Bechere E., D.L. Auld, E. Hequet. 2009. Development of “naked-tufted” seed coat mutants for potential use in cotton production. Euphytica. DOI 10.1007/s10681-009-9890-y
ABSTRACT: Use of chemical mutagenesis has been highly successful in most major crops. The objective of this research was to develop ‘naked-tufted’ seed mutants and to incorporate this genetic trait into cotton to enhance crop quality and reduce processing costs. In 1997, six commercial cultivars were treated with 2.45% v/v ethyl methane sulfonate. In 1999, three M3 plants were identified that had partially naked seed coats. The trait was stabilized through individual plant selections from 2000 to 2004. During 2005 and 2006, the homozygous naked-tufted M8 mutant lines were evaluated for lint yield, lint percent, fibers/seed, fibers/mm2, fiber quality, seed oil content, ginning efficiency and yarn spinning performance. Overall, the naked-tufted seed mutants had lower lint yield, lower fibers/seed, lower lint/seed, and lower fibers/mm2 when compared with their original fuzzy parents. The lint turnout from the mutants was similar to the fuzzy parents and the commercial cultivars. The naked-tufted seed mutants had higher seed oil percent, 6–17% lower short fiber contents, significantly reduced seed coat neps (37–42%), higher elongation and yarn tenacity than their fuzzy counterparts. Preliminary data also showed that the naked-tufted mutants required less energy to gin.
Xu B., X. Yao, P. Bel, E. Hequet, and B. Wyatt. 2009. High Volume Measurements of Cotton Maturity by a Customized Microscopic System. Textile Research Journal, 79(10) 937-946.
ABSTRACT: Information about cotton maturity is desirable to cotton breeders and growers for cotton enhancement and to textile manufacturers for quality control. This paper reports on the development of a dedicated system that facilitates direct, fast and high volume measurements of cotton maturity from longitudinal views, and the experimental results. The system examines cotton fibers in a projected 2-D image to measure the variations in fiber width, which reveal the severity of fiber convolutions, and the fiber translucence that reflects the thickness of the secondary wall. This paper describes the methodology for extracting these features and how they relate to cotton maturity.
Braden C.A., C.W. Smith, and E.F. Hequet. 2009. Combining Ability of Near-Long Staple Upland Cotton, Crop Science, 49:756-762.
ABSTRACT: Fiber length is one of the most important properties of cotton fibers, with longer fibers allowing for faster processing speeds and a wider array of end products. Four elite, near-long-staple upland cotton (Gossypium hirsutum L.) genotypes with diverse programmatic origins, TAM 94L-25, Fibermax 832, TTU 202, and Acala 1517-99, and one short-staple genotype, Tamcot CAMD-E, were crossed and evaluated in a diallel without reciprocals for six fiber-length measurements at College Station, TX, in 2001 and 2002. Genotypic variation (P 0.05) and significant general combining ability (GCA) were identified for upper-half mean length (UHML), fiber length by weight (FLw), fiber length by number (FLn), and upper-quartile length by weight (UQLw). Significant variation for specific combining ability (SCA) was identified for FLw, FLn, and short-fiber content by weight (SFCw). Fibermax 832 exhibited the longest fibers for all length measurements, but TAM 94L-25 had the highest GCA effects for UHML, FLw, FLn, and UQLw and thus would be the best parent to use in parental combinations to improve fiber length. The highest desirable SCA effects resulted from the Fibermax 832 x Acala 1517-99 combination. Combining-ability data among these genotypes, which represented diverse U.S. germplasm pools, suggest that most U.S. cotton breeding programs could improve fiber length by using TAM 94L-25 in combination with their breeding lines.
Smith C.W., S. Hague, P.S. Thaxton, E. Hequet, and D. Jones. 2009, Registration of eight extra long staple upland cotton germplasm lines, Journal of plant registrations, 3(1):81-85
ABSTRACT: Eight extra-long staple (ELS) upland cotton (Gossypium hirsutum L.) germplasm lines, TAM A106-15 ELS (Reg. No. GP-894, PI 654359), TAM A106-16 ELS (Reg. No. GP-895, PI 654360), TAM B147-21 ELS (Reg. No. GP-896, PI 654361), TAM B182-33 ELS (Reg. No. GP-897, PI 654362), TAM C66-16 ELS (Reg. No. GP-898, PI 654363), TAM C66-26 ELS (Reg. No. GP-899, PI 654364), TAM C147-42 ELS (Reg. No. GP-900, PI 654365), and TAM C155-22 ELS (Reg. No. GP-901, PI 654366), were developed by the Cotton Improvement Laboratory, Department of Soil and Crop Sciences, Texas AgriLife Research (Texas A&M University, College Station), and released in 2008 as part of an ongoing effort to create germplasm with combinations of improved fiber quality parameters, especially upper half mean (UHM) length and fiber bundle strength. All ELS lines exhibited high volume instrument (HVI) UHM fiber length greater than 32.0 mm, which is the minimum UHM to be classified as ELS upland according to Cotton Incorporated. Seven of the eight lines equaled or exceeded the minimum UHM length of 34.8 mm for pima (G. barbadense L.) in the USDA 2007 pima loan schedule in at least one performance trial. Fiber bundle strengths of the eight lines were equal to or higher than ‘Fibermax 832’.
Smith C.W., C.A. Braden, and E. Hequet. 2009. Generation Mean Analysis of Near Long Staple Fiber Length in TAM 94L-25 Upland Cotton, Crop Science, 49:1638-1646
ABSTRACT: The U.S. traditionally markets upland cotton with a high volume instrument (HVI) upper-half mean length (UHML) of 27 mm (34 staple) although international trade requires a minimum of 27.8 mm (35 staple). Genotypes have been developed that exhibit UHML of approximately 30 mm (38 staple) that are referred to as near-long-staple uplands (NLSU). The objective of this research was to determine gene action and heritability for near-long-staple length in a unique set of upland cotton genotypes. TAM 94L-25, an NLSU, was crossed with three programmatically diverse NLSU phenotypes and a short-staple upland (SSU) to produce the F1, F2, BCP1, and BCP2 generations for generation mean analysis (GMA). Generations were grown in a randomized complete block design at College Station, TX in 2001 and 2002. Seedcotton was ginned on a laboratory gin and advanced fiber instrument system (AFIS) fiber properties were determined. Additional improvement in fiber length is possible by crossing TAM 94L-25 with the other NLSU phenotypes included in this study. Environment affected genetic expression with narrow sense heritability (h2) for fiber length generally lower in the TAM 94L-25/NLSU families. Transgressive segregates were found in all families.