Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-24T12:37:10.395Z Has data issue: false hasContentIssue false

Somatic embryogenesis and artificial seeds in forage legumes

Published online by Cambridge University Press:  19 September 2008

Bryan D. McKersie*
Affiliation:
Department of Crop Science, University of Guelph, Guelph, Ontario, N1G 2W1, Canada
Daniel C.W. Brown
Affiliation:
Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Ottawa, Ontario, K1A 0C6, Canada
*
*Correspondence

Abstract

Among the forage legumes somatic embryogenesis has been most studied in alfalfa (Medicago sativa L.) reflecting inherent breeding problems and the high demand for seeds of this species. Current methods of somatic embryogenesis are reviewed with emphasis on each of the 3 stages involved: the acquisition of competence, the induction of somatic embryogenesis, and somatic embryo development and maturation. The role of plant growth regulators is particularly stressed. Artificial seed production, the development of reduced-generation synthetics or hybrids and genetic transformation of alfalfa are considered. Research on somatic embryogenesis and plant transformation in a wide range of other forage legumes is examined but it is suggested that the application of artificial seed technology is unlikely in forage legumes other than alfalfa.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anandarajah, K. and McKersie, B.D. (1990a) Enhanced vigor of dry somatic embryos of Medicago sativa L with increased sucrose. Plant Science 71, 261266.CrossRefGoogle Scholar
Anandarajah, K. and McKersie, B.D. (1990b) Manipulating the desiccation tolerance and vigor of dry somatic embryos of Medicago sativa L with sucrose, heat shock and abscisic acid. Plant Cell Reports 9, 451455.CrossRefGoogle ScholarPubMed
Anandarajah, K. and McKersie, B.D. (1992) Influence of plating density, sucrose and light during development on the germination and vigour of Medicago sativa somatic embryos after desiccation. Seed Science Research 2, 133140.CrossRefGoogle Scholar
Arcioni, S., Mariotti, B.G., Damiani, F. and Pezzotti, M. (1988) Birdsfoot trefoil (Lotus corniculatus L.), crownvetch (Coronilla varia L.) and sainfoin (Onobrychis viciifolia Scop.). pp 548572 in Bajaj, Y.P.S. (Ed.) Biotechnology in agriculture and forestry, Vol 6, Crops, II. Berlin, Springer-Verlag.Google Scholar
Atanassov, A. and Brown, D.C.W (1984) Plant regeneration from suspension culture and mesophyll protoplasts of Medicago sativa L. Plant Cell Tissue and Organ Culture 3, 149162.CrossRefGoogle Scholar
Austin, S. and Bingham, E.T. (1996) The potential use of transgenic alfalfa as a bioreactor for the production of industrial enzymes. pp 409424 in McKersie, B.D., Brown, D.C.W. (Eds) Biotechnology and the improvement of forage legumes. Wallingford, UK, cab international.Google Scholar
Bauchan, G.R., Cambell, T.A.O., Neill, N.R. and Elgin, J.H. Jr., (1991) Self-incompatibility in two alfalfa populations. Crop Science 30, 12051210.CrossRefGoogle Scholar
Beach, K.H. and Gresshoff, P.M. (1988) Characterization and culture of Agrobacterium rhizogenes transformed roots of forage legumes. Plant Science 57, 7381.CrossRefGoogle Scholar
Bingham, E.T. (1989) Registration of Regen-S alfalfa germplasm useful in tissue culture and transformation research. Crop Science 29, 10951096.CrossRefGoogle Scholar
Bingham, E.T. (1991) Registration of alfalfa hybrid Regen-SY germplasm for tissue culture and transformation research. Crop Science 31, 1098.Google Scholar
Bingham, E.T., Hurley, L.V., Kaatz, D.M. and Saunders, J.W. (1975) Breeding alfalfa which regenerates from callus tissue in culture. Crop Science 15, 719721.CrossRefGoogle Scholar
Bingham, E.T., McCoy, T.J. and Walker, K.A. (1988) Alfalfa tissue culture. pp 903929 in Hanson, A.A., Barnes, D.K. and Hill, R.R. (Eds) Alfalfa and alfalfa improvement. Madison, Wisconsin, American Society of Agronomy.Google Scholar
