Hugh Pritchard - Profile on Academia.edu (original) (raw)

Papers by Hugh Pritchard

Research paper thumbnail of Physiological and biochemical studies of seed storage parameters in Carica papaya

Research paper thumbnail of A comparative study of seed viability in Inga species: desiccation tolerance in relation to the physical characteristics and chemical composition of the embryo

Seed Science and Technology

Research paper thumbnail of Desiccation-induced dormancy in papaya (Carica papaya L.) seeds is alleviated by heat shock

Desiccation-induced dormancy in papaya (Carica papaya L.) seeds is alleviated by heat shock

Seed Science Research

ABSTRACT

Research paper thumbnail of Simultaneous preservation of orchid seed and its fungal symbiont using encapsulation-dehydration is dependent on moisture content and storage temperature. CryoLetters

Research paper thumbnail of Chapter 26 Fluorescein Diacetate and Orchid Seed Viability in UK and Kenyan Species

Research paper thumbnail of Cryopreservation and global warming

Research paper thumbnail of Determination of intra-specific variation in orchid seed viability using fluorescein diacetate

Seed Science and Technology

Research paper thumbnail of Seed cryopreservation and longevity of two Salix hybrids

Cryo letters

The effects of desiccation and storage temperature on the viability and longevity of willow seeds... more The effects of desiccation and storage temperature on the viability and longevity of willow seeds was investigated using two hybrids, Salix rehderiana x (Salix x capreola) [cross 458] and Salix x sericans x Salix viminalis [cross 512]. Freshly harvested seed of both crosses survived silica gel drying down to c. 3 to 5 % moisture content. Hybrid 458 seed stored in liquid nitrogen (-196°C) for 3 d retained viability when equilibrated to £ 45 % RH (prestorage), showed slightly reduced survival at 65 % RH and exhibited no survival at 82 % RH. The level of survival after 68 d for seeds pre-equilibrated to either c. 10 or 65 % RH (5 or 10 % moisture) and stored at four temperatures was -196°C > -20°C > 2°C > 16°C. At all temperatures, drier seed stored better than wetter seed. For hybrid 512, seed longevity at 20°C > 40°C > 60°C, and a 10 % fall in pre-storage seed RH resulted in a c. 2-fold increase in longevity at each storage temperature. The response of hybrid willow seeds to desiccation and cooling raises possibilities for the long-term seed conservation of Salix species by cryopreservation.

Research paper thumbnail of Orthodox behaviour of oil palm seed and cryopreservation of the excised embryo for genetic conservation. Ann Bot 52: 381-384

Research paper thumbnail of Osmotic stress as a pregrowth procedure for cryopreservation 3. Cryobiology of sycamore and soybean cell suspensions

Research paper thumbnail of 100-seed test for desiccation tolerance and germination: a case study on eight tropical palm species

100-seed test for desiccation tolerance and germination: a case study on eight tropical palm species

Seed Science and Technology, 2004

ABSTRACT

Research paper thumbnail of Cryopreservation of desiccation-tolerant seeds

Cryopreservation of desiccation-tolerant seeds

Methods in molecular biology (Clifton, N.J.), 2007

The cryopreservation of desiccation-tolerant seeds depends on two key steps: specimen dehydration... more The cryopreservation of desiccation-tolerant seeds depends on two key steps: specimen dehydration in an environment that ensures the attainment of water contents below the high-moisture freezing limit; and transfer and maintenance at a subzero temperature that may be optimized in relation to the seed-lot moisture content and species. Temperatures about 70 degrees C below the glass transition temperature (Tg-70) or lower are recommended for seed storage. For fully desiccation-tolerant (type I) seeds, cryopreservation success tends to be independent of cooling regime and subzero (degrees C) temperature treatment when the seeds are dry. However, to maximize recovery of partially desiccation-tolerant (type II) seeds there can be a requirement for slow cooling, avoidance of storage at certain subzero temperatures, and controlled imbibition following cryopreservation, particularly for endospermic seeds that are high in lipid.

Research paper thumbnail of Black M, Bradford KJ, Vázquez-Ramos J. 2000. Seed biology: advances and applications. Proceedings of the Sixth International Workshop on Seeds, Mérida, Mexico, 1999. 508 pp. Wallingford, UK: CAB Publishing. £95 (hardback)

Research paper thumbnail of Thermal thresholds as predictors of seed dormancy release and germination timing: altitude-related risks from climate warming for the wild grapevine Vitis vinifera subsp. sylvestris

Annals of botany, 2012

The importance of thermal thresholds for predicting seed dormancy release and germination timing ... more The importance of thermal thresholds for predicting seed dormancy release and germination timing under the present climate conditions and simulated climate change scenarios was investigated. In particular, Vitis vinifera subsp. sylvestris was investigated in four Sardinian populations over the full altitudinal range of the species (from approx. 100 to 800 m a.s.l). Dried and fresh seeds from each population were incubated in the light at a range of temperatures (10-25 and 25/10 °C), without any pre-treatment and after a warm (3 months at 25 °C) or a cold (3 months at 5 °C) stratification. A thermal time approach was then applied to the germination results for dried seeds and the seed responses were modelled according to the present climate conditions and two simulated scenarios of the Intergovernmental Panel on Climate Change (IPCC): B1 (+1·8 °C) and A2 (+3·4 °C). Cold stratification released physiological dormancy, while very few seeds germinated without treatments or after warm st...

