Effect of Soaking, Moist Chilling, and Temperature on Germination of Striped Maple (Acer pensylvanicum) Seed Anthony Bourgoin and Dale Simpson Canadian Forest Service Fredericton, NB

Range of Striped Maple

Silvics Small tree up to 10 m tall Grows on well-drained, cool moist soils Shade tolerant Flowers in late May; seed falls mid October Trees are monoecious and/or dioecious

Identification

Dormancy Embryo – inhibitors Testa – reduces imbibition – reduces leaching of inhibitors – restricts radicle elongation Pericarp

Experimental Design 5 Seed lots – 3 single-tree, 2 bulk 4 Soaks – 0, 48, 72, 96 hours 3 Chill times – 16, 24, 32 weeks 2 Germination temp. regimes – 5/15°C, 20/30°C 4 Replications of 25 seed each

Germination Assessed every 7 days for 56 days (8 weeks) Successful germinants had properly developed cotyledons, hypocotyl and radicle Cutting test done on ungerminated seed

Data Analysis Total germination at 8 weeks Data transformed by arcsin square root Data analyzed using SAS

Impact of Soaking Time on Seed Moisture Content Soaking time (hrs)Seed MC (%) Results

Seed lot Mean germ. Soak time Mean germ. Chill time Mean germ. Germ. temp. Mean germ. 117 *65 a a1648 a 5/1590 a a4857 b2459 b20/3023 b 118 *53 b7259 b3262 c c9658 b 123 *39 d 1 means with different letters are significantly different at P=0.05 * single-tree collection

Results 5/15°C 20/30°C

Results 16 weeks chill 32 weeks chill

Conclusions Soaking seed for 48 hours was sufficient to promote high germination Moist chilling for 16 weeks was adequate to promote high germination Seed germination was maximized at temperatures of 5/15°C Secondary dormancy was induced at germination temperatures of 20/30°C