A study published Monday by a team of campus researchers, in conjunction with researchers from other institutions, aims to improve existing knowledge of the cassava genome.
According to the study, originally published in the journal Nature Biotechnology, cassava is a crop that provides nutrients to more than half a billion people worldwide.
Jessica Lyons, a campus postdoctoral scholar on the research team, said that until recently, cassava constituted an “orphan crop” — that is, cassava breeders did not have many resources to refer to when attempting to improve crop yields.
“The idea (of this study) is to provide advanced genomic and genetic tools to the cassava community,” Lyons said of the team’s attempt to increase the understanding of the cassava’s genome — its complete DNA makeup.
“Given that the genome … encodes the recipe for life, we can liken the genome assembly process to reconstructing an old jigsaw puzzle,” said Jessen Bredeson, a campus specialist on the team, in an email.
The team also sequenced other plant species’ genomes to “elucidate relations” between them and the cassava genome, according to Lyons. Doing so enabled the researchers to better understand potential beneficial genetic variations for the cassava, which can be obtained through interbreeding, Lyons said in an email.
Lyons explained that the team plans to use its findings to combat hunger, particularly in Africa, where cassava is a commonly cultivated “fallback crop.” The roots of the cassava plant, full of starch, are a good source of calories and can be preserved underground until needed.
In the 1930s, scientists interbred the cassava plant with the Ceara rubber tree to provide the cassava with greater resistance to certain diseases, Lyons said. The plant, however, remains particularly susceptible to pathogens, which can drastically decrease crop yields, explained a campus press release.
Lyons noted that the study is particularly remarkable for finding the exact locations in some of the cassava species’ genomes where the segments of the Ceara rubber tree’s DNA were inherited.
“What’s amazing is we were able to identify the genetic signature of that interbreeding,” Lyons said, adding that this achievement will help with further breeding efforts of the cassava plant.
The research was partially funded by the Bill and Melinda Gates Foundation, which gave grants to the two principal investigators — campus professor Daniel Rokhsar and Dow AgroSciences researcher Steve Rounsley — who had been at the University of Arizona at the time they received the grant.
“This kind of research supports the Bill & Melinda Gates Foundation’s agricultural strategy which is focused on empowering smallholder farmers with the knowledge, tools, and technologies to improve their livelihoods and lift themselves and their families out of poverty,” said Rinn Self, a policy and advocacy program officer for the foundation, in an email.