EMBRYOLOGICAL OBSERVATIONS ON UNPOLLINATED OVARY CULTURE OF MULBERRY (MORUS ALBA L.)

A three-step procedure was adopted for the induction of gynogenesis in two cultivars of mulberry (Morus alba L.). This includes in vitro flowering, inflorescence segment culture and isolated ovary culture. In the third step, that is, isolated ovary culture, the cultured ovaries burst and an embryo emerged from the ovary. The present paper investigates the ontogeny of the developing gynogenic embryo. The study confirmed that the gynogenic embryo emerged from the egg cell. Before the onset of division of the egg, all other cells of the embryo sac degenerated in the majority of ovules, but in exceptional cases the polar nuclei will be retained along with the dividing egg cell. The presence of the gynogenic embryo along with free-nuclear autonomous endosperm is the most important feature of the present investigation. Autonomous endosperm is formed from either the polar nuclei or secondary nucleus. In both cultivars used for the experiment, the percentage of ovaries showing proembryo induction during inflorescence segment culture is much higher than that of ovaries producing gynogenic plants during isolated ovary culture. This suggests the degeneration of some gynogenic embryos during the initial stages of induction.

[1]  A. Bhatnagar,et al.  A reproducible protocol for the production of gynogenic haploids of mulberry, Morus alba L. , 1999, Euphytica.

[2]  A. Jain,et al.  Induction of haploid callus and embryogenesis in in vitro cultured anthers of mulberry (Morus indica) , 1996, Plant Cell, Tissue and Organ Culture.

[3]  J. Keller.  Culture of unpollinated ovules, ovaries, and flower buds in some species of the genus Allium and haploid induction via gynogenesis in onion (Allium cepa L.) , 1990, Euphytica.

[4]  B. Sangwan-Norreel,et al.  In vitro gynogenesis in Beta vulgaris L.: Effects of plant growth regulators, temperature, genotypes and season , 1989, Plant Cell, Tissue and Organ Culture.

[5]  C. Zhou,et al.  In vitro induction of haploid plants from unpollinated ovaries and ovules , 1982, Theoretical and Applied Genetics.

[6]  J. Bouharmont,et al.  Origin of gynogenetic embryos of Beta vulgaris L. , 2004, Sexual Plant Reproduction.

[7]  L. Cistué,et al.  Production of gynogenic haploids of Hordeum vulgare L. , 2004, Plant Cell Reports.

[8]  E. Kuta,et al.  Autonomous endosperm development in unpollinated ovaries of Brassica napus L. cv. Topas cultured in vitro , 2002 .

[9]  B. Bohanec,et al.  Embryological study on gynogenesis in onion (Allium cepa L.) , 2001, Sexual Plant Reproduction.

[10]  L. Przywara,et al.  Autonomous endosperm induction by in vitro culture of unfertilized ovules of Viola odorata L. , 1999, Sexual Plant Reproduction.

[11]  M. Stępień,et al.  In vitro culture of unpollinated ovules of Viola odorata L. , 1997 .

[12]  E. Keller,et al.  Ovary and ovule culture for haploid production , 1996 .

[13]  Venkateswarlu Modala,et al.  Induction of calli and organ-like structures in isolated pollen culture of mulberry, Morus australis POIRET. , 1993 .

[14]  A. Kapur,et al.  EMBRYO DIFFERENTIATION IN ANTHER CULTURES OF MULBERRY , 1992 .

[15]  R. Mól.  In vitro gynogenesis in Melandrium album: from parthenogenetic embryos to mixoploid plants , 1992 .

[16]  G. Sita,et al.  Gynogenic plants from ovary cultures of Mulberry ( Morus indica ) , 1991 .

[17]  L. Herrmann,et al.  Production of Haploid Sugar Beet (Beta vulgaris L.) by Culturing Unpollinated Ovules , 1990 .

[18]  C. Zhou,et al.  In Vitro Gynogenesis , 1990 .

[19]  J. Keller.  Results of anther and ovule culture in some species and hybrids in the genus Allium L. , 1990 .

[20]  R. C. Muren.  Haploid Plant Induction from Unpollinated Ovaries in Onion , 1989, HortScience.

[21]  L. Chrétien,et al.  Production of haploids in Gerbera jamesonii via ovule culture: influence of fall versus spring sampling on callus formation and shoot regeneration , 1988 .

[22]  A. Sauton.  Effect of season and genotype on gynogenetic haploid production in muskemlon, Cucumis melo L. , 1988 .

[23]  Qin Jun,et al.  In vitro PRODUCTION OF HAPLOID PLANTS FROM MULBERRY (Morus) ANTHER CULTURE , 1987 .

[24]  L. H. San,et al.  Obtention de plantes haploïdes par culture in vitro d'ovaires et d'ovules non fécondés de tournesol (Helianthus annuus L.) , 1987 .

[25]  C. Zhou,et al.  In vitro culture of unfertilized ovules in Helianthus annuus L. , 1986 .

[26]  C. Zhou,et al.  In vitro culture of unpollinated ovaries in Oryza sativa L. , 1986 .

[27]  Z. Chang,et al.  In Vitro Embryogenesis in Unfertilized Embryo Sacs of Oryza sativa L. , 1981 .

[28]  F. Skoog,et al.  A revised medium for the growth and bioassay with tobacco tissue culture , 1962 .

[29]  Plant Microtechnique , 1941, Nature.