Aspects of the Cryobiology of the Intertidal Harpacticoid CopepodTigriopus brevicornis(O. F. Müller)

Cold-resistance studies of marine invertebrates have concentrated on intertidal sedentary organisms, which are often subjected to subzero air temperatures in winter. Mobile rock pool inhabitants have been rarely studied because such habitats are thought to buffer environmental variation. However, it is not uncommon for small upper-shore rock pools ( approximately 2 by 1 cm) to become completely frozen. Such supralittoral habitats are subject to extreme physicochemical fluctuations especially in salinity (0 to 300 per thousand) and temperature (-1 to +32degreesC) due to evaporation and dilution. The dominant invertebrate in such habitats is the harpacticoid copepod Tigriopus brevicornis. Aspects of the cryobiology of T. brevicornis were investigated using differential scanning calorimetry (DSC). Thermograms obtained from DSC allowed determinations of freeze-onset (supercooling point, SCP), melt-onset, and melt-peak (melting point, MP) temperatures, together with estimation of the proportion of water freezing in the samples. The effects of acclimation salinity, temperature, starvation, and reproductive state on these cryobiological parameters were investigated. Acclimation to increasing salinity depressed the SCP, with the highest salinity (70 per thousand) producing the lowest SCP, melt-onset, and MP temperatures at -27.5, -15.2, and -9.5degreesC respectively. The highest acclimation temperature (20degreesC) produced the lowest SCP (-23.4degreesC). Starvation significantly increased the SCP, melt-onset, and MP temperatures in comparison to fed individuals acclimated to the same salinity. The presence of eggs or ovaries in individual copepods elevated the SCP compared to nongravid females and males. LT50 studies showed that acclimation to high salinity improved the ability of T. brevicornis to survive in frozen seawater. Seventy parts per thousand acclimated individuals had an LT50 of 64.9 h compared with just 1.4 h for 5 per thousand acclimated individuals in frozen seawater at -5degreesC. The study shows that the cold-resistance capabilities of T. brevicornis can be affected by several different factors, and the link between the osmoconforming nature of this species and its cold resistance is discussed. Copyright 1997 Academic Press. Copyright 1997Academic Press     

Biological control of brown rot (Moniliana laxa Ehr.) on apricot (Prunus armeniaca L. cv. Hacıhaliloğlu) by Bacillus, Burkholdria, and Pseudomonas application under in vitro and in vivo conditions

In 2002 and 2003, a study was conducted to determine the effect of bacterial strains, Burkholdria OSU 7, Bacillus OSU 142, and Pseudomonas BA 8, on biological control of brown rot disease (Monilinia laxa Ehr.) on apricot cv. Hacıhaliloğlu in Malatya province of Turkey. Apricot orchard at full blooming stage was inoculated with conidial suspension (1 × 10⁶ spores/ml) of M. laxa Ehr. After inoculation, two apricot trees for each application were treated with each of the three biological control agents (Burkholdria gladii OSU 7, Bacillus subtilis OSU 142, and Pseudomonas putida BA 8) by spraying (1 × 10⁹ cfu/ml) on inoculated branches. Disease incidence was evaluated for untreated (control 1) and four different treatment groups including commercial disease management (control 2, positive control: 3% Bourdox in fall, 50% Cupper at pink flower, 30 g/100 l Corus at first blooming, and 300 g/100 l Captan at last blooming stage) and treatments including each of the three bacterial strains (OSU 7, OSU 142, and BA 8). The results showed that disease incidence for negative control (control 1) was 9.94, which was significantly higher than disease incidence for commercial application (2.57%) or bacterial treatments (2.82–5.00%) in the first year. In 2003, the lowest disease incidence observed in OSU 7 treatment (6.80%), while disease incidence rate for positive control and negative control were 9.45% and 28.46%, respectively. This result may suggest that OSU 7 has potential to be used as biopesticide for effective management of brown rot disease on apricot.     

