Registration of Mutant Population MD 15 M4 Gossypium hirsutum L. with Enhanced Fiber Quality

Abstract

Mutant population MD 15 M4 (Reg. No. GP‐957, PI 665638) is a unique mutant germplasm population of upland cotton (Gossypium hirsutum L.). This germplasm was developed by the USDA‐ARS, Stoneville, MS and released in June 2012. In 2008, about 5000 seeds of a germplasm line, MD 15, were chemically mutagenized with 3.2% v/v of ethyl methanesulfonate. The treated seeds were hand planted in the field at Lubbock, TX in 2008 to produce the M1. One boll was hand picked from each of about 2000 surviving M1 plants, and this bulk was planted at Stoneville in 2009 to produce the M2. In 2010, the M3 was generated by the same procedure. In 2011, one boll from each plant was bulked and labeled MD 15 M4. In 2010 and 2011, random samples of the M3 and M4, along with the unmutated parent were planted in replicated progeny rows, and fiber length, fiber strength, uniformity, micronaire, and seed index were measured. Significant sample variances between the mutants and parent were observed for lint percentage, fiber strength, and micronaire in 2011. The higher standard deviation for fiber strength of the mutants (40.5) than that of the parent (38.7) indicated that the data points are spread out over a larger range of values for the mutants. We believe that chemical mutagenesis can be used as one of the tools to help improve some of the economically important traits in cotton.