Author : Nanditha B.P, Nethra.P, Ashwini M and RV Koti

Zinc oxide nanoparticles (Nps) was synthesized using Hibiscus leaf extract and Aspergillus niger and characterized by Particle size analyzer and Dynamic Light scattering method. The average particle size obtained was approximately <100 nm.  Different concentrations of ZnO NPs were used for standardization of seed priming in Sorghum. The seeds were soaked for 10 hours in different concentrations of ZnO NPs synthesized from hibiscus leaf extract and Aspergillus niger (@ 500 ppm & 1000 ppm), along with chemically synthesized ZnO NPs (50nm and 100nm @ 500ppm & 1000 ppm each), recommended bulk ZnSO4 (500 ppm) and control (water soaking). Later it was shade dried and kept for germination in the germination paper for a period of 12 days. The observations were recorded such as germination rate, shoot length, root length, Root: shoot and seedling vigour index. It was observed that among all the treatments, the ZnO NPs synthesized from Aspergillus niger @ 1000ppm showed significantly highest germination rate (96.42%), root length (27.85cm), shoot length (20.60 cm), and seedling vigour index (4672)  as compared to control [germination rate (89.28%), root length (25.05cm) and shoot length (17.55cm) and seedling vigour index (3803)] and it was on par with ZnO NPs@ 1000ppm from Hibiscus leaf extract. This study concludes that the green synthesized ZnO nanoparticles @ 1000 ppm is optimum for seed priming in Sorghum.

Keywords: Green synthesis, Nanoparticles, Aspergillus niger, Sorghum, seed priming