Bowley, S. R. (1996) Breeding methods for forage legumes. pp 2542 in McKersie, B.D., Brown, D.C.W. (Eds) Biotechnology and the improvement of forage legumes. Wallingford, UK, CAB INTERNATIONAL.Google Scholar
Bowley, S.R., Kielly, G.A., Anandarajah, K., McKersie, B.D. and Senaratna, T. (1993) Field evaluation following two cycles of backcross transfer of somatic embryogenesis to commercial alfalfa germplasm. Canadian Journal of Plant Science 73, 131137.CrossRefGoogle Scholar
Briskin, D. and Hanson, J.B. (1992) How does the plant plasma membrane H+-ATPase pump protons? Journal of Experimental Botany 43, 269289.CrossRefGoogle Scholar
Brown, D.C.W. (1988) Germplasm determination of in vitro somatic embryogenesis in alfalfa. HortScience 23, 526531.CrossRefGoogle Scholar
Brown, D.C. and Atanassov, A. (1985) Role of genetic background in somatic embryogenesis in Medicago. Plant Cell Tissue and Organ Culture 4, 111122.CrossRefGoogle Scholar
Brown, D.C.W., Tian, L., Buckley, D.J., Lefebvre, M., McGrath, A. and Webb, J. (1994) Development of a simple particle bombardment device for gene transfer into plant cells. Plant Cell, Tissue and Organ Culture 37, 4753.CrossRefGoogle Scholar
Carman, J.G. (1990) Embryogenic cells in plant tissue cultures — occurrence and behavior. In Vitro Cellular and Developmental Biology 26, 746753.CrossRefGoogle Scholar
Carron, T.R., Robbins, M.P. and Morris, P. (1994) Genetic modification of condensed tannin biosynthesis in Lotus corniculatus. 1. Heterologous antisense dihydroflavonol reductase down-regulates tannin accumulation in ‘hairy root’ culture. Theoretical and Applied Genetics 87, 10061015.CrossRefGoogle Scholar
Casseb, G.I. and Varner, J.E. (1988) Cell wall proteins. Annual Review of Plant Physiology and Plant Molecular Biology 39, 321353.CrossRefGoogle Scholar
Chang, S.S., Park, S.K., Kim, B.C., Kang, B.J., Kim, D.U. and Nam, H.G. (1994) Stable genetic transformation of Arabidopsis thaliana by Agrobacterium inoculation in planta. Plant Journal 5, 551558.CrossRefGoogle Scholar
Childers, W.R. and Barnes, D.K. (1972) Evolution of hybrid alfalfa. Agricultural Science Review 10, 1118.Google Scholar
Crea, F., Bellucci, M., Damiani, F. and Arcioni, S. (1995) Genetic control of somatic embryogenesis in alfalfa (Medicago sativa L. cv. Adriana). Euphytica 81, 151155.CrossRefGoogle Scholar
Cvikrova, M., Meravy, L., Machackova, I. and Eder, J. (1991) Phenylalanine ammonia-lyase, phenolic acids and ethylene in alfalfa (Medicago sativa L.) cell cultures in relation to their embryogenic ability. Plant Cell Reports 10, 251255.CrossRefGoogle ScholarPubMed
Damiani, F. and Arcioni, S. (1991) Transformation of Medicago arborea L. with an Agrobacterium rhizogenes binary vector carrying the hygromycin resistance gene. Plant Cell Reports 10, 300303.CrossRefGoogle ScholarPubMed
Davis, W. (1971) Hybrid alfalfa production. United States patent no. 3570181.Google Scholar
Deak, M., Kiss, G.B., Koncz, C. and Dudits, D. (1986) Transformation of Medicago by Agrobacterium mediated gene transfer. Plant Cell Reports 5, 97100.CrossRefGoogle ScholarPubMed
De Jong, A.J., Schmidt, E.D.L. and de Vries, S.C. (1993) Early events in higher-plant embryogenesis. Plant Molecular Biology 22, 367377.CrossRefGoogle ScholarPubMed
Denchev, P., Velcheva, M. and Atanassov, A. (1991) A new approach to direct somatic embryogenesis in Medicago. Plant Cell Reports 10, 338341.Google ScholarPubMed
D'Halluin, K., Botterman, J. and De Greef, W. (1990) Engineering of herbicide-resistant alfalfa and evaluation under field conditions. Crop Science 30, 866871.CrossRefGoogle Scholar
Dixon, R.A., Paiva, N.L. and Masoud, S. (1994) Engineering alfalfa for disease resistance. Thirty-fourth North American Alfalfa Improvement Conference. Guelph, Ontario, Canada, p. 47.Google Scholar
Dos, Santos A.V.P., Cutter, E.G. and Davey, M.R. (1983) Origin and development of somatic embryos in Medicago sativa L. Protoplasma 117, 107115.Google Scholar
Du, S., Erickson, L. and Bowley, S.R. (1994) Effect of plant genotype on the transformation of cultivated alfalfa (Medicago sativa) by Agrobacterium tumefaciens. Plant Cell Reports 13, 330334.Google ScholarPubMed
