This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Web of Science (39) Citing Articles via Google Scholar Google Scholar Articles by Taylorson, R. B. Articles by Hendricks, S. B. Search for Related Content PubMed PubMed Citation Articles by Taylorson, R. B. Articles by Hendricks, S. B. Agricola Articles by Taylorson, R. B. Articles by Hendricks, S. B.

Articles

Phytochrome Transformation and Action in Seeds of Rumex crispus L. during Secondary Dormancy

^a Agricultural Environmental Quality Institute, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland 20705

Promotion of germination by red light fails after prolonged dark imbibition of Rumex crispus L. seeds, indicative of a secondary dormancy. The degree and rate of inception of the dormancy increases with increasing temperature. Following establishment of the dormancy, germination response to red light can be restored by either prolonged cold treatment or brief high temperature shifts. Loss of phytochrome was not a factor in the initial establishment of the dormancy. When the seeds are in secondary dormancy, the chromophore of phytochrome can be transformed to the far red-absorbing form, but the far red-absorbing form cannot induce germination. The responses to changes in temperature suggested dependence of germination on order disorder transitions in components of the seeds.