Patrick Friesen | University of Toronto (original) (raw)
Uploads
Papers by Patrick Friesen
Journal of Experimental Botany, Mar 18, 2014
SSRN Electronic Journal, 2021
Biomass and Bioenergy, 2022
Journal of Experimental Botany, 2015
Journal of Experimental Botany, 2014
Biomass and Bioenergy, 2017
Plant, Cell & Environment, 2016
Journal of experimental botany, Jan 6, 2015
There is much interest in cultivating C4 perennial plants in northern climates where there is an ... more There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates-Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)-all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to ...
Journal of experimental botany, Jan 18, 2015
The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotet... more The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotetraploid hybrids of Miscanthus sinensis and Miscanthus sacchariflorus grown in a field setting. Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h(-1) to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature. Electrolyte leakage and rhizome sprouting assays after the cold treatment assessed plant and tissue viability. Results from the continuous-cooling trial showed that Miscanthus rhizomes from all genotypes tolerated temperatures as low as -6.5 °C; however, the slower, staged-cooling procedure enabled rhizomes from two diploid lines to survive temperatures as low as -14 °C. Allopolyploid genotypes showed no change in the lethal temperature threshold between the continuous and staged-cooling procedure, indicating that they have little ability to acclimate to subzero temperatures. The ...
Journal of experimental botany, Jan 6, 2015
There is much interest in cultivating C4 perennial plants in northern climates where there is an ... more There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates-Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)-all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to ...
Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit se... more Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit severe mortality
in the year after planting, and poor frost tolerance of leaves. Spartina pectinata (prairie cordgrass), a productive C4
perennial grass native to North America, has been suggested as an alternative biofuel feedstock for colder regions;
however, its cold tolerance relative to M. × giganteus is uncertain. Here, we compare the cold tolerance thresholds
for winter-dormant rhizomes and spring/summer leaves of M. × giganteus and three accessions of S. pectinata. All
genotypes were planted at a field site in Ontario, Canada. In November and February, the temperatures corresponding
to 50% rhizome mortality (LT50) were near −24°C for S. pectinata and −4°C for M. × giganteus. In late April, the
LT50 of rhizomes rose to −10°C for S. pectinata but remained near −4°C for M. × giganteus. Twenty percent of the
M. × giganteus rhizomes collected in late April were dead while S. pectinata rhizomes showed no signs of winter
injury. Photosynthesis and electrolyte leakage measurements in spring and summer demonstrate that S. pectinata
leaves have greater frost tolerance in the field. For example, S. pectinata leaves remained viable above −9°C while
the mortality threshold was near −5°C for M. × giganteus. These results indicate M. × giganteus will be unsuitable for
production in continental interiors of cool-temperate climate zones unless freezing and frost tolerance are improved.
By contrast, S. pectinata has the freezing and frost tolerance required for a higher-latitude bioenergy crop.
Journal of Hydrology, Jan 1, 2009
Journal of Experimental Botany, Mar 18, 2014
SSRN Electronic Journal, 2021
Biomass and Bioenergy, 2022
Journal of Experimental Botany, 2015
Journal of Experimental Botany, 2014
Biomass and Bioenergy, 2017
Plant, Cell & Environment, 2016
Journal of experimental botany, Jan 6, 2015
There is much interest in cultivating C4 perennial plants in northern climates where there is an ... more There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates-Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)-all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to ...
Journal of experimental botany, Jan 18, 2015
The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotet... more The cold tolerance of winter-dormant rhizomes was evaluated in diploid, allotriploid, and allotetraploid hybrids of Miscanthus sinensis and Miscanthus sacchariflorus grown in a field setting. Two artificial freezing protocols were tested: one lowered the temperature continuously by 1°C h(-1) to the treatment temperature and another lowered the temperature in stages of 24h each to the treatment temperature. Electrolyte leakage and rhizome sprouting assays after the cold treatment assessed plant and tissue viability. Results from the continuous-cooling trial showed that Miscanthus rhizomes from all genotypes tolerated temperatures as low as -6.5 °C; however, the slower, staged-cooling procedure enabled rhizomes from two diploid lines to survive temperatures as low as -14 °C. Allopolyploid genotypes showed no change in the lethal temperature threshold between the continuous and staged-cooling procedure, indicating that they have little ability to acclimate to subzero temperatures. The ...
Journal of experimental botany, Jan 6, 2015
There is much interest in cultivating C4 perennial plants in northern climates where there is an ... more There is much interest in cultivating C4 perennial plants in northern climates where there is an abundance of land and a potential large market for biofuels. C4 feedstocks can exhibit superior yields to C3 alternatives during the long warm days of summer at high latitude, but their summer success depends on an ability to tolerate deep winter cold, spring frosts, and early growth-season chill. Here, we review cold tolerance limits in C4 perennial grasses. Dozens of C4 species are known from high latitudes to 63 °N and elevations up to 5200 m, demonstrating that C4 plants can adapt to cold climates. Of the three leading C4 grasses being considered for bioenergy production in cold climates-Miscanthus spp., switchgrass (Panicum virgatum), and prairie cordgrass (Spartina pectinata)-all are tolerant of cool temperatures (10-15 °C), but only cordgrass tolerates hard spring frosts. All three species overwinter as dormant rhizomes. In the productive Miscanthus×giganteus hybrids, exposure to ...
Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit se... more Miscanthus × giganteus grown in cool temperate regions of North America and Europe can exhibit severe mortality
in the year after planting, and poor frost tolerance of leaves. Spartina pectinata (prairie cordgrass), a productive C4
perennial grass native to North America, has been suggested as an alternative biofuel feedstock for colder regions;
however, its cold tolerance relative to M. × giganteus is uncertain. Here, we compare the cold tolerance thresholds
for winter-dormant rhizomes and spring/summer leaves of M. × giganteus and three accessions of S. pectinata. All
genotypes were planted at a field site in Ontario, Canada. In November and February, the temperatures corresponding
to 50% rhizome mortality (LT50) were near −24°C for S. pectinata and −4°C for M. × giganteus. In late April, the
LT50 of rhizomes rose to −10°C for S. pectinata but remained near −4°C for M. × giganteus. Twenty percent of the
M. × giganteus rhizomes collected in late April were dead while S. pectinata rhizomes showed no signs of winter
injury. Photosynthesis and electrolyte leakage measurements in spring and summer demonstrate that S. pectinata
leaves have greater frost tolerance in the field. For example, S. pectinata leaves remained viable above −9°C while
the mortality threshold was near −5°C for M. × giganteus. These results indicate M. × giganteus will be unsuitable for
production in continental interiors of cool-temperate climate zones unless freezing and frost tolerance are improved.
By contrast, S. pectinata has the freezing and frost tolerance required for a higher-latitude bioenergy crop.
Journal of Hydrology, Jan 1, 2009