Onions Haploid Induction Haploid Plant Induction via in Vitro Gyno- genesis and Plant Regeneration in Onion In the late 1980s to the early 90s,almost at the same time,three research teams reported that gynogenesis onion haploid induction had achieved success,but the obtain haploid plant regeneration rate is relatively low,and the method is relatively complicated. Later,by changing the composition of the culture medium and improving the training conditions,so that the training procedure was simplified and the induced efficiency was improved. Culture way:un-pollinated ovule,ovary,bud(3~5 days before flowering) Direction:increasing regeneration frequency,doubling chromosome,genetic stability
Onions Haploid Induction Haploid Plant Induction via in Vitro Gynogenesis and Plant Regeneration in Onion In the late 1980s to the early 90s, almost at the same time, three research teams reported that gynogenesis onion haploid induction had achieved success, but the obtain haploid plant regeneration rate is relatively low, and the method is relatively complicated. Later, by changing the composition of the culture medium and improving the training conditions, so that the training procedure was simplified and the induced efficiency was improved. Culture way: un-pollinated ovule, ovary, bud (3 ~5 days before flowering) Direction: increasing regeneration frequency, doubling chromosome, genetic stability
Onions Haploid Induction a.Unopened flower buds (2.5-3.5 mm in diameter); b.Flower buds inoculated on the media: c.Emergence of gynogenic embryo on B5 medium with 2.0 mg L!2,4-D+2.0 mg L-1 6- BA; d.The enlargement of gynogenic embryo: e.Tube plantlets from gynogenic embryo on the hormone-free B5 medium:; f.Acclimatization of tube plantlet; g.Chromosomes in root tip cells of a diploid plant (2n=16); h.Chromosomes in root tip cells of a haploid regenerated plant f (n=8) Fig.2 The development of onion flower buds in vitro and induction of gynogenesis
Fig. 2 The development of onion flower buds in vitro and induction of gynogenesis a. Unopened flower buds（2.5–3.5 mm in diameter）； b. Flower buds inoculated on the media； c. Emergence of gynogenic embryo on B5 medium with 2.0 mg·L-1 2,4-D + 2.0 mg·L-1 6- BA； d. The enlargement of gynogenic embryo； e. Tube plantlets from gynogenic embryo on the hormone-free B5 medium； f. Acclimatization of tube plantlet； g. Chromosomes in root tip cells of a diploid plant （2n = 16）； h. Chromosomes in root tip cells of a haploid regenerated plant f（n = 8） Onions Haploid Induction