, and its low fertility has limited its application for breeding. Chromosome doubling could improve the genetic adaptability, fertility, and nutritive value of this species ( Chen and Kirkbride Jr., 2000 ; Dhooghe et al., 2011 ; Gomes et al., 2014
polyploidy, or chromosome doubling, can be accomplished in several ways. Commonly, seedlings or shoots tips are treated with colchicine (in vitro or in vivo). Colchicine, a mitotic spindle inhibitor affecting chromosome separation during mitosis, has been
combination(s) that resulted in the greatest percentage of chromosome doubling. Fig. 1. Prunus laurocerasus ‘Otto Luyken’ explant during treatment in culture tubes (25 × 150 mm) filled with 10 mL of solidified MS medium into which the base of the explant was
breeding programs, several obstacles still restrict its efficiency. Critical parameters include the role of genotype, the heritability of high gynogenic responsiveness, the chromosome doubling efficiency, and the male fertility of doubled haploid lines
these chemicals for chromosome doubling varies depending on the plant species, concentration levels, and treatment duration. Restored fertility, increased flower and leaf sizes, and shortened internodes often accompany ploidy manipulation ( Pryor and
gametes or spontaneous chromosome doubling in embryonal initials ( Khoshoo, 1959 ). Only diploids and tetraploids were recovered in the current study. In contrast, Contreras et al. (2010) observed 9.3% mixoploids after 30 d treatment of japanese
due to chromosome doubling could increase biomass production and polysaccharide contents. The results showed that tetraploid cultivars produced significantly higher fresh weights compared with the diploid cultivar. Polyploidization also changed the
Jacobsen, 2003 ; Thao et al., 2003 ). Since the discovery by Blakeslee and Avery (1937) of the effectiveness of colchicine for the achievement of chromosome doubling in plants, colchicine has been successfully used to obtain polyploid plants of many
( Colchicum autumnale ), for chromosome doubling has opened a large reservoir of possibilities in polyploidization ( Hassawi and Liang, 1991 ). Although increasing the levels of secondary metabolites as a result of polyploidy induction has been reported for
Regenerating calli of Allium fistulosum × A. cepa interspecific F1 hybrids were treated in vitro with colchicine. A factorial experiment (colchicine concentration × time) was used to recover tetraploids from calli treated with colchicine in vitro. Shoot production of regenerating calli following in vitro colchicine treatment decreased with increasing colchicine concentration and treatment time. Cytological analyses of root tip cells from regenerated plantlets showed that chromosomes of control plantlets (not treated with colchicine) were not doubled. Chromosomes of some plantlets regenerated from in vitro colchicine treated calli were doubled, resulting in tetraploids. Calli treated with 0.1 or 0.2% colchicine in BDS (Dunstan & Short, 1977) liquid medium for 48 or 72 hours yielded the highest number of tetraploid plantlets. These results demonstrate that in vitro colchicine treatment of regenerating calli of interspecific F1 hybrids is effective in recovering tetraploids.