Fossil oaks of Primorye, USSR, and the origin of oak forests

This paper gives a new locaticn for fossil oaks in Rettikhovka, Primoiye, USSR, from coal-bearing deposits of Miocene age. The large number of different oak species at the above site (leaf imprints) is evidence of their important role in the plant communities of the past. The authors agree with those scientists who maintain that the extant oaks in the Soviet Far East are of autochthonous origin. Two new fossil Quercus species with compound-lobed leaves are described, viz. Q. sichotensis Ablaev & Gorovoi and Q . sp.     

Formation of a Stable “Active” Complex between Cytochrome <Emphasis Type="Italic">c</Emphasis> and Yeast Peroxidase

THE mechanism of oxidation of cytochrome c in vivo is still unknown¹. One reason for this is that the usual mitochondrial system involved is insoluble and the membrane binding site is ill-defined and heterogeneous². Solubilization of the terminal oxidase led to the discovery^3–5 of complexes between it and cytochrome c, but whether these involved the protein^4,5, lipid⁶, or haem⁷ groups of the oxidase is uncertain. According to one kinetic interpretation⁸ such complexes are abortive and play no part in catalysis. And the occurrence of an oxidase-c complex in situ has not been proved.     

Intracellular Regime for the Assembly of the Chlorophyll-Protein Complex CPI in Cyanidium caldarium

Mass cultures of Cyanidium caldarium exhibit a developmentalstage of temporary bleaching during cultivation in permanentlight (Zagon and Brandt, 1985). This loss of chlorophyll a isnot accompanied by a loss of the CPI-apoprotein. This essentialthylakoid protein is also inserted into the thylakoid membranewithout the presence of chlorophyll a. Subsequent assembly withthe pigment, however, increases the intrinsic binding of theCPI-apoprotein. The temporary bleaching of C. caldarium canbe imitated essentially by addition of levulinic acid or cycloheximide,but not by chloramphenicol or streptomycin. The cooperationof the nucleocytoplasm and of the photosyn-thetically activecompartments with respect to the assembly of CPI is discussed. Key words: Assembly, chlorophyll-protein complex, Cyanidium caldarium, regulation     

The reproductive biology of a distylous tree, Sarcotheca celebica (Oxalidaceae) in Sulawesi, Indonesia

Sarcotheca celebica is a tree endemic lo Sulawesi (and Kabaena Island). Kike many species in the Oxalidaceae it is heterostylous (here distylous). The small red flowers, which last less than one day, are produced in loose inflorescences which bloom over a long flowering season (several months). There are two whorls of stamens in each plant, which overlap in length, perhaps indicating a tristylous origin. Long–styled and short–styled plants differed in the measurements of stamens, styles and pollen grains. Only a small amount of pollen was produced by long–styled plants. Effective insect pollinators were mainly large Hymenoptcra, especially Xylocopa species, which visited many flowers and different trees in rapid succession. A wide diversity of insects visited flowers of both morphs, and numbers visiting each morph were approximately equal. The only successful experimental pollinations were from pollen of short–styled plants onto stigmas of long–styled plants. Automatic self–pollination did not occur. In nature not all flowers produced fruit, some fruits were set with no seeds and a low number of seeds was set in all fruits. The differences in seed set per fruit between short–styled, long–styled and experimental crosses indicate that pollinator visits were insufficient for maximum seed set in some fruits, but selective abortion of seeds must also be occurring. We suggest that S. celebica may represent an intermediate stage in the evolution of dioecy from distyly, with the short–styled flowers making their major genetic contribution through pollen and long–styled flowers through ovules.     

