RELATIONSHIPS AMONG FREEZING, LOW TEMPERATURE FLOODING, AND ICE ENCASEMENT TOLERANCE IN ALFALFA
| Autor: | S. R. Bowley, B. D. McKERSIE |
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| Rok vydání: | 1990 |
| Předmět: | |
| Zdroj: | Canadian Journal of Plant Science. 70:227-235 |
| ISSN: | 1918-1833 0008-4220 |
| DOI: | 10.4141/cjps90-025 |
| Popis: | In order to select cultivars with improved tolerance to environmental stresses, the relationship among tolerance to environmental stresses needs to be determined. This study evaluated 16 populations of alfafla for their tolerance to freezing (−8 to −16 °C), low temperature flooding (21 and 28 d), and ice encasement (10 and 14 d). Stresses were applied on field-grown plants excavated in November. Dry matter yield of the regrowth was determined 40 d following application of the stress. Two stands differing in plant ages (seeding year and first production year) over 2 yr were assessed. Seeding year plants were smaller in size, had fewer crown buds, lower moisture contents, and greater regrowth yields in the absence of stress. Regrowth yield was linearly related to stress level. Seeding year plants had greater absolute reductions in yield when subjected to freezing and icing stress, but less relative (to control) yield reduction when subjected to freezing stress compared to first production year plants. Plant age did not affect yield reduction of plants exposed to icing stress. Superiority index (Pi) ranking of the populations varied with environmental stress and was not correlated with moisture content, number of buds, or fall growth habit. Differential rankings of Pi among the freezing, flooding, and ice encasement stresses indicated that tolerance to one environmental stress will not necessarily give tolerance to other stresses. Selection for improved stress tolerance in alfalfa should be based on assessment of all stresses.Key words: Alfalfa, stress tolerance, environmental stress, Medicago sativa L. |
| Databáze: | OpenAIRE |
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