Artigo
Physiological plasticity is important for maintaining sugarcane growth under water deficit
Registro en:
MARCHIORI, P. E. R. et al. Physiological plasticity is important for maintaining sugarcane growth under water deficit. Frontiers in Plant Science, [S.l.], v. 8, Dec. 2017.
Autor
Marchiori, Paulo E. R.
Machado, Eduardo C.
Sales, Cristina R. G.
Espinoza-Núñez, Erick
Magalhães Filho, José R.
Souza, Gustavo M.
Pires, Regina C. M.
Ribeiro, Rafael V.
Institución
Resumen
The water availability at early phenological stages is critical for crop establishment and
sugarcane varieties show differential performance under drought. Herein, we evaluated
the relative importance of morphological and physiological plasticity of young sugarcane
plants grown under water deficit, testing the hypothesis that high phenotypic plasticity
is associated with drought tolerance. IACSP95-5000 is a high yielding genotype and
IACSP94-2094 has good performance under water limiting environments. Plants were
grown in rhizotrons for 35 days under three water availabilities: high (soil water matric
potential [9m] higher than −20 kPa); intermediate (9m reached −65 and −90 kPa at
the end of experimental period) and low (9m reached values lower than −150 kPa). Our
data revealed that morphological and physiological responses of sugarcane to drought
are dependent on genotype and intensity of water deficit. In general, IACSP95-5000
showed higher physiological plasticity given by leaf gas exchange and photochemical
traits, whereas IACSP94-2094 showed higher morphological plasticity determined
by changes in leaf area (LA) and specific LA. As IACSP94-2094 accumulated less
biomass than IACSP95-5000 under varying water availability, it is suggested that high
morphological plasticity does not always represent an effective advantage to maintain
plant growth under water deficit. In addition, our results revealed that sugarcane varieties
face water deficit using distinct strategies based on physiological or morphological
changes. When the effectiveness of those changes in maintaining plant growth under
low water availability is taken into account, our results indicate that the physiological
plasticity is more important than the morphological one in young sugarcane plants.