Observation and description of morphological variations for flowers and fruits in persimmon

Persimmon (Diospyros kaki Thunb.) was considered as the most economically important fruits in the clade of Diospyros genus because its high nutrient value for fruit consumption. Due to long-term cultivation and domestication, persimmon displays plenty of morphological variation, but its morphological characterizations remain less investigated. In present study, we developed a tutorial for description of flower and fruit morphological variations of persimmon in the National Field GenBank for Persimmon (NFGP) of China. A total of 133 mutation types were detected for 24 traits which comprised of 12 flower characters and 12 fruit traits according to nearly 1200 persimmon germplasms, with an average mutation type of 5.5. Among 12 descriptive flower traits, petals color showed the highest of 8 types and followed by the receptacle shape with 7 types. Flower sex and color of corolla tube exhibited the lowest variations (3 types). Furthermore, among 658 observed persimmons, 598 accessions had only female flowers, with the highest proportion (89.39%). However, there is only one sample among 607 accessions with no open petals in the trait of petals open degree, accounting for 0.16%. For the 12 fruit characters, fruit shape demonstrated the highest of 20 types and followed by 8 types for the fruit skin color, while the grooves on fruit side showed the lowest variations (3 types). Most cultivars had no fruit indent, which accounted for 77.11% of the total variance; while the fusiform type of ventricle shape was found in one accession accounting for 0.18% of the total accessions. Taken together, we have established a tutorial according to the flowers and fruits for accessing persimmon morphological variations and provide the potential to select candidate accessions for further breeding programs.