Patterns of phytophagous insect herbivory and abundance on juvenile regrowth of Eucalyptus subgenera coexisting in southeastern Tasmania

Abstract Eucalypts from the subgenus Monocalyptus tend to be more abundant and dominate species from the subgenus Symphyomyrtus where they occur together in the mixed species stands of southeastern Australia. The differential impacts of herbivory by phytophagous insects has been postulated as a causal mechanism in the creation and maintenance of such stands. This research aimed to quantify phytophagous insect abundance and herbivory in mixed species juvenile regrowth of Eucalyptus globulus, E. viminalis (Symphyomyrtus), E. obliqua and E. pulchella (Monocalyptus} southwest of Hobart, Tasmania. Monocalyptus experienced a higher level of herbivory than Symphyomyrtus. However, mean damage levels were relatively low at less than 11% throughout. Furthermore, due to the positively skewed nature of herbivory data the mean was an inappropriate measure of central tendency; median damage levels ranged from 4.9% to 8.4%. Patterns of herbivory tended to be different for each eucalypt species: E. obliqua was particularly prone to chewing damage, E. pulchella and E. globulus suffered higher levels of distortion while E. viminalis was least affected by insect attack. Even though some trends in insect community structure seemed apparent at the level of eucalypt subgenus, closer examination revealed patterns of abundance were characteristic of each Eucalyptus species. The composition of foliar damage corresponded with the prominence of particular insect groups. Sucking insects tended to dominate the fauna except on E. obliqua where chewing insects in general, and chrysomelids in particular, were most prevalent. Both the distribution and magnitude of herbivory suggested that phytophagous insects had a negligible effect on competition between coexisting juvenile eucalypts and were unlikely to be responsible for the dominance of Monocalyptus or the maintenance of mixed species stands.     

Origin of the subgeneraCyclampterium, Paralampterium andSciadiopeplus fromLophocyrtis (Lophocyrtis) (Radiolaria, Theoperidae)

Work on the exceptionally well-preserved, rapidly accumulating Bath Cliff Section, Barbados and supplementary Deep Sea Drilling Project samples, has revealed the evolutionary origins of three stratigraphically useful species in theCryptoprora ornata Zone straddling the Eocene/Oligocene boundary and demonstrated the origin of the genusCyclampterium. Elucidation of the origin ofCyclampterium milowi necessitates a revision of the generaLophocyrtis andCyclampterium.Lophocyrtis (Lophocyrtis)jacchia is the ancestor ofL. (Cyclampterium)hadra, the earliest member in the subgenusCyclampterium which comprises the anagenetic lineage leading fromL. (C.)hadra toL. (C.)neatum. The monotypic subgenusSciadiopeplus branches off from an early member in theCyclampterium lineage. The new speciesL. (L.)exitelus andL. (S.)oberhaensliae terminate the subgeneraLophocyrtis andSciadiopeplus, respectively. During the investigation it also became clear that morphotypes resembling earlyL. (C.)milowi could be found in mid and high latitude assemblages in the late Early and late Middle Eocene. The origin of one these morphotypes was also traced toL. (Lophocyrtis)jacchia giving rise to the new subgenusParalampterium. This lineage includes the new speciesL. (Paralampterium)dumitricai and two species questionably assigned to it,L. (Paralampterium)?longiventer and the new speciesL. (Paralampterium) ?galenum. The relationship ofL. (P.)dumitricai toL. (P.) ?longiventer andL. (P.) ?galenum is unknown.     

Mitochondrial DNA evolution in theobscura species subgroup ofDrosophila

Summary Mitochondrial DNA (mtDNA) restriction site maps for nine species of theDrosophila obscura subgroup and forDrosophila melanogaster were established. Taking into account all restriction enzymes (12) and strains (45) analyzed, a total of 105 different sites were detected, which corresponds to a sample of 3.49% of the mtDNA genome. Based on nucleotide divergences, two phylogenetic trees were constructed assuming either constant or variable rates of evolution. Both methods led to the same relationships. Five differentiated clusters were found for theobscura subgroup species, one Nearctic, represented byDrosophila pseudoobscura, and four Palearctic, two grouping the related triads of speciesDrosophila subobscura, Drosophila madeirensis, Drosophila guanche, andDrosophila ambigua, Drosophila obscura, Drosophila subsilvestris, and two more represented by one species each,Drosophila bifasciata, andDrosophila tristis. The different Palearctic clusters are as distant between themselves as with the Nearctic one. For the related speciesD. subobscura, D. madeirensis, andD. guanche, the pairD. subobscura-D. madeirensis is the closest one. The relationships found by nucleotide divergence were confirmed by differences in mitochondrial genome size, with related species sharing similar genome lengths and differing from the distant ones. The total mtDNA size range for theobscura subgroup species was from 15.5 kb forD. pseudoobscura to 17.1 forD. tristis.     

