bluuebunny/crossref_metadata_2025 huggingface dataset:
Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement
Authors: Greenstreet Simon P. R. , Fraser Helen M. , Piet Gerjan J.
Published: January 2009

Greenstreet, S. P. R., Fraser, H. M., and Piet, G. J. 2009. Using MPAs to address regional-scale ecological objectives in the North Sea: modelling the effects of fishing effort displacement. – ICES Journal of Marine Science, 66: 90–100. The use of Marine Protected Areas (MPAs) to address regional-scale objectives as part of an ecosystem approach to management in the North Sea is examined. Ensuring that displacement of fishing activity does not negate the ecological benefits gained from MPAs is a major concern. Two scenarios are considered: using MPAs to safeguard important areas for groundfish species diversity and using them to reduce fishing impacts on benthic invertebrates. Appropriate MPAs were identified using benthic invertebrate and fish abundance data. Fishing effort redistribution was modelled using international landings and fishing effort data. Closing 7.7% of the North Sea to protect groundfish species diversity increased the fishing impact on benthic invertebrates. Closing 7.3% of the North Sea specifically to protect benthic invertebrates reduced fishing mortality by just 1.7–3.8%, but when combined with appropriate reductions in total allowable catch (TAC), 16.2–17.4% reductions in fishing mortality were achieved. MPAs on their own are unlikely to achieve significant regional-scale ecosystem benefits, because local gains are largely negated by fishing effort displacement into the remainder of the North Sea. However, in combination with appropriate TAC reductions, the effectiveness of MPAs may be enhanced.
Transcriptome Profiling in Hybrid Poplar Following Interactions withMelampsoraRust Fungi
Authors: Azaiez Aïda , Boyle Brian , Levée Valérie , Séguin Armand
Published: January 2009

In natural conditions, plants are subjected to a combination of biotic stresses and often have to cope with simultaneous pathogen infections. In this report, we aim to understand the global transcriptional response of hybrid poplar NM6 (Populus nigra × P. maximowiczii) to infection by two biotrophic Melampsora fungi, Melampsora larici-populina and M. medusae f. sp. deltoidae. These pathogens triggered different responses after inoculation of poplar leaves. Transcript profiling using the GeneChip Poplar Genome Array revealed a total of 416 differentially expressed transcripts whose expression level was ≥twofold relative to controls. Interestingly, approximately half of the differentially expressed genes in infected leaves showed altered expression following interaction with either of the Melampsora spp. We also infected poplar leaves simultaneously with both Melampsora spp. to investigate potential interaction between the responses to the individual pathogens during a mixed infection. For this mixed inoculation, the number of differentially expressed transcripts increased to 648 and our analysis showed that infection with both fungi also induced a common set of genes. The genes induced after Melampsora spp. infection were mainly related to primary and secondary metabolic processes, cell-wall reinforcement and lignification, defense and stress-related mechanisms, and signal perception and transduction.
Silencing of Kex2 Significantly Diminishes the Virulence of Cryphonectria parasitica
Authors: Jacob-Wilk Debora , Turina Massimo , Kazmierczak Pam , Van Alfen Neal K.
Published: January 2009

Cryphonectria parasitica is the causal agent of chestnut blight. Infection of this ascomycete with Cryphonectria hypovirus 1 (CHV1) results in reduction of virulence and sporulation of the fungus. The virus affects fungal gene expression and several of the CHV1 downregulated genes encode secreted proteins that contain consensus Kex2 processing signals. Additionally, CHV1 has been shown to colocalize in infected cells primarily with fungal trans-Golgi network vesicles containing the Kex2 protease. We report here the cloning, analysis, and possible role of the C. parasitica Kex2 gene (CpKex2). CpKex2 gene sequence analysis showed high similarity to other ascomycete kexin-like proteins. Southern blot analyses of CpKex2 showed a single copy of this gene in the fungal genome. In order to monitor the expression and evaluate the function of CpKex2, antibodies were raised against expressed protein and Kex2-silenced mutants were generated. Western blots indicate that the Kex2 protein was constitutively expressed. Growth rate of the fungus was not significantly affected in Kex2-silenced strains; however, these strains showed reduced virulence, reduced sexual and asexual sporulation, and reductions in mating and fertility. The reduced virulence was correlated with reduced Kex2 enzymatic activity and reduced relative mRNA transcript levels as measured by real time reverse-transcriptase polymerase chain reaction. These results suggest that secreted proteins processed by Kex2 are important in fungal development and virulence.
Inactivation of the Lipoxygenase ZmLOX3 Increases Susceptibility of Maize to Aspergillus spp.
Authors: Gao Xiquan , Brodhagen Marion , Isakeit Tom , Brown Sigal Horowitz , Göbel Cornelia , Betran Javier , Feussner Ivo , Keller Nancy P. , Kolomiets Michael V.
Published: January 2009

