Photosynthetic rate is an indicator of vegetation performance as a carbon sequestration element on earth. At the same time, primary productivity is also function of photosynthetic rate and canopy cover. The photosynthetic capacity of an ecosystem is limited by the foliage pigment content due to the active participation of pigmentation in photon capture. Hence, the quantitative assessment of fol...

A high-~rforman~e liquid chromato~aphy method was used for the deter~ation of the eggshell pigment constituent. Using this method, the content proto~rphyrin IX in seven bird species was quantified. It was found that this compound is most abundant in the eggs of the blackbird (65.55 nmol per egg), but when the amount is related to the eggshell mass, then the greatest amount is in the egg of the ...

Pigment I (4,4/-diapocarotene-4-oic acid). — This component comprised about 8% of the total pigment content and was relatively nonpolar. The UV/VIS-absorption spectrum in ethanol showed two maxima at 477 and 508 nm and an inflexion at 456 nm. Saponification, acetylation, and reduction tests (NaBH4) were negative. The acidic nature of the pigment pointed to the presence of a carboxylic group. Th...

Predictions of chlorophyll content (chla+b) or any other canopy biophysical parameter from airborne or satellite canopy reflectance are generally carried out through four different methodologies: i) directly studying the statistical relationships between ground-measured biochemical data and canopy-measured reflectance (Johnson et al., 1994; Matson et al., 1994); ii) applying the leaf-level rela...

1. The blue-green alga Anacystis nidulans was cultured under steady state conditions at 25 and 39 degrees C. and under several different light intensities to give five different types of cells. 2. Cells were submitted to pigment analysis based upon acetone extracts and aqueous extracts obtained by sonic disintegration. The different cell types show a threefold range of chlorophyll content and a...

In the Lower Grand Coulee, Washington, Diaptomus nevadensis in Soap Lake contains larger amounts of the carotenoid astaxanthin than in Lake Lenore. During winter, Diaptomus sicilis contains larger amounts of pigment in both lakes, but in summer individuals from Lake Lenore are much reduced in pigment while those from Soap Lake are unchanged. The amount of astaxanthin might be a reflection of th...

We tested the hypothesis that mate choice is responsible for countergradient variation in the sexual coloration of Trinidadian guppies (Poecilia reticulata). The nature of the countergradient pattern is that geographical variation in the carotenoid content of the orange spots of males is counterbalanced by genetic variation in drosopterin production, resulting in a relatively uniform pigment ra...