Decontamination of seed borne disease in pepper (Capsicum annuum L.) seed and the enhancement of seed quality by the emulated plasma technology

Abstract

Fungal diseases are a leading cause of crop destruction. The antifungal impact of plasma technology emulation against phytopathogenic fungi is documented in this research. The purpose of this research was to analyze the impact of plasma technology emulation against mycelium growth and spore germination of Colletotrichum gloeosporioides, a causal agent of anthracnose disease in pepper (Capsicum annuum L.) seeds and its effect on pepper seed quality. The emulation of plasma condition in liquid media was simply created by treating sterilized water or hydrogen peroxide (H2O2) solution with UV-C irradiation to obtain the emulation of plasma activated water (EPAW) and plasma activated H2O2 solution (EPAS-H2O2), respectively. Accordingly, in vitro study, mycelium and spores of C. gloeosporioides fungi like (Cgfl) were treated with sterilized water (control), H2O2 solution at 1, 3 and 5%, EPAW and EPAS-H2O2 at 1, 3 and 5% for 60 min. The treated mycelium and spores were placed on PDA medium and incubated at 25 ± 3 ℃. The results revealed that only EPAS-5% H2O2 treatment completely inhibited both mycelium growth and spore germination. Spores were more sensitive to EPAW and EPAS-H2O2 than mycelium. Under scanning, the electron microscope (SEM) showed that the EPAW and EPAS-H2O2 condition destroyed the cell structure of fungal pathogens, leading to the loss of cell membrane integrity and morphological changes. The effects of 5% H2O2, EPAW and EPAS-5% H2O2 on the quality of artificially inoculated pepper seeds were determined in comparison with fungicide (0.15% w/v captan) treated seeds and non-treated seeds (only water). The results indicated that EPAS-5% H2O2 showed the best result to suppress the seed infection and improved seed germination as compared to other treatments, and stimulated seed quality as employing high germination index, seedling growth rate and fresh and dry weight of seedlings. This study implies that the application of plasma technology emulation is the simple and innovative treatment, which proved to be extremely effective towards seed decontamination and enhancement of pepper seed quality.