Effectiveness of Colchicine and Oryzalin at Inducing Polyploidy in Watsonia lepida N.E. Brown

Abstract

<jats:p>Genetic modification and manipulation offers the possibility of introducing novel traits into existing plants, thereby increasing marketability. Polyploid induction has in the past produced plants that are more compact and have larger flowers, leaves, and fruit, making them more desirable to consumers. The effect of pulse treatments (0, 24, 48, and 72 h) of colchicine (25, 50, 125, and 250 μ<jats:sc>m</jats:sc>) or oryzalin (30, 60, 90, and 120 μ<jats:sc>m</jats:sc>) on in vitro-grown <jats:italic>Watsonia lepida</jats:italic> N.E. Brown shoots was investigated. Explant survival was higher and more consistent with oryzalin treatment compared with treatment with colchicine. More mixoploids than tetraploids were produced with both compounds. The optimum treatment for producing tetraploids was 120 μ<jats:sc>m</jats:sc> oryzalin for 24 h. Of the 30% explants that survived this treatment, 33% were found to be stable tetraploids.</jats:p>

Micropropagation of iridaceae—a review

“…Flowering of acclimatised W. laccata plants occurred in the first season of ex vitro growth, while corms of W. vanderspuyiae flowered in the second season, suggesting these methods could benefit plant propagators by reducing production time. Pulse treatments (0, 24, 48 and 72 h) of colchicine (25, 50, 125 and 250 lM) or oryzalin (30, 60, 90 and 120 lM) on in vitro grown Watsonia lepida seedlings produced plants of mixed ploidy more frequently than stable tetraploids (Ascough et al 2008b). Best tetraploid induction occurred when seedling explants containing the meristem were treated with 120 lM oryzalin for 24 h.…”

USVL-360, a Novel Watermelon Tetraploid Germplasm Line

“…USVL-360 is a pure line selection from an autotetraploid plant generated by treating a diploid CLC PI 299379 seedling with the herbicide Oryzalin (3, 5-dinitro-N4, N4dipropylsulfanilamide; Agrisel, Suwanee, GA). The application of 0.01% Oryzalin (on three consecutive mornings) to the apical meristem of young seedlings (3 to 5 d postgermination) arrested their growth, inducing differentiation of the apical meristem cells and regeneration of a tetraploid stem (Ascough et al, 2008;Contreras et al, 2010). When the regenerated stems (with apparent tetraploid attributes) began to flower in the greenhouse, they were self-pollinated.…”

Colchicine-induced Somatic Polyploids from In Vitro-germinated Seeds of South African Watsonia Species

“…Chromosome doubling has been used extensively as a tool for creating novelty in ornamental crops (Ascough et al, 2008;Hancock, 1997;Väinölä, 2000). Horticultural benefits of polyploidization include thicker stems and leaves, larger and more intensely colored flowers, novel flower coloration, lower phenotypic variability, a protracted flowering period, a more compact growth habit, improved drought tolerance, and raised photosynthetic capacity (Chen et al, 2006;Hancock, 1997;Sparnaaij, 1979).…”