The phylogenetic placement of Ostropales within Lecanoromycetes (Ascomycota) revisited

Results of molecular studies regarding the phylogenetic placement of the order Ostropales and related taxa within Lecanoromycetes were thus far inconclusive. Some analyses placed the order as sister to the rest of Lecanoromycetes, while others inferred a position nested within Lecanoromycetes. We assembled a data set of 101 species including sequences from nuLSU rDNA, mtSSU rDNA, and the nuclear protein-coding RPB1 for each species to examine the cause of incongruencies in previously published phylogenies. MP, minimum evolution, and Bayesian analyses were performed using the combined three-region data set and the single-gene data sets. The position of Ostropales nested in Lecanoromycetes is confirmed in all single-gene and concatenated analyses, and a placement as sister to the rest of Lecanoromycetes is significantly rejected using two independent methods of alternative topology testing. Acarosporales and related taxa (Acarosporaceae group) are basal in Lecanoromycetes. However, if the these basal taxa are excluded from the analyses, Ostropales appear to be sister to the rest of Lecanoromycetes, suggesting different ingroup rooting as the cause for deviating topologies in previously published phylogenies.     

华北平原地区景观格局对麦田害螨种群数量的影响

农业生产的集约化经营导致农田景观格局日趋单一,而农田景观格局的变化势必对害虫种群产生深刻的影响,阐明景观因子对害虫种群的作用是通过生境管理进行害虫控制的基础。以华北平原地区的山东省为研究区域,24个县级单元为样点,通过对卫星遥感影像和土地覆盖分类数据的分析,获取了样点单元的景观格局指数,同时定点调查了样点单元的麦田害螨种群数量。利用相关性分析明确了影响麦田中两种害螨—麦岩螨(Petrobia latens(Müller))和麦圆叶爪螨(Penthaleus major(Duges))种群发生的主要景观因子。研究结果表明景观因子对麦田中两种害螨种群均有显著影响,而两种害螨对景观因子的响应并不一致。麦岩螨的发生量与森林的最大斑块面积指数和平均斑块面积均呈显著正相关,而与森林类的形状和水体的景观形状指数均存在显著负相关;麦圆叶爪螨的发生量同水体的总面积、斑块面积比例、最大斑块面积指数以及县域范围的平均斑块面积均呈显著负相关,而与水体类的形状呈显著正相关。因此在麦田害螨发生较重的地区,在区域性景观规划时,可以通过优化农田周围的森林和水体管理,不利于其种群发生,从而达到对麦田害螨种群生态调控的目的。     

Genome Analysis inNeurospora crassa;Cloning of Four Lociarginine-1(arg-1),methionine-6(met-6),unknown-7(un-7), andribosome production-1(rip-1) and Associated Chromosome Walking

We have cloned fourNeurospora crassagenes by complementation analysis. Cloned genes include thearginine-1(arg-1),methionine-6(met-6),unknown-7(un-7), andribosome production-1(rip-1) loci. Chromosome walks were initiated in ordered cosmid libraries from the cloned loci. A total of about 700 kb of theNeurosporagenome is covered in these walks.     

灰岩山姜，中国山姜属(姜科)一新记录种

报道了中国姜科山姜属植物1新记录种:灰岩山姜(Alpinia calcicola),并提供形态特征描述、地理分布及彩色图片。凭证标本保存在中国科学院华南植物园标本馆(IBSC)。     

Acaricidal activity of the essential oil from Tetradenia riparia (Lamiaceae) on the cattle tick Rhipicephalus (Boophilus) microplus (Acari; Ixodidae)

