The research paper "Origin and de novo domestication of sweet oranges" by Professor Xu Qiang's team from Huazhong Agricultural University was published online in the journal Nature Genetics on March 5.

This study analyzed the origin model of sweet oranges using whole-genome information and established a molecular breeding pathway for rapid de novo domestication of citrus, providing a case for the rapid breeding of perennial fruit trees. The key metabolites regulating citrus quality and resistance formation were identified, elucidating a synergistic improvement strategy for fruit quality and resistance through tissue-specific approaches. This study provides an important theoretical basis for obtaining new germplasm that combines high quality and significant disease resistance through rapid domestication.

Based on high-resolution genomic analysis, the study inferred the wild-domesticated citrus relationship, clarifying that sweet oranges originated from a cross between sour oranges and mandarins. This research provides rich germplasm resources and genetic evidence to address the long-standing debate over the origin of sweet oranges.

The de novo domestication for rapid breeding of citrus. [Photo/news.hzau.edu.cn]

Starting from the source, the research simulated the process of creating sweet oranges and conducted de novo domestication work. Initially, genetic diversity was greatly enriched through sexual processes, followed by the fixation of superior genotypes through non-fusion reproduction and grafting, thereby establishing a molecular breeding pathway for the rapid de novo domestication of citrus. Ultimately, a diverse range of flavors and ulcer-resistant sweet oranges and other hybrid new strains were cultivated, providing an efficient and precise means for the improvement of citrus breeding.