Revista U.D.C.A Actualidad & Divulgación Científica
Print version ISSN 0123-4226
POSADA, Fánor Casierra; PENA-OLMOS, Jaime E and ULRICHS, Christian. GROWTH AND PHOTOCHEMICAL EFFICIENCY OF PHOTOSYSTEM II IN STRAWBERRY PLANTS (Fragaria sp.) AFFECTED BY THE LIGHT QUALITY: AGRONOMIC IMPLICATIONS. rev.udcaactual.divulg.cient. [online]. 2011, vol.14, n.2, pp. 43-53. ISSN 0123-4226.
Photomorphogenesis is any change in form or function of an organism occurring in response to changes in the light environment. Light quality is mainly sensed by the presence of different light receptors specific for different wavelengths. The influence of light quality on the growth and photochemical efficiency of photosystem II (PSII) in strawberry plants (Fragaria sp., cv. Chandler) was examined in a factorial set up, under greenhouse in Tunja / Colombia. Plants grew under diverse light qualities (yellow, green, blue, red, transparent, and control without colored cover) provided by polypropylene filter films. Determinations of minimum (F0), maximum (Fm), variable (Fv), and terminal (Ft) fluorescence and maximum photochemical efficiency (Fv/Fm) of dark-adapted leaves were done 32 weeks after the transplant. Related to growth, control plants recorded highest dry matter and specific leaf weight. Plants growing under the red filter developed highest leaf area. The green film reduced the growth. The color films changed the dry matter partitioning patterns in the plants organs, specially the green filter. Filtered light affected the chlorophyll fluorescence variables, related to control plants. Regards to control plants, Fv , Fm and Ft were higher in plants growing under all covers. While F0 was higher under the transparent and yellow films, Fv /Fm was lower under these covers. The results were discussed in relation to possible implications for appropriate agronomic practices.
Keywords : Photomorphogenesis; dry matter; biomass partitioning; colored light; Fv /Fm; minimal fluorescence; maximal fluorescence.