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
| Autor: | Gianluigi Bacchetta, Martino Orru, Efisio Mattana, Hugh W. Pritchard |
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| Rok vydání: | 2012 |
| Předmět: |
Time Factors
Light Climate Change Population Climate change Germination Plant Science Biology Botany Vitis Biomass Vitis vinifera education education.field_of_study Geography Altitude Global warming Temperature Seed dormancy food and beverages Original Articles Plant Dormancy Horticulture Stratification (seeds) Italy Seeds Dormancy |
| Zdroj: | Annals of Botany. 110:1651-1660 |
| ISSN: | 1095-8290 0305-7364 |
| Popis: | † Background and Aims 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). † Methods Dried and fresh seeds from each population were incubated in the light at a range of temperatures (10– 25 and 25/10 8C), without any pre-treatment and after a warm (3 months at 25 8C) or a cold (3 months at 5 8C) 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 8C) and A2 (+3.4 8C). † Key Results Cold stratification released physiological dormancy, while very few seeds germinated without treatments or after warm stratification. Fresh, cold-stratified seeds germinated significantly better (.80 %) at temperatures ≥20 8C than at lower temperatures. A base temperature for germination (Tb )o f 9. 0–1 1.3 8C and a thermal time requirement for 50 % of germination (u50) ranging from 33.6 8Cd to 68.6 8Cd were identified for nondormant cold-stratified seeds, depending on the populations. This complex combination of thermal requirements for dormancy release and germination allowed prediction of field emergence from March to May under the present climatic conditions for the investigated populations. † Conclusions The thermal thresholds for seed germination identified in this study (Tb and u50) explained the differences in seed germination detected among populations. Under the two simulated IPCC scenarios, an altitude-related risk from climate warming is identified, with lowland populations being more threatened due to a compromised seed dormancy release and a narrowed seed germination window. |
| Databáze: | OpenAIRE |
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