A revision of epidendrum subgenus epidanthus (Orchidaceae)

Epidendrum subgenusEpidanthus (L. O. Williams) Barringer (Orchidaceae) is a group of small, slender-stemmed epiphytes formerly classified in the genusEpidanthus L. O. Williams. The seven species are distributed from southern Mexico to Columbia in wet forests, usually above 1000 m in elevation. Species of subgenusEpidanthus are distinguished from the rest ofEpidendrum by their linear leaves, slender stems, and two pollinia. The new speciesEpidendrum aurigineum is described and the new nameEpidendrum, insolatum is created forE. crassum (Dressler) Mora-Retana & J. García.     

Intragenomic movement,sequence amplification and concerted evolution in satellite DNA in harvest mice,Reithrodontomys: Evidence from in situ hybridization

Three DNA probes isolated from three species ofReithrodontomys (R. montanus, R. megalotis, R. fulvescens) were used to examine within and among species variation in the chromosomal location of satellite DNA and constitutive heterochromatin. These probes hybridized to the centromeric regions on all chromosomes in six species of the subgenusReithrodontomys. Additionally, nearly all extra-centromeric C-band positive regions (with the exception of some heterochromatic material on the X and Y) hybridized to these probes. Within the subgenusReithrodontomys both the chromosomal distribution and organization of satellite DNA has changed throughout evolution. The evolutionary transition has been from a totally centromeric position inR. fulvescens to centromeric and non-centromeric regions in other species that have undergone extensive chromosomal rearrangements from the primitive karyotype for peromyscine rodents. In addition, the monomer repeat of the satellite sequence differs betweenR. fulvescens (monomer defined by PstI) and the remaining species in the subgenusReithrodontomys (monomer defined by EcoRI). These results suggest at least two amplification events for this satellite DNA sequence. Models and mechanisms concerned with the homogenization and spread of satellite sequences in complex genomes are evaluated in light of theReithrodontomys data. From a phlyogenetic standpoint, the satellite sequences composing heterochromatic regions were restricted to the subgenusReithrodontomys, which supports morphological differences used to recognize two subgenera,Reithrodontomys andAporodon. Probes failed to hybridize to any part of the karyotype ofR. mexicanus (subgenusAporodon) or to seven species from other closely related genera (Baiomys, Neotoma, Nyctomys, Ochrotomys, Onychomys, Peromyscus, Xenomys), some of which are considered as potential sister taxa forReithrodontomys.     

Glycerol-3-phosphate dehydrogenase (G-3-PDH; EC 1.1.1.8) variation in Brazilian stingless bees and in wasp species

In only 1 bee species(Tetragona clavipes) of 24 sampled in 145 colonies (0.69%) did we detect the presence of more than one allele for glycerol-3-phosphate dehydrogenase (EC 1.1.1.8), an enzyme that is involved in flight. In 34 colonies containing 9 wasp species, 5 colonies of only 2 species(Polybia paulista andP. sericea) showed variation in larval G-3-PDH (14.7%). The small amount of variation observed for theG-3-PDH-1 locus in the bee and wasp species analyzed in the present study agrees with that reported for the G-3-PDH system in other insects.Research supported by FAPESP and CNPq-PIG IV.     

Evidence from RAPD markers in the evolution ofEchinochloa millets (Poaceae)

Echinochloa (Poaceae) includes two domesticated species,Echinochloa utilis (Japanese barnyard millet) andE. frumentacea (Indian sawa millet) and 20–30 wild species. The two millets are morphologically very variable and overlap in spikelet and inflorescence characteristics. Both species are hexaploids based on x = 9. Cytogenetic studies point to the hexaploid wild speciesE. crusgalli andE. colona as possible progenitors ofE. utilis andE. frumentacea, respectively. The tetraploidE. oryzoides is considered as a possible genome donor to wild and domesticated barnyard millet. Markers from Random Amplified Polymorphic DNA method were used to assess the proposed phylogeny and examine the genetic diversity in both domesticated and wild species. The data were analyzed numerically.Echinochloa utilis andE. frumentacea appear very distinct, but grouped withE. crusgalli andE. colona, respectively. The tetraploidE. oryzoides show strong genetic affinity to theE. utilis—E. crusgalli group. The data are in general agreement with the cytogenetic information; however, some disagreements on the interpretation of some of the cytogenetic information is raised. The variability in DNA markers observed in the domesticated species, particularlyE. frumentacea, points to the feasibility of using RAPD markers in cultivar fingerprinting and breeding programs of these millets.     

