Molecular phylogeography and the evolution and conservation of Amazonian mammals

The phylogeographic structure of 15 genera of Amazonian marsupials and rodents is summarized based on comparative sequence of the mitochondrial cytochrome b gene. The data are limited in geographical coverage, with samples widely scattered throughout Amazonia from the base of the Andes in Peru to the Guianan coast and eastern Brazil. We use this approach to define species boundaries, based minimally on the principle of reciprocal monophyly, in conjunction with morphological or other genetic discontinuities. The taxa so defined are older than previously appreciated, with many lineages dating from 1 to more than 3 Myr, and thus apparently predating the early Pleistocene. We relate patterns of concordant geographical shifts with underlying tectonic history and to current positions of major rivers. Finally, we provide comments on the utility of these data and patterns to conservation, articulating a need to incorporate phylogeographic information as part of the rationale in establishing conservation priorities at the organismal and geographical area levels.     

Membrane-Associated Polysaccharides Composition, Nutritional Requirements and Cell Differentiation in Herpetomonas roitmani: Influence of the Endosymbiont

Herpetomonas roitmani , a trypanosomatid containing a bacterial endosymbiont, was cured by high doses of chloramphenicol. Wild-type and cured flagellates were compared as to polysaccharide composition, nutritional requirements and cellular differentiation. Fucose (18.0%), xylose (15.7%), mannose (38.9%), galactose (10.8%), glucose (16.4%) and inositol (< 1.0%) were identified as polysaccharide components of cured H. roitmani as assessed by gas-liquid chromatography. However, the wild-type strain displayed a markedly different sugar profile, in that xylose was absent and inositol preferentially synthesized, whereas the other monosaccharide components remained unchanged. Variations in nutritional pattern also occurred between both strains. The bacterial endosymbiont seems to provide the flagellates with nutritional factors, including usual amino acids, vitamins, purine (as adenine) and hemin. The process of cell differentiation was also significantly influenced by the endosymbiont. Opisthomastigote forms predominate (72.0%) in cured as compared with wild-type H. roitmani (37.0%).     

STUDIES IN THE INTERACTIONS BETWEEN SPECIES OF VERTICILLIUM

It is shown that five parasitic species of Verticillium , viz. V. alboatrum, V. Dahliae, V. ticorpus, V. nigrescens and V. nubilum , developed together on agar media or wheat grains as saprophytes without causing mutual antagonism but, when these were injected together, as a mixed spore suspension, into antirrhinum and tomato, suppression of V. tricorypus, V. nigescens and V. nubilum by either one or other of the remaining two invariably resulted. The two most virulent pathogens, V. alboatrum and V. Dahliae , were not recoverable from soil after the elapse of 6 months from the time of inoculation; while the other three less virulent pathogens could be isolated after about 12 months in the soil. It is concluded that V. alboatrurn and V. Dahliae may be described as 'root inhabiting' and V. nigrescens and V. nubilurn as 'soil inhabiting', while V. tricorpus may be considered as an intermediate type.     

Host/parasite relations up to the time of tuber initiation in potato plants infected with Verticillium spp

The growth pattern of potato plants, infected with V. albo-atrum and V. dahliae, was studied, using growth-analysis techniques, during the initial stages of development up to tuber initiation. During the first 5–6 weeks of growth the morphology of the infected plants was not affected, but the distribution of dry weight materials between various plant organs and the growth rates of the whole plants were affected much sooner. In contrast to healthy plants, those infected exhibited lower specific leaf areas, higher leaf weight ratios and higher leaf area ratios, and, under dry conditions, lower relative growth rates and lower unit leaf rates. Thus during the incubation phase of the disease, although effects of infection are not immediately apparent, Verticillium pathogens have a considerable influence upon the development of the host.     

Effect of main stem number and lateral stem development in potato plants infected with Verticillium albo-atrum and V. dahliae

‘Early-dying’ disease was examined in potato plants (King Edward) with varying numbers of main stems and lateral stems. Infection with Verticillium affected neither the number of main stems produced nor the stem number/ lateral number/yield inter-relationships, but did slightly reduce lateral development. The host growth pattern, however, markedly influenced the severity of disease: infected plants with a single main stem or a few, compared with those having many main stems, showed delayed symptom expression and also produced many laterals which further reduced disease severity and increased longevity. Thus yield reductions as a result of infection are likely to be smaller in single-stemmed plants showing considerable lateral development than in those plants with many main stems and few or no laterals.     

