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Attributes of public and private cotton breeding programs.

2000; Volume: 4; Issue: 2 Linguagem: Inglês

1524-3303

Daryl T. Bowman,

Plant Virus Research Studies

Reduction in number and size of public cotton (Gossypium barbadense and hirsutum L.) breeding programs and the parallel increase in private breeding efforts have resulted in many younger breeders not being trained in cotton breeding. As a service to these younger breeders and the wellestablished breeders, I surveyed U.S. cotton breeders, both public and private. The objective of this study was to report on many aspects of breeding methods used by private and public breeders. There continues to be a major effort in conventional cotton breeding by private breeders; nearly half of the public breeders’ effort is in conventional cultivar development using conventional breeding methods. Transgenic cultivars occupied the majority of the U.S. cotton acreage in 1999, but only 35% of private breeders’ efforts are in this area. Pedigree breeding schemes are followed by most private and public breeders. The majority of parental material for private breeders is from lines developed in-house, while public breeders use a more balanced source of in-house material, commercial cultivars, and other public germplasm. Both private and public breeders average 100 genetic combinations each year, resulting in 3700 nursery plots for private breeders and 600 nursery plots for public breeders. Selection pressure is low in the F2 and F3 generations but increases in the F4 generation for private breeders. Public breeders average 40% for all three generations. Breeders, both private and public, tend to start yield testing with F4 lines more than in any other generation. For all Daryl T. Bowman, Crop Science Dep., North Carolina State Univ., Raleigh, NC 27695-8604. Received 18 Nov. 1999. *Corresponding author (daryl_bowman@ncsu.edu). 131 BOWMAN ET AL.: ATTRIBUTES OF PUBLIC AND PRIVATE BREEDING PROGRAMS breeders, yield continues to be the prime factor in choosing parents. Cotton breeding has evolved from individual farmers in the 1800s making selections and manipulating pollen to the gene transformations of the 1990s. The number of professional cotton breeders today is greater than at any time in U.S. history; private cotton breeders increased sixfold from 1974 to 1998 (Bowman 1999). The number of public breeding programs fell by nearly half during that same period (Bowman, 1999). The number of public institutions that train applied cotton breeders has dwindled to five universities: Louisiana State, Mississippi State (USDA and AES), North Carolina State, Texas A&M, and the University of Arkansas. Geneticists are being trained at these institutions and at New Mexico State University. Consequently, many of the younger cotton breeders were not trained in applied cotton breeding per se. These breeders are learning on the job, but often are not being mentored by seasoned, experienced cotton breeders. The Delta and Pine Land Seed Co. has recognized the problem and is establishing associate breeder positions. These positions will be similar to post-doctoral positions at public institutions in that they will provide on-the-job training to those who will serve as assistants to the main breeder at a particular station. It was against this backdrop that I decided to survey and compare U.S. private and public breeding programs. The results published here should serve to inform new cotton breeders as well as established breeders about how their colleagues operate. Meredith (1980) conducted a survey of breeding objectives in 1979 and from that was able to predict a flush of new, earlier-maturing cultivars, which came about in the early 1990s. Breeding objectives were not part of my survey, although breeders were asked what traits they looked for in parents.