The use of 2n gametes for introgression breeding in Oriental x Asiatic lilies

摘要: Besides being an important horticultural crop, lily ( Lilium ) also serves as interesting model plant for molecular cytogenetic research several reasons. a) The crop includes cultivars of different taxonomic species each which possess valuable traits that need to be combined in the new cultivars. b) genomes are so well differentiated genetically individual chromosomes can clearly identified F 1 hybrids progenies through DNA situ hybridization techniques. c) large number and position homoeologous recombinant segments detected. d) Through careful selection, or nitrous oxide treatment, 2n gametes obtained sterile interspecific hybrids. Taking advantage these favourable attributes lily, a investigation was conducted on possibilities introgression characters between Oriental Asiatic lilies use gametes. For this purpose, more than 700 genotypes hybrid × were produced by using special techniques ovule and/or embryo culture All diploid OA (2n=2x=24) highly but 12 found produce notable frequencies. Six analyzed GISH intergenomic recombination meiotic nuclear restitution. In all cases there evidence occurrence first division restitution (FDR) three types cytological abnormalities, viz., post metaphase I (PMI); II (PMII) asymmetric cytokinesis (Chapter 2). used parents, both male female, crosses with parental species, i.e., AA OO, allotetraploid 4x-OA (derived from doubling chromosome oryzalin ). From crosses, 246 triploid 14 tetraploid obtained. constitution some allotriploid BC1 analysed GISH. This confirmed presence O A genome them possessing segments. These recombinations had obviously occurred during development 3). selected population BC (38 plants) FISH order identify determine Intergenomic recombination. analyses indicated most progeny plants originated FDR. However, small proportion IMR. Three kind where when considering segments: reciprocal products crossover present / , represents centromere A, segment vice versa); (b) one normal (O, (c) (A, 4). Furthermore, aim utilizing allotriploids (2n=3x=36) breeding two kinds made, female parent AOA parents versa (2x - 3x 2x); crossed allotetraploids (4x-OA) other producers. used, those Flowcytometry ploidy determination results counting showing concurrence. case 2x near-diploid 4x near-tetraploid, tetraploid, near-pentaploid pentaploid indicate aneuploid euploid (x, 2x, pollen grains. analysis identification possible. Those transmitted their achieving 5). Finally, N2O treatments formation induced Out eight treated, six totally known low genotypes, able gamete producers production considerably increased 0-30% 55-80%. revealed genomes, indicating FDR IMR mechanisms responsible formation. 6). show advantages generate genetic variation possibility progeny. It shows further achieved assortment among genomes. levels manipulated depending upon level parents. induction provides many completely sexual polyploidization monitoring trough techniques, accurate insights into process