Tetradenia riparia (Lamiaceae) is a well-known herbal medicine with a variety of useful properties, including its acaricidal effect. This experiment was carried out to study the bioacaricidal activity of T. riparia essential oil (EO) against engorged females of Rhipicephalus (Boophilus) microplus (Acari; Ixodidae). For this purpose, nine serial concentrations (12.50%, 6.25%, 3.75%, 1.80%, 0.90%, 0.45%, 0.22%, 0.11%, and 0.056% w/v) of T. riparia were used for the adult immersion test (AIT). For the larval packet test (LPT), we used 14 serial concentrations (100.00%, 50.00%, 25.00%, 12.50%, 6.25%, 3.65%, 1.82%, 0.91%, 0.45%, 0.228%, 0.114%, 0.057%, 0.028%, and 0.014% w/v). The results for AIT showed 100.00% and 2.05% mortality, 19.00 and 90.20% for the total number of eggs, egg-laying inhibition of 0.00% and 90.20%, hatchability inhibition of 0.00% and 70.23%, and product effectiveness of 100.00% and 2.89%, respectively. The AIT indicated that the LC₅₀ and LC_99.9, calculated using the Probit test, were for mortality (%) 0.534 g/mL (0.436–0.632) and 1.552 g/mL (1.183–1.92); for total number of eggs were 0.449 g/mL (0.339–0.558) and 1.76 g/mL (1.27–2.248); and for hatchability inhibition were 0.114 g/mL (0.0–0.31) and 2.462 g/mL (1.501–3.422), respectively. Larvae between 14 and 21 days old were fasted and placed in each envelope. Bioassays were performed at 27° ± 1 °C, RH ? 80%. Larval mortality was observed 24 h after treatment and showed 10.60–100% mortality in the LPT bioassay. The LPT showed that the LC₅₀ and LC_99.9 were 1.222 g/mL (0.655–1.788) and 11.382 g/mL (7.84–14.91), respectively. A positive correlation between T. riparia EO concentration and tick control, was observed by the strong acaricidal effects against R. (B.) microplus, and the mortality rate of ticks was dose-dependent. Our results showed that T. riparia is a promising candidate as an acaricide against resistant strains of R. (B.) microplus.     

Effect of trypsin inhibitor from Crotalaria pallida seeds on Callosobruchus maculatus (cowpea weevil) and Ceratitis capitata (fruit fly)

A proteinaceous trypsin inhibitor was purified from Crotalaria pallida seeds by ammonium sulfate precipitation, affinity chromatography on immobilized trypsin-Sepharose and TCA precipitation. The trypsin inhibitor, named CpaTI, had M(r) of 32.5 kDa as determined by SDS-PAGE and was composed of two subunits with 27.7 and 5.6 kDa linked by disulfide bridges. CpaTI was stable at 50 degrees C and lost 40% of activity at 100 degrees C. CpaTI was also stable from pH 2 to 12 at 37 degrees C. CpaTI weakly inhibited chymotrypsin and elastase and its inhibition of papain, a cysteine proteinase, were indicative of its bi-functionality. CpaTI inhibited, in different degrees, digestive enzymes from Spodoptera frugiperda, Alabama argillacea, Plodiainterpunctella, Anthonomus grandis and Zabrotes subfasciatus guts. In vitro and in vivo susceptibility of Callosobruchus maculatus and Ceratitis capitata to CpaTI was evaluated. C. maculatus and C. capitata enzymes were strongly susceptible, 74.4+/-15.8% and 100.0+/-7.3%, respectively, to CpaTI. When CpaTI was added to artificial diets and offered to both insect larvae, the results showed that C. maculatus was more susceptible to CpaTI with an LD(50) of 3.0 and ED(50) of 2.17%. C. capitata larvae were more resistant to CpaTI, in disagreement with the in vitro effects. The larvae were more affected at lower concentrations, causing 27% mortality and 44.4% mass decrease. The action was constant at 2-4% (w/w) with 15% mortality and 38% mass decrease.     

