ABSTRACT
Peroxyacetic acid mixture Perosan, composed of peroxyacetic acid, hydrogen peroxide and acetic acid, was evaluated for eco-friendly management of tomato bacterial wilt by Ralstonia pseudosolanacearum. Perosan drastically suppressed in vitro growth of R. pseudosolanacearum in liquid cultures in dose- and incubation time-dependent manners. Higher perosan doses (0.1 and 1%) caused lowered pH and phytotoxicity to detached leaves of two tomato cultivars Cupirang and Benekia 220 in aqueous solution. Treatment with 0.01% of Perosan delayed wilting symptom significantly in the detached leaves of two cultivars inoculated with R. pseudosolanacearum (107 cfu/ml). Soil drenching of 5% Perosan solution in pots caused severe tissue collapse of tomato seedlings at the four-week-old stage of two tomato cultivars. Treatment with 1% Perosan by soil-drenching significantly reduced bacterial wilt in the tomato seedlings of two cultivars. These findings suggest that Perosan treatment can be applied to suppress bacterial wilt during tomato production.
ABSTRACT
In traditional Korean medicine, lotus (Nelumbo nucifera Gaertn) roots have been used as an antidiabetic and an antiproliferative remedy. However, scientific publications on lotus properties are very limited. Therefore, it was decided to investigate the Korean white lotus cultivars in order to find out their bioactivity. It was found that all lotus cultivars (Inchisa, Muan, Garam, and Chungyang) possess high amounts of bioactive compounds: total phenols, between 7.95 +/- 0.8 and 4.21 +/- 0.3 mg of gallic acid equivalents (GAE)/g dry weight (DW); ascorbic acid, between 15.8 +/- 1.1 and 22.3 +/- 1.7 mg of ascorbic acid/g DW; and amino acids, between 15.05 +/- 0.82% and 16.62 +/- 0.90% DW. The highest contents of polyphenols (7.95 +/- 0.8 mg of GAE/g DW) and the highest levels of antioxidant [by 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl assays, 54.27 +/- 6.1 and 21.98 +/- 2.5 microM Trolox equivalents/g DW, respectively] and antiproliferative activities on both human cancer cell lines (Calu-6 for human pulmonary carcinoma and SMU-601 for human gastric carcinoma, 59.75 +/- 3.99% and 71.21 +/- 2.79% cell viability, respectively) were found in the Chungyang cultivar. Fluorometry and Fourier transform infrared spectroscopy can be applied as rapid methods for determination of bioactive compounds, such as polyphenols. The correlation between the bioactive compounds and the antioxidant activity was high. In conclusion, all Korean white lotus cultivars are valuable medicinal foods, and in order to receive the best results a combination of lotus cultivars has to be consumed.