A new study illuminates the avocado’s family history and lays the foundation for the species’ improvement.
Scientists including Texas Tech University’s own Luis Herrera-Estrella have sequenced the avocado genome, shedding light on the ancient origins of this buttery fruit and laying the groundwork for future improvements to farming.
With regard to modern affairs, the study reveals for the first time that the popular Hass avocado inherited about 61 percent of its DNA from Mexican varieties and about 39 percent from Guatemalan ones. Avocados come in many types, but the Hass — first planted in the 1920s — comprises the bulk of avocados grown around the world.
The research also provides vital reference material for learning about the function of individual avocado genes, and for using genetic engineering to boost productivity of avocado trees, improve disease resistance and create fruit with new tastes and textures.
The study is important for agriculture. The growing global market for avocados was worth about $13 billion in 2017, with Mexico, the largest producer, exporting some $2.5 billion worth of the fruit that year, according to Statista. Around the world, avocados are spread on tortillas, mashed up to decorate flavor toast, rolled into sushi and blended into milkshakes, a popular treat in parts of Southeast Asia.
Scientists sequenced not only the Hass avocado, but also avocados from Mexico, Guatemala and the West Indies, which are each home to genetically distinct, native cultivars of the fruit.
“Avocado is a crop of enormous importance globally, but particularly to Mexico,” said Herrera-Estrella, the President’s Distinguished Professor of Plant Genomics in the College of Agricultural Sciences & Natural Resources at Texas Tech, who led and completed much of the work at the National Laboratory of Genomics for Biodiversity (LANGEBIO) in Mexico, where he was director prior to joining Texas Tech in 2018.
“Although most people will have only tasted Hass or a couple of other types, there are a huge number of great avocado varieties in the species’ Mexican center of diversity, but few people will have tried them unless they travel south of the U.S. border. These varieties are genetic resources for the avocado’s future. We needed to sequence the avocado genome to make the species accessible to modern genomic-assisted breeding efforts.”
The project was led by LANGEBIO, Texas Tech and the University at Buffalo. The research was published Tuesday in the Proceedings of the National Academy of Sciences.
“Our study sets the stage for understanding disease resistance for all avocados,” said Victor Albert, the Empire Innovation Professor of Biological Sciences in the University at Buffalo’s College of Arts and Sciences and a visiting professor at Nanyang Technological University, Singapore. “If you have an interesting tree that looks like it’s good at resisting fungus, you can go in and look for genes that are particularly active in this avocado. If you can identify the genes that control resistance, and if you know where they are in the genome, you can try to change their regulation. There’s major interest in developing disease-resistant rootstock on which elite cultivars are grafted.”