Plant and fungal lipoxygenases (LOX) catalyze the oxidation of polyunsaturated fatty acids, creating fatty-acid hydroperoxides (oxylipins). Fungal oxylipins are required for normal fungal development and secondary metabolism, and plant host–derived oxylipins interfere with these processes in fungi, presumably by signal mimicry. The maize LOX gene ZmLOX3 has been implicated previously in seed-Aspergillus interactions, so we tested the interactions of a mutant maize line (lox3-4, in which ZmLOX3 is disrupted) with the mycotoxigenic seed-infecting fungi Aspergillus flavus and Aspergillus nidulans. The lox3-4 mutant was more susceptible than wild-type maize to both Aspergillus species. All strains of A. flavus and A. nidulans produced more conidia and aflatoxin (or the precursor sterigmatocystin) on lox3-4 kernels than on wild-type kernels, in vitro and under field conditions. Although oxylipins did not differ detectably between A. flavus–infected kernels of the lox3-4 and wild-type (WT) maize, oxylipin precursors (free fatty acids) and a downstream metabolite (jasmonic acid) accumulated to greater levels in lox3-4 than in WT kernels. The increased resistance of the lox3-4 mutant to other fungal pathogens (Fusarium, Colletotrichum, Cochliobolus, and Exserohilum spp.) is in sharp contrast to results described herein for Aspergillus spp., suggesting that outcomes of LOX-governed host-pathogen interactions are pathogen-specific.
Molecular Cytogenetic Characterization of a New T2BL·1RS Wheat-Rye Chromosome Translocation Line Resistant to Stripe Rust and Powdery Mildew
Authors: Wang Chunmei , Zheng Qi , Li Lihui , Niu Yongchun , Wang Haibo , Li Bin , Zhang Xiaotian , Xu Yunfeng , An Diaoguo
Published: January 2009

Wheat (Triticum aestivum) genotypes with rye (Secale cereale) 1RS chromosomal translocations are widely used in wheat breeding programs because 1RS carries genes for resistance to several diseases. However, some of the pathogens have evolved into new races that overcome the resistance due to extensive use of cultivars with the resistance genes from rye. Therefore, identification and deployment of new resistance sources with desirable agronomic characteristics are important and urgent. We have used winter rye cultivar German White as a source of genes for desirable traits in wheat improvement. A new genotype named WR04-32 was produced through hybridization and chromosome manipulation between common winter wheat cultivar Xiaoyan 6 and German White. This genotype was highly resistant to a wide spectrum of the wheat stripe rust (Puccinia striiformis f. sp. tritici) and powdery mildew (Blumeria graminis f. sp. tritici) pathotypes prevalent in China. The polymerase chain reaction (PCR) result using EST-STS (expressed sequence tag-site tagged sequence) marker STSWE126 specific to 1RS confirmed 1RS in WR04-32, and it was further proved to be a wheat-rye T2BL·1RS translocation line using sequential genomic in situ hybridization (GISH) and multicolor fluorescence in situ hybridization (FISH) with probes pAs1 and pSc119.2 (or pHvG38). In addition to its resistance to stripe rust and powdery mildew, WR04-32 was genetically stable and had desirable agronomic traits, making it a desirable germplasm for wheat breeding.
Bright-Field and Fluorescence Microscopic Study of Development of Erysiphe polygoni in Susceptible and Resistant Bigleaf Hydrangea
Authors: Li Yonghao , Windham Mark T. , Trigiano Robert N. , Reed Sandra M. , Spiers James M. , Rinehart Timothy A.
Published: January 2009

Temporal development of Erysiphe polygoni and responses of bigleaf hydrangeas (Hydrangea macrophylla) to the fungal attack were investigated using bright-field and fluorescence microscopy. Conidia germinated 2 h after inoculation (HAI) and formed primary appressoria at the tip of the primary germ tubes within 4 HAI. Secondary germ tubes were initiated from primary appressoria or other parts of conidia 12 HAI. Hyphae developed through elongation of secondary germ tubes, and paired lateral appressoria were formed along hyphae within 2 days after inoculation (DAI). Conidiophores and conidia were formed 5 DAI. In the susceptible cultivar Nikko Blue and the resistant cultivar Veitchii, the fungus established a parasitic relationship, which was indicated by the formation of haustoria under primary appressoria and development of secondary germ tubes at 1 DAI. A hypersensitive response (HR) and accumulation of callose were detected in both resistant and susceptible cultivars at 3 DAI. Resistance to powdery mildew in Veitchii was evident by manifestation of early accumulation of callose, relatively high percentage of necrotic infected cells, and restricted colony development compared to the susceptible cultivar Nikko Blue. Restricting hyphal growth and sporulation by early response of callose accumulation and HR are important resistance mechanisms that could be used in screening hydrangeas for resistance to powdery mildew.
Susceptibility of Fraser Fir to Phytophthora capsici
Authors: Quesada-Ocampo L. M. , Fulbright D. W. , Hausbeck M. K.
Published: January 2009

Phytophthora cinnamomi, P. drechsleri, P. citricola, and P. cactorum limit Fraser fir production, whereas P. capsici affects Solanaceous, Cucurbitaceous, and Fabaceous crops. Some vegetable growers in Michigan plant conifers for the Christmas tree market in fields infested with P. capsici. To determine the susceptibility of Fraser fir to P. capsici, stems (no wound or 1- or 3-mm-diameter wound) or roots (2 or 4 g of infested millet seed or 2 or 5 × 103 zoospores/ml of a zoospore suspension) of seedlings were inoculated with each of four P. capsici isolates and incubated in growth chambers (20 or 25°C). In addition, Fraser fir seedlings were planted in two commercial fields naturally infested with P. capsici. All P. capsici isolates tested incited disease in the seedlings regardless of incubation temperature or inoculation method. Seedlings (72%) planted in P. capsici–infested fields developed disease symptoms and died. Most of the P. capsici isolates obtained from the Fraser fir seedlings infected while in the field were recovered from root tissue. Identification was confirmed by species-specific direct colony polymerase chain reaction. The pathogen was successfully recovered from stems of all stem-inoculated seedlings, and from roots and stems of all root-inoculated seedlings; the phenotype of the recovered isolate matched the phenotype of the inoculum. This study suggests that planting Fraser fir in fields infested with P. capsici could result in infection and that adjustments in current rotational schemes are needed.
Rainfall Thresholds as Support for Timing Fungicide Applications in the Control of Potato Late Blight in Ecuador and Peru
Authors: Kromann Peter , Taipe Arturo , Perez Willmer G. , Forbes Gregory A.
Published: January 2009

