Effect of different carbon sources on in vitro propagation of yellow passion fruit

Passion fruit belongs to genus Passiflora, which includes nearly 400 known species that are mostly found in tropical regions of the American continent, of which 120 are native from Brazil. Under in vitro conditions, plants partially lose autotrophism, requiring an exogenous source of carbohydrates. The objective of this work was to evaluate the effect of distinct carbon sources (sucrose, glucose and lactose) in different concentrations on in vitro propagation of yellow passion fruit. Stem segments with a bud and the excised apex were inoculated on MS medium supplemented or not with carbohydrates at concentrations of 0, 30, 59 and 88 mM L^‑1, according to the treatment. The experimental design was completely randomized in a 3×4 factorial (source of carbohydrates × carbohydrate concentration), with five replicates, each consisting of a bottle with four explants. After 60 days of cultivation, average number of leaves, number of shoots, shoot length, number of roots and length of the longest root were recorded. Highest number of leaves and shoots were obtained with 88 mM L^‑1 glucose on MS culture media. Longer shoots and roots and increased number shoots were found with 88 mM L^‑1 sucrose supplemented in the culture media.