Pollination ofOpuntia lindheimeri and related species

The large, yellow, bowl-shaped flowers ofOpuntia lindheimeri, O. discata, O. phaeacantha major, andO. compressa in Texas are visited by various species of beetles and bees. The beetles and small bees (Perdita, Dialictus) are pollen thieves. The pollinators are the medium-sized and larger bees (Melissodes, Diadasia, Lithurge, Megachile, Agapostemon, etc.). Different species of theOpuntia lindheimeri group have the same pollination system and there is no evidence of any floral isolation between them. The pollination system of these species ofOpuntia in Texas is essentially the same as that ofEchinocereus fasciculatus andFerocactus wislizeni in Arizona.Pollination of North American Cacti, II.—SeeGrant & Grant (1979).     

Prevalence and development of storage fungi in peanut Arachis hypogaea seed

Summary A batch of peanutArachis hypogaea seed were divided into 4 2-kilogram portions and stored 6 months at 22–28° C. One portion was stored with the moisture content slowly increasing from 4 to 28 %; the other portions were maintained at approximately 4.5, 8.9 and 11.5 %. After 1, 2, 3, 4, and 6 months storage, 100 seed of each treatment were cultured on malt-10 % NaCl agar and the fungi isolated identified. The storage fungi present after intervals of storage were compared with those initially present. In seed stored at 4.4 % moisture,Aspergillus species remained about the same andPenicillium decreased. At 8.9 % moistureA. flavus, A. repens andPenicillium were reduced, andA. amstelodami andA. ruber increased. At 11.5 % moisture, 100% of the seed yieldedA. ruber after 4 months storage and the other storage fungi decreased to 0–2 %. The moisture content of seed stored at 99 % R. H. increased slowly to 28 % and resulted in monthly changes in the dominant fungi. Under such a circumstance with competition between these storage fungi,A. ruber grew best at 12–15 %,A. repens at 18.5 %,A. flavus andPenicillium at 20 %, andA. amstelodami between 20–28 %.Fusarium increased very rapidly as moisture content increased above 18 %.This investigation was supported by Agricultural Research Service, U.S. Department of Agriculture, Contract No. 12-14-100-8179 (34), administered by the Crops Research Division, Beltsville, Maryland.Former Research Associate, North Carolina State University, Raleigh, N. C., currently Research Plant Pathologist, Market Quality Research Division, Agricultural Research Service, United States Department of Agriculture; and Professor, North Carolina State University, Raleigh, N.C.Paper number 2489 of the Journal Series of the North Carolina State University Agricultural Experiment Station, Raleigh, North Carolina.     

Pollination ofOpunta basilaris andO. littoralis

The flowers ofOpuntia basilaris andO. littoralis in southern California are visited commonly by beetles(Carpophilus, Trichochrous) and bees (especially anthophorids, megachilids, and halictids), but are pollinated mainly by the bees. This agrees with observations presented in the previous papers in this series for other cactus species in Arizona and Texas. The available evidence indicates that the large, diurnal, cup-shaped flowers in cacti of the American Southwest are primarily bee-pollinated. Our earlier view that theseOpuntia flowers are also pollinated to a significant extent bynitidulid andmelyrid beetles must be modified now in the light of further evidence. Some pollination probably is carried out by small beetles, but it probably represents only a small proportion of the total pollination.Pollination of North American Cacti, III.—See alsoGrant & Grant (1979) andGrant & al. (1979).     

Ascomycetes on Celastrus paniculata Willd

Summary The paper deals with Ascomycetes fungi onCelastrus paniculata Willd,Hysterium celastrina Tilak andBagnisiella celastrina Tilak are new species described whileEutypella stellulata (Fr)Sacc. forms a new host record.     

The effect of three species of mites upon fungal growth on wheat

Every week, for 20 weeks, the growth of naturally occurring grain storage fungi on wheat infested with the three commonest British grain storage mites,Acarus siro, Glycyphagus destructor andTyrophagus longior, was compared with that on uninfested wheat.The number of colonies of theAspergillus glaucus group per gram were always less on grain infested with mites than on uninfested grain.Penicillium spp. were also less numerous on grain which was infested withA. siro but did not appear to be affected by the other mites. In contrast, two fungi which are pathogenic to mites,Aspergillus restrictus andWallemia sebi, were more abundant in the presence of certain mites. The former was associated withG. destructor, the latter withG. destructor andA. siro.The three species of mites either feed on theA. glaucus group andPenicillium spp., or inhibit them by an unknown secretion. Pathogenic fungi are probably avoided. Mites are therefore an important variable in studies on fungal growth during grain drying and storage.     

