Assessing the breeding potential of day-neutral converted racestock germplasm in the Pee Dee cotton germplasm enhancement program

• Published in: Euphytica 2014-02, Vol.195 (3), p.453-465
• Main Authors: Campbell, B. T, Greene, J. K, Wu, J, Jones, D. C
• Format: Article
• Language: English
• Subjects: agronomic traits; Agronomy. Soil science and plant productions; alleles; Biological and medical sciences; Biomedical and Life Sciences; Biotechnology; correlation; Cotton; DNA; fiber quality; Fundamental and applied biological sciences. Psychology; Generalities. Genetics. Plant material; genetic background; Genetic diversity; genetic improvement; Genetic resources; Genetic resources, diversity; genetic variation; Genetics and breeding of economic plants; germplasm; Gossypium hirsutum; Heterosis. Floral biology applications: apomixy, male sterility, incompatibility, varia; Hybrids; Life Sciences; Offspring; Plant breeding; Plant breeding: fundamental aspects and methodology; Plant Genetics and Genomics; Plant material; Plant Pathology; Plant Physiology; Plant reproduction; Plant Sciences; selection methods
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-013-1007-y

The primitive, upland cotton landrace collection represents one of the untapped genetic resources in cotton breeding programs. Efforts to utilize these resources have been slow, but the development of day-neutral converted germplasm lines offers tremendous potential for broadening the genetic base in upland cotton. Using topcross hybrids involving elite germplasm from the unique Pee Dee germplasm enhancement program, we evaluated the breeding potential of a select number of day-neutral converted racestocks. The mean performance of parental lines and F₂ topcross hybrids along with genetic effect estimates indicate that day-neutral converted germplasm lines decreased agronomic performance while increasing fiber quality performance. Results suggest that crosses between day-neutral converted racestocks and elite Pee Dee germplasm lines result in new allelic combinations associated with improved fiber quality performance that interact in a non-additive way. However, it appears that converted racestocks transmit negatively correlated alleles for agronomic performance and fiber quality. These negatively correlated allelic combinations present a major challenge for cotton breeding programs. Future efforts that incorporate DNA based selection methods to identify and fix introgressed segments from converted racestocks and their offspring should enhance the use of the genetic variation present in the primitive racestock germplasm accessions.