HYDATHODE ANATOMY AND THE RELATIONSHIP BETWEEN GUTTATION AND PLANT WATER STATUS IN STRAWBERRY (FRAGARIA X ANANASSA DUCH.)
Hydathodes on strawberry leaves occurred subapically in the adaxial epidermis near the top of leaf serrations. In fully expanded leaves of field grown strawberry plants, 'Allstar', the hydathodes covered .007 mm2 and contained numerous plates. This substance did not appear to have interfered with the guttation. Many tracheary elements were associated with a hydathode. Field observations of strawberry plants suggested that the presence or absence of guttation was related to plant water status. Leaves with guttation had a pre-dawn leaf water potential (PLWP) higher than -0.1 MPa (Mega Pascal) and those without guttation had PLWP lower than -0.1 MPa. PLWP and leaf osmotic potential were curvilinearly related. The mid-day leaf-minus-air temperatures of plants with pre-dawn guttation were more negative than those without guttation which indicates that leaves with guttation have more open stomata and greater transpiration rates. These results suggest that guttation on strawberry leaves is an indicator of subtle differences in strawberry plant water status that might be useful in scheduling irrigation.
Takeda, F. and Michael Glenn, D. (1989). HYDATHODE ANATOMY AND THE RELATIONSHIP BETWEEN GUTTATION AND PLANT WATER STATUS IN STRAWBERRY (FRAGARIA X ANANASSA DUCH.). Acta Hortic. 265, 387-392