Fungi that cause mouldiness of processed sheet rubber in Western Nigeria

The fung isolated from mouldy processed sheet rubber in Western Nigeria wereAspergillus fumigatus Fres,Aspergillus flavus Link andAspergillus aculeatus Iisuka. When inoculated on sterilized, uninfected sheet rubber, bothA. fumigatus andA. flavus produced symptoms which were similar to those originally observed on mouldy processed sheet from the rubber estate.

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Zusammenfassung Die folgenden Pilze sind vom verschimmelten, bearbeiteten Rubber isoliert worden:Aspergillus fumigatus Fres,A. flavus Link andA. aculeatus Iisuka. WennA. fumigatus undA. flavus an sterilisiertem, nicht infiziertem Rubber verimpft worden sind, haben sie identische Läsionen am sterilen Rubber verursacht.

     

Pollination biology ofOpuntia polyacantha andOpuntia phaeacantha (Cactaceae) in southern Colorado

The phenology, compatibility system, and pollinator fauna ofOpuntia polyacantha Haw. andO. phaeacantha Engelm. in southern Colorado were studied and compared. The total blooming periods overlap, but the peak of blooming differs between the species withO. polyacantha blooming first and for longer. Neither species is apomictic,O. polyacantha is largely self-incompatible andO. phaeacantha is self-compatible but may not automatically fully self-pollinate. Examination of flowering structures showed that the former has larger flowers with more perianth parts and heavier (but fewer) anthers. Further the flowers of the allogamous species are visited by greater diversity (but similar abundance) of pollinators. Medium to large bees of the generaDiadasia, Lithurge, Melissodes, Bombus, Agapostemon andMegachile were found to be effective pollinators of the Opuntias studied. The two species were compared as to their floral attributes, breeding systems, and pollinators, and the possible role of competition for pollinators is discussed with respect to its role in their evolutionary paths.     

Thermophilous fungi of birds' nests

Summary Twenty seven species of thermophilous fungi were found on plant debris in the nests of twelve passerine bird species in Nottinghamshire of whichDactylomyces thermophilus, Humicola insolens, Penicillium duponti, Stilbella thermophila andTorula thermophila are new records for Britain.Certain species, such asAspergillus fumigatus, Chaetomium thermophile, Coprinus delicatulus, Humicola insolens, Thermoidium sulphureum andThermomyces languinosus were present in most of the 54 nests surveyed, usually at a high frequency.The species populations of thermophilous nest fungi are similar to those on plant debris on the soil surface and in the grassland vegetation. They are closely related to thermophilous floras known from various composts. The relatively high frequency of strictly thermophilic species found on organic debris of the various nests indicates that nests are warmed up by the birds while using the nests, and, probably, also by the sun and air during the summer months.The number of thermophilous species and their frequency on the plant debris of the nests varies considerably in the twelve bird species. The number of species as well as their frequency was exceptionally low in Sandmartin's nests but the nests of Blackbird, Hedge Sparrow and of the Thrushes were rich in thermophilous fungi.All the 27 thermophilous fungi recorded from the birds' nests may be regarded a) as saprophytes with no known harmful relationships to birds and other animals, such asAllescheria terrestris, Botryotrichum species,Chaetomium thermophile, Coprinus delicatulus, Humicola insolens, Penicillium duponti, Sporotrichum thermophile, Stilbella thermophila, Thermoidium sulphureum, Thielavia sepedonium andTorula thermophila, or b) as saprophytes on the plant debris of the nests but with known potential pathogenicity to birds, other animals and man, e.g.,Absidia ramosa, Aspergillus fumigatus, A. terreus, Dendrostilbella boydii (=conidialAllescheria boydii),Emericella nidulans, Endomyces lactis, Mucor pusillus, Paecilomyces varioti, Rhizopus arrhizus, R. cohnii andThermomyces lanuginosus.     

