Author
CHEATHAM, C - MISSISSIPPI STATE UNIV | |
Jenkins, Johnie | |
McCarty, Jack | |
WATSON, C - MISSISSIPPI STATE UNIV | |
WU, J - MISSISSIPPI STATE UNIV |
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 4/11/2003 Publication Date: 7/1/2003 Citation: CHEATHAM, C.L., JENKINS, J.N., MCCARTY JR, J.C., WATSON, C.E., WU, J. GENETICS VARIANCES AND COMBINING ABILITY OF CROSSES AND AMERICAN CULTIVARS, AUSTRALIAN CULTIVARS, AND WILD COTTONS. JOURNAL OF COTTON SCIENCE. 2003. V.7.P.16-22. Interpretive Summary: New cultivars continue to emerge with earlier maturity and increased yield; however, similar advances have not been made with improvement in fiber quality. This study was conducted to determine the combining ability and genetic characteristics of yield and fiber properties associated with two cultivars developed in Australia and offered for sale in the U.S., two experimental genotypes with good fiber strength, and five U.S. Delta cultivars from diverse breeding programs. These nine cotton (Gossypium hirsutum L.) genotypes were crossed and parents and F2's were grown in four environments and evaluated for yield, yield components, and fiber traits. The amount of useful genetic variability was calculated. The nine parents varied significantly in general combining ability for yield and fiber traits. A cultivar, Fibermax 832, from Australia was the best general combiner. Experimental line B1388 was a good general combiner for fiber strength, although other properties decreased when using this parent in crosses. The data indicated that new and improved cultivars from crosses involving Fibermax 832 could be developed for the U.S. that have increased yield and improved fiber properties. Technical Abstract: New cultivars continue to emerge with earlier maturity and increased yield traits; however, similar advances associated with improvement in fiber quality are lacking. This study was conducted to determine the combining ability and genetic characteristics of yield and fiber properties associated with two Australian cultivars (good fiber properties), two experimental genotypes (good fiber strength), and five U.S. Delta cultivars from diverse breeding programs. Nine cotton (Gossypium hirsutum L.) genotypes were crossed in a half-diallel mating scheme, and parents and F2's were grown in four environments. Parents and F2's were grown in field plots in 1999 and 2000 and evaluated for yield, yield components, and fiber traits. Variance components and genetic effects were calculated utilizing an extended additive-dominance model with Genetic x Environment interaction effects and a mixed norm quadratic unbiased estimation (MINQUE) method of analysis. The nine parents varied significantly in general combining ability for yield and fiber traits. Australian cultivar, Fibermax 832, was the best combiner. Experimental line, B1388, was a good general combiner for fiber strength, although other properties decreased when using this parent in crosses. Pure-line genotypes from crosses involving Fibermax 832 could perhaps be developed which have increased yield and improved fiber properties. |