A recent genetic analysis has shed new light on the origins of citrus fruits, pointing to China as their place of origin.
The exact birthplace of various citrus fruits has long been a subject of debate among researchers, with potential locations including northeastern Australia, southern China, or the southeastern foothills of the Himalayas. However, a study published in Nature Genetics suggests that the first species within the Citrus genus likely originated approximately 8 million years ago in what is now south-central China.
The study, led by horticulturist Qiang Xu from Huazhong Agricultural University, constructed a family tree using genetic data from 314 citrus and citrus-related plants, encompassing 15 different citrus species. Additionally, fieldwork was conducted to locate wild citrus trees, further supporting the idea that the oldest citrus fruits, including the trifoliate orange (C. trifoliata), are primarily found in south-central China.
The research also acknowledged that some citrus species have their origins in regions previously suggested by earlier studies, such as pomelo and citron fruits originating in the Himalayan foothills, and certain wild limes evolving in Australia.
Furthermore, the study identified a gene known as PH4, which is linked to the tartness of citrus fruits as it regulates the citric acid content in the fruit. This discovery has significant implications, as it can aid in the development of more resilient plant varieties that still produce delicious fruit.
Understanding the evolution of citrus fruits is not only of historical interest but also has practical applications in agriculture, potentially leading to the creation of more robust and flavorful citrus crops.