Accumulated rainfall thresholds were studied in seven field experiments conducted in Ecuador and Peru for their value in timing applications of fungicide to control potato late blight, caused by Phytophthora infestans. Fungicide regimes based on accumulated rainfall thresholds ranging from 10 to 70 mm were compared with calendar spray schemes of every 5 or 7 days. Very low thresholds of 10 to 20 mm gave similar levels of control and resulted in similar number of sprays as did calendar spraying. However, neither low thresholds nor calendar sprays were effective in protecting susceptible potato genotypes in over half of the experiments. Thresholds of 25 to 50 mm of rainfall led to reduction in the number of sprays needed to protect resistant cultivars but also resulted in high levels of disease on susceptible cultivars. We conclude that timing fungicide sprays based on accumulated rainfall thresholds could be a successful component of integrated management strategies that include cultivars with moderate or high levels of resistance. The simplicity of measuring accumulated rainfall means that the technology can potentially be used by resource-poor farmers in developing countries.
Soybean Stem Lignin Concentration Relates to Resistance to Sclerotinia sclerotiorum
Authors: Peltier A. J. , Hatfield R. D. , Grau C. R.
Published: January 2009

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is an economically important disease of soybean (Glycine max) in the north-central United States and other temperate regions throughout the world. The occurrence and severity of Sclerotinia stem rot in the field is highly dependent upon prevailing environmental conditions, which can prove problematic when evaluating soybean accessions for resistance. The identification of an environmentally stable plant trait associated with resistance to S. sclerotiorum could be used to indirectly screen for resistance and would prove useful in the identification and development of resistant germplasm. Observations of the soybean–S. sclerotiorum interaction suggest a role for preformed stem lignin content in disease resistance. Although S. sclerotiorum produces numerous enzymes that degrade plant cell wall components, no lignin-degrading enzymes have been reported. Despite a hypothesized direct relationship between preformed lignin content and disease resistance, previous studies on soybean have correlated lignin content to nutritional value and not to disease resistance. We hypothesized that plants with low stem lignin are more susceptible and exhibit greater Sclerotinia stem rot severity than plants with high lignin concentrations. Six soybean accessions that varied in response to S. sclerotiorum were selected for study in a series of field experiments. Soybean stems were sampled at reproductive developmental stages that correspond to specific events in both soybean plant development and the Sclerotinia stem rot disease cycle. The lignin concentration of stem component samples was quantified. Soybean accessions expressed statistically different disease phenotypes in both 2004 and 2006. Lignin concentrations differed among accessions, growth stages, and plant parts. Results were contrary to our hypothesis, with positively ranked correlations observed between accession Sclerotinia stem rot severity and lignin concentration for all nodes and internodes assayed. For the R3 growth stage, lignin concentration of the internode between the fourth and fifth trifoliate leaves correlated best with disease severity data from each year (P = 0.005). These results indicate that resistance is related to low stem lignin concentration and that soybean stem lignin concentration can be used as a biological marker to select for resistance to S. sclerotiorum.
Similarity, Pattern, and Grouping of Soybean Fungal Diseases in the United States: Implications for the Risk of Soybean Rust
Authors: Li X. , Yang X. B.
Published: January 2009

Ten biological or ecological characteristics of pathogens/diseases were used to quantitatively describe 34 soybean (Glycine max) fungal diseases in the United States. These characteristics included optimal temperatures for disease development, host ranges, characteristics of disease cycle, and the pathogens' survival capacity. Gower's general similarity coefficients for pairs of diseases were determined and used in principal coordinate analysis (PCoA) to project the diseases into a two-dimensional space, in which significant patterns were identified for some of the characteristic variables, e.g., means of pathogen dispersal. Similarity coefficients indicated that soybean rust (Phakopsora pachyrhizi) resembled soybean downy mildew (Peronospora manshurica) and Leptosphaerulina leaf spot (Leptosphaerulina trifolii). Cluster analysis with multiscale bootstrapping identified two major clusters with high significance level (P > 0.95). In a loose cluster (P = 0.86), soybean rust was grouped with brown spot (Septoria glycines), frogeye leaf spot (Cercospora sojina), Phyllosticta leaf spot (Phyllosticta sojicola), purple seed stain (Cercospora kikuchii), downy mildew, and Leptosphaerulina leaf spot. Estimated soybean yield losses in the United States from 1996 to 2005 and the geographical distribution information of the diseases in this cluster implied that the potential geographical distribution range of soybean rust may include most U.S. soybean production regions and that yield losses would be light in the north but moderate in the south if environmental conditions are conducive.
New Host Races of Meloidogyne arenaria, M. incognita, and M. javanica from Horticultural Regions of Spain
Authors: Robertson L. , Díez-Rojo M. A. , López-Pérez J. A. , Buena A. Piedra , Escuer M. , Cepero J. López , Martínez C. , Bello A.
Published: January 2009