Dubios, B.R. and Dubios, J.M. (1991) A quantitative analysis of the role of K+ channels in mitogenesis of neuroblastoma cells. Cell Signalling 3, 333339.Google Scholar
Dudits, D., Bogre, L. and Guorgyey, J. (1991) Molecular and cellular approaches to the analysis of plant embryo development from somatic cells in vitro. Journal of Cell Science 99, 475484.Google Scholar
Dunbier, M.W. and Bingham, E.T. (1975) Maximum heterozygosity in alfalfa: results using haploid-derived autotetraploids. Crop Science 15, 527531.CrossRefGoogle Scholar
Emons, A.M.C. (1994) Somatic embryogenesis: cell biological aspects. Acta Botanica Neerlandica 43, 114.CrossRefGoogle Scholar
Finstad, K., Brown, D.C.W. and Joy, K. (1993) Characterization of competence during induction of somatic embryogenesis in alfalfa tissue culture. Plant Cell, Tissue and Organ Culture 34, 125132.CrossRefGoogle Scholar
Fujii, J.A., Slade, D. and Redenbaugh, K. (1989) Maturation and greenhouse planting of alfalfa artificial seeds. In Vitro Cellular and Developmental Biology 25, 11791182.CrossRefGoogle Scholar
Fujii, J., Slade, A.D., Olsen, R., Ruzin, S.E. and Redenbaugh, K. (1990) Alfalfa somatic embryo maturation and conversion into plants. Plant Science 72, 93100.CrossRefGoogle Scholar
Fujii, J.A.A., Slade, D., Aguirre, Rascon J. and Redenbaugh, K. (1992) Field planting of alfalfa artificial seeds. In Vitro Cellular and Developmental Biology 28P, 7380.CrossRefGoogle Scholar
Gamborg, O.L., Miller, R.A. and Ojima, K. (1968) Nutrient requirements of suspension cultures of soybean root cells. Experimental Cell Research 50, 151158.CrossRefGoogle ScholarPubMed
George, E.F. (1996) Plant propagation by tissue culture. Edington, Exegetics.Google Scholar
Golds, T.J., Lee, J.Y., Ghose, T.K. and Davey, M.R. (1991) Agrobacterium rhizogenes mediated transformation of the forage legumes Medicago sativa and Onobrychis viciifolia. Journal of Experimental Botany 42, 11471157.CrossRefGoogle Scholar
Gray, D.J. and Purohit, A. (1991) Somatic embryogenesis and development of synthetic seed technology. Critical Reviews in Plant Science 10, 3361.CrossRefGoogle Scholar
Groose, R.W. and Li, Y.G. (1993) Registration of diploid alfalfa (Medicago sativa spp falcata) germplasms for biotechnology research and development. Crop Science 33, 1116.CrossRefGoogle Scholar
Gyorgyey, J., Gartner, A., Nemeth, K., Magyar, Z., Hirt, H., Heberle, Bors E. and Dudits, D. (1991) Alfalfa heat shock genes are differentially expressed during somatic embryogenesis. Plant Molecular Biology 16, 9991007.CrossRefGoogle ScholarPubMed
Handberg, K. and Stougaard, J. (1992) Lotus japonicus, an autogamous, diploid legume species for classical and molecular genetics. Plant Journal 2, 487496.CrossRefGoogle Scholar
Henry, Y., Vain, P. and DeBuyser, J. (1994) Genetic analysis of in vitro plant tissue culture responses and regeneration capacities. Euphytica 79, 4558.CrossRefGoogle Scholar
Hernandez-Fernandez, M.M. and Christie, B.R. (1989) Inheritance of somatic embryogenesis in alfalfa (Medicago sativa L.). Genome 32, 318321.CrossRefGoogle Scholar
Hill, K.R., Jarvis-Eagen, N., Halk, E.L., Krahn, K.J., Liao, L.W., Matheson, R.S., Merlo, D.J., Neslon, S.E., Rashka, K.E. and Loesch-Fried, L.S. (1991) The development of virus-resistant alfalfa (Medicago sativa L.). Bio/Technology 9, 373377.Google ScholarPubMed
Horbowicz, M. and Obendorf, R.L. (1994) Seed desiccation tolerance and storability: dependence on flatulence-producing oligosaccharides and cyclitols – review and survey. Seed Science Research 4, 385405.CrossRefGoogle Scholar
Horbowicz, M., Obendorf, R.L., McKersie, B.D. and Viands, D.R. (1995) Soluble saccharides and cyclitols in alfalfa (Medicago sativa L.) somatic embryos, leaflets and mature seeds. Plant Science 109, 191198.CrossRefGoogle Scholar
Jensen, J.S., Marcker, K.A., Otten, L. and Schell, J. (1986) Nodule-specific expression of a chimaeric soybean leghaemoglobin gene in transgenic Lotus corniculatus. Nature 321, 669674.CrossRefGoogle Scholar