Research paper thumbnail of Gene Banks

Encyclopedia of Biodiversity, 2001

Research paper thumbnail of Cryopreservation of Orthodox (Desiccation Tolerant) Seeds

Cryopreservation of Orthodox (Desiccation Tolerant) Seeds

Plant Cryopreservation: A Practical Guide, 2008

... FAO, Rome, Italy Gonzalez-Benito ME, Fernandez-Llorente F, Perez-Garcia F (1998) Interaction ... more ... FAO, Rome, Italy Gonzalez-Benito ME, Fernandez-Llorente F, Perez-Garcia F (1998) Interaction between cryopreservation, rewarming rate and seed humidification ... Plant Physiol 90: 1121–1128 Volk GM, Crane J, Caspersen AM, Hill LM, Gardner C, Walters C (2006) Mas-sive ...

Research paper thumbnail of The effect of moisture content on the low temperature responses of Araucaria hunsteinii seed and embryos

Research paper thumbnail of Butenolide from plant-derived smoke functions as a strigolactone analogue: Evidence from parasitic weed seed germination

Butenolide from plant-derived smoke functions as a strigolactone analogue: Evidence from parasitic weed seed germination

South African Journal of Botany, 2008

ABSTRACT

Research paper thumbnail of Seed mass variation potentially masks a single critical water content in recalcitrant seeds

Seed mass variation potentially masks a single critical water content in recalcitrant seeds

Seed Science Research, 2004

Page 1. Seed mass variation potentially masks a single critical water content in recalcitrant see... more Page 1. Seed mass variation potentially masks a single critical water content in recalcitrant seeds Matthew I. Daws1*, Christiane S. Gaméné2, Sheila M. Glidewell3 and Hugh W. Pritchard1 1Seed Conservation Department, Royal ...

Research paper thumbnail of Determination of orchid seed viability using fluorescein diacetate

Determination of orchid seed viability using fluorescein diacetate

Plant, Cell and Environment, 1985

ABSTRACT

Research paper thumbnail of Physiological and biochemical studies of seed storage parameters in Carica papaya

Research paper thumbnail of A comparative study of seed viability in Inga species: desiccation tolerance in relation to the physical characteristics and chemical composition of the embryo

Seed Science and Technology

Research paper thumbnail of Desiccation-induced dormancy in papaya (Carica papaya L.) seeds is alleviated by heat shock

Desiccation-induced dormancy in papaya (Carica papaya L.) seeds is alleviated by heat shock

Seed Science Research

ABSTRACT

Research paper thumbnail of Simultaneous preservation of orchid seed and its fungal symbiont using encapsulation-dehydration is dependent on moisture content and storage temperature. CryoLetters

Research paper thumbnail of Chapter 26 Fluorescein Diacetate and Orchid Seed Viability in UK and Kenyan Species

Research paper thumbnail of Cryopreservation and global warming

Research paper thumbnail of Determination of intra-specific variation in orchid seed viability using fluorescein diacetate

Seed Science and Technology

Research paper thumbnail of Seed cryopreservation and longevity of two Salix hybrids

Cryo letters

The effects of desiccation and storage temperature on the viability and longevity of willow seeds... more The effects of desiccation and storage temperature on the viability and longevity of willow seeds was investigated using two hybrids, Salix rehderiana x (Salix x capreola) [cross 458] and Salix x sericans x Salix viminalis [cross 512]. Freshly harvested seed of both crosses survived silica gel drying down to c. 3 to 5 % moisture content. Hybrid 458 seed stored in liquid nitrogen (-196°C) for 3 d retained viability when equilibrated to £ 45 % RH (prestorage), showed slightly reduced survival at 65 % RH and exhibited no survival at 82 % RH. The level of survival after 68 d for seeds pre-equilibrated to either c. 10 or 65 % RH (5 or 10 % moisture) and stored at four temperatures was -196°C > -20°C > 2°C > 16°C. At all temperatures, drier seed stored better than wetter seed. For hybrid 512, seed longevity at 20°C > 40°C > 60°C, and a 10 % fall in pre-storage seed RH resulted in a c. 2-fold increase in longevity at each storage temperature. The response of hybrid willow seeds to desiccation and cooling raises possibilities for the long-term seed conservation of Salix species by cryopreservation.

