|May Iii, Oscar|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/1996
Publication Date: N/A
Interpretive Summary: This research documents the contribution of public and private cotton breeding firms to cotton variety genetic diversity. Genetic diversity among varieties reduces vulnerability of the crop to a disease or insect pathogen. Genetic diversity also supports long-term improvements in traits of economic importance such as lint yield and fiber quality. Among private ebreeding firms, the most influential cotton improvement efforts have been conducted by Stoneville Pedigreed Seed Company and Coker Pedigreed Seed Company. These firms have produced the most varieties, and in turn, their varieties have been used in crosses by other companies to develop varieties. Public breeding programs have also influenced cotton genetic diversity. The New Mexico Agricultural Experiment Station, Texas Agricultural Experiment Station, College Station, and the USDA-ARS cotton breeding program at Florence, SC, have all produced germplasm that has been nused to produce varieties by both public and private breeding firms. Thes data demonstrate the importance of continuing public breeding efforts to maintain the genetic base of cotton.
Technical Abstract: The pedigrees of cotton cultivars released between 1970 and 1990 have been subjected to coefficient of parentage analysis. The mean coefficient of parentage among the 260 cultivars is only 0.07, implying a broad genetic base. Selection within cultivars and germplasm lines has been common in cotton cultivar development. In computing coefficient of parentage, we assumed a relationship of 0.75 between a cultivar and a reselection from that cultivar. This loss of 25% of the genetic material could indicate that the mean coefficient of parentage of 0.07 is a conservative estimate of genetic diversity. The influence of public and private breeding efforts on cotton genetic diversity is also highlighted. The most influential private breeding firm has been Stoneville Pedigreed Seed Company. Cultivars bred by the Stoneville Pedigreed Seed Company have contributed to the development of 216 cultivars released by other private and public breeding firms. Influential public breeding programs include the New Mexico Agricultural Experiment Station, The Texas Agricultural Experiment Station, College Station, and the USDA-ARS breeding program at Florence, SC. These public breeding programs have bred germplasm that has been used to develop 112, 48, and 33 cultivars, respectively. These data indicate the importance of continuing both private and public breeding efforts to maintain the genetic base of cotton.