Phylogenetic relationships of Ceratitis fruit flies inferred from nuclear CAD and tango/ARNT gene fragments: Testing monophyly of the subgenera Ceratitis (Ceratitis) and C. (Pterandrus)

Systematic studies of Ceratitis (Tephritidae) fruit flies using molecular (i.e., COI, ND6, and period genes) and morphological (plus host-use characters) data have recently challenged the monophyly of the subgenera Ceratitis (Ceratitis) and Ceratitis (Pterandrus). In this paper, we report on the phylogenetic utility of three single-copy nuclear gene regions (two non-overlapping fragments of the carbamoylphosphate synthetase, CPS, locus of CAD, and a fragment of tango) within these taxa and investigate evolutionary relationships based on a concatenated ca. 3.4 kb data set that includes the six protein encoding gene regions. Results indicate that the CAD and tango genes provide useful phylogenetic signal within the taxa and are compatible with the previously studied genes. The two subgenera, as currently classified, are not monophyletic. Our molecular phylogenetic analyses support a revised classification in which (1) the subgenus C. (Pterandrus) comprises two lineages called A and B, (2) the C. (Pterandrus) B species should be included in C. (Ceratitis), and (3) the newly defined subgenera C. (Pterandrus) (=Pterandrus section A) and C. (Ceratitis) [=C. (Ceratitis) + C. (Pterandrus) section B] are reciprocally monophyletic.     

Microcalorimetric studies of the interactions between cytochromes c and c1 and of their interactions with phospholipids

Thermotropic properties of purified cytochrome c₁ and cytochrome c have been studied by differential scanning calorimetry under various conditions. Both cytochromes exhibit a single endothermodenaturation peak in the differential scanning calorimetric thermogram. Thermodenaturation temperatures are ionic strength, pH, and redox state dependent. The ferrocytochromes are more stable toward thermodenaturation than the ferricytochromes. The enthalpy changes of thermodenaturation of ferro- and ferricytochrome c₁ are markedly dependent on the ionic strength of the solution. The effect of the ionic strength of solution on the enthalpy change of thermodenaturation of cytochrome c is rather insignificant. The formation of a complex between cytochromes c and c₁ at lower ionic strength causes a significant destabilization of the former and a slight stabilization of the latter. The destabilization of cytochrome c upon mixing with cytochrome c₁ was also observed at high ionic strength, under which conditions no stable complex was detected by physical separation. This suggests formation of a transient complex between these two cytochromes. When cytochrome c was complexed with phospholipids, no change in the thermodenaturation temperature was observed, but a great increase in the enthalpy change of thermodenaturation resulted.     

中国的兰伯特盘菌属和兰斯盘菌属

本文报道中国兰伯特盘菌属15种和兰斯盘菌属6个分类单元,其中小晚兰斯盘菌为新种.同时,提供了上述两个属的分种检索表.     

Molecular phylogeny of the genus Stereocaulon (Stereocaulaceae, lichenized ascomycetes)

In the present study phylogenetic relationships of the genus Stereocaulon (lichenized ascomycetes) were examined using DNA sequences from the ITS1–5.8 S–ITS2 rDNA gene cluster and from the protein-coding β-tubulin gene. In addition to the fruticose species traditionally classified in Stereocaulon, representatives of the crustose species that have recently been transferred to the genus were included. Muhria, a monotypic genus that is morphologically similar to Stereocaulon, differing only in apothecia ontogeny, was also incorporated. The analyses included 101 specimens from the ingroup representing 49 taxa. Sequences from both DNA regions were analysed simultaneously using direct optimization under the parsimony optimality criterion. The results support the inclusion of the crustose species and Muhria in Stereocaulon, while the current infrageneric classification is not supported. As Muhria is securely nested within Stereocaulon the new combination Stereocaulon urceolatum comb. nov. (syn. Muhria urceolata) is made. Further, species concepts need to be re-examined, as some species do not appear as monophyletic entities in the phylogeny.     

