Browsing by Subject "fiber length"
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Item Inheritance of cotton fiber length and distribution(Texas A&M University, 2006-10-30) Braden, Chris AlanFiber quality data from five upland cotton (Gossypium hirsutum L.) genotypes, which were grown at College Station, TX during 2001 and 2002, were subjected to diallel and generation means analyses to determine the potential for improvement of fiber length and to determine the inheritance of length distribution data. Four near-long staple (NLS) upland cotton genotypes and one short-staple genotype were crossed in all combinations, excluding reciprocals. Estimates of general (GCA) and specific combining ability (SCA) for fiber length based on Griffing??????s diallel Model I, Method 4 were calculated for high volume instrumentation (HVI) upper-half mean (UHM) fiber length and advance fiber information system (AFIS) mean fiber length by weight (FLw), mean fiber length by number (FLn), upper quartile length by weight (Uqlw), fiber length distribution cross entropy (using 3 different standard or check distributions - CEA, CEB, and CEC), fiber length distribution kurtosis (FLwKurt), and fiber length distribution skewness (FLwSkew) for FLw. Across environments, GCA effects were significant for fiber length measurements of UHM, FLw, FLn, Uqlw, and SFCw and distribution measurements of CEA, CEB, FLwKurt, and FLwSkew. On the basis of GCA effects, TAM 94L-25 was the best parent to be used in a cross to improve upland fiber length, while Acala 1517-99 was the parent of choice to improve distribution among the 4 parents tested. The inheritance of AFIS fiber length measurements and distribution data was estimated using parents, F1, F2, and backcross generations. The magnitude and significance of the estimates for non-allelic effects in the parental combinations suggest that epistatic gene effects are present and important in the basic mechanism of AFIS fiber length and length distribution inheritance for the populations studied. Gene effects and variances for all AFIS fiber length and distribution data measurements were inherited differently in different environments and specific parental combination, suggesting environmentally specific mechanisms. Developing genotypes with enhanced fiber length and an optimal fiber length distribution should be a priority to improve spinning performance and product quality of U.S. upland cotton.Item Transgressive Segregation for Fiber Properties of Three Selected Populations in Cotton(2014-12-16) Meritt, Benjamin TylerImproved 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.