The National Institute of Forest Science (NIFoS) under the Korea Forest Service announced Wednesday that it has planted disease-resistant pine trees in a pilot program aimed at preventing the spread of pine wilt disease.
Pine wood nematode, a thread-shaped parasitic worm approximately 1 millimeter in length, spreads through insect vectors such as the Japanese pine sawyer beetle and the spruce longhorn beetle. Most infected pine trees are known to die from the disease.
Damage from pine wilt disease peaked at approximately 2.18 million trees in 2014 before declining. However, the trend reversed in 2023, partly due to the effects of climate change, and approximately 1.49 million trees were affected in 2025.
NIFoS has been conducting ongoing research to select disease-resistant pine trees to contain the spread of pine wilt disease. Researchers identified surviving individual trees in areas severely affected by pine wilt disease in 2015, collected their seeds and produced seedlings. The surviving individuals were ultimately selected as disease-resistant pines after undergoing four rounds of artificial inoculation.
The institute then produced seedlings genetically identical to the disease-resistant individuals through grafting propagation. On Tuesday, 200 of these seedlings were planted in a pilot program in the Yeonghae-myeon area of Yeongdeok-gun, North Gyeongsang Province. This marks the first field application of breeding research results on pine wilt disease resistance.
"This pilot planting is the first step in applying our pine wilt disease resistance research to the field," said Oh Chang-young, head of the Forest Tree Resources Research Division at NIFoS. "We will continue to contribute to the development of molecular markers for selecting disease-resistant individuals and the sustained production of disease-resistant pine trees."