Susceptibility of two Coconut Pests,Oryctes rhinoceros [Col.: Scarabaeidae] andTirathaba rufivena [Lep.: Pyralidae], to the entomoparasitic nematodeSteinernema feltiae [= Neoaplectana carpocapsae]

Bioassay indicated that 1 st instar larvae ofOryctes rhinoceros are resistant to infections by the nematodeSteinernema feltiae (estimated LD₅₀: 90 nematodes) but thatTirathaba rufivena larvae larger than 15 mm are highly susceptible (estimated LD₅₀: 3 nematodes). The “All” strain and the “mexican” strain ofS. feltiae gave very similar responses. In a field trial 300,000 nematodes were sprayed on each of 25 palms to controlT. rufivena. Although some mortality from nematodes was observed, the treatment failed to reduce the pest population significantly.     

Chemosystematics ofSuillaceae andGomphidiaceae (suborderSuillineae)

The chemotaxonomic findings relating to the generaBoletinus, Suillus, Gastroboletus, Gomphidius, andChroogomphus are summarized and discussed, using published data as well as our own hitherto unpublished evidence of pigments and chromogens. The study confirms repeatedly made claims that these genera are closely related. In addition to the presence of pigments which are typical for most members of theBoletales (e.g., pulvinic acid derivatives, terphenyl quinones, cyclopentenones), prenylated phenols and quinones can also be constantly detected here (with the exception ofBoletinus), just as inRhizopogon. Accordingly,Suillus is more closely related to theGomphidiaceae andRhizopogonaceae than to the remaining boletes. It is therefore necessary to establish a new family (Suillaceae which includeBoletinus, Suillus, andGastrosuillus) and a new suborder (Suillineae which includeSuillaceae, Gomphidiaceae, andRhizopogonaceae) within theBoletales. Chemosystematics ofBoletales 2. For part 1 seeBesl & al. (1986). Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Sippen derOleaceae,Scrophulariaceae, Plantaginaceae undAsteraceae

Different members of the Angiosperm familiesOleaceae, Scrophulariaceae, Plantaginaceae andAsteraceae with variable modes of pollination were studied in relation to ultrastructure of pollenkitt and exine. In entomophilous representatives the mostly electron-dense and homogeneous pollenkitt is located on the outside layer of the exine, making the pollen sticky. In related anemophilous taxa the pollenkitt mostly is electrontransparent and inhomogeneous; it becomes inactive by remaining in the loculus or sinking to the bottom of the exine caves; this makes the pollen powdery. According to such criteria,Fraxinus ornus andRhinanthus serotinus are entomophilous, whileFraxinus excelsior is anemophilous. The pollen ofLathraea squamaria eventually becomes powdery and suited for wind dispersal. The broad transition field between entomo- and anemophily is demonstrated byPlantago andArtemisia. Plantago lanceolata is anemophilous, whilePl. serpentina andPl. media are amphiphilous.Artemisia nitida andA. mutellina are entomophilous,A. absinthium, A. pedemontana andA. gabriellae are amphiphilous, but tend towards entomo- (A. absinthium) or anemophily (A. gabriellae), whileA. chamaemelifolia and especiallyA. vulgaris are anemophilous.

     

The role of competitive dominance in the invasive ability of the Argentine ant (Linepithema humile)

To assess the importance of competition in the advance of invasive species, bait stations have been used to determine the dominance hierarchy of a community of native ants in Doñana National Park, southern Spain, and the status of the introduced species Linepithema humile (Argentine ant). Some native species, e.g. Cataglyphis floricola or Camponotus pilicornis, seem to be subordinate, i.e. occupy a low position in the competitive hierarchy; some are dominant (e.g. Pheidole pallidula), and others (e.g. Aphaenogaster senilis) occupy an intermediate position in the hierarchy. The Argentine ant is a competitively dominant species, because of its aggressive behavior and relative abundance. Irrespective of their position in the dominance hierarchy, L. humile and some native species adopt what games theory terms “the bourgeois strategy” during agonistic encounters with other species. Lone workers tend to be submissive in encounters whereas workers in the presence of other colony members are aggressive. L. humile was the only species which aggressively displaced large numbers of ants of other species from the bait. L. humile also expanded its range in the course of the experiment, displacing native species from parts of the study area.     