In total, 140 populations of the genus Meloidogyne collected from representative horticultural regions of Spain and maintained at the Department of Agroecology, Institute of Agrarian Sciences, Madrid were characterized using perineal morphology, sequenced characterized amplified region polymerase chain reaction with species-specific primers, and bioassay. Using a modified North Carolina differential host test as a basis, 13 Meloidogyne populations did not fit into the published race scheme. These populations had very limited host ranges, reproducing only on susceptible tomato cv. Marmande and sometimes also on tobacco cv. NC95 and the pepper cv. Sonar in the case of Meloidogyne arenaria. They did not reproduce on cotton or peanut. The species and new races were identified as M. incognita races 5 (6 populations) and 6 (2 populations) and M. javanica race 5 (2 populations), with new records of M. arenaria race 3 (2 populations) and M. javanica race 1 (23 populations) for Spain.
Preharvest Application of a Boscalid and Pyraclostrobin Mixture to Control Postharvest Gray Mold and Blue Mold in Apples
Authors: Xiao C. L. , Boal R. J.
Published: January 2009

After harvest, apples (Malus × domestica) may be kept in cold storage for up to 12 months prior to packing. Gray mold caused by Botrytis cinerea and blue mold caused by Penicillium expansum are common postharvest fruit rot diseases affecting apples and are controlled commonly by applications of fungicides after harvest. To search for an alternative strategy, Pristine (a premixed formulation of boscalid and pyraclostrobin) as a preharvest treatment was evaluated for control of postharvest gray mold and blue mold in cultivars Fuji and Red Delicious apples during 2004 to 2006. Pristine (0.36 g per liter of water) was applied 1, 7, or 14 days before harvest. For comparison, thiram (2.04 g per liter of water) was applied 7 days before harvest and ziram (2.4 g per liter of water) was applied 14 days before harvest, to Fuji and Red Delicious, respectively. Fruit were harvested at commercial maturity, wounded with a finishing nail head, inoculated with conidial suspensions of either B. cinerea or P. expansum, stored in air at 0°C, and evaluated for decay after 8 or 12 weeks. In 2004 and 2005, Pristine was equally effective when applied to Fuji 1 or 7 days before harvest, reducing gray mold incidence by 93 to 99% and blue mold incidence by 78 to 94% compared with the nontreated control. Thiram reduced gray mold incidence by 38 to 85%. Thiram reduced blue mold incidence by 22% in 2004 but not in 2005. On Red Delicious, Pristine was equally effective when applied 7 or 14 days before harvest and reduced gray mold incidence by 69 to 85% and blue mold incidence by 41 to 70%. Ziram applied 2 weeks before harvest reduced gray mold incidence by 97 and 94% in 2005 and 2006, respectively, but it did not reduce blue mold incidence. The results indicate that Pristine applied within 2 weeks before harvest may be an effective alternative to postharvest fungicides for control of postharvest gray mold and blue mold in Fuji and Red Delicious apples.
Control of Russet Crack Disease in Sweetpotato Plants Using a Protective Mild Strain of Sweet potato feathery mottle virus
Authors: Yamasaki Shuichi , Sakai Junichi , Kamisoyama Shigeru , Goto Hideyo , Okuda Mitsuru , Hanada Kaoru
Published: January 2009

A mild isolate (designated as 10-O) of Sweet potato feathery mottle virus (SPFMV) was obtained from Ipomoea batatas. This isolate rarely caused skin discoloration and did not cause russet crack disease on the storage roots of I. batatas that are typical of infection with the severe strain of SPFMV (SPFMV-S). The yield of the 10-O–infected I. batatas ranged from 92 to 105% of the yield of healthy I. batatas. The coat protein gene of 10-O encodes 315 amino acids and has sequence identities of 91.1% at the nucleotide level and 95.6% at the amino acid level with the corresponding region of SPFMV-S. When I. batatas cuttings were inoculated with 10-O and later challenged with SPFMV-S, russet crack symptoms were much reduced and SPFMV-S was not detected in the challenged plants. These results indicate that 10-O can be an effective biological control agent against russet crack disease.
First Report of a 16SrI-C Group Phytoplasma Associated With a Yellows-Type Disease Affecting Willow Plants in China
Authors: Wei T. , Wu Y. F. , Wu K. K. , Hou W. , Li Y. R.
Published: January 2009

In May of 2008, a phytoplasma-like disease was observed on willows (Salix babylonica Linn) grown in the Shaanxi Province. Affected plants showed yellowed leaves with green veins and dieback. Incidence of the disease was less than 10%. Samples were collected from 10 symptomatic and five asymptomatic willow plants from five different areas in Shaanxi Province. Total DNA was extracted from 0.5 g of leaf midrib and stem phloem tissue with a modified cetyltrimethylammoniumbromide (CTAB) method (3). Resulting DNA extracts were analyzed by a nested PCR assay using phytoplasma 16S rRNA gene primer pairs R16mF2/R16mR1 followed by R16F2n/R16R2 (1), which amplified a 1,452- and a 1,246-bp product, respectively. Sequences of amplicons were almost the same. Restriction fragment length polymorphism (RFLP) analysis of the nested 1.2-kb 16S rDNA products with AluI, MseI, HhaI, HpaI, RsaI, HinfI, and TaqI endonucleases (2) indicated that all symptomatic plants were infected by a phytoplasma belonging to aster yellows group (16SrI) subgroup C (16SrI-C) ‘Candidatus Phytoplasma asteris’. None of the symptomless plants tested positive. Nucleotide sequence analysis of cloned 16S rDNA (GenBank Accession No. FJ179166) confirmed the results on the basis of RFLP analyses. Subsequently, the presence of the phytoplasmas in symptomatic plants was also confirmed by transmission electron microscopy. To our knowledge, this is the first molecular evidence of the presence of a phytoplasma associated with a yellows-type disease of willows in northern China and its association with aster yellow group 16SrI, subgroup 16SrI-C.