Jian-Ping, Y. and Qi-Quan, S. (1991) Transformation of Lotus corniculatus L. mediated by Agrobacterium tumefaciens. Scientia Sinica 34, 932937.Google Scholar
Kamp, Glass M., Powell, D., Reddy, G.B., Baligar, V.C. and Wright, R.J. (1993) Biotechniques for improving acid aluminum tolerance in alfalfa. Plant Cell Reports 12, 590592.Google Scholar
Kapros, T., Bogre, L., Nemeth, K., Bako, L., Gyorgyey, J., Wu, S.C. and Dudits, D. (1992) Differential expression of histone H3 gene variants during cell cycle and somatic embryogenesis in alfalfa. Plant Physiology 98, 621625.CrossRefGoogle ScholarPubMed
Kepczynski, J., McKersie, B.D. and Brown, D.C.W. (1992) Requirement of ethylene for growth of callus and somatic embryogenesis in Medicago sativa L. Journal of Experimental Botany 43, 11991202.CrossRefGoogle Scholar
Khan, M.R.I., Tabe, L.M., Heath, L.C., Spencer, D. and Higgins, T.J.V. (1994) Agrobacterium-mediated transformation of subterranean clover (Trifolium subterraneum L.). Plant Physiology 105, 8188.CrossRefGoogle ScholarPubMed
Kielly, G.A. and Bowley, S.R. (1992) Genetic control of somatic embryogenesis in alfalfa. Genome 35, 474477.CrossRefGoogle Scholar
Krochko, J.E. and Bewley, J.D. (1988) Use of electrophoretic techniques in determining the composition of seed storage proteins in alfalfa. Electrophoresis 9, 751763.CrossRefGoogle ScholarPubMed
Krochko, J.E. and Bewley, J.D. (1990) Identification and characterization of the seed storage proteins from alfalfa (Medicago sativa). Journal of Experimental Botany 41, 505514.CrossRefGoogle Scholar
Krochko, J.E., Charbonneau, M.R., Coulter, K.M., Bowley, S.R. and Bewley, J.D. (1990) A comparison of seed storage protein in subspecies and cultivars of Medicago sativa. Canadian Journal of Botany 68, 940948.CrossRefGoogle Scholar
Krochko, J.E., Pramanik, S.K. and Bewley, J.D. (1992) Contrasting storage protein synthesis and messenger RNA accumulation during development of zygotic and somatic embryos of alfalfa (Medicago sativa L.). Plant Physiology 99, 4653.CrossRefGoogle ScholarPubMed
Krochko, J.E., Bantroch, D.J., Greenwood, J.S. and Bewley, J.D. (1994) Seed storage proteins in developing somatic embryos of alfalfa: defects in accumulation compared to zygotic embryos. Journal of Experimental Botany 45, 699708.CrossRefGoogle Scholar
Kuchuck, N., Komarnitski, I., Shakhovsky, A. and Gleba, Y. (1990) Genetic transformation of Medicago species by Agrobacterium tumefaciens and electroporation of protoplasts. Plant Cell Reports 8, 660663.CrossRefGoogle Scholar
Lai, F.M. and McKersie, B.D. (1993) Effect of nutrition on maturation of alfalfa (Medicago sativa L.) somatic embryos. Plant Science 91, 8795.CrossRefGoogle Scholar
Lai, F. and McKersie, B.D. (1994a) Regulation of starch and protein accumulation in alfalfa (Medicago sativa L.) somatic embryos. Plant Science 100, 211219.Google Scholar
Lai, F. and McKersie, B.D. (1994b) Regulation of storage protein synthesis by nitrogen and sulphur nutrients in alfalfa (Medicago sativa L.) somatic embryos. Plant Science 103, 209221.CrossRefGoogle Scholar
Lai, F.M. and McKersie, B.D. (1994c) Scale-up of somatic embryogenesis in alfalfa (Medicago sativa L.). I Subculture and indirect secondary somatic embryogenesis. Plant Cell, Tissue and Organ Culture 37, 151158.CrossRefGoogle Scholar
Lai, F. and McKersie, B.D. (1995) Germination of alfalfa (Medicago sativa L.) seeds and somatic embryos. I. Effect of nutrient supplements. Journal of Plant Physiology 146, 731735.CrossRefGoogle Scholar
Lai, F., Senaratna, T. and McKersie, B.D. (1992) Glutamine enhances storage protein synthesis in Medicago sativa L somatic embryos. Plant Science 87, 6977.CrossRefGoogle Scholar
Lai, F., Lecouteux, C.G. and McKersie, B.D. (1995) Germination of alfalfa (Medicago sativa L.) seeds and somatic embryos. I. Mobilization of storage reserves. Journal of Plant Physiology 145, 507513.CrossRefGoogle Scholar
