Utilization of Novel Alleles Found in Obsolete Germplasm for the Improvement of Upland Cotton (LT)

Narrowing genetic variability is a developing issue in upland cotton (Gossypium hirsutum). In many cases novel alleles for the improvement of fiber quality traits, especially for fiber length and strength, are sought in other cultivated species (G. barbadense) or in wild relatives (e.g. G. mustelinum).  Each of the options can be difficult to intercross or tend to bring along detrimental alleles which require pre-breeding efforts to make useful breeding populations. This study seeks to find positively associated fiber quality alleles in obsolete elite cultivars found within the USDA germplasm collection and other sources by using 127 lines backcrossed to modern cultivar TAM B182-33 which is representative of the TAMU cotton breeding program. Analysis will be conducted on F2 progeny grown in 2018, 2019 and 2020 at three locations for compatibility with this line. In this way, novel variation could be found that could be readily used or used with comparatively little preparation in continued trait advancement within the TAMU program. A structural analysis will also be conducted in 2019 and 2020 using six cultivars selected on the basis of their backcross performance, three found to be high performing and three found to be low performing, as well as their genetic distance from each other. This analysis will help in the understanding of epistatic effects within the population and how genes from the obsolete cultivars are utilized.