Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/9/2005
Publication Date: 9/1/2005
Citation: McCarty Jr., J.C., Jenkins, J.N. 2005. Registration of 21 day length-neutral flowering primitive cotton germplasm lines. Crop Science. 45:2134. Interpretive Summary: Cotton fiber quality, yield and stress tolerance needs improvement. Additional genetic variability for these desirable traits is required. The cotton collection of primitive accessions contains a wealth of genetic variability; however, the flowering response of many of the accessions is day-length dependent. The failure to flower and set fruit under the long-day regime of the growing season is a major hurdle to the utilization of most primitive cotton germplasm. Accessions have been converted to day-neutrality, which do not require short days to initiate flowering, utilizing a backcross breeding approach. Useful genetic variability has been measured in the day-neutral lines for agronomic and fiber traits. These day-neutral accessions are available to improve cotton and to expand its genetic base.
Technical Abstract: Cotton, Gossypium hirsutum L., is an important crop that is grown in warmer climates throughout the world. To improve agronomic and fiber traits sources of genetic variability are required. The collection of primitive cotton accessions is a resource 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 has limited the utilization of most primitive cotton germplasm. Twenty-one accessions were crossed to a day-neutral donor parent and converted to day-neutrality utilizing the backcross breeding method. The day-neutral germplasm lines have been grown in field tests and useful genetic variability has been measured for agronomic and fiber traits. The day-neutral lines are now available for use in cotton breeding programs for trait improvement and to expand genetic variability.