An optimum environment for the culturing of cytospora isolates from stone fruits. II. Carbon sources

Summary Six isolates (Cytospora cincta Fr. andC. leucostoma Fr.) were innoculated to liquid and solid synthetic laboratory media containing nine different sources of carbon.One of the isolates did not grow. The remaining five grew at rates, and in relationships, which segregated them in accordance with their species grouping. These relationships were more nearly constant than any other relationships previously noted in Idaho for these or otherCytopora isolates.Two conclusions were reached: 1) For best growth and sporulation, maltose should be incorporated in the laboratory culture medium and not the commonly used dextrose, which was demonstrated to be an inferior source of carbon; and 2) separate investigations, which utilize different carbon sources in the laboratory media, are likely to yield sufficiently different results that co-identity of species strains used by the separate workers may not be evident.Approved by the Director of the Idaho Agricultural Experiment Station as Research Paper No. 489.     

Mycotoxin-producing potential of fungi associated with qat (Catha edulis) leaves in yemen

Forty-four fungal species belonging to 20 genera were isolated from 30 samples of qat leaves. The most frequent genera wereAspergillus, Alternaria, Penicillium, andCladosporium followed byFusarium, Drechslera, Chœtomium, andMucor. The most prevalent species in above genera wereAspergillus niger, A. flavus, A fumigatus, Alternaria alternata, Penicillium chrysogenum, P. citrinum, Cladosporium cladosporioides, andFusarium verticillioides. From these fungi, 17 species (39%) related to 7 genera (35%) proved to be true endophytes. Eleven out of 75 isolates were mycotoxigenic.A. alternata produced alternariol and alternariol monomethyl ether whereasA. flavus produced aflatoxins B₁ and B₂. Ochratoxin A, sterigmatocystin, citrinin and T-2 toxin were produced byA. ochraceus, A. versicolor, P. citrinum andF. oxysporum, respectively. The presence of such toxigenic fungi associated with qat leaves is considered to be a threat to public health.     

Fungi on Acacia arabica Linn

Summary The paper deals with three new species of Deuteromycetous fungi e.g.Diplodia acaciae, Cytospora acaciae, andFusicoccum indicum collected on dead stems ofAcacia arabica Linn.     

Fungal microflora of seeds of Pisum sativum L. and its control

Five varieties ofPisum sativum L. were tested for seedborne fungi. Tests were conducted by standard International Seed Testing methods. It was observed that fungi likeAlternaria, Aspergillus, Rhizopus, Mucor andFusarium were associated with all the five varieties tested.Fusarium andRhizopus were dominant in all the varieties. They were also responsible for reduction in germination percentage of seeds. Early December was selected for testing the efficacy of certain fungicides (namely, Agrosan G.N., Ceresan, Copper carbonate, Tafasan, Tillex, Stardex and Sulphur) against seedborne fungi ofPisum sativum L., Agrosan G.N. and Ceresan gave the better control of seedborne pathogens without any adverse effect on germination.     

Cellulose-decomposing fungi of salt marshes in Egypt

Seventy-five species and three varieties which belong to thirty-four genera were identified from 74 soil samples collected from salt marshes in Egypt. The most frequent fungi wereAspergillus fumigatus, Aspergillus niger, Cladosporium herbarum andAlternatia alternata, followed byAspergillus terreus,Curvularia spicifera andPenicillium notatum. Six genera were of moderate occurrence:Penicillium, Futarium, Curvularia, Rhizopus, Stachybotrys, andChaetomium. Five genera were of low occurrence:Paecilomyces, Oephalosporium, Epicoccum, Mucor andMyrothecium.     

Monocentric fungi on species of rhizosolenia from saline habitats

Summary Eight monocentric fungi are reported in two provisionally identified species ofRhizosolenia from sea-water. Only two species are assigned specific names. These areRhizophydium planktonicum Canter andR. fragilariae Canter. A fungus with depressed-globose sporangia is included as a form ofR. fragilariae. Two unidentified species ofChytridium are reported. A fungus tentatively assigned toZygorhizidium and a form provisionally assigned toPetersenia are also reported and described insofar as their characteristics are known.     

Bacterial and fungal metabolites of rhizospheric microflora of cotton antagonistic to Rhizoctonia solani Kühn

Summary Growth response ofRhizoctonia solani Kühn, the damping-off fungus, to metabolites of selected antagonistic rhizospheric bacteria and fungi of some Egyptian cotton varieties, namely, two strains ofBacillus subtilis Cohn,Aspergillus terreus Thom, andAspergillus flavus Link produced in culture media containing nitrate- or ammonium-nitrogen sources, proved the potency ofB. subtilis metabolites in inhibitingR. solani mycelial growth whether from nitrate- or ammonium-nitrogen culture media. Metabolite filtrates ofB. subtilis (II) are more potent than those ofB. subtilis (I). Increasing concentration of bacterial metabolite filtrates resulted in a decreased mycelial dry weight ofR. solani. The bacterial inhibitory factor forR. solani mycelial growth is partially affected by heat. Metabolite filtrates ofA. terreus from nitrate-nitrogen are slightly more potent than from ammonium-nitrogen culture media while an opposite relation is evident withA. flavus metabolites. Growth responses ofR. solani to different experimental dilutions of metabolite filtrates ofA. terreus andA. flavus proved the intervention of the nutritive factor in witholding growth of the damping-off fungus.     

