Transgressive Segregation for Fiber Properties of Three Selected Populations in Cotton

Improved fiber quality adds value to U.S. upland cotton and makes U.S. cotton more competitive in global markets. Improving characteristics like fiber length, strength, uniformity and elongation will allow American cotton to be used for a wider range of end products. The issue currently, however, is that breeders must develop more efficient methodology to improve selection of these characteristics.

This study was developed to observe two equivalent generations of a breeding scheme in order to monitor selection opportunities for these desirable fiber traits via comparison of transgressive segregation. A simple pedigree and then pedigree plus backcross system was used that allowed us to look at the F3 and BC1F2 generations following the cross of Tamcot 22/TAM B 182-33 ELSU, 06 WE 62-4/Tamcot 22, and Tamcot 22/04 SID 84-2. Tamcot 22 is a high yielding, average quality cultivar, TAM B 182-33 ELSU is an extra-long staple germplasm release, 06 WE 62-4 is a breeding line with exceptional fiber strength, and 04 SID 84-2 is a breeding line with exceptional length and strength derived from an interspecific cross.

High volume instrument analysis (HVI) of fiber produced from these families and generations in 2011 and 2012 did not suggest any pattern associated with transgressive segregation by family. The majority of the positive transgressive segregates were found in the BC1F2 generation that was backcrossed to the high quality parent (TAM B 182-33 ELSU, 06 WE 62-4, 04 SID 84-2), and our observations did not resemble previous findings by other groups. When averaged over both years, the family derived from the interspecific cross contained the most transgressive segregates.