Li Ningxian, a local healthcare worker and fruit grower in Nanfeng county, Jiangxi province, discovered in 2004 that some of his Nanfeng oranges matured about six weeks earlier than usual. Although he attempted to propagate these early-maturing branches, the variety proved unstable with sugar content. Lacking expertise, Li sought help from Yi Hualin, a professor at Huazhong Agricultural University (HZAU)'s College of Horticulture & Forestry Sciences, who specializes in citrus breeding, with the help of local government.

Yi Hualin (L)and Li Ningxian inspect products in the orchard. [Photo/news.hzau.edu.cn]

The two have been working together since 2019.

Yi's intervention involved hands-on guidance in soil improvement, irrigation, pruning, and pest control. By the end of 2022, the "Guiyuehong" variety was officially recognized by the Ministry of Agriculture and Rural Affairs. This new variety matures 40 to 50 days earlier than traditional Nanfeng oranges, and can alleviate harvest pressure and potentially boost farmers' incomes.

The Nanfeng orange, produced specifically in Jiangxi, is celebrated for its smooth, golden skin, thin peel, juicy texture, and unique aroma, and has a 1,700-year history as a royal tribute. However, since 2015, it has faced market decline due to inconsistent quality and competition from high-quality hybrids. The industry is keen to revitalize the Nanfeng orange, addressing issues like poor fruit quality, occasional seeds, and weak aroma.

To tackle these challenges, simply verifying the "Guiyuehong" breed is not enough.

Led by Cao Li's team from Southwest University and Yi Hualin's team, a new project that uses both traditional and modern breeding techniques, including gene editing, to develop improved Nanfeng oranges with desirable traits, was established.

The improvement of the "Guiyuehong" is central to this initiative. Yi's team has set up a 300-acre demonstration orchard in Nanfeng, testing and refining the variety.

The project team plans to crossbreed existing hybrids with high-quality varieties to produce new generations that maintain the best traits of Nanfeng oranges while incorporating advantages from other varieties. This process will require ongoing research.

Yi (L, 2nd) and his team discuss cultivation and management techniques with local agricultural technicians at the Nanfeng Orange Demonstration Orchard. [Photo/news.hzau.edu.cn]

China's citrus industry faces issues such as variety degradation, market homogenization, and a lack of high-end products, according to Yi. Scientists, including Yi's team, continue to address these challenges, contributing to the development and promotion of new citrus varieties across the country.

In the past five years, Yi led his team to inspect the growing of "Guiyuehong" breed every early September.

During this year's visit, Yi also assessed the impact of prolonged high temperatures on citrus cultivation and discussed orchard management and integrated economic development with the local people.