Accumulation of sugar alcohols by filamentous fungi

Five hundred isolates of different xerophilic and non-xerophilic fungi belonging to 10 genera and 74 species were screened for alditol (sugar alcohol) accumulation. Ninety-two of the isolates failed to grow on a salt medium, most of the isolates (408) produced alditols; 348,44 and 16 of them produced low, moderate and high levels of alditols, respectively. The high alditol producers belonged to five species ofAspergillus, six species ofEurotium andFennellia flavipes. Glycerol andd-mannitol were the main constituents of alditol pools of the 16 high alditol producers.d-Arabinitol andmeso-erythritol were also formed but at low concentrations by several of the tested isolates.     

The genus Gymnoascus Baranetzky

Summary The genusGymnoascus Baranetzky is monographed and found to include five valid species including one previously recognized species,G. reessii, one new combination,G. johnstoni, two new species,G. longitrichus andG. corniculatus, and a species originally described as aGymnoascus but included inMyxotrichum since 1893,G. uncinatus. Twenty species previously described as belonging toGymnoascus are excluded from the genus or are considered as doubtful representatives.Supported in part by Botany Department Research Grant # 1344, University of California, Los Angeles, California.     

Orchard pollination in Capitol Reef National Park,Utah, USA. Honey bees or native bees?

Capitol Reef National Park in central Utah, USA surrounds 22 managed fruit orchards started over a century ago by Mormon pioneers. Honey bees are imported for pollination, although the area in which the Park is embedded has over 700 species of native bees, many of which are potential orchard pollinators. We studied the visitation of native bees to apple, pear, apricot, and sweet cherry over 2 years. Thirty species of bees visited the flowers but, except for pear flowers, most were uncommon compared to honey bees. Evidence that honey bees prevented native bees from foraging on orchard crop flowers was equivocal: generally, honey bee and native bee visitation rates to the flowers were not negatively correlated, nor were native bee visitation rates positively correlated with distance of orchards from honey bee hives. Conversely, competition was tentatively suggested by much larger numbers of honey bees than natives on the flowers of apples, apricots and cherry; and by the large increase of native bees on pears, where honey bee numbers were low. At least one-third of the native bee species visiting the flowers are potential pollinators, including cavity-nesting species such as Osmia lignaria propinqua, currently managed for small orchard pollination in the US, plus several fossorial species, including one rosaceous flower specialist (Andrena milwaukiensis). We suggest that gradual withdrawal of honey bees from the Park would help conserve native bee populations without decreasing orchard crop productivity, and would serve as a demonstration of the commercial value of native pollinators.     

Mould biodiversity in homes I. Air and surface analysis of 130 dwellings

Summary Air and surface sampling to quantify and identify fungi were conducted over a 10-year period in 130 Belgian homes, including flats and houses. Homes were selected based on the medical files of allergic, mostly asthmatic patients to assess possible mould responsibility in the aetiology of the disease. Air sampling was done with Reuter centrifugal air sampler using different sampling times and incubation temperatures to detect mesophilic and thermotolerant or thermophilic fungi. More than 50 genera were detected, withCladosporium, Penicillium andAspergillus being the most common. The main species detected wereAspergillus versicolor, several species ofPenicillium, Cladosporium sphaerospermum andCladosporium herbarum. Surface sampling was conducted concomitant with air sampling. Surfaces with and without visible mould growth were tested equally by Rodac contact plates or swabs. AlthoughCladosporium herbarum was shown to be a common species in indoor environments by air sampling, it was not detected by surface sampling from visible mould growth. This finding suggests that its presence in dwellings is from an outdoor origin and not indicative of indoor proliferation.Aspergillus versicolor, Cladosporium sphaerospermun, andPenicillium chrysogenum were the most common species isolated from surfaces showing visible mould growth.