Larkin, P.J. (1987) Somaclonal variation: history, method and meaning. Iowa Journal of Research 64, 393434.Google Scholar
Lecouteux, C., Lai, F.M. and McKersie, B.D. (1993) Maturation of somatic embryos by abscisic acid, sucrose and chilling. Plant Science 94, 207213.CrossRefGoogle Scholar
Leprince, O., McKersie, B.D. and Hendry, G.A. (1993) The mechanisms of desiccation tolerance in developing seeds. Seed Science Research 3, 231246.CrossRefGoogle Scholar
Lupotto, E. (1983) Propagation of an embryogenic culture of Medicago sativa L. Zeitschrift für Pf lanzenphysiologie 111, 95104.CrossRefGoogle Scholar
Lupotto, E. (1986) The use of single somatic embryo culture in propagating and regenerating lucerne (Medicago sativa L.). Annals of Botany 57, 1924.CrossRefGoogle Scholar
McCleary, B.V. and Matheson, N.K. (1974) α-D-Galactosidase activity and galactomannan and galactosylsucrose oligosaccharide depletion in germinating legume seeds. Phytochemistry 13, 17471757.CrossRefGoogle Scholar
McCleary, B.V. and Matheson, N.K. (1976) Galactomannan utilization in germinating legume seeds. Phytochemistry 15, 4347.CrossRefGoogle Scholar
McElroy, A.R. and Brown, D.C.W. (1992) A transplant plug technique for production of alfalfa (Medicago sativa L.) plants from somatic embryos. Canadian Journal of Plant Science 72, 483485.CrossRefGoogle Scholar
McKersie, B.D. and Bowley, S.R. (1993) Synthetic seeds in alfalfa. pp 231255 in Redenbaugh, K. (Ed.) Synseeds: applications of synthetic seeds to crop improvement. Boca Raton, CRC Press.Google Scholar
McKersie, B. D. and Brown, D.C.W. (1996) Biotechnology and the improvement of forage legumes. Wallingford, UK, cab international.Google Scholar
McKersie, B.D., Chen, Y., de Beus, M., Bowley, S.R., Bowler, C., Inzé, D., D'Halluin, K. and Botterman, J. (1993) Superoxide dismutase enhances tolerance of freezing stress in transgenic alfalfa (Medicago sativa L.). Plant Physiology 103, 11551163.CrossRefGoogle ScholarPubMed
McKersie, B.D., Senaratna, T., Bowley, S.R., Brown, D.C.W., Krochko, J.E. and Bewley, J.D. (1989) Application of artificial seed technology in the production of hybrid alfalfa (Medicago sativa). In Vitro Cellular and Developmental Biology 25, 11831188.CrossRefGoogle Scholar
Maheswaran, G. and Williams, E.G. (1984) Direct somatic embryoid formation on immature embryos of Trifolium repens, Trifolium pratense and Medicago sativa, and rapid clonal propagation of Trifolium repens. Annals of Botany 54, 201211.CrossRefGoogle Scholar
Maheswaran, G. and Williams, E.G. (1985) Origin and development of somatic embryos formed directly on immature embryos of Trifolium repens in vitro. Annals of Botany 56, 619630.CrossRefGoogle Scholar
Maheswaran, G. and Williams, E.G. (1986a) Clonal propagation of Trifolium pratense, T. resupinatum and T. subterraneum by direct somatic embryogenesis on cultured immature embryos. Plant Cell Reports 5, 165168.CrossRefGoogle Scholar
Maheswaran, G. and Williams, E.G. (1986b) Direct secondary somatic embryogenesis from immature sexual embryos of Trifolium repens cultured in vitro. Annals of Botany 57, 109117.Google Scholar
Maheswaran, G. and Williams, E.G. (1987) Uniformity of plants regenerated by direct somatic embryogenesis from zygotic embryos of Trifolium repens. Annals of Botany 59, 9397.CrossRefGoogle Scholar
Manners, J.M. (1988) Transgenic plants of the tropical pasture legume Stylosanthes humilis. Plant Science 55, 6168.CrossRefGoogle Scholar
Meijer, E.G.M. (1989) Developmental aspects of ethylene biosynthesis during somatic embryogenesis in tissue cultures of Medicago sativa. Journal of Experimental Botany 40, 479484.CrossRefGoogle Scholar
Meijer, E.G.M. and Brown, D.C.W. (1987) A novel system for rapid high frequency somatic embryogenesis in Medicago sativa. Physiologia Plantarum 69, 591596.CrossRefGoogle Scholar
Meijer, E.G.M. and Brown, D.C.W. (1988) Inhibition of somatic embryogenesis in tissue cultures of Medicago sativa by aminoethoxyvinylglycine, aminooxyacetic acid, 2,4-dinitrophenol and salycylic acid at concentrations which do not inhibit ethylene biosynthesis and growth. Journal of Experimental Botany 39, 263270.CrossRefGoogle Scholar
