The responses of rates of net photosynthesis (F^) to photosynthetic photon fluence rate (i), leaf temperature and CO2 were studied inhalf-sib families of greenhouse and field grown black locust (Robinia pseudoacacia L.) seedlings. The response of to 1 was similar in both greenhouse and field grown seedlings, except the quantum yields were lower in the field grown seedlings. The saturáting / was as low as 600 pmol m'^ s'’ in some seedlings but did not saturate at 1900 púiol m'^ s'^ in others. The optimum temperature for in field grown seedlings was shghtly lower than the greenhouse grown seedlings. increased rapidly with increased CO2 up to 350 pmol mol'^ but beyond SOO pmol mol'* the increase was gradual in some families. On average, stomata represented only 23 % of the limitation to Pii with no differences between families observed. Family x I, family x temperature and family X CO2 were not significant for Pj^.
Young plants of Calamagrostis epigejos (L.) Roth were grown in controlled environments with two regimes of CO2 in the air: normál (350 cm^ m'^) and elevated (700 cm^ m‘3). The relative growth rate of plants grown at elevated CO2 was increased by about 20 % in comparison with control plants cultivated at ambient CO2 concentration. Partitioning of assimilates into roots (+ rhizomes) and shoots was the same in both treatments. Slightly lower values of specifíc leaf area, leaf mass ratio and leaf area ratio were found in the plants grown at elevated CO2. The net photosynthetic rate (P^) was measured gasometrically in plants from both treatments at 350 and 700 cm^ m"^ CO2 in the leaf chamber. There were no signifícant differences between plants grown at either CO2 concentration in their responses to radiation and CO2 conditions during measurements, i.e., no regulation of photosynthetic processes in response to elevated CO2 was detectable. at saturating irradiance and maximum apparent quantum yield of photosynthesis were always considerably higher at doubled CO2 concentration during measurements.
The morphology of the nematode Klossinemella iheringi (Travassos, Artigas et Pereira, 1928), the type species of the genus Klossinemella Costa, 1961, was studied using specimens collected from the serrasalmid fish, Mylesinus paraschomhurgkii légu, Santos et Ferreira, 1989 (a new host record), from the Trombetas River, Para State, Brazil, by both light and scanning electron microscopy. This species was also recorded from the Jari River (Pará State), the Uatuma, Pitinga and Capucapu Rivers (Amazonas State), and the Araguari River (Amapá State). An examination by SEM made it possible, for the first time in this genus, to study in detail the structure of the cephalic end. Characteristic features are the presence of 8 cephalic papillae arranged in two circlets, well developed lateral amphids, and especially a crown of 8 cephalic, Y-shaped sclerotized pieces (outgrowths). The male possesses 8 pairs of caudal papillae (3 preanals, 1 adanal and 4 postanals), two unequal spicules (0.156-0.294 mm and 0.069-0.099 mm long) and a gubemaculum (0.027-0.045 mm in length); previously undescribed deirids were also found. This is the first record of this parasite from the Amazon River basin. The genus Proatractis G. Caballero, 1971 is considered a synonym of Klossinemella Costa, 1961, belonging to the cosmocercoid family Atractidae, and its type species is transferred to the latter genus as Klossinemella parvicapilico-rnnala (G. Caballero, 1971) comb. n.
Four new species of feather mites belonging to three different genera of the family Pteronyssidae are described from passerine birds of South Africa: Pteroherpus africanus sp, n, from the garden bulbul Pycnonotus barbatus (Desfontaines) (Pycnonotidae), Pteroherpus cysticolae sp. n. from the wing-snapped cisticola Cisticola ayresii Hartlaub (Sylviidae), Pteronyssoides promeropis sp. n. from the Gurney’s sugarbird Promerops gurneyi Verreaux (Promeropidae), and Sturnotrogus creatophorae sp. n. from the wattled starling Creatophora cinerea Menschen (Sturnidae). A brief review of recent publications on the taxonomy of the family Pteronyssidae is given.