Isolation and characterization of polymorphic microsatellite loci in the scarlet ibis (Eudocimus ruber— Threskiornithidae‐Aves)

Here we presented 10 polymorphic microsatellite loci obtained from scarlet ibis through an enriched genomic library. The analysis of 45 individuals from three Brazilian natural populations showed allelic diversity ranged from three to 17 alleles, observed heterozygosity ranged from 0.03 to 0.92, and expected heterozygosity ranged from 0.06 to 0.92. These highly variable microsatellite loci can provide means for assessing overall genetic variation in its remnant natural populations, which may help the development of effective conservation programs.     

Molecular phylogeny and systematics of leaf‐mining flies (Diptera: Agromyzidae): delimitation of Phytomyza Fallén sensu lato and included species groups,with new insights on morphological and host‐use evolution

Abstract Phytomyza Fallén is the largest genus of leaf‐mining flies (Agromyzidae), with over 530 described species. Species of the superficially similar genus Chromatomyia Hardy have been included in Phytomyza by some authors and the status of the genus remains uncertain. Using 3076 bp of DNA sequence from three genes [cytochrome oxidase I (COI), CAD (rudimentary), phosphogluconate dehydrogenase (PGD)] and 113 exemplar species, we identified and tested the monophyly of host‐associated species groups in Phytomyza and Chromatomyia and investigated the phylogenetic relationships among these groups. Chromatomyia is polyphyletic and nested largely within Phytomyza; two small groups of species, however, are related more closely to Ptochomyza and Napomyza. Therefore, we synonymize Chromatomyia syn.n. , Ptochomyza syn.n. , and Napomyza syn.n. with Phytomyza, recognizing Ptochomyza, Napomyza and Phytomyza sensu stricto as subgenera of Phytomyza. We recognize five major clades within Phytomyza sensu stricto that comprise the majority of species ascribed previously to Chromatomyia and Phytomyza. Many species groups recognized previously were recovered as monophyletic, or virtually so, but some (e.g. robustella and atomaria groups) required emendation. On the basis of the proposed phylogeny and recent taxonomic literature, we present a preliminary revision of 24 species groups within Phytomyza, but leave many species unplaced. Evolution of internal pupariation (within the host’s tissue), regarded as a defining character of the former Chromatomyia, is discussed with regard to the new phylogeny, and we suggest a correlation with stem or leaf midrib mining. The large size of the Phytomyza lineage and an inferred pattern of host family‐specific species radiations make it a promising candidate for the study of macroevolutionary patterns of host shift and diversification in phytophagous insects. The proposed generic synonymies necessitate a number of new combinations. The following 46 species described in Chromatomyia are transferred to Phytomyza: P. actinidiae (Sasakawa) comb.n. , P. alopecuri (Griffiths) comb.n. , P. arctagrostidis (Griffiths) comb.n. , P. beigerae (Griffiths) comb.n. , P. blackstoniae (Spencer) comb.n. , P. centaurii (Spencer) comb.n. , P. chamaemetabola (Griffiths) comb.n. , P. cinnae (Griffiths) comb.n. , P. compta (Spencer) comb.n. , P. cygnicollina (Griffiths) comb.n. , P. doolittlei (Spencer) comb.n. , P. elgonensis (Spencer) comb.n. , P. eriodictyi (Spencer) comb.n. , P. flavida (Spencer) comb.n. , P. fricki (Griffiths) comb.n. , P. furcata (Griffiths) comb.n. , P. griffithsiana (Beiger) comb.n. , P. hoppiella (Spencer) comb.n. , P. ixeridopsis (Griffiths) comb.n. , P. kluanensis (Griffiths) comb.n. , P. leptargyreae (Griffiths) comb.n. , P. linnaeae (Griffiths) comb.n. , P. luzulivora (Spencer) comb.n. , P. mimuli (Spencer) comb.n. , P. mitchelli (Spencer) comb.n. , P. montella (Spencer) comb.n. , P. nigrilineata (Griffiths) comb.n. , P. nigrissima (Spencer) comb.n. , P. orbitella (Spencer) comb.n. , P. paraciliata (Godfray) comb.n. , P. poae (Griffiths) comb.n. , P. pseudomilii (Griffiths) comb.n. , P. qinghaiensis (Gu) comb.n. , P. rhaetica (Griffiths) comb.n. , P. scabiosella (Beiger) comb.n. , P. seneciophila (Spencer) comb.n. , P. shepherdiana (Griffiths) comb.n. , P. spenceriana (Griffiths) comb.n. , P. styriaca (Griffiths) comb.n. , P. subnigra (Spencer) comb.n. , P. suikazurae (Sasakawa) comb.n. , P. symphoricarpi (Griffiths) comb.n. , P. syngenesiae (Hardy) comb.n. , P. thermarum (Griffiths) comb.n. , P. torrentium (Griffiths) comb.n. and P. tschirnhausi (Griffiths) comb.n. Furthermore, we transfer all species of Napomyza to Phytomyza, resulting in the following new combinations: P. achilleanella (Tschirnhaus) comb.n. , P. acutiventris (Zlobin) comb.n. , P. angulata (Zlobin) comb.n. , P. arcticola (Spencer) comb.n. , P. bellidis (Griffiths) comb.n. , P. carotae (Spencer) comb.n. , P. cichorii (Spencer) comb.n. , P. curvipes (Zlobin) comb.n. , P. dubia (Zlobin) comb.n. , P. filipenduliphila (Zlobin) comb.n. , P. flavivertex (Zlobin) comb.n. , P. flavohumeralis (Zlobin) comb.n. , P. genualis (Zlobin) comb.n. , P. grandella (Spencer) comb.n. , P. humeralis (Zlobin) comb.n. , P. immanis (Spencer) comb.n. , P. immerita (Spencer) comb.n. , P. inquilina (Kock) comb.n. , P. kandybinae (Zlobin) comb.n. , P. lacustris (Zlobin) comb.n. , P. laterella (Zlobin) comb.n. , P. manni (Spencer) comb.n. , P. maritima (Tschirnhaus) comb.n. , P. merita (Zlobin) comb.n. , P. mimula (Spencer) comb.n. , P. minuta (Spencer) comb.n. , P. montanoides (Spencer) comb.n. , P. neglecta (Zlobin) comb.n. , P. nigriceps (van der Wulp) comb.n. , P. nugax (Spencer) comb.n. , P. pallens (Spencer) comb.n. , P. paratripolii (Chen & Wang) comb.n. , P. plumea (Spencer) comb.n. , P. plumigera (Zlobin) comb.n. , P. prima (Zlobin) comb.n. , P. pubescens (Zlobin) comb.n. , P. schusteri (Spencer) comb.n. , P. scrophulariae (Spencer) comb.n. , P. suda (Spencer) comb.n. , P. tanaitica (Zlobin) comb.n. , P. tenuifrons (Zlobin) comb.n. , P. vivida (Spencer) comb.n. , P. xizangensis (Chen & Wang) comb.n. and P. zimini (Zlobin) comb.n. Phytomyza asparagi (Hering) comb.n. and P. asparagivora (Spencer) comb.n. are transferred from Ptochomyza. In Phytomyza ten new names are proposed for secondary homonyms created by generic synonymy: P. echo Winkler nom.n. for P. manni Spencer, 1986; P. californiensis Winkler nom.n. for C. montana Spencer, 1981 ; P. griffithsella Winkler nom.n. for C. griffithsi Spencer, 1986; P. vockerothi Winkler nom.n. for C. nigrella Spencer, 1986; P. kerzhneri Winkler nom.n. for N. nigricoxa Zlobin, 1993; P. asteroides Winkler nom.n. for N. tripolii Spencer, 1966; P. minimoides Winkler nom.n. for N. minima Zlobin, 1994; P. nana Winkler nom.n. for N. minutissima Zlobin, 1994; P. ussuriensis Winkler nom.n. for N. mimica Zlobin, 1994 and P. zlobini Winkler nom.n. for N. hirta Zlobin, 1994.     

The vestured pits of Eucalyptus regnans F. Muell.: a study using scanning electron microscopy

Scanning electron microscopy has been used to examine the surface architecture, before and after various chemical treatments, of the pits in the walls of vessels, vasicentric and fibre tracheids, and parenchyma cells, which together make up the wood of Eucalyptus regnans. The treatments included water at 150°C under pressure, hydrofluoric acid, delignifying agents and potassium permanganate. All bordered pits were vestured; half-bordered pits were vestured, partially vestured or non-vestured. No distinction could be made between warts and vestures on morphological or chemical grounds. An hypothesis is advanced which relates vesture formation to prolongation of the activity of the protoplast in pits as the cells die. Vestures, on the basis of this hypothesis, could be regarded as enlarged or conglomerate warts.