2011 Annual Report
1a.Objectives (from AD-416)
To improve the utility of G. barbadense chromosome substitution lines for G. hirsutum breeding. To develop and release to the public a random mated population(s) that has unique combinations of alleles from the two species. To develop a breeding scheme that facilitiates the recombination of alleles from G. barbadense and G. hirsutum.
1b.Approach (from AD-416)
Seventeen CS-B lines have been crossesd to five elite cultivars from different commercial breeding programs in the U.S. ('DP 90', 'SureGrow 747', 'PSC 355', ST474, and FM 966). The CS-B lines ae CS-B01, CS-B02, CS-B04, CS-B06, CS-B07, CS-B16, CS-B17, CS-B18, CS-B25, CS-B05sh, CS-B11sh, CS-B12sh, CS-B14sh, CS-B15sh, CS-0B22sh, CS-B22Lo, and CS-B26Lo. The designations sh and Lo indicate that only the short or the long arm of a chromosome from G. barbadense is in the CS-B line. We will begin the random mating with two or three F1 hybrids from each of these 17 CS-B lines with two or three of the five cultivars. We will use the bulk pollen methodology of Miravalle to accomplish random mating, thus we will have 51 familes many of which will be half-sibs. The F1 hybrids will have one of five elite cultivars as one parent and a particular CS-B line as the other parent. From the cultivar parents we expect to gain adaptability, yield, and other necessary properties. From the CS-B parent we expect to gain alleles from particular chromosomes or chromosome arms from G. barbadense. These chromosome or chromosome arms should contain many alleles for fiber quality because of the very high fiber quality of the G. barbadense parent.
We crossed 18 chromosome substitution lines with FiberMax FM966, Suregrow SG747, and Phytogen PSC355. These chromosome substitution lines each had one specific chromosome or part of a chromosome from Gossypium (G.) barbadense substituted into G. hirsutum. By crossing these 18 lines, each of which contains a different and specific complete or a partial chromosome from G. barbadense with these three cultivars and developing a random mated population, we are developing an introgressed population. Development of this population should provide a population with plants with varying degrees of genetic introgression from G. barbadense combined with the high yield and adaption of the three cultivars. This approach is expected to minimize the problems of genetic linkage drag associated with conventional whole genome crosses between the two species. We have completed Cycle 4 and the random mated population in the winter nursery in the winter of 2010-2011. This is the final cycle (C4) of random mating. This should be a valuable resource for cotton breeders and geneticists. Progress was monitored by frequent contacts by phone and e-mail as well as a meeting each year among all cooperators and Cotton Incorporated. Quarterly reports were provided to Cotton Incorporated.