The Ultrastructure of Spores (Protozoa: Microsporida) from Lophius americanus,the Angler Fish1

ABSTRACT. Spinal and cranial ganglia of American angler fish, Lophius americanus, are often infected with microsporidia. This protozoon elicits the formation of large, spore-filled, hypertrophied host cells, cysts. Previous reports of microsporidia in European lophiids identify the parasite as Spraguea lophii, a genus which has recently been shown to be dimorphic. The spores from L. americanus are monomorphic (2.8 × 1.5 μm) and uninucleate. Each spore contains a polar tube that forms six to nine coils. Spraguea lophii differs from the microsporidium described in L. americanus in several ways. Spraguea lophii has two spore types: a large spore (4.0 × 1.25 μm) containing a diplokaryon and three to four polar tube coils and a smaller uninucleate spore (3.5 × 1.5 μm) with five to six polar tube coils. Because of these major differences, the microsporidium from L. americanus is removed from the genus Spraguea and returned to its original genus, Glugea, as a new species, G. americanus n. sp. Other ultrastructural characteristics of G. americanus are included: the posterior vacuole encloses two distinct membranous structures; one is tubular and resembles a “glomerular tuft” and the second is lamellar and composed of concentric membrane whorls, additionally, the straight or manubroid portion of the polar tube proceeds beyond the posterior vacuole before it turns anteriorly and begins to coil.     

Seasonal prevalence of adult mosquitoes at Casuarina and Leanyer,Darwin

Mosquito populations were sampled fortnightly for 2 years, using EVS solid CO₂ baited light traps, to monitor seasonal activity of females in the vicinity of new urban development at Casuarina Swamp and Leanyer Swamp, Darwin. The relative abundance of different species was related to seasonal conditions and the influence of urban stormwater on the larval habitats within the two environments. Differences were observed between sites due to the site ecology, and between years and between seasons but, in general, the early dry season was dominated by Culex annulirostris, Anopheles bancroftii and An hilli, while Aedes vigilax and Cx annulirostris were predominant in the late dry season and early wet season at both sites. The late wet season at Leanyer Swamp was dominated by An hilli and An bancroftii, while at Casuarina Swamp, Cx annulirostris was the predominant species. The prevalence of vector species indicates the need for control measures to protect the local communities from mosquitoborne disease.     

The Development of Protein Bodies in the Storage Tissues1

Homogenates of the developing endosperms of maize, wheat, andbarley and of developing cotyledons of peas have been separatedon sucrose density gradients. Protein bodies have been recognizedby their content of storage proteins, their density, and theirappearance under the electron microscope. The distribution ofthe endoplasmic reticulum was followed by measuring NADH-cytochromec reductase. Glutamate dehydrogenase, catalase, and triose phosphatedehydrogenase—respectively marker enzymes for mitochondria,microbodies, and plastids—were also present in the gradients.Differences were found between the different species with respectto the association between the endoplasmic reticulum and thestorage proteins. There was no evidence for any vacuolar markerenzymes associated with the cereal protein bodies. The proteinbodies of wheat and barley appear to be similar to each otherbut differ from maize in that the latter have much more endoplasmicreticulum associated with them. In contrast the protein bodiesof peas co-sediment with vacuolar marker enzymes.     

Salinity and in vitro Ageing Effects on Primary Photosynthetic Processes of Thylakoids Isolated from Pisum sativum and Spinacia oleracea

The effects of in vitro ageing and salinity of the reactionmedium on the primary photochemistry of photosystem II and thepattern of energy distribution within the photochemical apparatusof thylakoids isolated from Pisum sativum and Spinacia oleraceaare described. Analyses of the low temperature induction curvesof fluorescence emission at 695 and 735 nm and of low temperatureabsorption and fluorescence emission spectra were used to examinethese processes. In vitro ageing over short periods reducedthe photochemical activity and changed the energy distributionwithin thylakoids of P. sativum, but had little effect on thylakoidsof S. oleracea. A synergistic effect of in vitro ageing andsalinity of the reaction medium was observed for P. sativumthylakoids. Ageing effects could be minimized by addition of100 mM NaCl to the resuspension medium. Changes in NaCl concentrationin the reaction medium produced large and similar changes inthe primary photochemical functioning of thylakoids from P.sativum and S. oleracea, which could be attributed mainly tothe cation species, Na^$; however, experiments using mannitolto produce osmotic stress indicated some small osmotically inducedchanges in photofunction of the thylakoids. Optimal primaryphotochemical activity of photosystem II, for both species,was observed with 200 mM NaCl. Cation-induced regulation ofexciton distribution appears to be facilitated by controllingthe degree of energy coupling between the light-harvesting chlorophylla/b complex and the two photosystems, I and II, and not by regulationof coupling between photosystems I and II.