|
Descripción
|
|
|---|---|
| Low temperature is major environmental factor affecting growth, survival and distribution of plants. A growing body of evidence indicates that nitrogen (N) rich seedlings have higher field performance than poor N plants, due to their higher ability to rapidly produce new roots. Furthermore, N nutrition has an important role in the frost acclimation of pine seedlings that may be related with higher antifreeze protein concentration. We analysed the influence of three N fertilization levels on the frost resistance of four Mediterranean pine species: Pinus halepensis and P. pinea, which live at low lands; P. pinaster, from mid altitude sites; and P. nigra, which mainly thrives in high mountain areas. Seedlings were grown under three N fertilization regimes (high: 150 mg N, low: 20mg N and autumn fertilization: 40mg N+ 60mg N in autumn) for eight months. Frost resistance was measured in November 2012 and in January 2013 by exposing shoots and roots of seedlings to an artificial frost test. Seedling needles damage was assessed by chlorophyll fluorescence while roots damage was determined by electrolyte leakage (EL). Finally all seedlings were assessed by visual evaluation of needle damage (VDI) two months after the frost test. N fertilization significantly improved the frost resistance of all species, specially in shoots, with autumn fertilization stimulating maximum hardening. However, the pattern in roots was not so clear, as the effect of fertilization on frost resistance of roots depended upon test temperature, season and species. Chlorophyll fluorescence and VDI showed similar shoot degree of damage, while only VDI technique in roots, but not EL, allowed a precise discrimination among fertilization and species. In addition, the mountain species P. nigra showed the highest frost resistance, followed by P. pinaster and finally P. pinea and P. hapelensis, which were the most vulnerable to frosts. In conclusions, the geographical distribution of pine species seems to be correlated with low winter temperatures. Our results evidence that this distribution differences might be attributed to differences in pine frost resistance. Also, we evidence that N nutrition, mainly when applied in the autumn enhances seedling frost resistance. | |
|
Internacional
|
Si |
|
Nombre congreso
|
medPINE5- International Conference on Mediterranean pines |
|
Tipo de participación
|
960 |
|
Lugar del congreso
|
Solsona |
|
Revisores
|
Si |
|
ISBN o ISSN
|
|
|
DOI
|
|
|
Fecha inicio congreso
|
22/09/2014 |
|
Fecha fin congreso
|
26/09/2014 |
|
Desde la página
|
127 |
|
Hasta la página
|
127 |
|
Título de las actas
|
5th International Conference on Mediterranean Pines (medpine5) Solsona, Spain, September 22-26, 2014 http://medpine5.ctfc.es/ |