Progress of collection, conservation and innovative utilization of persimmon resources in the National Germplasm Repository (Yangling)

Persimmon (Diospyros kaki Thunb.), a member of the family Ebeneceae and genus Diospyros, is a traditional fruit crop in China. The National Persimmon Germplasm Resources Nursery is the largest persimmon plant resource nursery in the world. The collected resources cover 16 provinces and regions in China, Japan, the Republic of Korea, the United States, Israel, Italy and others. By 2024, a total of 937 persimmon germplasm resources have been systematically characterized and securely preserved, playing a pivotal role in advancing fundamental research and the development of new cultivars. This study would provide a comprehensive overview of the global distribution, production, and preservation of persimmon germplasm resources, with a particular emphasis on the current status of collection, preservation, and evaluation efforts in China. Furthermore, it would highlight recent advancements in the effective utilization of these resources and outline future priorities to enhance long-term preservation and innovative utilization strategies in China. In China, 36 native male persimmon germplasm resources have been collected, preserved, and characterized. Notable preserved varieties included Jinzaoshi, Heishi, Qiyuezao, Mopanshi, Fuping Jianshi, Yueshenshi, Youhou, Taishu, and compatible rootstocks Puzhen No. 1 and Puzhen No. 2. For instance, Luotian Tianshi persimmon would produce both male and perfect flowers in specific years. As the only native Chinese pollination-constant non-astringent (PCNA) variety with male flowers, it serves as a valuable parental resource for hybridization. Gongshi persimmon is recognized for its large fruit size and early maturation, Shutouhong persimmon for its exceptionally large fruit, and Zhanfanghou persimmon for its high soluble solid content. Among the 14 resources capable of bearing perfect flowers, 8 accessions can develop into fruits. Taiwan Zheng-shi persimmon, with both central and lateral flowers developing into perfect flowers, exhibits the highest fruiting ability at over 95%, being a unique ornamental resource. These male resources, characterized by extended flowering periods and abundant pollen, are invaluable as breeding parents and pollination varieties for sweet persimmons. D. kaki is predominantly cultivated in East Asia and Mediterranean regions. Persimmons are classified into four types based on natural astringency loss and flesh color changes: pollination constant & non-astringent persimmon (PCNA), pollination-variant non-astringent (PVNA), pollination- variant astringent (PVA), and pollination- constant astringent (PCA). The PCNA type, which does not require post-harvest astringency removal, is further divided into Japanese PCNA (JPCNA) and Chinese PCNA based on differences in astringency loss during growth and maturity. In contrast, PVNA, PVA, and PCA types retain varying levels of astringency until maturity and are collectively referred to as non-PCNA types. In China, over 900 persimmon cultivars have been reported, with only a few classified as PCNA.