|Gutierrez, Osman - MISSISSIPPI STATE UNIV|
|Bowman, Daryl - NORTH CAROLINA STATE UNIV|
|Watson, Clarence - OKLAHOMA STATE UNIVERSITY|
|Jones, Don - COTTON INC|
Submitted to: Germplasm Release
Publication Type: Germplasm Release
Publication Acceptance Date: March 29, 2007
Publication Date: April 30, 2007
Citation: Jenkins, J.N., McCarty Jr., J.C., Gutierrez, O.A., Hayes, R.W., Bowman, D.T., Watson, C.E., Jones, D. 2007. Notice of release of RMUP-C5, a random mated population of Upland cotton germplasm. USDA, Mississippi Agricultural and Forestry Experiment Station, North Carolina Agricultural Research Service, and Cotton, Inc. Germplasm Release. 4/30/07. 6 p. Interpretive Summary: Interpretive summary not required for Germplasm Release.
Technical Abstract: The Agricultural Research Service of the United States Department of Agriculture, Mississippi Agricultural and Forestry Experiment Station, North Carolina State University, and Cotton Incorporated, Cary, NC, announce the release of RMUP-C5, a population of upland cotton that has been random mated for 6 cycles beginning with a half diallel of 11 diverse upland parents. The aim of this project was to develop elite breeding populations of cotton through random mating. Eleven diverse cotton lines were chosen for random mating so that the populations developed would have applicability to the entire US Cotton Belt. Lines chosen were Acala Ultima developed by CPCSD in California, Pyramid developed in the MAR program by the Texas Agriculture Experiment Station, Coker 315 developed by Coker Pedigreed Seed Co., Stoneville 825 a nectariless cultivar developed by Stoneville Pedigreed Seed Co., Fibermax 966 developed by Bayer Crop Science, M-240RNR a root-knot nematode resistant line developed by ARS, Paymaster HS 26 a High Plains cultivar developed by Paymaster Technologies Inc., Deltapine Acala 90 developed by Delta and Pine Land Co., Suregrow 747 developed by Sure-Grow, Phytogen PSC 355 developed by Mississippi Agriculture and Forestry Experiment Station and licensed to Phytogen Seeds, and Stoneville 474 developed by Stoneville Pedigreed Seeds. These represent a diverse group of lines from several breeding programs. Pedigrees for Pyramid can be found in Crop Science 44:343, 2004: for M-240 RNR, Crop Science 36:820, 1996: and for the other 9 in MAFES Bulletin 1155, 2006. The 11 lines were crossed in a one-half diallel to produce 55 half-sib families. Random mating of the F1 from the half diallel was called Cycle 0 (C0). These 55 half sib families were kept separate in the mating process. The half diallel crosses, the C1, C3, and C5 cycles were made at Mississippi State, MS, where 80 plants per half sib family were grown. The C0, C2, and C5 cycles were made at the winter nursery in Mexico where 15 hills (60 plants) of each half sib family were grown. Random mating was accomplished in each cycle by mixing pollen from an equal number (2-5) of blooms, bagged as candles the previous day, from each of the 55 half sib families each day of pollination and using this bulked pollen to pollinate 10 emasculated and protected flowers per day on each of the 55 half sib lines. Pollination did not start until at least 5 blooms per family were available. This process was repeated until approximately 100 emasculated flowers were pollinated on each half sib family. Each cycle of random mating thus resulted in about 75 crossed bolls harvested per half sib family. About 2 weeks were involved in pollination for each cycle. After each cycle of random mating, a random sample of crossed seed within each half sib family was planted in individual plots (15 hills in Mexico and 80 plants in Mississippi) and the next cycle of random mating was made. Following each cycle of random mating a random sample of seed from each of the 55 families was planted and self pollinated to represent that cycle of random mating and to produce enough seed for field evaluations. Random mated seed and S1 seed from each cycle or random mating were kept in storage. The seed being released (RMUP-C5) are C5S1 bulked seed. These are a bulk sample of equal number (1000) of seed from each of the 55 half sib families in the C5S1 generation. Because of the importance of this random mating population and its expected usefulness to the cotton breeding community, three sets of reference data are provided for the seed being released. Set one is comprised of C0S1, C5S1, and the 11 parents. Set 2 is comprised of C0S1 through C5S1, plus the 11 parents. Set 3 is comprised of the C0S1 and C5S1 within each of the 55 half sib families, plus the 11 parents. To provide planting seed for data set one, an equal number of seed from each of the 55 half sib families from C0S1 were bulked and called C0S1 and an equal number of seed from each of the 55 half sib families from C5S1 were bulked and called C5S1. To provide planting seed for data set 2 this bulk procedure was followed to provide seed for each of the cycles 0 though 5. To provide planting seed for data set 3, seed of C0S1 and C5S1 for each of the 55 half sib families were used. Seed for data set 1 and 2 were planted as 4 replications in a randomized complete block at two locations on the Plant Science Research Farm at Mississippi State, MS, in 2006 and yield and HVI fiber data (one location) were obtained. These data can be used to compare yield and fiber properties of C0S1 and C5S1 with that of the parental lines. Seed for data set 3 was planted as a split-plot randomized complete block experiment with the 55 half-sib families being whole plots and cycles of random mating being the split plots at two locations on the Plant Science Research Farm at Mississippi State, MS, in 2006. Because data set 3 has 110 entries plus 11 parents, only ranges and means are provided to show the diversity of the 55 half-sib families. These data show the great diversity among the parents and provide evidence that RMUP-C5 is truly a unique population that should be useful for breeding. We suggest that this population can be used for direct plant to row selection or that one boll or lock could be bulk harvested from each plant and planted, and individual plant selections be made in the S2 or later generations. We further suggest that breeders who plant this population harvest a large random sample of bolls and maintain this bulk for further research and cultivar development.