References: (1) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (2) I.-M. Lee et al. Inst. J. Syst. Bacteriol. 48:1153, 1998. (3) Y. Qi et al. Biotechnol. Bull. 4:44, 2004.
First Report of Laurel Wilt Disease Caused by Raffaelea lauricola on Camphor in Florida and Georgia
Authors: Smith J. A. , Mount L. , Mayfield A. E. , Bates C. A. , Lamborn W. A. , Fraedrich S. W.
Published: January 2009

Laurel wilt is a recently described (1) vascular disease of redbay (Persea borbonia (L.) Spreng) and other plants in the family Lauraceae. The wilt is caused by Raffaelea lauricola, a fungus vectored by the nonnative redbay ambrosia beetle (Xyleborus glabratus Eichhoff) (1,2). Since 2003, laurel wilt has caused widespread mortality of redbay in Georgia, South Carolina, and Florida (1) and has recently been found on avocado in Florida (4). Since June of 2007, wilted shoots and branch dieback have been observed in several camphor trees (Cinnamomum camphora (L.) Sieb.) in residential areas of McIntosh and Glynn counties in Georgia and Baker County in Florida. Symptomatic camphor trees ranged from 4.5 to 12 m high and occurred in areas where redbay mortality due to laurel wilt has been frequently observed during the last 2 to 3 years. In some camphor trees, only the smaller branches (<2 cm in diameter) were wilting or dead, whereas in other trees (e.g., Baker County, Florida), the larger branches and substantial portions of the crown were also symptomatic. Rapid wilt that affects entire trees that is usually observed in redbay, has not been observed in camphor. Some camphor trees in residential areas of Jekyll Island, Georgia (Glynn County), where extensive wilt of redbay has occurred, have exhibited only localized wilt of some shoots or branches and other camphors remain asymptomatic. Removal of bark from wilted branch sections revealed black-to-brownish staining in the sapwood, characteristic of laurel wilt. Although no evidence of ambrosia beetles was observed on these samples, more extensive surveys are needed to determine the role of this vector in laurel wilt of camphor. Wood chips from symptomatic areas of branches were surface sterilized and plated on cycloheximide-streptomycin malt agar as previously described (1,4) and R. lauricola was routinely isolated. Small subunit (18S) sequences from rDNA were amplified by PCR and sequenced using primers NS1 and NS4 (3). BLASTn searches revealed homology to R. lauricola C2203 (GenBank Accession No. EU123076, 100% similarity, e-value of 0.0, and a total score of 1,886). The small subunit rDNA sequence for this isolate has been deposited into GenBank ( http://www.ncbi.nlm.nih.gov/Genbank/index.html ) and has been assigned Accession No. EU 853303. The presence of laurel wilt in camphor provides an opportunity to understand the pathogen distribution and possible resistance mechanisms in this host, which could have implications for efforts to remediate the impacts of the disease in redbay and other species in the Lauraceae in the southeastern United States.

References: (1) S. W Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington et al. Mycotaxon 104:399, 2008. (3) M. A. Innis et al. PCR Protocols, A Guide to Methods and Applications. Academic Press. San Diego, CA, 1990. (4) A. E. Mayfield, III et al. Plant Dis. 92:976, 2008.
First Report of Downy Mildew Caused by a Peronospora sp. on Basil in Florida and the United States
Authors: Roberts P. D. , Raid R. N. , Harmon P. F. , Jordan S. A. , Palmateer A. J.
Published: January 2009

Basil is grown as a specialty crop in greenhouse and field production in Florida and other regions of the United States. Downy mildew on basil (Ocimum basilicum) was detected from four production sites (Collier, Hendry, Miami-Dade, and Palm Beach counties) in south Florida in the fall of 2007, and within months, it was also found in west-central north Florida (Hillsborough County). Incidence reached nearly 100% on some of the affected crops and caused complete yield losses on basil grown both in the field for fresh market and potted herbs market. Symptoms developed during transit on basil that appeared symptomless at harvest. Symptoms initially appeared as yellowing on the lower leaves that was typically delineated by the veins, although in some cases the entire leaf area of the leaf surface was affected. A gray, fuzzy growth was apparent on the abaxial leaf surface. Microscopic observation detected dichotomous branching, hyaline sporangiophores (220 to 750 × 4 to 9 μm) bearing single sporangia. Sporangia were light brown, ovoid to slightly ellipsoid, and measured 14 to 15 × 15 to 18 μm. Oospores were not observed. Leaves of potted basil plants and coleus (Solenostemon scutellarioides) were inoculated with a suspension containing 1 × 105 sporangia/ml and sprayed till runoff (approximately 15 ml per plant) with a hand-held pressurized aerosol canister. Plants were covered with a plastic bag for 24 h and maintained in the greenhouse under ambient conditions. Noninoculated plants served as controls. After 7 days, symptoms typical of downy mildew occurred only on the inoculated basil plants and sporulation was confirmed microscopically. The internal transcribed spacer regions of an isolate collected in Hendry County were sequenced bidirectionally. The consensus sequence was deposited into GenBank (Accession No. FJ346561). Sequence data matched (100% homology) with a Peronospora sp. reported on sweet basil in Switzerland (GenBank Accession No. AY884605) and was similar (99% homology) to an isolate (GenBank Accession No. DQ523586) reported on coleus, although inoculation to coleus failed to confirm pathogenicity on this host. The sequence data also distinguished the isolate from P. lamii (87% homology) previously reported to occur on basil. The pathogen was identified as a Peronospora sp. based on morphological characteristics and sequencing homology (1–3).

