Relationship between transpiration and water potential in grafted scions of Picea

Autor: W. M. Proebsting, R. C. Beeson
Rok vydání: 1988
Předmět:
Zdroj: Physiologia Plantarum. 74:481-486
ISSN: 1399-3054
0031-9317
DOI: 10.1111/j.1399-3054.1988.tb02006.x
Popis: Total water and osmotic potential, turgor pressure and transpiration rate were measured on scions of Picea pungens (Englemann) during union development. In controlled environments, declines in water potential were correlated with lower transpiration rates to about −2.0 MPa. Water potentials below −2.0 MPa resulted in graft failure and were associated with sharply increased transpiration rates. Bulk turgor pressures remained high in the needles during this period of declining water potential and increasing transpiration. Transpiration rates of successful and unsuccessful greenhouse grafts were not significantly different during union development. Transpiration rates of these grafts were highest around dawn, then declined throughout the day only to increase again after sunset. High bulk needle turgor values (1.3 MPa), maintained by osmotic adjustment, may prevent stomatal closure of Picea scions at water potentials below −2.0 MPa.
Databáze: OpenAIRE
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