A Bibliometric Analysis of Walnut Breeding Research: Evolution of Breeding Strategies

The breeding of walnut (Juglans regia L.) is of strategic importance for global food security and agricultural biodiversity. A comprehensive analysis of the scientific environment and research development in walnut breeding is important for determining future breeding directions. In this study, a total of 705 publications indexed under the keyword ‘Walnut Breeding’ in the Web of Science database were subjected to a comprehensive bibliometric analysis in order to evaluate the current research environment. The obtained data examined patterns of co-authorship, citation-based country interactions, corporate affiliations and keyword densities using VOSviewer for network visualization and mapping. The findings confirm that more than 75% of the total publications are original research articles and that the field is primarily based on empirical studies. In walnut breeding research, the journals ‘Horticulture’ and ‘Plant Sciences’ hold a dominant position. UC Davis Walnut breeding, Chinese forestry Academy and serves as the main centers of leading research centers and activities at Purdue University. Citation analysis identifies ‘Vahdati K.’, ‘McGranahan G.H.’, and ‘Sütyemez M.’ as influential actors shaping the conceptual framework of the field. Moreover, evidence supports that the USA, Türkiye, Iran, and China play central roles in global collaboration networks. The keyword density map demonstrates a change from conventional germplasm research toward molecular and environmental topics, including documents analysis, association mapping, and climate change adaptation, marking a paradigm change. By systematically documenting scientific progress and major research directions over the past quarter-century, this study, reveals current literature gaps and provides a strategic guide for national and international breeding initiatives. Finally, this research provides a comprehensive overview of walnut breeding, contributing to informed decision-making and the knowledge base of researchers and industry stakeholders.