扇脉杓兰和无距虾脊兰的核型分析

为了解扇脉杓兰(Cypripedium japonicum Thunb.)和无距虾脊兰(Calanthe tsoongiana T. Tang et F. T. Wang)的核型,采用根尖压片法对扇脉杓兰和无距虾脊兰的染色体数目和核型进行了研究。结果表明,扇脉杓兰体细胞的染色体数为22,核型公式为2n=2x=22=16m+2sm+2st+2t,染色体相对长度组成为2n=22=2L+6M2+12M1+2S,核不对称系数为60.01%,核型分类为2B型;而无距虾脊兰体细胞的染色体数为40,核型公式为2n=2x=40=28m+10sm+2st,染色体相对长度组成为2n=40=8L+10M2+16M1+6S,核不对称系数为59.84%,核型分类为2B型;两者核型都较为对称。其中,无距虾脊兰的核型为首次报道。这为扇脉杓兰和无距虾脊兰的进化地位和种质保护提供了细胞学证据。     

香槐属分类学研究随记

基于对标本和文献的比较研究,确认豆科香槐属(Cladrastis Raf.)中小叶香槐(C.parvifolia C.Y.Ma)、藤香槐(C.scandens C.Y.Ma)、秦氏香槐(C.chingii DuleyVincent)与本属分布最广的翅荚香槐[C.platycarpa(Maxim.)Makino]为同种植物。其中,小叶香槐被处理为翅荚香槐的一变种,即C.platycarpa var.parvifolia(C.Y.Ma)Z.Q.Song,D.X.XuS.J.Li,藤香槐与秦氏香槐被处理为翅荚香槐原变种的两个新异名。同时讨论了翅荚香槐的分类地位及其散布。     

Molecular phylogeny of the Acre clade (Crassulaceae): Dealing with the lack of definitions for Echeveria and Sedum

The phylogenetic relationships within many clades of the Crassulaceae are still uncertain, therefore in this study attention was focused on the “Acre clade”, a group comprised of approximately 526 species in eight genera that include many Asian and Mediterranean species of Sedum and the majority of the American genera (Echeveria, Graptopetalum, Lenophyllum, Pachyphytum, Villadia, and Thompsonella). Parsimony and Bayesian analyses were conducted with 133 species based on nuclear (ETS, ITS) and chloroplast DNA regions (rpS16, matK). Our analyses retrieved four major clades within the Acre clade. Two of these were in a grade and corresponded to Asian species of Sedum, the rest corresponded to a European–Macaronesian group and to an American group. The American group included all taxa that were formerly placed in the Echeverioideae and the majority of the American Sedoideae. Our analyses support the monophyly of three genera – Lenophyllum, Thompsonella, and Pachyphytum; however, the relationships among Echeveria, Sedum and the various segregates of Sedum are largely unresolved. Our analyses represents the first broad phylogenetic framework for Acre clade, but further studies are necessary on the groups poorly represented here, such as the European and Asian species of Sedum and the Central and South American species of Echeveria.     

Hypocrella panamensis sp. nov. (Clavicipitaceae, Hypocreales): a new species infecting scale insects on Piper carrilloanum in Panama

A new species, Hypocrella panamensis, is described from collections and cultures obtained on Barro Colorado Island, Panama. In order to aid in placement of this fungus, phylogenetic analyses were conducted using LSU (rDNA) sequences. Hypocrella panamensis is characterized by possessing pulvinate stromata with a Lecanicillium-like anamorphic state and superficial perithecia. Hypocrella panamensis consistently grouped in a clade containing Hypocrella nectrioides, H. phyllogena, and H. africana (100 % PP). Most species of Hypocrella possess Aschersonia or Hirsutella anamorphs. Hypocrella panamensis is unique in the genus Hypocrella in possession of a Lecanicillium-like anamorphic state. In its biological habit Hypocrella panamensis is similar to other species in Hypocrella in that it infects and degrades the scale insect, then grows superficially on nutrients that emerge to the plant surface through the stylet wound.     

