Breeding of a new papaya cultivar Zhufeng with high yield, good quality, and better storability

Zhufeng is a new papaya cultivar selected from the F1 generation single plants of artificial hybridization (GZ2013005 × GZ2014002) in 2016, exhibiting high yield, good quality, and better storability characteristics. Briefly, this artificial hybridization (GZ2013005 × GZ2014002) yielded 214 seeds, which were sown in November 2017 and finally produced 151 healthy seedlings. Zhufeng was selected in 2017 due to its moderate plant height, high flower count, strong continuous fruit-setting ability, and longer fruit shelf life. Clonal seedlings were derived through tissue culture of lateral buds after stem removal. From 2018 to 2021, comparative variety trials and multi- location trials were conducted in Guangzhou, Foshan, and Yangjiang, culminating in its final selection in 2021. This cultivar was granted Plant Variety Rights by the Ministry of Agriculture and Rural Affairs of China in 2023 (Variety Right No.: CNA20211000174). The plant exhibited moderate vigor and plant height, showing as 237.0 cm in plant height, 166.5 cm in stem height, 44.6 cm in stem circumference, 79.8 cm in leaf length, 92.8 cm in leaf width, 97.9 cm in green petiole length, and 11.1 cm in petiole circumference. The inflorescence rach averages 8.9 cm in length and bears numerous flowers with white corollas (3.7 cm longth, 3.2 cm in diameter). Fruits were elliptical with orange- red flesh and 3.1 cm in thickness. The average single fruit weight was 916.0 g with an average longitudinal diameter of 20.5 cm and a transverse diameter of 11.2 cm. Key fruit quality parameters were: soluble solids content (SSC) 12.6%, reducing sugar content 106 g · kg-1 , total acid content 1.42 g · kg-1 , vitamin C content 1.09 g · kg-1 , and crude fiber content 0.7%. The fruits shelf life under ambient conditions is about 11 days. In the Pearl River Delta region, the period from spring-transplanted plants to initial flowering was about 59 d, with the lowest fruiting height at 37.8 cm. Plant spacing was 1.8-2.2 m × 2.5 m (130-150 plants per 666.7 m2 ) yielding 59.1 kg per plant and 7092 kg per 666.7 m2 . This variety exhibited strong adaptability and excellent fruit storage tolerance, but was susceptible to papaya ringspot virus (PRSV). Orchard establishment should prioritize areas free from PRSV pathogens, with deep soil layers, loose texture, and excellent drainage/irrigation conditions. In areas with high groundwater level, plan drainage/irrigation ditches must be pre-planned. Apply sufficient basal fertilizer during land preparation, with a recommended rate of ≥30 tons per hectare. Regular manual weeding is essential; herbicides should be avoided, and ground cover (plastic film or weed control fabric) is recommended. Fertigation systems are advised for water and nutrient management to maintain soil moisture, while preventing waterlogging in case of root rot. Taken together, this cultivar exhibits wider adaptability and is suitable for cultivation in major papaya-producing regions of China, including Guangdong, Guangxi, Hainan, Yunnan, and Fujian. However, it is susceptible to PRSV, requiring focused disease management. It is suggested to adopt rotation planting mode.