References: (1) L. Belbahri et al. Mycol. Res. 109:1276, 2005. (2) S. Francis. CMI Descriptions of Pathogenic Fungi and Bacteria. No. 688. CMI, Kew, England, 1981. (3) A. McLeod et al. Plant Dis. 90:1115, 2006.
First Report of Fusarium solani Causing Wilt of Olea europaea in Nepal
Authors: Vettraino A. M. , Shrestha G. P. , Vannini A.
Published: January 2009

Leaf drop, wilt, and mortality were observed in September of 2007 on approximately 10% of 1- to 2-year-old olive (Olea europaea cv. Leccino) plants shipped from Europe and growing in a nursery in the District of Makwampur, Nepal. Roots of symptomatic and asymptomatic plants were disinfected in 1% NaOCl, cut into 1 cm long pieces, plated on 2% potato dextrose agar, and maintained at 20°C with 14 h of light per day. Colonies with white mycelium developed after 3 days. Microconidia and three-septated macroconidia averaged 11 × 3.9 μm and 38 × 5 μm, respectively. Chlamydospores were produced singly and in pairs. On the basis of culture characteristics, the fungus was identified as Fusarium solani (2). The ITS1-5.8S-ITS2 DNA sequences of 10 monoconidial cultures shared 99% identity with F. solani strains available on the NCBI databases (GenBank Accession Nos. 1115947 and 1115999). Pathogenicity tests were conducted with F. solani isolates NR1 and NR2 obtained from symptomatic plants. Twelve-month-old rooted cuttings of O. europaea cv. Leccino were transferred to pots containing a soilless mix and F. solani-infected oat grains (10:1 vol/vol). Fifteen plants of each F. solani isolate were inoculated. Noninfested sterilized oat grains were used for the control treatment. Symptoms on inoculated plants included leaf abscission followed by wilting and plant death approximately 10 days after inoculation and resembled those observed on the naturally infected plants. Noninoculated control plants remained healthy. The fungus was reisolated from roots of symptomatic tissues and was identical in appearance to the isolates used to inoculate the plants. No colonies of F. solani were isolated from noninoculated plants. F. solani has been reported as weakly pathogenic on olive in Spain (4) and highly aggressive on olive in Argentina (1) and India (3). To our knowledge, this is the first report of F. solani causing wilt and mortality of young olive plants in Nepal.

References: (1) S. Babbit et al. Plant Dis. 86:326, 2002. (2) C. Booth. Fusarium Laboratory Guide to the Identification of the Major Species. CMI, Kew, England, 1977. (3) R. L. Munjal et al. Studies on diseases of olive in Himachal Pradesh. Page 437 in: Improvement of Forest Biomass. Symposium Proceedings. Indian Society of Tree Scientists. P. K. Kosla, ed. Sdan, India, 1982. (4) M. E. Sánchez Hernández et al. Eur. J. Plant Pathol. 104:347, 1998.
First Report of New Phytoplasma Diseases Associated with Soybean, Sweet Pepper, and Passion Fruit in Costa Rica
Authors: Villalobos W. , Moreira L. , Rivera C. , Lee I.-M.
Published: January 2009

A new soybean disease outbreak occurred in 2002 in a soybean (Glycine max) plantation in Alajuela Province, Costa Rica. Symptoms on the affected plants included general stunting, small leaves, formation of excessive buds, and aborted seed pods. In the same region, two other diseases, one in sweet pepper (Capsicum annuum) fields and another affecting passion fruit (Passiflora edulis) vines, were also found. Symptoms on sweet pepper plants included unusually dark green leaves, some of which exhibited a rugose symptom with a zigzag pattern to the midvein, and purple vein discoloration. Passion fruit vines exhibited bud proliferation. Collectively, symptoms resembled those commonly attributed to phytoplasmal infections. Total nucleic acid was extracted from veinal tissues of leaves or buds (soybean). A nested PCR assay using primer pair P1/P7 followed by R16F2n/R16R2 (1) was employed for the detection of putative phytoplasmas that might be associated within symptomatic plants. All seven symptomatic plants (three soybean, three sweet pepper, and one passion fruit) tested, but not healthy controls, yielded positive results. Restriction fragment length polymorphism (RFLP) analysis of nested PCR products using restriction enzymes AluI, BfaI, HhaI, MseI, and RsaI indicated that the three diseases were associated with a very similar or identical phytoplasma. RFLP patterns and sequence analysis of cloned 16S rDNAs (GenBank Accession Nos. FJ226068–FJ226073) revealed that the phytoplasma shared less than 97.5% sequence homology with all previously classified phytoplasmas, and, as such, represents a new taxon most closely related to 16SrXII group (1) strains. To our knowledge, this is the first report of a new phytoplasma associated with diseases of soybean, sweet pepper, and passion fruit in Costa Rica.

Reference: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998.
First Report of Soybean Pod and Stem Blight Caused by Diaporthe phaseolorum var. sojae in Taiwan
Authors: Chen C. H. , Wang T. C. , Seo M. J.
Published: January 2009

