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Papers by Frédérick Laforge

Research paper thumbnail of Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization

Scientia Horticulturae, 1991

Growth of plantlets of asparagus (Asparagus officinalis L.), raspberry (Rubus idaeus L.) and stra... more Growth of plantlets of asparagus (Asparagus officinalis L.), raspberry (Rubus idaeus L.) and strawberry (FragariaXananassa Duch.), treated during the in vitro rooting stage under three photosynthetic photon flux densities (PPFD) (80, 125 and 250 #mol s-~ m-2) (17.5, 26.9 and 53.8 W m-z (PAR), respectively) and three CO2 enrichment levels (CDE) (330, 1650 and 3000/lmol mol-~), was monitored during the acclimatization stage. For the three species, generic differences were observed in the plant response to treatments. A significant residual growth enhancement was caused by CDE. High PPFD in vitro increased the dry weight of strawberry and fresh weight of asparagus in acclimatization. Raspberry leaf dry weight was increased by 262% in acclimatization after in vitro treatment with high CDE. This enhanced the performance of micropropagated plantlets in acclimatization and reduced by 2 weeks the acclimatization period with raspberry. Our results suggest that in vitro leaves may be a source of nutritional reserves for leaves initiated ex vitro, but do not exclude a morphogenetic effect of CO2 during the in vitro rooting stage.

Research paper thumbnail of Miniature Growth Chambers for the Study of Environmental Conditions in Vitro

Canadian Journal of Plant Science, 1990

Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting... more Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting in vitro culture, provide an accurate and inexpensive method to perform multifactorial experiments under these conditions. Temperature control was achieved by an electronic device combined with a heating cable and a heat exchanger (water to air). Two-dimensional temperature variations in the chamber were within 1 °C of the set point temperature. Nine chambers were placed under photosynthetic photon flux (PPF) of 80, 125 and 250 μmol m−2 s−1 and CO2 concentrations of 330, 1650 and 3000 μL L−1. Gas concentrations in both the chambers and the test tubes with in vitro cultures were monitored and fresh weight accumulation of raspberry (Rubus idaeus), strawberry (Fragaria × ananassa) and asparagus (Asparagus officinalis) cultures were recorded during a growth experiment. Carbon dioxide accumulation in the culture tubes during the night and subsequent depletion during the day indicated CO2 fix...

Research paper thumbnail of Effect of CO2 enrichment and high photosynthetic photon flux on the development of autotrophy and growth of tissue-cultured strawberry, raspberry and asparagus …

Symposium on High …, 1988

Abstract: The research objectives were to determine the effects of high photosynthetic photon flu... more Abstract: The research objectives were to determine the effects of high photosynthetic photon fluxes (PPF) and CO 2 enrichment on the growth and anatomy of tissue-cultured plants and to determine what is the contribution of these factors in the development of ...

Research paper thumbnail of MINIATURE GROWTH CHAMBERS FOR THE STUDY OF ENVIRONMENTAL CONDITIONS IN VITRO

Canadian Journal of Plant Science, 1990

Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting... more Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting in vitro culture, provide an accurate and inexpensive method to perform multifactorial experiments under these conditions. Temperature control was achieved by ...

Research paper thumbnail of Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization

Laforge, F., Lussier, C., Desjardins, Y. and Gosselin, A., 1991. Effect of light intensity and CO... more Laforge, F., Lussier, C., Desjardins, Y. and Gosselin, A., 1991. Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization. Scientia Hortic., 47: 259-269.

Research paper thumbnail of Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization

Scientia Horticulturae, 1991

Growth of plantlets of asparagus (Asparagus officinalis L.), raspberry (Rubus idaeus L.) and stra... more Growth of plantlets of asparagus (Asparagus officinalis L.), raspberry (Rubus idaeus L.) and strawberry (FragariaXananassa Duch.), treated during the in vitro rooting stage under three photosynthetic photon flux densities (PPFD) (80, 125 and 250 #mol s-~ m-2) (17.5, 26.9 and 53.8 W m-z (PAR), respectively) and three CO2 enrichment levels (CDE) (330, 1650 and 3000/lmol mol-~), was monitored during the acclimatization stage. For the three species, generic differences were observed in the plant response to treatments. A significant residual growth enhancement was caused by CDE. High PPFD in vitro increased the dry weight of strawberry and fresh weight of asparagus in acclimatization. Raspberry leaf dry weight was increased by 262% in acclimatization after in vitro treatment with high CDE. This enhanced the performance of micropropagated plantlets in acclimatization and reduced by 2 weeks the acclimatization period with raspberry. Our results suggest that in vitro leaves may be a source of nutritional reserves for leaves initiated ex vitro, but do not exclude a morphogenetic effect of CO2 during the in vitro rooting stage.

Research paper thumbnail of Miniature Growth Chambers for the Study of Environmental Conditions in Vitro

Canadian Journal of Plant Science, 1990

Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting... more Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting in vitro culture, provide an accurate and inexpensive method to perform multifactorial experiments under these conditions. Temperature control was achieved by an electronic device combined with a heating cable and a heat exchanger (water to air). Two-dimensional temperature variations in the chamber were within 1 °C of the set point temperature. Nine chambers were placed under photosynthetic photon flux (PPF) of 80, 125 and 250 μmol m−2 s−1 and CO2 concentrations of 330, 1650 and 3000 μL L−1. Gas concentrations in both the chambers and the test tubes with in vitro cultures were monitored and fresh weight accumulation of raspberry (Rubus idaeus), strawberry (Fragaria × ananassa) and asparagus (Asparagus officinalis) cultures were recorded during a growth experiment. Carbon dioxide accumulation in the culture tubes during the night and subsequent depletion during the day indicated CO2 fix...

Research paper thumbnail of Effect of CO2 enrichment and high photosynthetic photon flux on the development of autotrophy and growth of tissue-cultured strawberry, raspberry and asparagus …

Symposium on High …, 1988

Abstract: The research objectives were to determine the effects of high photosynthetic photon flu... more Abstract: The research objectives were to determine the effects of high photosynthetic photon fluxes (PPF) and CO 2 enrichment on the growth and anatomy of tissue-cultured plants and to determine what is the contribution of these factors in the development of ...

Research paper thumbnail of MINIATURE GROWTH CHAMBERS FOR THE STUDY OF ENVIRONMENTAL CONDITIONS IN VITRO

Canadian Journal of Plant Science, 1990

Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting... more Miniature (65-L) growth chambers, designed and tested to study environmental conditions affecting in vitro culture, provide an accurate and inexpensive method to perform multifactorial experiments under these conditions. Temperature control was achieved by ...

Research paper thumbnail of Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization

Laforge, F., Lussier, C., Desjardins, Y. and Gosselin, A., 1991. Effect of light intensity and CO... more Laforge, F., Lussier, C., Desjardins, Y. and Gosselin, A., 1991. Effect of light intensity and CO2 enrichment during in vitro rooting on subsequent growth of plantlets of strawberry, raspberry and asparagus in acclimatization. Scientia Hortic., 47: 259-269.