Potential for endophyte symbiosis to increase resistance of the native grass <Emphasis Type="Italic">Poa alsodes</Emphasis> to invasion by the non-native grass <Emphasis Type="Italic">Microstegium vimineum</Emphasis>

Microbial symbionts can improve the competitive ability and stress tolerance of plant hosts and thus may enhance native plant resistance against invaders. We investigated whether symbiosis between a native grass, Poa alsodes, and a fungal endophyte (Neotyphodium sp.) improved the grass’s ability to compete against Microstegium vimineum (Japanese stiltgrass), a common invader in the eastern USA. We challenged naturally endophyte-symbiotic and experimentally endophyte-free P. alsodes plants with the invader. In the first experiment, we manipulated symbiosis and water availability to test for context-dependency in symbiont benefits. In the second experiment, we manipulated symbiosis and M. vimineum diversity (the number of invader populations), since greater intraspecific diversity is expected to improve invasion success and might alter the efficacy of symbiosis in invasion resistance. In both experiments, presence of the endophyte reduced the per plant biomass of M. vimineum and increased P. alsodes biomass. We found no evidence that benefits of the symbiont depended on water availability, and population-level diversity had a minor influence on M. vimineum: inflorescence number showed a parabolic relationship with increasing numbers of M. vimineum populations. Overall, symbiosis in the native grass had stronger effects on invader growth than either water availability or invader genetic diversity. Our results suggest that endophyte symbioses in native plants can increase host performance against an invader, although this conclusion needs confirmation in more complex field settings where other important factors, such as herbivores and fluctuating abiotic conditions, come into play.     

Drought-induced oxidative damage and antioxidant responses in peanut (<Emphasis Type="Italic">Arachis</Emphasis><Emphasis Type="Italic">hypogaea</Emphasis> L.) seedlings

Two cultivars of peanut (Arachis hypogaea L.) which were designated as resistant (Florispan) and sensitive (Gazipasa) according to their growth retardation under drought stress conditions were compared for their oxidative damage and antioxidant responses. Sixteen days-old peanut seedlings were subjected to PEG-6000 solutions of two different osmotic potentials; −0.4 and −0.8 MPa, and various growth parameters, photosystem II activity, changes in malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and proline levels, activities of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POX) and gluthatione reductase (GR) enzymes were determined. Both cultivars exhibited water deficit at −0.8 MPa osmotic potential of PEG-6000 and H₂O₂ levels significantly increased during exposure to −0.4 MPa osmotic potential. However, H₂O₂ levels were under control in both cultivars at exposure to −0.8 MPa osmotic potential. Significant proline accumulation was observed in the tissues of cv. Florispan at −0.8 MPa osmotic potential, whereas proline accumulation did not appear to be an essential part of the protection mechanism against drought in cv. Gazipasa. No significant variation in chlorophyll fluorescence values were detected in neither of the cultivars. Enzyme activity measurements revealed that Gazipasa copes well with lesser magnitudes of drought stress by increasing the activity of mainly APX, and during harsh stress conditions, only APX maintains its activity in the tissues. In cultivar Florispan, GR activity appears to take role in lesser magnitudes of drought stress, whereas CAT and APX activities appear to be very crucial antioxidative defenses during intense stress conditions. The results indicate that, the level of proline and activities of the enzymes CAT and APX are important mechanisms for the maintenance of drought tolerance in peanut plants.     

Winter and spring ecology of <Emphasis Type="Italic">Anaphes nitens</Emphasis>, a solitary egg-parasitoid of the <Emphasis Type="Italic">Eucalyptus</Emphasis> snout-beetle <Emphasis Type="Italic">Gonipterus scutellatus</Emphasis>

We investigated the effects of temperature, photoperiod, food and host availability, and body size on the overwintering abilities of the egg parasitoid Anaphes nitens Girault (Hymenoptera, Mymaridae) under natural conditions. Seven groups of eighty females received one of four treatments (n = 20): (i) honey and hosts, (ii) water and hosts, (iii) honey, or (iv) water. Seven groups of forty males received only honey or water (n = 20). To test if short day-length is the main cue for larval dormancy, the experiment was replicated inside a climate chamber at 20°C and under a winter photoperiod. A. nitens overwinters because of quiescence or oligopause inside the hosts and increased adult longevity. Mean pre-emergence mortality was up to 26% indoors and 15.2% outdoors, males being more affected. Development time had a significant and positive effect on body size. Honey-fed females without hosts had the highest longevity (53 days). Mother’s diet and size affected development time, body size, longevity, and fecundity of the progeny. The results confirm the good adaptation of the parasitoid to the environmental conditions of NW Spain and its ability to synchronize its life cycle with the phenology of the host. Handling editor: Drik Babendreier.     

