Chlorophyll Fluorescence in Relation to Diurnal Changes of Three Ficus species

Diurnal changes in chlorophyll fluorescence features in leaves of three Ficus species (F. nemoralis, F. roxburghii and F. racemosa) grown under nursery conditions were recorded in April 2003 by a portable Hansatech plant efficiency analyzer. Significant variations were observed on chlorophyll fluorescence parameters viz., Fo, Fv and Fm. Further, photochemical efficiency of photosystem (PS) II measured as Fv/Fm ratio, varied with species and with the time of observation. F. roxburghii and F. racemosa showed midday depression in Fv/Fm ratio at late noon hours (14:00 hr). However, in case of F. nemoralis mid-day depression was observed at 12:00 hr. It is therefore concluded that chlorophyll fluorescence features occurrence of mid-day depression in Fv/Fm ratio is species specific and not common phenomenon to all species.