The distribution of P-element sequences inDrosophila: Thewillistoni andsaltans species groups

Summary This report describes the distribution of P-element sequences among members of the closely relatedwillistoni andsaltans species groups of the subgenusSophophora. Gel-blotting analyses showed that many, but not all, species from each of these groups possess sequences with homology to the P transposable element ofDrosophila melanogaster, a sophophoran species belonging to themelanogaster species group. Furthermore, P-homologous fragments are present in lower numbers inwillistoni- andsaltans-group species than inD. melanogaster P strains, and, in some species of those two groups, exhibit species-characteristic hybridization patterns. On the basis of these results, it is proposed that P elements have had a long evolutionary history in thewillistoni andsaltans lineages.     

Molecular phylogeny and evolution of the AsianAconitum subgenusAconitum (Ranunculaceae)

Classification of the genusAconitum (Ranunculaceae) has long been considered quite difficult because its species show high levels of morphological and ecological variability. The molecular phylogeny of Asian aconites,Aconitum subgenusAconitum was, therefore, studied based on RFLP and sequences of the intergenic spacer between thetrnL (UAA) 3′ exon andtrnF (GAA), and of thetrnL intron, of the chloroplast DNA. UsingAconitum subgenusLycoctonum as an outgroup, we obtained a statistically reliable molecular tree composed of six clades branched radiatively at the very base. There are three clades of Japanese aconites, a single clade of the species of Yunnan and Himalayas, and two clades of Siberian plants. All the tetraploid taxa of Japan we studied did not show any difference based on the molecular characters analyzed, though they have been classified into many taxa. Evolution and phytogeography of the Asian aconites as well as the phylogeny are discussed.     

Giemsa C-banded karyotypes and taxonomic relationships of some North AmericanAllium species and their relationship to Old World species (Liliaceae)

The somatic karyotypes of six North AmericanAllium species and the EuropeanA. scorzonerifolium have been investigated using a Giemsa C-banding technique. All species have a chromosome number of 2n = 14. InA. scorzonerifolium and the three North American speciesA. dichlamydeum, A. fibrillum andA. unifolium C-bands are restricted to two pairs of nucleolar chromosomes. Each chromosome has a band proximal to the nucleolar constriction and a positively banded satellite. InA. acuminatum, in addition to the bands associated with the nucleolar constrictions, all chromosomes also have pericentromeric bands.A. cernuum exhibits a distinctive banding style: two chromosome pairs with bands adjacent to the nucleolar constrictions and four pairs with telomeric bands on their short arms. In the karyotype ofA. geyeri neither C-bands nor nucleolar chromosomes were found.—A comparison of the banding styles together with other cytological and morphological characters of these species with old world members ofAllium reveals:A. cernuum closely resembles species within subgenusRhizirideum, whereas the other species studies exhibit many similarities with subgenusMolium. Their sectional grouping and their relationships with Old World species are discussed.     

On the taxonomy of theDaphnia hyalina-galeata complex (Crustacea: Cladocera)

Populations of theDaphnia hyalina-galeata complex from Central, North and South Europe have been compared morphologically. The main purpose of this investigation is delimitation of the critical speciesDaphnia galeata, based on a thorough examination of the original materials from G. O. Sars' collection, and taking into account hitherto overlooked or insufficiently appreciated characters. According to their morphology and ecology,Daphnia hyalina, Daphnia galeata andDaphnia cucullata have to be treated taxonomically as separate species. In view of the short and high antennula mound and other morphological characteristics,Daphnia gracilis Hellich andDaphnia hyalina lacustris sensu Lilljeborg belong to the speciesDaphnia galeata. In the common range ofDaphnia galeata andDaphnia cacullata there occurs quite frequently an intermediary form, which according to genetic evidence is a hybrid of these two species. Although apparently this hybrid form is stabilized genetically to a large extent and is capable of identical reproduction, it should not be considered as a species in the usual sense.The present work intends to put the notoriously confused systematics of theDaphnia hyalina-galeata complex on a firm basis. It concludes with a key, which should enable also non-specialists to identify uniquely the three species and the hybrid form in question.     