Freeze/thaw stress in<Emphasis Type="Italic"> Ceanothus</Emphasis> of southern California chaparral

Freeze/thaw stress was examined in chaparral shrubs of the genus Ceanothus to determine the interactive effects of freezing and drought and to consider which is the more vulnerable component, the living leaves (symplast) or the non-living water transport system (apoplast). We hypothesized that where Ceanothus species co-occurred, the more inland species C. crassifolius would be more tolerant of low temperatures than the coastal species C. spinosus, both in terms of leaf survival (LT(50), or the temperature at which there is 50% loss of function or viability) and in terms of resistance to freezing-induced embolism (measurements of percent loss hydraulic conductivity due to embolism following freeze/thaw). Cooling experiments on 2 m long winter-acclimated shoots resulted in LT(50) values of about -10 degrees C for C. spinosus versus -18 degrees C for C. crassifolius. Freeze-thaw cycles resulted in no change in embolism when the plants were well hydrated (-0.7 to -2.0 MPa). However, when plants were dehydrated to -5.0 MPa, C. spinosus became 96% embolized with freeze/thaw, versus only 61% embolism for C. crassifolius. Stems of C. crassifolius became 90% and 97% embolized at -6.6 and -8.0 MPa, respectively, meaning that even in this species, stems could be more vulnerable than leaves under conditions of extreme water stress combined with freeze/thaw events. The dominance of C. crassifolius at colder sites and the restriction of C. spinosus to warmer sites are consistent with both the relative tolerance of their symplasts to low temperatures and the relative tolerance of their apoplasts to freeze events in combination with drought stress.     

Fungal endophytes of turmeric (<Emphasis Type="Italic">Curcuma longa</Emphasis> L.) and their biocontrol potential against pathogens <Emphasis Type="Italic">Pythium aphanidermatum</Emphasis> and <Emphasis Type="Italic">Rhizoctonia solani</Emphasis>

Endophytic fungi have been isolated from the healthy turmeric (Curcuma longa L.) rhizomes from South India. Thirty-one endophytes were identified based on morphological and ITS–rDNA sequence analysis. The isolated endophytes were screened for antagonistic activity against Pythium aphanidermatum (Edson) Fitzp., and Rhizoctonia solani Kuhn., causing rhizome rot and leaf blight diseases in turmeric respectively. Results revealed that only six endophytes showed >?70% suppression of test pathogens in antagonistic dual culture assays. The endophyte T. harzianum TharDOB-31 showed significant in vitro mycelial growth inhibition of P. aphanidermatum (76.0%) and R. solani (76.9%) when tested by dual culture method. The SEM studies of interaction zone showed morphological abnormalities like parasitism, shriveling, breakage and lysis of hyphae of the pathogens by endophyte TharDOB-31. Selected endophytic isolates recorded multiple plant growth promoting traits in in vitro studies. The rhizome bacterization followed by soil application of endophyte TharDOB-31 showed lowest Percent Disease Incidence of rhizome rot and leaf blight, 13.8 and 11.6% respectively. The treatment of TharDOB-31 exhibited significant increase in plant height (85 cm) and fresh rhizome yield/plant (425 g) in comparison with untreated control under greenhouse condition. The confocal microscopy validates the colonization of the TharDOB-31 in turmeric rhizomes. The secondary metabolites in ethyl acetate extract of TharDOB-31 were found to contain higher number of antifungal compounds by high resolution liquid chromatograph mass spectrometer analysis. Thereby, endophyte T. harzianum isolate can be exploited as a potential biocontrol agent for suppressing rhizome rot and leaf blight diseases in turmeric.     