Morris, P., Carron, T.R., Webb, K.J. and Robbins, M.P. (1994) Distribution of condensed tannins in flowering plants of Lotus corniculatus var japonicus and tannin accumulation by transformed root cultures. Lotus Newsletter 24, 6063.Google Scholar
Murashige, T. and Skoog, F. (1962) A revised medium for rapid growth and bioassays with tobacco cultures. Physiologia Plantarum 15, 473479.CrossRefGoogle Scholar
Napierala, K. (1995) The induction of somatic embryogenesis in suspension cultures of Medicago sativa L. MSc Thesis, University of Guelph.Google Scholar
Narvaez-Vasquez, J., Orozco-Cardenas, M.L. and Ryan, C.A. (1992) Differential expression of a chimeric CaMV-tomato proteinase inhibitor I gene in leaves of transformed nightshade, tobacco and alfalfa plants. Plant Molecular Biology 20, 11491157.CrossRefGoogle ScholarPubMed
Ninkovic, S., Miljus-Djukic, J. and Neskovic, M. (1995) Genetic transformation of alfalfa somatic embryos and their clonal propagation through repetitive somatic embryogenesis. Plant Cell, Tissue and Organ Culture 42, 255260.CrossRefGoogle Scholar
Nolan, K.E., Rose, R.J. and Gorst, J.R. (1989) Regeneration of Medicago truncatula from tissue culture: increased somatic embryogenesis using explants from regenerated plants. Plant Cell Reports 8, 278281.CrossRefGoogle ScholarPubMed
Nomura, K. and Komamine, A. (1986) Molecular mechanisms of somatic embryogenesis. (Ed.) Oxford Surveys of Plant Molecular and Cell Biology, 3, 456465.Google Scholar
Novak, F.J. and Konecna, D. (1982) Somatic embryogenesis in callus and cell suspension cultures of alfalfa (Medicago sativa L.). Zeitschrift für Pflanzenphysiologie 105, 279284.CrossRefGoogle Scholar
Parrott, W.A. (1991) Auxin-stimulated somatic embryogenesis from immature cotyledons of white clover. Plant Cell Reports 10, 1721.CrossRefGoogle ScholarPubMed
Parrott, W.A. and Bailey, M.A. (1993) Characterization of recurrent somatic embryogenesis of alfalfa on auxin-free medium. Plant Cell, Tissue and Organ Culture 32, 6976.CrossRefGoogle Scholar
Parrott, W.A. and Collins, G.B. (1983) Callus and shoot-tip culture of eight Trifolium species in vitro with regeneration via somatic embryogenesis of Trifolium rubens. Plant Science Letters 28, 189194.CrossRefGoogle Scholar
Pederson, G.A. (1986) In vitro culture and somatic embryogenesis of four Trifolium species. Plant Science 45, 101104.CrossRefGoogle Scholar
Pereira, L.F. and Erickson, L. (1995) Stable transformation of alfalfa (Medicago sativa L.) by particle bombardment. Plant Cell Reports 14, 290293.CrossRefGoogle ScholarPubMed
Piccirilli, M., Pupilli, F. and Arcioni, S. (1988) Lotus tenuis Wald. and Kit.: in vitro conditions for plant regeneration from protoplasts and callus of various explants. Plant Science 55, 7782.CrossRefGoogle Scholar
Pomeroy, K., Brown, D.C.W. and Takahata, Y. (1994) Response of Brassica napus L. microspore-derived embryos to exogenous abscisic acid and desiccation. In Vitro Cellular and Developmental Biology 30P, 196203.CrossRefGoogle Scholar
Quesenberry, K.H. and Smith, R.R. (1993) Recurrent selection for plant regeneration from red clover tissue culture. Crop Science 33, 585589.CrossRefGoogle Scholar
Ray, I.M. and Bingham, E.T. (1989) Breeding diploid alfalfa for regeneration from tissue culture. Crop Science 29, 15451548.CrossRefGoogle Scholar
Redenbaugh, K., Fujii, J.A. and Slade, D. (1991) Synthetic seed technology. pp 3574 in Vasil, I.K. (Ed.) Cell culture and somatic cell genetics of plants, Vol 8. New York, Academic Press.Google Scholar
Reich, T.J., Iyer, V.N. and Miki, B.L. (1986) Efficient transformation of alfalfa protoplasts by the intranuclear microinjection of Ti plasmids. Bio/Technology 4, 10011004.CrossRefGoogle Scholar
Reinert, J. (1958) Morphogenese und ihre Kontrolle an Gewebekulturen aus Karotten. Naturwissenschaften 45, 344345.CrossRefGoogle Scholar
