Shan Lin
Liaodong University
Dandong, Yuanbao, CHINA
heyao Xiong
Liaodong University
Dandong, Liaoning, China (People's Republic)
Baizhu Qian
Liaodong University
Dandong, Liaoning, China (People's Republic)
Ye Sun
Liaodong University
Dandong, Liaoning, China (People's Republic)
Xiaochen Lu
Liaodong University
Dandong, Liaoning, China (People's Republic)
Fengjun Zhao
Liaodong University
Dandong, Liaoning, China (People's Republic)
Actinidia arguta (kiwiberry), a valuable deciduous fruit tree renowned for its exceptional nutritional composition, has recently been affected by a stigma-end rot disease in Northeastern China, leading to total crop loss during cold storage. Field surveys were conducted across five orchards in Liaoning Province on three cultivars (Lvjiaren, Danyang, and Maolvfeng) during 2023–2024, from which 142 fungal isolates were obtained from symptomatic fruit. Morphological characterization and multi-locus phylogenetic analyses revealed eight fungal species were associated with the disease: Diaporthe eres, a novel Diaporthe sp., Colletotrichum aenigma, C. boninense, C. fructicola, C. nymphaeae, C. siamense, and C. sojae. Pathogenicity assays validated the virulence of representative isolates on healthy fruits. To identify inoculum sources, overwintering twigs and seasonal tissues (flower buds, open flowers, leaves, bark, berries) were sampled from April to September, 2024. Isolation data indicated twigs as a potential primary inoculum source, with leaf spots and bark as secondary sources. An increased frequency of fungal isolation during flower opening suggested that the blooming stage may represent a critical window for infection initiation. This study clarifies the etiology of kiwiberry fruit rot and provides essential insights for developing integrated disease management protocols to mitigate economic losses in commercial production.