Single-strand conformational polymorphism markers associated with a major QTL for fusarium head blight resistance in wheat

A major quantitative trait locus (QTL) associated with resistance to Fusarium head blight (FHB) was identified on chromosome 3BS between simple sequence repeat (SSR) markers Xgwm389 and Xgwm493 in wheat “Ning 7840”, a derivative from “Sumai 3”. However, the marker density of SSR in the QTL region was much lower than that required for marker-assisted selection (MAS) and map-based cloning. The objective of this study was to exploit new markers to increase marker density in this QTL region by using single-strand conformational polymorphism (SSCP) markers developed from wheat-expressed sequence tags (ESTs) on 3BS bin 8-0.78-1.0. Sixty-nine out of 85 SSCP primer pairs amplified PCR (polymerase chain reaction) products from the genomic DNA of “Chinese Spring”. Thirty-four primer pairs amplified PCR products that could form clear ssDNA (single strand DNA) bands through denaturation treatment. Ten SSCP markers had polymorphisms between Ning 7840 and “Clark”. Five of the ten polymorphic SSCP markers were located on chromosome 3B by nullitetrasomic analysis. Three SSCP markers (Xsscp6, Xsscp20, and Xsscp21) were mapped into the region between Xgwm493 and Xgwm533 and possessed a higher coefficient of determination (R²) than Xgwm493 and Xgwm533. The SSCP markers, Xsscp6, Xsscp20, and Xsscp21, can be used for map-based cloning of the QTL and for marker-assisted selection in FHB resistance breeding.     

P-type sieve-element plastids and the systematics of theArales (sensuCronquist 1988)—with S-type plastids inPistia

The sieve-element plastids of 126 species of theArales were investigated by transmission electron microscopy. With the exception ofPistia (with S-type plastids) all contained the monocotyledon specific subtype-P2 plastids characterized by cuneate protein crystals. While the species studied from bothAcoraceae andLemnaceae have form-P2c plastids (i.e., with cuneate crystals only), those of theAraceae belong to either form P2c (14 species), P2cs (the great majority) or P2cfs (Monstera deliciosa, only, with form-P2cs plastids in the otherMonstera species studied). The form-P2cs plastids of theAraceae are grouped into different categories according to the quantity and quality of their protein and starch contents. The subfamilyLasioideae is redefined to comprise all aroid P2c-taxa and those P2cs-genera that contain only one or very few starch grains. Only little starch is also recorded in the sieve-element plastids ofGymnostachys (Gymnostachydoideae), with the other plastid data denying a close relationship toAcorus. While equal amounts of starch and protein are generally present in sieve-element plastids of the subfamiliesPothoideae, Monsteroideae, Colocasioideae, Philodendroideae, andAroideae, maximum starch content and only very few protein crystals are found in form-P2cs plastids ofCalla (Calloideae),Ariopsis (Aroideae), andRemusatia (Colocasioideae?). In the latter, both morphology and size of sieve-element plastids are close to those ofPistia.—In theAraceae the diameters of the sieve-element plastids exhibit a great size range, but are consistent within a species and within a defined part of the plant body. Comparative data are mainly available for stem and petiole sieve-element plastids.—The accumulated data are used to suggest an affiliation of the species to subfamilies and to discuss the phylogeny of theArales. Forms and sizes of their plastids support a separation of bothAcoraceae andLemnaceae from theAraceae. The presence of S-type plastids inPistia does not favour direct and close relationships to the form-P2c genusLemna.—The prevailing form-P2cs plastids might support proposals that place theArales (together with also form-P2cs plastid containingDioscoreales) in the neighbourhood of basal dicotyledons. BesidesAsarum andSaruma (Aristolochiaceae), with monocotyledonous form-P2c plastids,Pistia (with dicotyledonous S-type plastids) gives another example for a link between the two angiosperm classes.     

Comparative capitular morphology and anatomy of Coreopsis L. and bidens L. (compositae), including a review of generic boundaries

The capitular and floral morphology and anatomy ofBidens L. andCoreopsis L. were studied. All the North American species ofCoreopsis were studied. Selected species ofBidens from North and South America andCoreopsis from South America were included. The results were compared with previous observations on African species ofBidens (incl.Coreopsis). Emphasis was given to character states of the ray florets, paleae, stylearm apices, outer phyllaries, achenes, and pollen grains. Some of the character states are unique features ofCoreopsis, e.g., globular and elongately conical receptacles, deltoid outer phyllaries, truncate and indistinctly 3–5-dentate, 3–4-lobed ray florets, narrowly spathulate paleae, subulate paleae with linear-filiform upper half, hairy and apically 3-cleft paleae, truncate, convex or shallowly conical stylearm apices with the sweeping hairs limited to the area above the stigmatic surfaces and the orbicular to circular achenes. The cylindric setaceous pappus bristles so commonly encountered inBidens are unknown inCoreopsis. The pappus bristles inCoreopsis are paleaceous but similar, though thicker ones are also found in African species ofBidens (incl.Coreopsis) with winged achenes. Twin-celled hairs (setulae) with differing degrees of wall thickness are found on the achenes ofCoreopsis sect.Pseudoagarista (Mexico and South America),Coreopsis sect.Pugiopappus (California), AfricanBidens with winged achenes (e.g.,B. prestinaria, B. macroptera) and some North AmericanBidens (e.g.,B. aristosa). Similar sclerotic parenchyma make up the achenial wings of species in both genera. These may be interpreted as homologous structures, indicating the underlying similarity of these taxa and their derivation from a common ancestral stock.     

