Analysis on hotspots and frontiers of Chinese Citrus research based on WOS and CiteSpace in the past decade

Abstract: Based on the 2010—2019 database from Web of Science, we analyzed the hotspots and fron- tiers of Citrus research in China, which could help relevant researchers to understand the current situa- tion in this field. Using“citrus”,“trifoliate orange”or“kumquat”as topic, a preliminary search was done on Web of Science, which resulted in the records of literature data published in China between 2010 and 2019. By using the analysis and retrieval function of WOS and Excel, the literature data were analyzed in terms of annual and literature subject categories. Based on the bibliometric analysis soft- ware CiteSpace, author, institution, co-word and co-citation were analyzed, respectively, so as to obtain the statistical data and the visualized network of Citrus research. Accordingly, research hotspots, intel- lectual structure and frontier topics were analyzed. A total of 3 168 citrus-related articles were retrieved from WOS database. The number of articles related to Citrus research increased steadily, and the con- tents involved various subjects and fields. Plant science was the largest publishing subject category, ac- counting for 18.88% of the total published articles, followed by food science technology, biology, horti-culture, chemistry, microbiology, agriculture, pharmacology, entomology, nutriology and so on. The top 3 most productive institutes were Huazhong Agricultural University, Southwest University and Zhejiang University, which are located in Hubei, Chongqing and Zhejiang, respectively, in accordance with the distribution of citrus production, suggesting that the research institutes of citrus in China were close- ly related to the geographic distribution of citrus cultivation. Academic teams with Deng Xiuxin and Wu Qiangsheng as the core have formed. The co-word analysis showed that the hotspots of citrus re- search in the past decade included omics, antioxidant system, phylogenetic analysis, huanglongbing, ar- buscular mycorrhiza, citrus essential oil, fruit quality, etc. In recent years, the omics studies have been widely used in various fields of citrus research. From 2010 to 2015, the high-burst terms, such as“my- corrhizal colonization”,“arbuscular mycorrhizal”,“host plants”and so on, indicated that the research focus of this stage was arbuscular mycorrhizal. From 2016 to 2019, the high-burst terms, such as“prin- cipal component analysis”“oxidative stress”“NF kappa B”and so on, indicated that the current hot- spots of citrus research were active ingredient and medicinal value of citrus. The timeline of co-citation clusters in citrus researches showed that the hotspots and their duration varied with time. The co-cita- tion analyses showed that the frontiers in research included huanglongbing, phylogenetic analysis, ac- tive ingredient extraction and functions analysis, arbuscular mycorrhiza, citrus fruit quality and so on. The above research topics have a strong sustainability. Among them, the literatures related to phyloge- netic analysis of citrus possess the strongest influence. In the process of knowledge evolution of citrus research,“the draft genome of sweet orange (Citrus sinensis)”from Xu Qiang was the most important work in this field. The highly cited and central literatures in citrus research mainly focus on the basic research fields such as omics and molecular biology, and the applied research is less. In the past decade, Chinese scholars have carried out extensive and indepth research on citrus from multidisciplinary fields. The main research forces were from universities, followed by research institutes. Most of the researches were theoretical studies and few were closely related to the citrus industry. In future, more ef- forts should be made to strengthen the conversion of basic research into practical application.