Developmental influence of in vitro light quality and carbon dioxide on photochemical efficiency of PS II of strawberry leaves (Fragaria x ananassa)

Abstract

The in uence of light quality and carbon dioxide concentration on the development of photosynthetic functional structures of strawberry leaves in vitro was examined. We assessed the photochemical quenching parameter of chlorophyll a photochemical ef ciency of photo system II (PSII) of strawberry leaves in vitro in a factorial set up. The main effects of light quality; averaged over CO 2 enriched, air  ow and closed systems, increased the initial chlorophyll  uorescence value from 485 for yellow light developed PS II system of leaves to 1142 for white light (control) developed ones. The photochemical ef ciency of PSII signi cantly increased from 0.64 under white light to 0.80 for yellow light developed leaves. The leaves developed under blue light were similar to that of control white light for many chlorophyll  uorescence parameters except the initial chlorophyll  uorescence level. The increase in photochemical ef ciency of PSII of strawberry leaves can be attributed to lower initial  uorescence values. Under blue light the total dry weight and total chlorophyll content were increased. The possible role of high mercury peak of white light and photoinhibition during development in vitro is discussed. leaves developed in a conventional closed tissue culture system at low light intensity (< 80 μmol m -2 s -1 ) or, of any plant developed under different spectral qualities and CO 2 regimes in vitro. We have tested the developmental in uence of light spectral qualities or CO 2 concentration on the photochemical ef ciency of PS II in strawberry leaves in vitro, while all other parameters: controllable biological, physical and chemical conditions were constant.