By Amanda Moises
Researchers at Boyce Thompson Institute and the National Engineering Research Center in Beijing have discovered the genome sequences of two pumpkin species known as Cucurbita maxima and Cucurbita moschata. This discovery is essential for further scientific research into the desirable traits of the two species as well as more information about breeding them. C. maxima is more desirable for fruit quality and nutrition while C. moschata is more desirable for resistance to disease. However, the hybrid of the two species, known as “Shintosa,” has an even higher resistance to disease and other stresses. Knowing the genomes of both species allows scientists to understand which genes are linked to these desirable traits and therefore maximize them for future hybrids.
The genome sequences also revealed an interesting evolutionary history about the ancestry of pumpkins. Researchers discovered that the pumpkin genome is actually a combination of two ancient genomes which combined to form an allotetraploid. In other words, pumpkins originally had four copies of each chromosome from two different species. However, modern pumpkins are diploid because the genome lost duplicated genes randomly from each ancestor over time. This is a strange occurrence for allotetraploid organisms because usually one genome dominates the other and retains the majority of its genes in the diploid species. Overall, the researchers were excited to uncover the pumpkin’s unusual evolutionary background and use the genome sequence to improve pumpkins for people around the world.
Boyce Thompson Institute. (2017, October 30). Pumpkin genomes sequenced, revealing uncommon evolutionary history. ScienceDaily. Retrieved November 6, 2017 from www.sciencedaily.com/releases/2017/10/171030095428.htm