Phylogenetic relationships in the genera<Emphasis Type="Italic"> Zostera</Emphasis> and<Emphasis Type="Italic"> Heterozostera</Emphasis> (Zosteraceae) based on<Emphasis Type="Italic"> matK</Emphasis> sequence data

Phylogenetic analysis of the plastid (chloroplast) DNA matK gene of Zosteraceae species was undertaken. A molecular phylogenetic tree based on matK sequence data showed the monophyly of Heterozostera tasmanica and subgenus Zosterella and did not support the separation of Heterozostera from the genus Zostera. The tree based on matK supported the monophyly of the subgenus Zostera, and showed that Zosteraceae consist of three main groups: Phyllospadix, which is clearly defined by being dioecious; the subgenus Zosterella and Heterozostera; and the subgenus Zostera. Character-state reconstruction of chromosome number and geographic distribution for our molecular phylogenetic tree showed that 2n=12 is a plesiomorphic character for Zostera and Heterozostera, that the chromosome number was doubled or tripled in two lineages, and that the initial speciation of Zostera and Heterozostera occurred in the Northern Hemisphere. The matK tree showed the close affinity of Z. noltii and Z. japonica, which have disjunct distributions. Zostera marina, which is the only widely distributed species in the subgenus Zostera, also occurring in the northern Atlantic, was shown to be embedded within other subgenus Zostera species.     

Four new species Of Mexican Castilleja (subgenus Castilleja,Scrophulariaceae) and their relatives

Castilleja subgenusCastilleja in the northern half of Mexico consists of nine species, which are treated here. The subgenus is characterized by a conspicuously colored calyx that is much more deeply cleft in front (abaxially) than in back (adaxially).Castilleja rhizomata,C. linifolia,C. mcvaughii, andC. pterocaulon are described as new, and are illustrated and mapped. The first three are compared toC. patriotica and C.tenuiflora, their closest relatives in the Tenuiflorae group, and the fourth is compared toC. ortegae, with which it constitutes the Ortegae group.Castilleja roei andC. tenuifolia of the Epichroma group are included in order to complete the census of subgenusCastilleja as encountered in the region of the new species. A key to the nine species of subgenusCastilleja from the northern half of Mexico is provided.     

Defoliation effects on the community structure of arbuscular mycorrhizal fungi based on 18S rDNA sequences

The effects of defoliation on arbuscular mycorrhizal (AM) associations in the field were investigated in terms of the community structure of AM fungi colonizing roots of grassland plants; the carbohydrate balance of the host plants was also determined. We focused on two plant species dominating Japanese native grasslands: the grazing-intolerant species Miscanthus sinensis and the grazing-tolerant species Zoysia japonica. Community structures of AM fungi were determined from 18S rRNA gene sequences. The dominant fungal group in both plant species was the Glomus clade, which was classified into several phylogenetic groups based on genetic distances and topology. In Miscanthus roots, the Glomus-Ab, Glomus-Ac, and Glomus-Ad groups were detected almost equally. In Zoysia roots, the Glomus-Ab group was dominant. Defoliation effects on the community structure of AM fungi differed between the plant species. In Miscanthus roots, the percentage of root length colonized (%RLC) by the Glomus-Ac and Glomus-Ad groups was significantly reduced by defoliation treatment. On the other hand, AM fungal group composition in Zoysia roots was unaffected by defoliation except on the last sampling date. Decreased %RLC by Glomus-Ac and Glomus-Ad coincided with decreased non-structural carbohydrate (NSC) levels in host plants; also, significant positive correlations were found between the %RLC and some NSC levels. On the other hand, the %RLC by Glomus-Ab in both plant species was unaffected by the NSC level. These results suggest that AM fungal groups have different carbohydrate requirements from host plants.Electronic Supplementary Material Supplementary material is available in the online version of this article at http://dx.doi.org/10.1007/s00572-003-0286-x     

Repeated DNA sequences and species relatedness in the genusEquisetum

The kinetics with which DNA reassociates and the thermal stability of rapidly reassociating (repetitive) DNA sequences have been monitored for six species in the genusEquisetum. Using the kinetic complexity for each of two repeated DNA sequence components as the basis for comparison, species in the subgenusEquisetum (E. arvense, E. fluviatile andE. telmateia) form one group and species in the subgenusHippochaete (E. hyemale, E. laevigatum andE. scirpoides) form another group. Using the difference in thermal stability between native and reassociated repetitive DNA for comparison, the same grouping of species is obtained.     