Seed germination and dormancy in the medicinal woodland herbs Collinsonia canadensis L. (Lamiaceae) and Dioscorea villosa L. (Dioscoreaceae)

We used a double germination phenology or “move-along” experiment (sensu Baskin and Baskin, 2003) to characterize seed dormancy in two medicinal woodland herbs, Collinsonia canadensis L. (Lamiaceae) and Dioscorea villosa L. (Dioscoreaceae). Imbibed seeds of both species were moved through the following two sequences of simulated thermoperiods: (a) 30/15 °C→20/10 °C→15/6 °C→5 °C→15/6 °C→20/10 °C→30/15 °C, and (b) 5 °C→15/6 °C→20/10 °C→30/15 °C→20/10 °C→15/6 °C→5 °C. In each sequence, seeds of both species germinated to high rates (>85%) at cool temperatures (15/6 and 20/10 °C) only if seeds were previously exposed to cold temperatures (5 °C). Seeds kept at four control thermoperiods (5, 15/6, 20/10, 30/15 °C) for 30 d showed little or no germination. Seeds of both species, therefore, have physiological dormancy that is broken by 12 weeks of cold (5 °C) stratification. Morphological studies indicated that embryos of C. canadensis have “investing” embryos at maturity (morphological dormancy absent), whereas embryos of D. villosa are undeveloped at maturity (morphological dormancy present). Because warm temperatures are required for embryo growth and cold stratification breaks physiological dormancy, D. villosa seeds have non-deep simple morphophysiological dormancy (MPD). Neither species afterripened in a 6-month dry storage treatment. Cold stratification treatments of 4 and 8 weeks alleviated dormancy in both species but C. canadensis seeds germinated at slower speeds and lower rates compared to seeds given 12 weeks of cold stratification. In their natural habitat, both species disperse seeds in mid- to late autumn and germinate in the spring after cold winter temperatures alleviate endogenous dormancy.     

Molecular and morphological characterization of Leveillula (Ascomycota: Erysiphales) on monocotyledonous plants

Leveillula on monocotyledonous plants have been recorded as L. taurica by several authors, whereas the fungus on Allium has been described as an independent species, namely L. allii, by some authors. We sequenced ca 600 bp of the rDNA ITS region for two Leveillula specimens from Allium and Polianthes (both from monocotyledons) and compared them with several already published sequences from Leveillula isolates from dicotyledons. Pair-wise percentages of sequence divergences were calculated for all Leveillula isolates. The ITS sequence of the Polianthes isolate was identical to L. taurica on Helianthus and Vicia. The sequence of the Allium isolate was 99.5 % identical to L. taurica on Euphorbia, Haplophylum, Peganum, etc. These results suggest close relationships between monocot and dicot pathogenic Leveillula species. The identity between two monocot isolates was 98.4 %. Phylogenetic analysis revealed that the two monocot isolates do not group into a clade together. This result suggests that Leveillula acquired parasitism to monocots at least twice independently.     

Ecology and impact of Allorhogas sp. (Hymenoptera: Braconidae) and Apion sp. (Coleoptera: Curculionoidea) on fruits of Miconia calvescens DC (Melastomataceae) in Brazil

Two fruit-feeding insects, a gall wasp, Allorhogas sp. (Hymenoptera: Braconidae), and a beetle, Apion sp. (Coleoptera: Curculionoidea), were evaluated in their native habitat in Brazil as potential biological control agents of Miconia calvescens DC (Melastomataceae). Allorhogas sp. occurred at two out of three field sites with native populations of M. calvescens, and Apion sp. occurred at all three sites. Both species exhibited aggregated distributions among M. calvescens trees sampled at each site. Allorhogas sp. infested 9.0% and 3.8% of fruits at each of two sites. The number of larvae and pupae of Allorhogas sp. and/or an unidentified parasitoid (Hymenopetera: Eulophidae: Tetrastichinae) ranged from one to five per infested fruit. Fruits infested with Allorhogas sp. were 20% larger and had 79% fewer seeds than healthy fruits. Although adults of Apion sp. were found on leaves and inflorescences of M. calvescens at all three sites, larvae and pupae were found in fruits at only one site, where a maximum of 1.4% of fruits were infested. Fruits infested by Apion sp. contained only one larva or pupa, and were 15% smaller and had 62% fewer seeds than healthy fruits. While a variety of apionids have been used for biological control in the past, this is the first time a braconid wasp has been considered for biological control of a weed.