Research paper thumbnail of Orthodox behaviour of oil palm seed and cryopreservation of the excised embryo for genetic conservation. Ann Bot 52: 381-384

Research paper thumbnail of Osmotic stress as a pregrowth procedure for cryopreservation 3. Cryobiology of sycamore and soybean cell suspensions

Research paper thumbnail of 100-seed test for desiccation tolerance and germination: a case study on eight tropical palm species

100-seed test for desiccation tolerance and germination: a case study on eight tropical palm species

Seed Science and Technology, 2004

ABSTRACT

Research paper thumbnail of Cryopreservation of desiccation-tolerant seeds

Cryopreservation of desiccation-tolerant seeds

Methods in molecular biology (Clifton, N.J.), 2007

The cryopreservation of desiccation-tolerant seeds depends on two key steps: specimen dehydration... more The cryopreservation of desiccation-tolerant seeds depends on two key steps: specimen dehydration in an environment that ensures the attainment of water contents below the high-moisture freezing limit; and transfer and maintenance at a subzero temperature that may be optimized in relation to the seed-lot moisture content and species. Temperatures about 70 degrees C below the glass transition temperature (Tg-70) or lower are recommended for seed storage. For fully desiccation-tolerant (type I) seeds, cryopreservation success tends to be independent of cooling regime and subzero (degrees C) temperature treatment when the seeds are dry. However, to maximize recovery of partially desiccation-tolerant (type II) seeds there can be a requirement for slow cooling, avoidance of storage at certain subzero temperatures, and controlled imbibition following cryopreservation, particularly for endospermic seeds that are high in lipid.

Research paper thumbnail of Black M, Bradford KJ, Vázquez-Ramos J. 2000. Seed biology: advances and applications. Proceedings of the Sixth International Workshop on Seeds, Mérida, Mexico, 1999. 508 pp. Wallingford, UK: CAB Publishing. £95 (hardback)

Research paper thumbnail of Thermal thresholds as predictors of seed dormancy release and germination timing: altitude-related risks from climate warming for the wild grapevine Vitis vinifera subsp. sylvestris

Annals of botany, 2012

The importance of thermal thresholds for predicting seed dormancy release and germination timing ... more The importance of thermal thresholds for predicting seed dormancy release and germination timing under the present climate conditions and simulated climate change scenarios was investigated. In particular, Vitis vinifera subsp. sylvestris was investigated in four Sardinian populations over the full altitudinal range of the species (from approx. 100 to 800 m a.s.l). Dried and fresh seeds from each population were incubated in the light at a range of temperatures (10-25 and 25/10 °C), without any pre-treatment and after a warm (3 months at 25 °C) or a cold (3 months at 5 °C) stratification. A thermal time approach was then applied to the germination results for dried seeds and the seed responses were modelled according to the present climate conditions and two simulated scenarios of the Intergovernmental Panel on Climate Change (IPCC): B1 (+1·8 °C) and A2 (+3·4 °C). Cold stratification released physiological dormancy, while very few seeds germinated without treatments or after warm st...

Research paper thumbnail of Gene Banks

Encyclopedia of Biodiversity, 2001

Research paper thumbnail of Cryopreservation of Orthodox (Desiccation Tolerant) Seeds

Cryopreservation of Orthodox (Desiccation Tolerant) Seeds

Plant Cryopreservation: A Practical Guide, 2008

... FAO, Rome, Italy Gonzalez-Benito ME, Fernandez-Llorente F, Perez-Garcia F (1998) Interaction ... more ... FAO, Rome, Italy Gonzalez-Benito ME, Fernandez-Llorente F, Perez-Garcia F (1998) Interaction between cryopreservation, rewarming rate and seed humidification ... Plant Physiol 90: 1121–1128 Volk GM, Crane J, Caspersen AM, Hill LM, Gardner C, Walters C (2006) Mas-sive ...

Research paper thumbnail of The effect of moisture content on the low temperature responses of Araucaria hunsteinii seed and embryos

Research paper thumbnail of Butenolide from plant-derived smoke functions as a strigolactone analogue: Evidence from parasitic weed seed germination

Butenolide from plant-derived smoke functions as a strigolactone analogue: Evidence from parasitic weed seed germination

South African Journal of Botany, 2008

ABSTRACT

Research paper thumbnail of Seed mass variation potentially masks a single critical water content in recalcitrant seeds

Seed mass variation potentially masks a single critical water content in recalcitrant seeds

Seed Science Research, 2004

Page 1. Seed mass variation potentially masks a single critical water content in recalcitrant see... more Page 1. Seed mass variation potentially masks a single critical water content in recalcitrant seeds Matthew I. Daws1*, Christiane S. Gaméné2, Sheila M. Glidewell3 and Hugh W. Pritchard1 1Seed Conservation Department, Royal ...

Research paper thumbnail of Determination of orchid seed viability using fluorescein diacetate

Determination of orchid seed viability using fluorescein diacetate

Plant, Cell and Environment, 1985

ABSTRACT