Based on the results of the Melonomics project of the Center for Research in Agrigenomics of the University of Barcelona (CRAG), which achieved the first complete sequence of the melon genome seven years ago, a research group of the Chinese Agricultural Sciences Academy, in collaboration with CRAG researchers, has managed to sequence the genome of 1,175 varieties of melon, i.e. virtually all the diversity of the Cucumis melo species.
In addition to contributing to the knowledge of the domestication of this species 4,000 years ago, this new genomic information “represents very valuable information that can be applied to the genetic improvement of melon to obtain new varieties in a faster and more precise way,” stated Jordi Garcia-Mas, a researcher at the Institute of Agricultural Food Research and Technology, IRTA, at CRAG, and one of the leaders of the study.
According to the researchers, the genetic improvement of melon could incorporate genomic editing techniques, such as CRISPR-CAS9, a technology that is already being developed in the Garcia-Mas laboratory.
Knowing the past for future improvements
According to the results of the study, the more than one thousand subspecies analyzed were domesticated independently in Asia from wild varieties of the two large subspecies.
Through association studies, the authors have managed to identify 208 regions of the melon genome that determine agronomic interesting characteristics, such as external color, pulp color, acidity, aroma, or the presence of sutures in the fruit's skin. All these data will be valuable tools for the genetic improvement of this plant species of high economic interest, with the aim of obtaining varieties that can be cultivated in a more sustainable way, which at the same time produce fruits of excellent quality.
The melon sector
According to data from the Food and Agriculture Organization of the United Nations (FAO), in 2017 the world produced more than 30 million tons of melon, half of which were produced in China. Spain is the main producer within the EU, and also the world's leading exporter.
The varieties that are currently consumed are grouped into the two large subspecies: melo and agrestis. The first one is grown all over the world, and it is the one that contains the most appreciated melon varieties for consumption, such as Piel de Sapo, Amarillo, Cantalup or Galia. The agrestis subspecies, on the other hand, is practically only cultivated in East Asia and contains varieties that produce melons that have less pulp and are bitter.
This new study has made it possible to find tools for the genetic improvement of melon, a much consumed fruit that, like so many others, will have to adapt to climate change.