Comparative embryology of threeGentianaceae species from the Central Caucasus and the European Alps

A comparative investigation was carried out on the ovule and seed development of three mountain species ofGentianaceae, the perennial speciesGentiana pyrenaica, and the two short-lived monocarpic speciesGentianella caucasea andG. germanica. In all three species most embryological characters conform to those generally found in the family of theGentianaceae. In some features, however,G. pyrenaica and the twoGentianella species differ from each other. InG. pyrenaica the ovule is anatropous, the integument 8–10 layered and the three reduced antipodals degenerate soon after fertilization. In contrast,G. caucasea andG. germanica form a hemitropous ovule, a 4–5 layered integument and up to 16 antipodal cells by secondary multiplication. All three species exhibit differences in synchronization between embryogenesis and endosperm development. Functional relations between the antipodal structure and the dynamics of seed development of the investigated species are postulated.     

Aechmea itapoana,a new species from Bahia (Brazil): Taxonomy and ecology

Aechmea itapoana is a new, conspicuous and distinct species from the coastal sand dune scrub of N.E. Brazil. Its possible relationships within subgenusChevaliera, toA. multiflora andA. rodriguesia are discussed.     

Mortality of lignotuberous seedlings of Eucalyptus species after an intense fire in montane forest

The survival of lignotuberous seedlings of Eucalyptus pauciflora, E. dalrympleana and E. dives following an intense experimental fire was monitored in montane forest in the Brindabella Ranges, Australian Capital Territory. Percentage survival was the same for each species (60%), but it was shown that an individual was more likely to survive if it was large and growing vigorously before the fire. Survival was also enhanced if the individual was growing in a patch of low litter load and if it experienced a locally low fire intensity. Lignotuberous seedlings of E. dalrympleana, a species of the subgenus Symphyomyrtus, recovered more quickly than the other two species which are of the subgenus Monocalyptus. This result parallels conclusions concerning different initial growth rates between seedlings of the subgenera.     

The β-tubulin gene family evolution in theDrosophila montium subgroup of themelanogaster species group

The 1-, 2-, and 3-tubulin genes have been mapped by in situ hybridization on the polytene chromosomes of 11 selected species (15 strains) belonging to theDrosophila montium subgroup. Although the hybridization pattern among the strains of the same species does not differ, this pattern is significantly different among the species. The -tubulin genes in themontium subgroup seem to be organized in a cluster, or in a semi-cluster, or are completely dispersed. The clustered arrangement is found in the North-Oriental sibling speciesD. auraria, D. triauraria, andD. quadraria. The semi-clustered arrangement, wherein the 1 and 2 genes are located at the same locus while 3 is at a different one, appears in the South-Oriental speciesD. bicomuta, D. serrata, andD. birchii, as well as in the Afrotropical speciesD. diplacantha andD. seguyi. The complete separation of the genes is observed in the Indian speciesD. kikkawai andD. jambulina and in the Afrotropical speciesD. vulcana. Based on the above results, a possible mode of evolution of the -tubulin genes in the montium subgroup is attempted. In addition, phylogenetic relationships among themontium species are discussed. Correspondence to: Z.G. Scouras     

A cladistic study of Arillastrum, Angophora and Eucalyptus (Myrtaceae)

A cladistic study of Anllastrum, Angophora and Eucalyptus (Myrtaceae). Transformed cladistic; character compatibility; branch and bound, and Farris-Wagner methods gave similar solutions in a cladistic study of Arillastrum, Angophora and Eucalyptus. These analyses, based on morphological characters, indicate that Eucalyptus is a monophyletic group and that its sister taxon is Angophora.
Within Eucalyptus , subgenera Blakella and Corymbia are sister taxa to all other groups; subgenera Monocalyptus, Idiogenes and Gaubaea form a monophyletic group with subgenus Monocalyptus sister to subgenera Idiogenes and Gaubaea ; subgenera Symphyomyrtus and Telocalyptus together also form a monophyletic group and, with Eucalyptus similis (subgenus Eudesmia group 4), are sister to the Monocalyptus group. Eucalyptus subgenus Telocalyptus (4 species), Eucalyptus subgenus Idiogenes (1 species) and Eucalyptus subgenus Gaubaea (2 species) should not be recognized as subgenera and some individual species need further examination. Eucalyptus subgenus Eudesmia is a paraphyletic group.
Some characters are identified as parallelisms, e.g. axillary inflorescences, sepaline operculum, bristle glands, and clustered anthers. A more congruent interpretation of the single operculum of Eucalyptus subgenus Monocalyptus as at least partly petaline rather than solely sepaline in origin is suggested.
The area relationships for the taxa are concordant with those derived from geological and climatological information. New Caledonia is sister area to Australia, and within Australia southwestern Australia is sister area to south-eastern and north-eastern Australia.