Background : The dried ripe fruits, leaf and root of boxthorn are widely used for medicinal purposes and as a functional food. Among them, frut is the most susceptible to anthracnose in the open field. Currently, there are only 5 fungicides registered in boxthorn anthracnose. In addition, resistance to fungicides caused by frequent use occurred in many open field, Therefore, a study on the fungicide resistance of boxthorn anthracnose was needed.
Methods and Results : In 2017, collected anthracnose from boxthorn fruit. The collected samples were isolated by a single spore isolation method and 20 isolates of Collectotrichum spp. were obtained To test for anthracnose fungicide resistance, propineb, tebuconazole, azoxystrobin and pyraclostrobin fungicide were used. Monitoring for fungicide resistance of Collectotrichum spp. causing boxthorn anthracnos to test fungicide were conducted by agar dilution method. The assay concentration were control, 0.01, 0.1, 1, 10, 100 ㎍/㎖ and strobilurin group of azoxystrobin and pyraclostrobin were treated salicylhydroxamic acid (SHAM) to the alternative breath suppression at a concentration of 100 ㎍/㎖. In the result, Prevention of fungicide propineb was more than 100 ㎍/㎖ of EC50, and tebuconazole was less than 1 ㎍/㎖ except for 1 isolate of EC50 azoxystrobin and pyraclostrobin showed a difference even though they had the same mode of action. Azoxystrobin showed almost no inhibition of mycelial growth except 6 isolates and remaining 6 isolates had EC50 of less than 1 ㎍/㎖, pyraclostrobin was divided into two groups of EC50, 6 isolates were less than 0.1 ㎍ /㎖ and 14 isolates were more than 1 ㎍/㎖.
Conclusion : In summary, response to fungicides of anthracnose, azoxystrobin of strobilurin group showed the highest resistance to fungicide. As these fungicide resistance continues to develop, we plan to register a new anthracnose fungicide and improve the control method.