Chinese Researchers Develop Herbicide Tolerant Watermelon

In China, a low planting density and a short canopy made field watermelon (Citrullus lanatus) severely threatened by weeds. Currently, only five herbicides are registered for watermelon weed control in China, most of which provide minimal control on broad-leaved weeds. Hence, alternative solutions for weed control are needed by watermelon growers.

In this research, the team of Shouwei Tian from the Beijing Academy of Agriculture and Forestry Sciences led a team of scientists to edit the watermelon acetolactate synthase (ALS) gene in hopes of conferring herbicide resistance. A designed sgRNA was transformed into the cotyledon of watermelon ZG94, an elite inbred variety used for the production of edible seeds and as a parent line to commercial hybrid seeds.

Analysis revealed that 45 out of 199 transgenic plants had the desired mutations, indicating an efficiency of 23% at T0 generation. These mutations were also proven to be transmitted to succeeding generations. The resulting genome-edited plants were found to be tolerant to sulfonylurea-based herbicides.

This study proves that the CRISPR-Cas9 system is a powerful tool for improvement of watermelon varieties.

For more information, read the article in Plant Cell Reports.