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Submitted to: World Cotton Research Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 11/1/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Improvement of cultivated crops requires genetic resources that may extend from exotic species to commonly grown cultivars. The introduction of useful traits to adapted cultivars is an ongoing process. The cotton collection of primitive accessions contains a wealth of genetic variability; however, many of the accessions are photoperiodic. The photoperiod response and failure to flower and set fruit under the long-day regime of the cotton-belt growing season is a major hurdle to the utilization of most primitive cotton germplasm. A program was initiated several years ago to incorporate day-neutral genes in these primitive accessions. Accessions have been converted to day-neutrality utilizing a backcross breeding approach. Useful genetic variability has been measured in the day-neutral lines for resistance to tobacco budworm, cotton bollworm, pink bollworm, boll weevil, root-knot nematode, and for agronomic and fiber traits. The day-neutral accessions are available for use in breeding programs for cultivar development and to expand genetic variability. Technical Abstract: Improvement of crop species requires genetic resources that may extend from primitive or exotic species to commonly grown cultivars. The introduction of desirable traits from germplasm sources to adapted cultivars is an ongoing process. The cotton, Gossypium hirsutum L., collection of primitive accessions contains a wealth of genetic variability; however, many of the accessions are photoperiodic. The photoperiod response and failure to flower and set fruit under the long-day regime of the temperate-zone growing seasons is a major hurdle to the utilization of most primitive cotton germplasm. A program was initiated several years ago to incorporate day-neutral genes in these primitive accessions. Accessions have been converted to day-neutrality utilizing a backcross breeding approach. Useful genetic variability has been measured in the day-neutral lines for resistance to Heliothis spp., Pectinophora gossypiella (Saund.), Anthonomus grandis Boheman, Meloidogyne incognita (Kofoid and White) Chitwood, and for agronomic and fiber traits. The day-neutral accessions are now available for use in breeding programs for cultivar development and to expand genetic variability. |