Cotton breeders face a significant challenge as cotton yield is inversely
related to fiber quality. As yield improves, fiber quality decreases, and
vice-versa.

To overcome this challenge, the research team led by Peng Chee from the
University of Georgia turned to obsolete cultivars of cotton with 'exotic'
genetic material. The team looked at the genetics of the Sealand cultivars,
which were developed from two different cotton species, Upland and Sea
Island. Sea Island cotton is also known as "Pima" or Egyptian cotton" from
the species Gossypium barbadense, and is used in high quality garments and
linens, due to its long, strong and fine fibers. Upland cotton from G.
hirsutum, mostly grown in the United States, has higher yields and broader
adaptation, but has lower fiber quality than Pima cotton. "The breeding
challenge lies in transferring Pima fiber quality to Upland," says Chee.

The research team generated genetic maps of two Sealand cultivars and found
that the superior fiber quality of Sealand cotton were in part due to genes
inherited from the Sea Island cotton. They also found that two of the three
genetic segments controlling fiber length in one of the Sealand cultivars
were inherited from the Sea Island parent. "Now that we know which part of
the genome controls fiber quality, we can now develop tools to select for
these traits. We can also select desirable combinations of genes to improve
multiple fiber quality traits," says Chee.

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