Somaclonal and chromosomal effects of genotype, ploidy and culture duration in Asparagus officinalis L.

Chromosome and morphological variations of embryogenic calli-derived plants of gynogenic haploid, diploid, triploid and tetraploid asparagus (Asparagus officinalis L.) were investigated. Artificial tetraploids were produced using colchicine treatment of seeds of diploid cultivar, ‘Poultom’. ‘Haidel’ (2X) was crossed with the artificial tetraploids, from which one gynogenic haploid, one diploid, 6 triploid, 3 mixoploids were obtained. Embryogenic calli were first obtained from crown buds, subsequently induced to form somatic embryos, and after 30 days, induced to germinate. Chromosome variation in embryogenic calli-derived plants increased with increasing duration of subculture, particularly when low ploidy levels of plants such as haploid and diploid were used as explants. Approximately 80% of haploid-derived plants showed morphological variations such as dwarfness and abnormal morphological characteristics, although no differences were observed in cladodes and stem characteristics between other polyploid-derived plants and their parents. The data presented here would supply important fundamental information for commercial mass-propagation using somatic embryogenesis. This revised version was published online in July 2006 with corrections to the Cover Date.