Reisch, B. and Bingham, E.T. (1980) The genetic control of bud formation from callus cultures of diploid alfalfa. Plant Science Letters 20, 7177.CrossRefGoogle Scholar
Sarria, R., Calderon, A., Thro, A.M., Torres, E., Mayer, J.E. and Roca, W.M. (1994) Agrobacterium-mediated transformation of Stylosanthes guianensis and production of transgenic plants. Plant Science 96, 119127.CrossRefGoogle Scholar
Saunders, J.W. and Bingham, E.T. (1972) Production of alfalfa plants from callus tissue. Crop Science 12, 804808.CrossRefGoogle Scholar
Schaefer, J. (1985) Regeneration in alfalfa tissue culture: characterization of intracelluar pH during somatic embryo production by solid-state P31 NMR. Plant Physiology 79, 584589.CrossRefGoogle Scholar
Schenk, B.U. and Hildebrandt, A.C. (1972) Medium and techniques for induction and growth of monocotyledonous and dicotyledonous plant cell culture. Canadian Journal of Botany 50, 199204.CrossRefGoogle Scholar
Schroeder, H.E., Khan, M.R.I., Knibb, W.R., Spencer, D. and Higgins, T.J.V. (1991) Expression of a chicken ovalbumin gene in three lucerne cultivars. Australian Journal of Plant Physiology 18, 495505.Google Scholar
Seitz-Kris, M.H. and Bingham, E.T. (1988) Interactions of highly regenerative genotypes of alfalfa (Medicago sativa L.) and tissue culture protocols. In Vitro Cellular and Developmental Biology 24, 10461052.CrossRefGoogle Scholar
Senaratna, T., McKersie, B.D. and Bowley, S.R. (1989) Desiccation tolerance of alfalfa (Medicago sativa L.) somatic embryos: influence of abscisic acid, stress pretreatments and drying rates. Plant Science 65, 253259.Google Scholar
Senaratna, T., McKersie, B.D. and Bowley, S.R. (1990) Artificial seeds of alfalfa (Medicago sativa L.): Induction of desiccation tolerance in somatic embryos. In Vitro Cellular and Developmental Biology 16, 8590.CrossRefGoogle Scholar
Shahin, E.A., Spielmann, A., Sukhapinda, K., Simpson, R.B. and Yashar, M. (1986) Transformation of cultivated alfalfa using disarmed Agrobacterium tumefaciens. Crop Science 26, 12351239.CrossRefGoogle Scholar
Sharp, W.R., Sondall, M.R., Caldas, L.S. and Maraffa, S.B. (1980) The physiology of in vitro asexual embryogenesis. Horticultural Reviews 2, 268310.CrossRefGoogle Scholar
Shetty, K. and McKersie, B.D. (1993) Proline, thioproline and potassium mediated stimulation of somatic embryogenesis in alfalfa (Medicago sativa L.). Plant Science 88, 185193.CrossRefGoogle Scholar
Skokut, T.A., Manchester, J. and Schaefer, J. (1985) Regeneration in alfalfa tissue culture: stimulation of somatic embryo production by amino acids and N-15 NMR determination of nitrogen utilization. Plant Physiology 79, 579583.CrossRefGoogle ScholarPubMed
Spano, L., Mariotti, D., Pezzotti, M., Damiani, F. and Arcioni, S. (1987) Hairy root transformation in alfalfa (Medicago sativa L.). Theoretical and Applied Genetics 73, 523530.CrossRefGoogle ScholarPubMed
Steward, F.C. (1958) Growth and development of cultivated cells. III Interpretations of the growth from free cell to carrot plant. American Journal of Botany 45, 709713.CrossRefGoogle Scholar
Stiller, J., Nasinec, V., Svoboda, S., Nemcova, B. and Machackova, I. (1992) Effects of agrobacterial oncogenes in kidney vetch (Anthyllis vulneraria L.). Plant Cell Reports 11, 363367.CrossRefGoogle ScholarPubMed
Stuart, D.A. and Nelsen, J. (1988) Isolation and characterization of alfalfa 7S and 11S seed storage protein. Journal of Plant Physiology 132, 129133.CrossRefGoogle Scholar
Stuart, D.A., Nelsen, J., Strickland, S.G. and Nichol, J.W. (1985) Factors affecting developmental processes in alfalfa cell cultures. pp 5973 in Henke, R.R., Hughes, K.W., Constantin, M.P. and Hollaender, A. (Eds) Tissue culture in forestry and agriculture. New York, Plenum Publishing.CrossRefGoogle Scholar
Stuart, D.A., Nelsen, J. and Nichol, J.W. (1988) Expression of 7S and 11S alfalfa seed storage proteins in somatic embryos. Journal of Plant Physiology 132, 134139.CrossRefGoogle Scholar
Sun, P. (1977) Production of alfalfa seeds. United States patent no. 4818693.Google Scholar