Development and encapsulation of the endoparasitoid,Microplitis croceipes (Hym.: Braconidae), in six candidate host species (Lep.)

Encapsulation and development of the endoparasitoid,Microplitis croceipes (Cresson), were studied in six atypical lepidopteran host species whose usual host isHelicoverpa zea (Boddie). The candidate hosts examined were: the fall armywormSpodoptera frugiperda (J. E. Smith); the beet armyworm,Spodoptera exigua (Hübner); the cabbage looper,Trichoplusia ni (Hübner); the greater wax moth,Galleria mellonella (L.); the Indian meal moth,Plodia interpunctella (Hübner); and the diamondback moth,Plutella xylostella (L.). BothS. exigua andT. ni were completely unsuitable forM. croceipes development due to the high rate of eggs that were encapsulated within three days after parasitism. Encapsulation inS. frugiperda included mainly parasitoid eggs and was first detected six days after parasitization at 25°C and two days at 30°C. Encapsulation inG. mellonella occurred only in the larval stage of the parasitoid. InP. interpunctella, parasitoid larvae reached the 3rd stadium, but none of them pupated. OnlyS. frugiperda andG. mellonella supported successful development ofM. croceipes from egg to adult. The percentage of parasitoids reaching the adult stage in these hosts was higher at 30°C than at 25°C (13% vs. 4% inS. frugiperda, and 21% vs. 3% inG. mellonella, respectively). However, these percentages were too low to substitute them as a more economical host for rearingM. croceipes. This biological information will be useful in additional laboratory studies directed toward reducing the rate of encapsulation (e.g., manipulation of host rearing temperature) to increase production ofM. croceipes on these hosts.     

Seven new calochroid and fulvoid species of Cortinarius

We describe seven new European species of Cortinarius. All species are based on analyses of morphological and DNA sequence data. They all belong to a well-supported clade comprising most species traditionally treated in Cortinarius subgenus Phlegmacium sections Fulvi and Calochroi (i.e. the/Calochroi clade). All taxa are either fulvoid (containing anthraquinoid pigments) or calochroid (without these pigments). Morphological and ecological data are presented for all species and compared with similar species. A dichotomous key is presented for C. calochrous and similar species, including all six newly described calochroid species. The calochroid species C. albertii, C. chailluzii, C. cisticola, C. sancti-felicis, C. selandicus and C. vesterholtii spp. nov., and the fulvoid species C. langeorum sp. nov. are described.     

The relationships ofPisolithus (Sclerodermataceae) to other fleshy fungi with particular reference to the occurrence and taxonomic significance of hydroxylated pulvinic acids

In the light of the discovery of hydroxylated pulvinic acids in the gasteromycetePisolithus arhizus, a possible relationship with the boletoid fungi and their relatives is explored. Biogenetic inter-relationships are indicated, including the host range ofApiocrea chrysosperma, and the distribution of phenylpyruvate-derived pigments offered in schematic form.     

Ultrastruktur und Verteilung des Pollenkitts in der insekten- und windblütigen GattungAcer (Aceraceae)

Several insect- and wind-pollinated species of the genusAcer have been investigated and compared in regard to pollen stickiness. The considerable amount of very inhomogeneous pollenkitt inA. negundo remains on the loculus wall or is deposited inside the exine cavities; thus the pollen is powdery. The small amount of non-homogeneous, granular pollenkitt inA. campestre mostly disappears into the exine cavities; only small droplets appear on the tectum surface; the pollen stickiness therefore is only moderate. On the other hand,A. pseudoplatanus andA. opalus produce an average amount of granular pollenkitt, which is deposited partially inside the exine and partially as a slender film on the tectum surface; in both the pollen is sticky.A. platanoides contains a great deal of granular and homogeneous pollenkitt; it does not only fill up the exine cavities but also extends as a thick, ± homogeneous, non-granular layer of pollenkitt over the tectum surface; therefore, the pollen is very sticky.—The characteristics of pollen agglutination together with other aspects of floral biology illustrate the wide spectrum between unequivocal entomophily and anemophily within the genusAcer: WhileA. negundo is anemophilous andA. platanoides is entomophilous, the remaining species investigated have a pollination syndrome with entomophilous and anemophilous features and are thus amphiphilous. The evolution withinAcer is tending not only towards dioecy, but also towards anemophily.

Herrn Prof. Dr.L. Geitler zum 80. Geburtstag gewidmet.     

Sero-systematics ofCytisus sect.Trianthocytisus (Fabaceae)

The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.