Canadian Forest Service Publications

Interior spruce seedlings compared with emblings produced from somatic embryogenesis. III. Physiological response and morphological development on a reforestation site. 1994. Grossnickle, S.C.; Major, J.E. Canadian Journal of Forest Research 24: 1397-1407.

Year: 1994

Issued by: Atlantic Forestry Centre

Catalog ID: 27456

Language: English

Availability: PDF (download)

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Interior spruce (Picea glauca (Moench) Voss X Picea engelmannii Parry) seedlings and emblings produced through somatic embryogenesis tissue culture were planted on a reforestation site in the central interior of British Columbia. Gas exchange and water relations patterns were monitored over the first growing season and morphological development was monitored over two growing seaons. During shoot elongation, osmotic potential at saturation and turgor loss point of seedlings and emblings increased, while their maximum bulk modulus of elasticity and total turgor decreased, resulting in utilized turgor exceeding 100%. From bud set in late July through October 8, osmotic potential at saturation and turgor loss point decreased, maximum bulk modulus of elasticity and total turgor increased, with total turgor between 55 and 70% for both seedlings and emblings. There were few seasonal differences in shoot water relations parameters of seedlings and emblings. One-year-old and current-year needle conductance (gwv) decreased as vapour pressure deficit (VPD) increased in a similar manner for both seedlings and emblings. Response surface models for net photosynthesis (Pn) of current-year needles showed Pn to increase as photosynthetically active radiation (PAR) increased to around 1000 mmol.m-2.s-1, and thereafter remained stable, but as VPD increased Pn decreased at all PAR levels. Emblings, compared with seedlings, had 15% greater Pn under optimal field site atmospheric conditions (i.e., VPD <3.0 kPa and PAR >1000 mmol.m-2.s-1). there was a linear increase in Pn as gwv increased in both seedlings and emblings, though 1-year-old needles had higher Pn for a given level of gwv than current-year needles. Height and diameter growth across the first and second growing season were similar for seedlings and emblings. Seedlings and emblings had similar total root weight after two growing seaons. After the first winter on the field site, survival was 87% for seedlings and 91% for emblings, while emblings had a lower proportion of their foliage damaged by winter conditions. Results indicate that seedlings and emblings are largely comparable in their field performance over two growing seaons on a reforestation site.