Grapevine l eaf rust (GLR) c aused b y Phakopsora euvitis diminishes fruit quality and reduces yield in viticulture, making it one of the world’s most significant fruit crop threats. To develop GLR-resistant grape varieties, substantial efforts have been made to select rust-resistant genes and determine effective strategies f or achieving durab le resistance in grapevines. This study aims to identify genetic resources resistant to GLR by investigating disease incidence in vineyards and symptom development in grapevines inoculated with pathogens. Fifty-seven genotypes from Ampelopsis brevipedunculata, Vitis acerifolia, V. aestivalis, V. amurensis, V. cinerea, V. coignetiae, V. flexuosa, V. labrusca, V. labruscana, V. rotundifolia, and V. vinifera were evaluated for rust disease incidence over four years (2021 –2024) at Yeunganm University. Three plants per genotype were potted and sprayed with a pathogen suspension to assess disease incidence on their adaxial leaf surfaces in a greenhouse. Variation in resistance to GLR was observed among genotypes within each species. Resistant genotypes of V. coignetiae exhibited no symptoms on their leaves, while severe infections were noted in the leaves of susceptible genotypes of A. brevipedunculata, V. amurensis, V. flexuosa, V. labruscana, and V. vinifera. None of the tested V. rotundifolia genotypes displayed yellow pustules and remained unaffected for three weeks after artificial inoculation. These findings highlight the potential of V. rotundifolia and V. coignetiae as valuable genetic resources for breeding rust-resistant grapevines. Chlorophyll content was comparable across all uninfected genotypes. While resistant genotypes maintained relatively stable chlorophyll levels, the average chlorophyll content in the majority of susceptible genotypes was significantly lower following inoculation than before. This negative relationship indicates a general decline in photosynthetic capacity due to disease development in grapevines. Identifying resistant genotypes among both resistant and susceptible genotypes across different Vitis species provides crucial insights for developing new grape varieties with improved resistance to GLR.

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
    1. Plant materials and pathogens
    2. Inoculation of pathogen
    3. Evaluation of rust disease incidence in field andgreenhouse environments
    4. Measurement of leaf chlorophyll content followingartificial inoculation
RESULTS AND DISCUSSIONS
    1. Assessment of rust disease severity across grapevinespecies and genotypes under greenhouse and fieldconditions
    2. Correlation between disease incidence of field infectionand greenhouse inoculation
    3. Correlation between disease incidence of greenhouseinoculation and leaf chlorophyll content in grapevinegenotypes
CONCLUSIONS
적 요
ACKNOWLEDGMENTS
REFERENCES

• Soon Young Ahn(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 안순영 (영남대학교 원예생명과학과)
• Hae Keun Yun(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 윤해근 (영남대학교 원예생명과학과) Corresponding author
• Seung Heui Kim(Fruit Tree Department, Korea National University for Agriculture and Fisheries, Jeonju 54874, Republic of Korea) | 김승희 (한국농수산대학교 과수과)
• Ramalingam Srinivasan(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 라말인감스리니바산 (영남대학교 원예생명과학과)
• Jae Hyun Lee(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 이재현 (영남대학교 원예생명과학과)
• Ji Min Yun(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 윤지민 (영남대학교 원예생명과학과)
• Zar Le Myint(Department of Horticulture and Life Science, Yeungnam University, Gyeongsan 38541, Republic of Korea) | 자리민 (영남대학교 원예생명과학과)