Abstract:
Smirnovia iranica, a native valuable woody species from Fabaceae, is an adaptable plant of central sandy areas of Iran. Changes in chlorophyll fluorescence and photosynthetic pigments characteristics were analyzed in the course of phenological stages including vegetative, flowering, seed ripening, and seed falling stages, respectively (VS, FS, SRS, and SFS). The results obtained from analysis of variance indicated that there was a significant difference among different phonological stages of S. iranica in terms of the mentioned characteristics. Extending phenological stages along with increasing water deficiency resulted in significant reduction in Fv /Fm ratio in SRS and SFS. A significant effect of progression in phenological stages on thermal dissipation of light energy (D) value was observed in SRS and reached to the highest value in SFS. In all evaluated plants, during phenological development, there were decreases in photochemical efficiency of photosystem II (ΦPSII), and from SRS. A similar influence of the extending phenological stages on ΦPSII was observed for electron transport rate (ETR). In SRS to SFS, the decrease of Chl. (a+b) and Car was paralleled with the decrease of Fv/Fm, which indicated that pigments breakdown was accompanied by the decreasing of the maximum photochemical efficiency. The results of this study suggest that extending phenological stages along with increasing water deficiency stress resulted in significant alterations in chlorophyll fluorescence parameters and pigment contents in SRS and SFS.
Machine summary:
"ir Desert 21-1 (2015) – 35-41 Variation characteristics of chlorophyll fluorescence of a typical Eremophyte (Smirnovia Iranica (Sabeti)) during phenological stages in the sand drift desert (Case study: In Kashan Region) A.
Changes in chlorophyll fluorescence and photosynthetic pigments characteristics were analyzed in the course of phenological stages including vegetative, flowering, seed ripening, and seed falling stages, respectively (VS, FS, SRS, and SFS).
Some basic, mutually independent, chlorophyll fluorescence parameters (FPs), such as maximum quantum yield of PSII photochemistry (Fv/Fm), photochemical efficiency of photosystem II, (ΦPSII), effective quantum yield (F’V/F’m), dissipation (quenching) of absorbed light energy to heat (D= 1- FV’/Fm’), and electron transport rate (ETR), can be calculated from Chl. FYs, that give insight into the photosynthetic processes in chloroplasts and can be used effectively in photosynthesis research (Ranjbarfordoei et al.
Table 1 shows a statistically highly significant negative effect of the water deficiency stress on the values of chlorophyll fluorescence parameters in the assimilatory organs of S.
D. , n=5; chlorophyll fluorescence parameters (Chl. FPs) The plants showed increases in F0 with progressing phenological stages (P≤0.
However, extending phenological stages along with increasing water deficiency stress resulted in significant reduction in Fv /Fm ratio in SRS and SFS.
The results of this study suggest that extending phenological stages along with increasing water deficiency stress resulted in significant alterations in chlorophyll fluorescence parameters and pigments content in SRS and SFS.
The results of this study suggest that extending phenological stages along with increasing water deficiency stress resulted in significant alterations in chlorophyll fluorescence parameters and pigments content in SRS and SFS."