LignicolousHyphomycetes from Czechoslovakia 6.Spadicoides andDiplococcium

Seventeen species belonging toSpadicoides Hughes andDiplococcium Grove collected in Central Europe mostly in Czechoslovakia are described and illustrated. Two new species are described inSpadicoides—S. carpatica Hol.-Jech.,S. penatium Hol.-Jech. and three new species inDiplococcium—D. bicolor Hol.-Jech.,D. insolitum Hol.-Jech. andD. parcum,Hol.-Jech.     

Cloning of mtDNA fragments homologous to mitochondrial S2 plasmid-like DNA in maize

Summary Mitochondria from S-type cytoplasmic male-sterile maize contain two small DNA species, S1 and S2, which are absent from other fertile and male-sterile cytoplasms. These species have been cloned in plasmid pBR322 by the homopolymer extension method. Probes made with these recombinant plasmids have been used to establish the homology between high molecular weight mitochondrial DNAs of fertile and male-sterile cytoplasms, and small mitochondrial plasmid-like molecules. Hybridization and mapping data show that S2 DNA copies are homologuous with sequences of the normal mitochondrial genome. A comparison of physical maps of different isolated mtDNA fragments indicates a heterogeneous arrangement of S2 sequences in the mtDNA population of normal fertile maize cytoplasm. The origin of this heterogeneity is discussed.     

Population density of aphids at the time of settling and ovariole maturation inCoccinella septempunctata [Col.: Coccinellidae]

In 1978 and 1979 in Central Bohemia the census of aphid populations on bean, sugar beet, cereals, maize, and alfalfa were taken at the time when overwinteredCoccinella septempunctata L. (1) settled and (2) the ovarioles of females ripened. Settling occurred immediately after aphid immigration. Minimum aphid density required for settling was estimated to about 10 aphids per 1 m² of field area. The aphid density at the time of ovariole ripening equaled 1 aphid per 200–400 cm² of leaf area.     

Comparison of different methods of glucose oxidase immobilization

Glucose oxidase was immobilized by covalent bond to two basic types of sorbents—glycidylmethacrylate copolymers and bead cellulose. These two types of carries were chemically modified, if needed, by the employing various procedures and subsequently used in the immobilization of native and oxidized glucose oxidase. The samples thus obtained were compared with those of immobilized glucose oxidase bound onto some common carriers. Samples which possessed not only a high absolute activity but also adequate mechanical and flow properties were characterized in greater detail with respect to the immobilization efficiency and kinetic properties of bound glucose oxidase.