Silver nanoparticles: a positive factor for in vitro flowering and fruiting of purple passion fruit (Passiflora edulis Sim f. edulis)

In the present study, the positive effects of AgNPs were demonstrated for adventitious shoot formation, in vitro flowering and fruiting of Passiflora edulis Sims f. edulis-an important commercial crop. The results showed that shoot regeneration from lTCL (87.67%) and oTCL (100%) explants were significantly improved on the medium supplemented AgNPs. The in vitro shoots derived from TCL explants were used for shoot multiplication. The treatment with 1.0 mg/L meta-topolin (mT) and 5 mg/L AgNPs enhanced the shoot multiplication with the highest number of shoots (13.67 shoots/explant), shoot height (4.33 cm), and total chlorophyll content (33.93 nmol/cm(2)). For flowering induction, shoot tips cultured in MS medium supplemented with 7 mg/L AgNPs gave the highest of flowering rate (51.67%) and number of flowers per shoot (2.33 flowers) after 60 days of culture. In addition, shoots cultured in medium supplemented with 7 mg/L AgNPs showed significantly lower endogenous hormone of GA(3), ABA, and melatonin levels than the control. In the treatment with 7 mg/L AgNPs, the flower bloom rate was 100% and the flower diameter was the largest (3.43 cm). The in vitro developed flowers self-fertilized and formed fruits. After 90 days of culture, the treatment supplemented with 7 mg/L AgNPs gave the highest fruiting rate (56.67%), number of fruits (1.67 fruits), and fruit diameter (1.13 cm). These findings pave the way for further research into flowering and fruiting mechanisms, as well as improving the efficient breeding process of this plant. Key message A first procedure has been established for in vitro flowering and fruiting of purple passion fruit via the application of nanotechnology and the thin cell layer technique. Silver nanoparticles significantly improved shoot formation, in vitro flowering and fruiting of purple passion fruit.