Narrative
NC18-06 resulted from a random mating population using multiple parents. Twelve cotton cultivars each with uniquely improved fiber quality and/or yield representing major cotton breeding programs of the United States were crossed with each other in a half diallele to produce the F1s. Equal amount of F1 hybrid seed from each of the 66 F1 hybrid combinations was mixed for planting in rows. The F1 hybrids and the progenies of the subsequent generations were randomly mated using natural outcrossing. Lines chosen for parents were: ‘Acala Ultima’ (A_Ultima, PI 603079), developed by California Planting Cotton Seed Distributors (Shafter, CA); ‘Coker315, PI 529530’, developed by Coker Pedigreed Seed Co. (Hartsville, SC); ‘Tamcot Pyramid’ (Pyramid, PI 617042), developed in the Texas Agriculture Experiment Station (Thaxton and El-Zik 2004); ‘Stoneville 825’ (STV825, PI 529524), developed by Stoneville Pedigreed Seed Co. (Stoneville, MS); ‘FiberMax 966’ (FM966, PI 619097), an Upland commercial cotton developed by Bayer Crop Science (Lubbock, TX); M-240RNR (M-240, PI 592511), a root knot nematode resistant line developed by the ARS (Shepherd et al., 1996); ‘Deltapine Acala 90’ (DP90, PI 529529), developed by Delta and Pine Land Co. (Scott, MS); ‘Sure-Grow 747’ (SG747, PI 656375), an Upland commercial cultivar developed by Sure-Grow Co. (Centre, AL); ‘Georgia King’ (GA_King, PI 552537) was developed and released by the University of Georgia (Baker, 1992); ‘Phytogen PSC 355’ (PSC355, PI 612974), ‘Stoneville 474’ (STV474, PI 578877), developed by Stoneville Pedigreed Seeds; and TM-1 (Texas Marker-1, PI 662944). Individual plants obtained after the fourth intermating cycle were self-pollinated in the field. About 700 F4 lines were grown for obtaining F4:5 lines in 2009. These F4:5 lines were planted in field for seed increase through self pollination in the summer of 2010. Released germplasm lines are selections from the F6 inbred lines.