Yield and quality of nondormant alfalfa (Medicago sativa L.) may be reduced by winter frost. This study surveyed 12 populations for injury and regrowth following artificial frost. Approximately 40 plants per population were grown in a greenhouse for 70 d in styrofoam flats for each of 2 treatments (control and frost) with 4 replications. At 70 d of age, plants were clipped to 4 cm, regrown for 14 d, exposed to 5°C for 5 d to harden, and then exposed to -3°C for 6-8 h. After 2-3 d plants were scored for damage, stem height and stem number. Measurements were repeated weekly for 21 d, including a final damage score. Simulated selection comparing index selection and direct selection demonstrated positive response to selection in all populations analyzed. Selection for growth rate ratio resulted in reduced damage score, while selection for reduced damage did not improve growth rate ratio. Index selection improved both traits. Results indicate that response following frost in alfalfa may be improved.
| Identifer | oai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/277900 |
| Date | January 1991 |
| Creators | Flynn, Mary Ann, 1963- |
| Contributors | Smith, Steven E. |
| Publisher | The University of Arizona. |
| Source Sets | University of Arizona |
| Language | en_US |
| Detected Language | English |
| Type | text, Thesis-Reproduction (electronic) |
| Rights | Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. |
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