Genera, Diaporthe and Phomopsis, from an important pathogenic complex of soybean (Glycine max) throughout the world, cause reductions in plant stands, yield, and seed health and quality (1). In a study of the Diaporthe/Phomopsis complex in Taiwan in March 2008, four stem samples with black fruiting structures in linear rows on senescent soybean were collected from the research fields at AVRDC, Shanhua, Tainan, Taiwan. Unidentified fungal isolates were obtained by surface disinfection of infected stems and plating excised tissues on potato dextrose agar (PDA). Colonies of the isolates showed ropelike white mycelia with yellowish tonalities. Small and scattered black stromata were observed frequently in the medium. Mutic pycnidia were found solitarily or aggregated in conidiomata on PDA plates after 10 days of incubation at 24°C with a 12-h photoperiod with near-UV light. All isolates produced α-conidia that measured 8.78 × 3.32 (7.00 to11.00 × 3.00 to 4.00) μm, and sporadically, β-conidia of 30.58 × 0.85 (26.00 to 33.00 × 0.60 to 1.20) μm. Perithecia were not observed in the collected stem samples or the fungal cultures on PDA. Restriction fragment length polymorphism patterns of the PCR products amplified by ITS4 and ITS5 primers for all isolates were identical to the patterns reported for Diaporthe phaseolorum var. sojae (3). Thus, all isolates were identified as D. phaseolorum var. sojae on the basis of morphologic and genetic characteristics (2,3). Pathogenicity was confirmed through inoculations during the V2 growth stage of soybean seedlings by atomizing conidial suspensions (1 × 107 α-conidia/ml) of each isolate on soybean seedlings as well as by injecting the inoculum into soybean stems separately. Four plants in each of three replications were inoculated for each method and six noninoculated plants served as controls. Plants were incubated in a growth chamber at 25°C and maintaining relative humidity at 100% by a humidifier for 48 h in darkness; thereafter, plants were maintained in the greenhouse at temperatures ranging from 23 to 34°C. Seven days after inoculation, red-brown leaf spots and coalescent lesions were observed on seedlings atomized by inoculum suspensions, as well as brown lesions and black pycnida in linear rows observed on plants inoculated by stem injection. No symptoms were observed on noninoculated plants. The fungal isolates obtained from inoculated soybeans were morphologically identical to those used as inoculum. The pathogenicity test was repeated twice. To our knowledge, this is the first explicit report identifying the causal agent of soybean pod and stem blight in Taiwan. The vouchers of infected specimens are available at AVRDC-The World Vegetable Center.

Reference: (1) R. P. Mulrooney. Plant Dis. 70:600, 1988. (2) R. N. Pioli et al. Phytopathology 93:136, 2003. (3) A. W. Zhang et al. Phytopathology 88:1306, 1998.
First Report of Avocado sunblotch viroid in Avocado from Michoacán, México
Authors: De La Torre-A R. , Téliz-Ortiz D. , Pallás V. , Sánchez-Navarro J. A.
Published: January 2009

The State of Michoacán, México cultivates approximately 100,000 ha of avocados (Persea americana M.) (4). During a survey from 2006 to 2007 in cv. Hass avocado groves in Tingambato County, in the State of Michoacán, deep yellow spots and streaks, which sometimes became necrotic or reddish, were observed on the skin of fruits and the pulp of the fruit also showed big yellow spots. Some young shoots developed fine, yellow streaks, and leaves of symptomatic trees sometimes showed irregular, white-to-yellow spots. These symptoms were similar to those recorded for Avocado sunblotch viroid (ASBVd) (3). To determine if ABSVd was associated with these symptoms, total RNA extracted (1) from the skin and pulp of symptomatic and asymptomatic fruits and also from leaves and bark of shoots from five trees collected in a commercial plot in Tingambato County was tested by a one-step reverse transcription (RT)-PCR protocol using one primer pair to amplify specifically the complete ASBVd genome sequence (3). All 30 samples of skin and pulp of fruits, leaves, and cortex of shoots from symptomatic trees yielded two PCR fragments with estimated sizes of 250 and 500 base pairs (bp) corresponding to the putative monomeric and dimeric forms of ASBVd, respectively. The 500-bp RT-PCR fragments obtained from the different samples were purified from an agarose gel and cloned. The 249-bp nucleotide sequence of the ASBVd genomic monomer was determined using the clones from the fruit skin from sample Arb No. 3 (GenBank Accession No. EU888588), pulp from sample Arb No. 5 (GenBank Accession No. EU888590), leaves from samples Arb No. 15 (GenBank Accession No. EU888589) and Arb No. 8 (GenBank Accession Nos. EU888591 and EU888592), and cortex of shoots from sample Arb No. 16 (GenBank Accession Nos. EU888593, EU888594, EU888595, EU888596, and EU888597). BLAST analysis of the ASBVd sequences showed a range of 98 to 100% nucleotide identity to ASBVd sequences (GenBank Accession Nos. AF404064, AF404051, or AF229821). A clone of the Michoacán ASBVd (GenBank Accession No. EU888593) was used to synthesize a Dig-High Prime-UTP-T7 (Roche, Mannheim, Germany) fluorescent riboprobe complementary to the ASBVd plus strand to perform a dot-blot analysis as described previously (2). All ASBVd samples positive by RT-PCR gave a strong signal in the dot-blot analysis. This riboprobe will be used to index the ASBVd in other commercial avocado groves in Michoacán. To our knowledge, this is the first report of ASBVd in Michoacán, México.

References: (1) D. J. Mackenzie et al. Plant Dis. 81:222, 1997. (2) J. A. Sánchez-Navarro et al. Plant Pathol. 47:780, 1998. (3) R. J. Schnell et al. Plant Dis. 81:1023, 1997. (4) D. Téliz and A. Mora. El aguacate y su Manejo Integrado. Mundiprensa, Mexico City, 2007.
Biodiversity research sets sail: showcasing the diversity of marine life
Authors: Webb Thomas J
Published: January 2009

The World Congress on Marine Biodiversity was held in the City of Arts and Sciences, Valencia, from 10 to 15 November 2008, showcasing research on all aspects of marine biodiversity from basic taxonomic exploration to innovative conservation strategies and methods to integrate research into environmental policy.
Survival costs of reproduction vary with age in North American red squirrels
Authors: Descamps Sébastien , Boutin Stan , McAdam Andrew G , Berteaux Dominique , Gaillard Jean-Michel
Published: January 2009

