Research and Development Center of Biorational Pesticides, Northwest A & F University, Yangling 712100, China.
Molecules. 2022 Feb 24;27(5):1531. doi: 10.3390/molecules27051531.
The canker caused by seriously harmed the production of East Asian apples and caused very significant economic losses. Considering the chemical residues and the improvement of people's awareness of environmental protection, there is a need for screening new green pesticides for the control of canker. Therefore, we conducted systematic evaluations on the antifungal activity of wood tar. In this research, the effective concentration (EC) of six strains of to wood tar was determined, and the EC ranged from 69.54 to 92.81 μg/mL. After treatment with wood tar, the hyphae of broke, swelled, and deformed; the permeability of the cell membrane increased; and the activity of pectinase reduced. Moreover, the expression levels of five genes related to pectinase also decreased significantly. In addition, the activities of phenylalanine ammonia lyase (PAL) and peroxidase (POD) of apple leaves treated with wood tar also increased. On detached apple branches, wood tar also showed therapeutic and protective activities. In the 2016-2019 field experiments, wood tar also showed good efficacy against canker and promoted the formation of callus. (In the experiments from 2016 to 2019, it can be seen that the control effect of 50% wood tar and 100% wood tar in the field is above 75% and promoted the formation of callus.) This study is the first to report the bidirectional efficacy of wood tar against and for trunk wound healing. The above results evidenced that wood tar has great potential to be developed as a natural alternative to commercial fungicides for the management of apple canker.
疫病疫霉严重危害东亚地区苹果生产，造成巨大经济损失。考虑到化学残留和人们环保意识的提高，需要筛选防治苹果疫腐病的新型绿色农药。因此，我们对木焦油的抑菌活性进行了系统评价。本研究测定了 6 株疫霉菌对木焦油的有效浓度（EC），EC 值范围为 69.54-92.81μg/mL。木焦油处理后，疫霉菌菌丝断裂、肿胀、变形，细胞膜通透性增加，果胶酶活性降低。同时，与果胶酶相关的五个基因的表达水平也显著降低。此外，木焦油处理后的苹果叶片苯丙氨酸解氨酶（PAL）和过氧化物酶（POD）活性也增加。在离体苹果枝条上，木焦油也表现出治疗和保护作用。在 2016-2019 年田间试验中，木焦油对苹果疫腐病也表现出良好的防治效果，并促进愈伤组织的形成。（在 2016 年至 2019 年的实验中，可以看出 50%木焦油和 100%木焦油在田间的防治效果均在 75%以上，并促进愈伤组织的形成。）本研究首次报道了木焦油对疫霉菌的双向防治作用及其对树干伤口愈合的促进作用。上述结果表明，木焦油具有开发为防治苹果疫腐病的天然替代商业杀菌剂的巨大潜力。
