Moderate water stress affects tomato leaf water relations in dependence on the nitrogen supply

Abstract

The responses of water relations, stomatal conductance (g s ) and growth parameters of tomato (Lycopersicon esculentum Mill. cv. Royesta) plants to nitrogen fertilisation and drought were studied. The plants were subjected to a long-term, moderate and progressive water stress by adding 80 % of the water evapotranspirated by the plant the preceding day. Well-watered plants received 100 % of the water evapotranspirated. Two weeks before starting the drought period, the plants were fertilised with Hoagland´s solution with 14, 60 and 110 mM NO 3 -(N14, N60 and N110, respectively). Plants of the N110 treatment had the highest leaf area. However, g s was higher for N60 plants and lower for N110 plants. At the end of the drought period, N60 plants showed the lowest values of water potential ( w ) and osmotic potential ( s ), and the highest values of pressure potential ( p ). N60 plants showed the highest s at maximum p and the highest bulk modulus of elasticity.Additional key words: Lycopersicon esculentum, osmotic adjustment, stomatal conductance, water potential.

Photosynthetic performance and acclimation of Incarvillea delavayi to water stress

“…The increase in LMA reduced g m , since g m varies significantly with leaf structure and often decrease with the increasing LMA (Terashima et al 2005). The increase in LMA could partially explain the decrease in g m and P N , as LMA was sensitive to drought (Flexas et al 2004, García et al 2007, Melgar et al 2008.…”

“…In previous studies, the understanding of the biochemistry and physiology of water stress relies largely on short-term experiments or growth under conditions, which are far different from their natural environment (Yeo 1998). García et al (2007) suggest that long-term water stress is needed to simulate more realistic responses to drought, since the way in which water stress is imposed might be important in understanding the response to drought, and also in evaluating the plant capacity to acclimate to stress.…”

Effectiveness of Drought Tolerance Indices to Identify Tolerant Genotypes with High Yielding Potential in Tomato (Solanum lycopersicum L.)

“…The reduction in plant height was associated with a decline in the cell elongation or enlargement and more leaf senescence under water stress, which might be due to turgor loss under drought (Manivannan et al, 2007). The growth reduction under water-stress conditions has been well characterized in tomato (Garcia et al, 2007). Therefore, plant height can be considered as an important trait for determining drought tolerance under water stress condition since increased plant height would allow greater biomass production and yield potential in crops.…”

Parámetros para el manejo del agua en tomate y chile dulce hidropónico bajo invernadero

“…del día 2, donde los valores de ψ h en tomate fueron -0,84 MPa en el tratamiento CR y -1,24 MPa en SR. En tomate bien regado García et al (2007) reportaron valores de ψ h de <-0,6 MPa y de -1,25 MPa bajo estrés hídrico, mientras que Ben-Asher et al (1992) reportaron mínimo estrés hídrico cuando el ψ h fue -1 MPa en cultivo de tomate bien regado. Por otra parte, Duniway (1971), citado por Zegbe y Behboudian (2006), estableció un umbral crítico en tomate de <-1 MPa, que teóricamente induciría al cierre estomático.…”

“…Por otra parte, Duniway (1971), citado por Zegbe y Behboudian (2006), estableció un umbral crítico en tomate de <-1 MPa, que teóricamente induciría al cierre estomático. En chile dulce CR los valores de ψ h (-0,98 MPa) fueron similares a los valores reportados por Thompson et al (2007a) y Dorji y Behboudian (2005; mientras que en chile SR (-1.3 MPa) fueron muy similares a los reportados por García et al (2007) en cultivos sin riego (-1,24 MPa).…”