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United States Department of Agriculture

Agricultural Research Service

Title: Evaluation of cotton populations for agronomic and fiber traits after different cycles of random mating

Authors
item McCarty, Jack
item Jenkins, Johnie
item Wu, Jiziang - MISSISSIPPI STATE UNIV
item Gutierrez, Osman - MISSISSIPPI STATE UNIV
item Hayes, Russell

Submitted to: Mississippi Agricultural and Forestry Experiment Station Technical Bulletin
Publication Type: Experiment Station
Publication Acceptance Date: October 8, 2007
Publication Date: September 1, 2008
Citation: McCarty Jr., J.C., Jenkins, J.N., Wu, J., Gutierrez, O.A., Hayes, R.W. 2008. Evaluation of cotton populations for agronomic and fiber traits after different cycles of random mating. Mississippi Agricultural and Forestry Experiment Station Bulletin 1168. 16 p.

Interpretive Summary: Random mating has been used to successfully break genetic linkage blocks resulting in crop improvements. In this study, 11 cotton lines from diverse breeding programs were used as parents to make 55 F2 populations with cycles of random mating ranging from 1 to 4. The parents, F2, and random mated populations were grown and evaluated in field plots in 2005 at Mississippi State, MS. Generally the parents had larger variations and ranges for agronomic and fiber traits than F2 hybrids and their corresponding populations at different cycles of random mating. The genetic variances among the 55 F2 populations decreased with increased cycles of random mating. High correlations were detected among traits for parents and F2 populations, but correlations among traits decreased with increased cycles of random mating. The results indicated that the linkage blocks have been broken after one to four cycles of random mating. The random mating populations should provide a genetic resource for selecting lines with improved agronomic and fiber traits.

Technical Abstract: Random mating, as one of several breeding approaches, has been used to successfully break genetic linkage blocks in crops for multiple-trait improvements. In this study, 11 cotton (Gossypium hirsutum L.) lines from diverse breeding programs were used as parents to make 55 F2 populations and 55 corresponding populations with cycles of random mating ranging from 1 to 4. The parents, F2, and random mated populations were grown and evaluated in field plots in 2005 at Mississippi State, MS. Generally, the results showed that parents had larger variances and ranges for agronomic and fiber traits measured than F2 hybrids and their corresponding populations at different cycles of random mating. The genetic variances among 55 F2 populations decreased with increased cycles of random mating. In general, the mean for parents showed significant differences from the mean of the populations at different cycles of random mating for most traits measured. High correlations were detected among traits for parents and F2 populations, but correlations among traits decreased with increased cycles of random mating. Higher correlations between F2 and random mated cycle one (C0S1) were detected than those among other random mated cycles. The results indicated that the linkage blocks have been broken after one to four cycles of random mating. The random mating populations should provide a genetic resource for selecting lines with improved agronomic and fiber traits.

Last Modified: 4/20/2014
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