Tabaeizadeh, Z. (1989) Genetic transformation of a pasture legume, Lotus corniculatus L. (birdsfoot trefoil). Biotechnology Letters 11, 411416.CrossRefGoogle Scholar
Tabe, L., Richardson, T.W., Moore, A., Schroeder, H. and Higgins, T.J. (1994) A biotechnological approach to improving forage protein quality in Medicago sativa. Thirty-fourth North American Alfalfa Improvement Conference. Guelph, Ontario, Canada.Google Scholar
Thomas, M.R., Rose, R.J. and Nolan, K.E. (1992) Genetic transformation of Medicago truncatula using Agrobacterium with genetically modified Ri and disarmed Ti plasmids. Plant Cell Reports 11, 113117.CrossRefGoogle ScholarPubMed
Thomas, T.I. (1993) Gene expression during plant embryogenesis and germination: an overview. Plant Cell 5, 14011410.Google ScholarPubMed
Thorpe, T.A. (1995) In vitro embryogenesis in plants. Current plant science and biotechnology in agriculture, Vol. 20, Dordrecht, Kluwer Publishing.Google Scholar
Tomes, D.T. (1979) Tissue culture procedure for propagation and maintenance of Lotus corniculatus birdsfoot trefoil genotypes. Canadian Journal of Botany 57, 137140.CrossRefGoogle Scholar
Tysdal, H.M., Kiesselbach, T.A. and Westover, H.L. (1942) Alfalfa Breeding. Nebraska Agriculture Experimental Station Research Bulletin No. 124.Google Scholar
Vlachova, M., Metz, B.A., Schell, J. and de Bruijn, F.J. (1987) The tropical legume Sesbania rostrata: tissue culture, plant regeneration and infection with Agrobacterium tumefaciens and rhizogenes strains. Plant Science 50, 213223.CrossRefGoogle Scholar
Voisey, C.R., White, D.W.R., Dudas, B., Appleby, R.D., Ealing, P.M. and Scott, A.G. (1994) Agrobacterium-mediated transformation of white clover using direct shoot organogenesis. Plant Cell Reports 13, 309314.CrossRefGoogle ScholarPubMed
Walker, K.A. and Sato, S.J. (1981) Morphogenesis in callus tissue of Medicago sativa: the role of ammonium ion in somatic embryogenesis. Plant Cell, Tissue and Organ Culture 1, 109121.CrossRefGoogle Scholar
Wan, Y., Sorensen, E.L. and Liang, G.H. (1988) Genetic control of in vitro regeneration in alfalfa (Medicago sativa L.). Euphytica 39, 39.CrossRefGoogle Scholar
Webb, K.J. (1986) Transformation of forage legumes using Agrobacterium tumefaciens. Theoretical and Applied Genetics 72, 5358.CrossRefGoogle ScholarPubMed
Webb, K.J., Woodcock, S. and Chamberlain, D.A. (1987) Plant regeneration from protoplasts of Trifolium repens and Lotus corniculatus. Plant Breeding 98, 111118.CrossRefGoogle Scholar
Weissinger, A.K. II, and Parrott, W.A. (1993) Repetitive somatic embryogenesis and plant recovery in white clover. Plant Cell Reports 12, 125128.CrossRefGoogle ScholarPubMed
Wenzel, C.L. and Brown, D.C.W. (1991) Histological events leading to somatic embryo formation in cultured petioles of alfalfa. In Vitro Cellular and Developmental Biology 27,P 190196.CrossRefGoogle Scholar
White, D.W.R. and Greenwood, D. (1987) Transformation of the forage legume Trifolium repens L. using binary Agrobacterium vectors. Plant Molecular Biology 8, 461469.CrossRefGoogle ScholarPubMed
Wilson, C., Bellen, H.J. and Gehring, W.J. (1990) Position effects on eukaryotic gene expression. Annual Review of Cell Biology 6, 679714.CrossRefGoogle ScholarPubMed
Yamada, T. and Higuchi, S. (1990) In vitro culture of genus Trifolium germplasm and plant regeneration. Journal of the Japanese Society of Grassland Science 36, 4755.Google Scholar
Yamada, T. and Okumura, K. (1996) Germplasm conservation. pp 4360 in McKersie, B.D., Brown, D.C.W. (Eds.) Biotechnology and the improvement of forage legumes. Wallingford, UK, CAB INTERNATIONAL.Google Scholar
Yu, K. and Pauls, K.P. (1993) Identification of a RAPD marker associated with somatic embryogenesis in alfalfa. Plant Molecular Biology 22, 269277.CrossRefGoogle ScholarPubMed
Zhang, Y. (1992) Induction and maturation of alfalfa somatic embryo. MSc Thesis, University of Guelph.Google Scholar
Zimmerman, J.L. (1993) Somatic embryogenesis: a model for early development in higher plants. Plant Cell 5, 14111423.CrossRefGoogle Scholar