Citron Watermelon (Citrullus amarus): A Potential and Alternative Rootstock for Grafted Watermelon (C. lanatus)

Grafting is an important technique in watermelon production systems to enhance biotic and abiotic stress tolerance, fruit yield, and quality. Grafting watermelon using compatible rootstocks of closely related Citrullus species offers opportunities for the development of watermelon crops possessing unique product profiles. Therefore, the objective of this review is to appraise the utilities of citron watermelon as a potential and candidate rootstock for grafted watermelon to develop unique graft combinations possessing market and consumer-needed attributes. We conducted a search in various databases, including Web of Science, Science Direct, and Scopus, and accessed the relevant peer-reviewed publications and composed five sections for the review. The first section outlined the benefits of citron watermelon rootstock on grafted watermelon against biotic stress tolerance. The second section discussed the impact of citron watermelon rootstock for inducing abiotic stress tolerance in grafted watermelon. Thirdly, citron watermelon rootstock/watermelon scion on fruit yield is discussed. The fourth section reviews fruit quality of grafted sweet watermelon as affected by citron watermelon rootstocks. Lastly, the genetic resources of citron watermelon and their attributes for rootstock applications in grafted watermelon are presented. The findings highlight citron watermelon as a promising alternative rootstock for improving resilience and fruit quality in grafted sweet watermelon production systems.