spena, G.L. Rotino. 18. Androgenesis in Brassica A Model System to Study the Initiation of Plant Embryogenesis J.B.M. Custers, et al. 19. Androgenesis in Cereals S.K. Datta. 20. In Vitro Gynogenesis S.S. Bhojwani, T.D. Thomas. 21. Inheritance of Cytoplasmic Traits -- Embryological Perspectives T. Kuroiwa, et al. Subject Index.

Current trends in the embryology of angiosperms.

Plants develop from meristems where cells proliferate and are partitioned into layers that eventually differentiate to form the various tissues and organs of the plant. A phenomenon unique to certain plant tissues is the ability to inducede nova a range of developmental patterns, including embryogenesis. The temporal and spacial distribution of these developmental competencies suggests that regulatory proteins, rather than a lack of signals or signal receptors, shield specific developmental genes from signals that otherwise would confuse development. Studies involving embryogenic cells demonstrate that they are not strongly shielded from developmental signals, thus they are not determined. Furthermore, the normal development of zygotic and somatic embryos is readily perturbed by abnormal physicochemical environments. This suggests that embryogeny remains developmentally plastic until differentiation is largely completed. The ability to induce somatic embryogenesis from specific tissues by specific signals is providing opportunities to further the molecular characterization of the menagerie of genetic regulation involved in development.

https://www.jstor.org/stable/info/4296509

N.P. Everett

Papers

Biochemical markers of embryogenesis in tissue cultures of the maize inbred B73