Enhanced Efficiency of In Vitro Rootstock Micro-propagation Using Silica-Based Nanoparticles and Plant Growth Regulators in Myrobalan 29C (Prunus cerasifera L.)

Different experiments were conducted to establish and optimize an efficient in vitro micropropagation protocol for Myrobalan 29C rootstocks. Disinfection of initial explants with AgNPs (2.5%) reduced the needed amount of NaClO (5.0%) by half. The highest rates of induced active buds were obtained in the DKW (90.63%), MS (86.67%), modified MS (82.22%), and WPM (78.15%) culture media supplemented with BAP (2.22 mu mol L-1) + GA(3) (2.88 mu mol L-1) + IBA (0.05 mu mol L-1) + Fe-EDDHA (228.72 mu mol L-1). The highest quality of the proliferated shoots (5.0) was also achieved using DKW medium. Inclusion of GA(3) (5.76 mu mol L-1), Fe-EDDHA (114.36-228.72 mu mol L-1), or BAP (2.22 mu mol L-1) were also able to enhance the rate of shoot multiplication. Compared to the agar-solidified culture system, the established shoots proliferated more efficiently when immersed by bioreactor in the liquid DKW culture medium on a regular basis. Exogenous application of silica-based nanoparticles (NPs) including the chemically synthesized silica NPs (TSiO2 NPs, 1.0 ppm), rice husk derived biogenic silica NPs (RSiO2 NPs, 10.0 ppm), or amine modified silica NPs (ASiO(2) NPs, 10.0 ppm) to the multiplication medium increased the number of regenerated lateral shoots by 520%, 360%, and 349%, respectively. Proliferated shoots with well-developed root system were obtained from the rooting medium supplemented with 19.68 mu mol L-1 IBA. Our results indicated that the rootstocks of Myrobalan 29C could be efficiently propagated under in vitro condition providing proper culture medium and optimal concentrations of additives and plant growth regulators were adopted.

Automated summary

This study established an efficient in vitro micropropagation protocol for Myrobalan 29C rootstocks. Disinfection of initial explants with AgNPs reduced the needed amount of NaClO. The addition of specific plant growth regulators induced active buds, and the use of a liquid culture system improved shoot proliferation. Inclusion of silica-based nanoparticles increased the number of regenerated lateral shoots. Proper culture medium and additive concentrations were crucial for root system growth.