the effect of automobile pollution was determined on chlorophyll content of four different tree species viz. azadirachta indica l., conocarpus erectus l., guiacum officinale l.and eucalyptus sp. growing along the roads of the city.  significant changes in the level of chlorophyll “a”, chlorophyll “b” and total chlorophyll “a+b” were found in the leaves of four tree species (a. indica, c. erectu...

Chlorophyll b is an ubiquitous accessory pigment in land plants, green algae, and prochlorophytes. Its biosynthesis plays a key role in the adaptation to various light environments. We isolated six chlorophyll b-less mutants by insertional mutagenesis by using the nitrate reductase or argininosuccinate lyase genes as tags and examined the rearrangement of mutant genomes. We found that an overla...

The epiplankton community was investigated during Meduza cruises along south north and offshore – inshore transects in the middle and southern Adriatic in spring 2002. The diel and vertical distribution of heterotrophic bacteria, phytoplankton pigment composition, microand mesozooplankton were assessed. At most stations we observed a thermocline at approximately 20 m and a prominent chlorophyll...

Different mulches have variable effects on soil physical properties and plant growth. This study aimed to compare the effects of mulching with inorganic (round gravel, RG), organic (wood chips, WC), and living (manila turf grass, MG) materials on soil properties at 0-5-cm and 5-10-cm depths, as well as on the growth and physiological features of Osmanthus fragrans L. 'Rixianggui' plants. Soil s...

Field observations carried out in the Neuse RiverPamlico Sound Estuarine System (NRE-PS), North Carolina, USA were used to develop optical algorithms for assessing inherent optical properties, IOPs (absorption and backscattering) associated with water quality components (WQC). WQCs including chlorophyll a (Chl), volatile (organic) suspended solids (VSS), fixed (inorganic) suspended solids (FSS)...

1. Three common species of freshwater phytoplankton, the diatom Nitzschia sp., green alga Sphaerocystis schroeteri and cyanobacterium Phormidium luridum, were grown under contrasting daylengths [18 : 6 h light : dark cycles (LD) versus 6 : 18 h LD] and phosphorus (P) regimes (P-sufficient versus 1 lM P). The rates of growth and photosynthesis, as well as growth efficiencies and pigment concentr...

Photosynthetic pigments from etiolated cucumber (Cucumis sativus var. Beit Alpha improved, Hazera Co., Gedera) cotyledons were extracted by direct immersion of the intact cotyledons into the solvent N,N-dimethylformamide (DMF). The solvent is especially efficient when pigment concentration is low; time and tools are saved and the loss of pigment that usually occurs in more complicated extractio...

The discovery of the Emerson enhancement effect in photosynthesis (3-6, 8) led to the suggestion that there are 2 photochemical reactions necessary for complete photosynthesis. A likely hypothesis is that the 2 reactions are carried on by different forms of chlorophyll a (10, 11). The enhancement effect in photosynthesis has been studied extensively in several laboratories (19) and it has been ...

Dimethylsulfoniopropionate (DMSP), produced by many marine phytoplankton, is the main precursor of the climate relevant gas dimethylsulfide (DMS). Currently, it is generally accepted that the relationship between DMSP and phytoplankton biomass (as chlorophyll a), while not representative of the absolute magnitude of the DMSP pool, is a good indicator of ecosystem structure. In this study we tes...