Light and Temperature Controls of Dormancy and Germination in Bentgrass Seeds1
- Vivian K. Toole and
- E. James Koch2
Germination on a two-way thermogradient plate indicated a temperature range for intensive study of alternating temperatures in germination chambers for ‘Emerald’, ‘Penncrow’, and ‘Seaside’ cultivars of A. palustris and for ‘Astoria’ and ‘Bardot’, but not ‘Highland’ cultivars of A. tenuis. Studies of the seeds subjected to reciprocal periods on the low and high parts of daily temperature cycles showed that optimum temperature alternations depended on the length of exposure to the higher temperature of the cycle. Germination for all cultivars, except Highland, were not significantly different from maximum germination in an incubation regimen of 15 C for 16 hours alternated with 25 C for 8 hours daily. Emerald, Penncross, and Seaside required red light during the 25 C part of the cycles for optimum germination. For optimum germination, Highland required 1 to 2 hours at 30, 35, or 40 C alternated with 23 and 22 hours at 15 C and light.
Germination of all cultivars was under phytochrome control. Astoria and Bardot required a red light treatment at marginal temperatures, but not at the optimum temperatures. All other cultlvars required red light to germinate at the optimum temperatures. Response to -light showed the typical reversible phytochrome reactionPlease view the pdf by using the Full Text (PDF) link under 'View' to the left.
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