The costs of reproduction are expected to be higher under unfavourable conditions, so that breeding in years of low food supply should have important costs. In addition, the costs of reproduction may be contingent on the age of individuals, and young growing and old senescent individuals should suffer higher costs than the prime-age ones. We tested these predictions by investigating the costs of reproduction as a function of food availability and age in female North American red squirrels using the long-term data on survival and reproduction. We found that the costs of reproduction were independent of food supply, and we did not detect any trade-off between the current and future reproduction. We also did not detect any survival cost of reproduction for the prime-age females, but found evidence for survival costs in yearlings and old (6 years or above) females with successfully breeding individuals having a lower chance of survival compared with unsuccessful or non-breeding ones. These results supported our prediction that the costs of reproduction depended on the age of female red squirrels and were higher in young growing and old senescent individuals. Our study also indicated that, in contrast to large herbivores, heterogeneity in individual quality and viability selection in red squirrels do not affect the study of trade-offs and of the age variation in life-history traits.
Pollinator experience, neophobia and the evolution of flowering time
Authors: Forrest Jessica , Thomson James D
Published: January 2009

Environmental changes, such as current climate warming, can exert directional selection on reproductive phenology. In plants, evolution of earlier flowering requires that the individuals bearing genes for early flowering successfully reproduce; for non-selfing, zoophilous species, this means that early flowering individuals must be visited by pollinators. In a laboratory experiment with artificial flowers, we presented captive bumble-bees (Bombus impatiens) with flower arrays representing stages in the phenological progression of a two-species plant community: Bees that had been foraging on flowers of one colour were confronted with increasing numbers of flowers of a second colour. Early flowering individuals of the second ‘species’ were significantly under-visited, because bees avoided unfamiliar flowers, particularly when these were rare. We incorporated these aspects of bee foraging behaviour (neophobia and positive frequency dependence) in a simulation model of flowering-time evolution for a plant population experiencing selection against late flowering. Unlike simple frequency dependence, a lag in pollinator visitation prevented the plant population from responding to selection and led to declines in population size. Pollinator behaviour thus has the potential to constrain evolutionary adjustments of flowering phenology.
Diversification trajectories and evolutionary life-history traits in early sharks and batoids
Authors: Kriwet Jürgen , Kiessling Wolfgang , Klug Stefanie
Published: January 2009

Different interpretations on the timing of early diversification and radiation of modern sharks and batoids (Neoselachii) in the Earth's history exist and are related to discrepancies in taxonomic and phylogenetic interpretations favouring a Late Triassic or earliest Jurassic diversification and subsequent radiation event, respectively. Sampling standardization based on pooled taxonomic occurrences made it possible to overcome the problem of a much richer neoselachian record in the Late Jurassic than earlier on. The standardized pattern of genus richness is one of low and fairly constant diversity in the Late Triassic and earliest Jurassic with a steep rise in the Toarcian (ca180 Myr ago), representing the maximum diversification rate in the Jurassic towards a Middle and Late Jurassic plateau. The major Toarcian diversification agrees with the conclusions based on phylogenetic analyses, but is in conflict with older interpretations based on raw data. Early Jurassic expansion of neoselachians was opportunistic in the aftermath of the end-Triassic mass extinction and the reasons for their rapid diversification and radiation probably include small body size, short lifespans and oviparity, enabling faster ecological reorganizations and innovations in body plans for adapting to changing environmental conditions.
A female songbird out-sings male conspecifics during simulated territorial intrusions
Authors: Illes Anya E , Yunes-Jimenez Laila
Published: January 2009

While birdsong is a model system for animal communication studies, our knowledge is derived primarily from the study of only one sex and is therefore incomplete. The study of song in a role-reversed species would provide a unique opportunity to study selective pressures and mechanisms specific to females, and to test the robustness of current theories in an empirically novel manner. We investigated function of female song in stripe-headed sparrows (Aimophila r. ruficauda), a Neotropical, duetting passerine, and found that during simulated territorial intrusions by a female, male or duetting pair, females: (i) sang more than males to same-sex and duet playback, (ii) played a leading singing role in all contexts, and (iii) showed a longer term song response than males. These results suggest that females sing competitively against other females, and that intrasexual selection may be greater among females than among males. This is the first songbird study to show a stronger vocal role in territory defence for females than males. Stripe-headed sparrows are group-living cooperative breeders, and preliminary data suggest that polyandry and/or resource defence may explain strong female singing behaviour. Stripe-headed sparrows may be a useful study species for expanding our knowledge of vocal communication in female animals.
Significant effects ofPgigenotype and body reserves on lifespan in the Glanville fritillary butterfly
Authors: Saastamoinen Marjo , Ikonen Suvi , Hanski Ilkka
Published: January 2009

Individuals with a particular variant of the gene phosphoglucose isomerase (Pgi) have been shown to have superior dispersal capacity and fecundity in the Glanville fritillary butterfly (Melitaea cinxia), raising questions about the mechanisms that maintain polymorphism in this gene in the field. Here, we investigate how variation in thePgigenotype affects female and male life history under controlled conditions. The most striking effect is the longer lifespan of genotypes with high dispersal capacity, especially in non-reproducing females. Butterflies use body reserves for somatic maintenance and reproduction, but different resources (in thorax versus abdomen) are used under dissimilar conditions, with some interactions with thePgigenotype. These results indicate life-history trade-offs that involve resource allocation and genotype×environment interactions, and these trade-offs are likely to contribute to the maintenance ofPgipolymorphism in the natural populations.