Comparative analysis of colchicine and bio-catharanthine as mutagenic agents for polyploid generation in wild passion fruit (Passiflora foetida)

Abstract

Wild type Passiflora foetida or a bush passion fruit is unappealing plant with small fruit size (2-3 cm) to be cultivated as a fruit crop. Plant breeding by polyploidization may improve plant production including increase the fruit size. Many researchers have used colchicine as plant chromosome-modifying agent for polyploidization. However, this potent mutagen is very expensive in developing countries and toxic. Hence, an alternative mutagen needs to be considered, such as the natural bio-catharanthine. This study aims to evaluate the effectiveness of colchicine and bio-catharanthine mutagens in polyploidization of P. foetida plants. Experiment was arranged in split-plot design with three replications. Main plot was combination of the mutagens and concentrations, the subplot was soaking durations. Twenty-five seeds each were soaked for 1-, 2- and 3-days in distilled water as control, colchicine (0.05%, 0.1%, 0.15%) and bio-catharanthine (0.5%, 1% and 1.5%) solutions. Result showed, bio-catharanthine concentration of 1% at immersion durations of 3-days and 1.5% at 1-, 2- and 3-days could only produce 89, 56, 74, and 71% grade 1 mixoploid plants accordingly. On the other hand, colchicine succeeded in obtaining tetraploid plants at concentration of 0.15% with 3-days soaking time even though at lower result (5%). Lower colchicine concentrations with shorter or the same soaking period could only produce 5% grade 2 mixoploid plants. Colchicine with one-tenth lower concentration than bio-catharanthine concentration is still more efficient in inducing polyploidy. Further research by involving bio-catharanthine concentration and varying the soaking time must be pursued to obtain higher-level ploidy.