INVESTIGADORES
LAGORIO MarÍa Gabriela
congresos y reuniones científicas
Título:
Photosystems ratio in Schefflera arboricola variegata leaves. Fluorescence spectra and
Autor/es:
GABRIELA B. CORDON Y M. GABRIELA LAGORIO
Lugar:
Cubatao. Brasil
Reunión:
Congreso; IX Encontro Latinoamericano de Fotoquímica e Fotobiologia; 2008
Institución organizadora:
CEPEMA
Resumen:
Abstract
Variegation is the appearance of differently colored areas in the leaves. White or yellow colored zones
are usually connected with a strong decrease of chlorophyll in plastids. In the present work we used
biospectroscopical methodologies to study comparatively the optical properties and fluorescence emission of
green and white leaves of Schefflera arboricola variegata, covering an important shortage in literature on this
field.
Non-destructive optical methods are relevant nowadays due to field applications and remote sensing to
assess plant health. In particular, reflectance, transmittance and emission spectroscopies are useful tools to
develop such methodologies. From reflectance and transmittance spectra, important optical parameters as the
absorption (k) and the scattering coefficient (s) may be obtained. Determination of these parameters is significant
in heterogeneous media like plant tissues, being connected with photons transport and photosynthesis inside the
leaves (1). On the other hand, fluorescence emission is a sensitive tool giving information on plant physiology and
stress situations.
In the present research, reflectance and transmittance spectra were obtained as a function of wavelength
with a spectrophotometer equipped with an integrating sphere. On the other hand, fluorescence emission was
obtained for both intact leaves at 298K and for diluted suspensions of the same powdered leaves at 77K. As
complementary work, photosynthetic pigments were extracted and quantitatively evaluated (3).