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Chlorophyll content in lichens is routinely used as an accurate indicator of lichen vigor, interspecific differences, and the effect of site-related environmental parameters. Traditional methods of chlorophyll extraction are destructive, time-consuming, expensive, and inoperable, especially when measuring large quantities of chlorophyll. However, non-destructive methods of measurement using portable chlorophyll meters are rarely used for lichens. Considering the characteristics of lichens such as rough blade surface and absence of chlorophyll b in cyanolichens, we compared the non-destructive methods with traditional methods and evaluated their applicability in studying lichen pigment content. Two instruments, SPAD-502 and CCM-300, were used to measure the pigment content of seven foliose lichen species. These pigment readings were compared with those determined using the dimethyl sulphoxide (DMSO) extraction method. Significant correlations were observed between SPAD/CCM values and pigments (chlorophyll and total carotenoids) extracted from chlorolichens, especially species with a smooth surface. The CCM-300 was more accurate in detecting the pigment content of foliose chlorolichens. However, both instruments showed certain limitations in the determination of pigment content in cyanolichens, especially gelatinous species. For example, CCM-300 often failed to give specific values for some cyanolichen samples, and both instruments showed low measurement accuracy for cyanolichens. Based on the high correlation observed between chlorophyll meter readings and pigments extracted from chlorolichens, equations obtained in this study enabled accurate prediction of pigment content in these lichens. [ABSTRACT FROM AUTHOR]

Aim of study: We evaluated the use of dimethylsulfoxide (DMSO) for the photometric determination of chlorophyll (Chla and Chlb) and carotenoids in Quercus ilex L. leaves by comparative analysis using aqueous-acetone extraction. Area of study: a Q. ilex dehesa in Las Majadas del Tietar, Cáceres, Spain Material and methods: Q. ilex leaves were sampled during two vegetative periods. Field SPAD-502 Chlorophyll measurements and photometric chlorophyll determinations were performed. Two procedures were used: extraction of intact foliar discs at 65ºC with DMSO and fine foliar powder with cold aqueous-acetone. Main results: DMSO produced Chlb overestimation and different fitting performance for SPAD vs pigment calibrations (R2=0.64, RMSE=0.20, p

The influence of foliar magnesium (Mg) application before flowering on chloroplast pigment indices was investigated in a 2-year field experiment with five soybean cultivars. Acetone extraction of pigments (chlorophyll a and b, total chlorophylls, and carotenoids as well as their ratios) was compared to chlorophyll meter (SPAD-502) readings. The untreated plants showed significant influence of cultivar on pigment concentrations, and pigment ratios were year-dependant. Foliar fertilization with Mg influenced chlorophyll concentration mostly in the year 2004, and carotenoids were not altered by Mg treatment. Cultivar differences prevailed in the next year when Mg treatment was less effective. The interactions among year, cultivar, and Mg application were showed to be significant for a particular parameter. The SPAD-502 readings significantly correlated with pigment concentrations only in the untreated plants in 2005. However, the foliar treatment influenced significantly SPAD readings in 2004, through the interaction with cultivar in once-treated plants and as a single factor in twice-treated plants. Grain yield was under significant positive influence of leaf Mg concentration in both years, and one treatment with Epsom salt was enough for significant grain yield increase. [ABSTRACT FROM AUTHOR]