Genetic relatedness of <Emphasis Type="Italic">Trichoderma</Emphasis> isolates antagonistic against <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="Italic">dianthi</Emphasis> inflicting carnation wilt

Twenty-eight isolates of Trichoderma belonging to four different species were screened in vitro for their antagonistic ability against Fusarium oxysporum f.sp. dianthi causing carnation wilt. Three different levels of antagonism observed in dual plate assay were further confirmed by cell-free culture filtrate experiments. Isolates showing class I level of antagonism produced maximum lytic enzymes, chitinases and beta-1,3-glucanases. Genetic variability of 25 selected isolates was assessed by random amplified polymorphic DNA technique and the amplified products were correlated for their level of antagonism. Unweighed pair-group method with arithmetical averages cluster analysis revealed prominent inter-and intraspecific genetic variation among the isolates. Based on their genetic relationship, the isolates were mainly distributed into 3 major groups representing T. atroviride, T. pseudokoningii and T. harzianum, with 20-35% interspecific dissimilarity. However, the polymorphism shown by the isolates did not correlate to their level of antagonism.     

<Emphasis Type="Italic">Xanthium italicum</Emphasis>, <Emphasis Type="Italic">Xanthium strumarium</Emphasis> and <Emphasis Type="Italic">Arctium lappa</Emphasis> as new hosts for <Emphasis Type="Italic">Diaporthe helianthi</Emphasis>

Sunflower (Helianthus annuus) stem canker caused by Diaporthe helianthi is one of the most important sunflower diseases in Croatia. Until recently, sunflower was the only known host for D. helianthi. In our research carried out in the area of Eastern Croatia, isolates of Diaporthe/Phomospis were collected from Xanthium italicum, X. strumarium and Arctium lappa. Using morphological, cultural and molecular ITS rDNA data, isolates from these weeds were identified as D. helianthi. The following isolates were used in the pathogenicity test: one isolate originated from sunflower (Su5/04), three from X. italicum (Xa2, Xa3 and Xa5), two from X. strumarium (Xa9 and Xa12), one from Xanthium sp. (Xa13) and one from A. lappa (Ar3). According to the results, it was determined that isolate Xa5 (originated from X. italicum) was the most pathogenic to sunflower stems. The average length of the lesion was 11.3 cm. The lowest level of pathogenicity was found in Xa9 (isolated from X. strumarium). The length of the lesion was 0.1 cm.     

Probiotic <Emphasis Type="Italic">Lactobacillus</Emphasis> strains: <Emphasis Type="Italic">in vitro</Emphasis> and <Emphasis Type="Italic">in vivo</Emphasis> studies

Three Lactobacillus strains (LOCK 0900, LOCK 0908, LOCK 0919) out of twenty-four isolates were selected according to their antagonistic activity against pathogenic bacteria, resistance to low pH and milieu of bile salts. Intragastric administration of a mixture of these strains to Balb/c mice affected cytokine T_H1-T_H2 balance toward nonallergic T_H1 response. Spleen cells, isolated from lactobacilli-treated mice and re-stimulated in vitro with the mixture of heat-inactivated tested strains, produced significantly higher amounts of anti-allergic tumor necrosis factor- and interferon-γ than control animals whereas the level of pro-allergic interleukin-5 was significantly lower. Lactobacillus cells did not translocate through the intestinal barrier into blood, liver and spleen; a few Lactobacillus cells found in mesenteric lymph nodes could create antigenic reservoir activating the immune system. The mixture of Lactobacillus LOCK 0900, LOCK 0908 and LOCK 0919 strains represents a probiotic bacterial preparation with possible use in prophylaxis and/or therapy of allergic diseases.     

<Emphasis Type="Italic">In vitro</Emphasis> susceptibility of viridans streptococci to leaf extracts of <Emphasis Type="Italic">Mangifera Indica</Emphasis>

The susceptibility of Viridans streptococci to leaf extracts of Mangifera indica was studied on 53 clinical isolates from 39 patients. All the isolates were found to be susceptible to both water and methanol extract of M. indica leaves. Minimum inhibitory concentration (MIC) of methanol extract for all isolates were <50 mg/mL and MIC of water extract for all isolates were <200 mg/mL. Methanol extract was found to have better action against Viridans streptococci than water extract.     

<Emphasis Type="Italic">Galleria</Emphasis><Emphasis Type="Italic">mellonella</Emphasis> are Resistant to <Emphasis Type="Italic">Pneumocystis</Emphasis><Emphasis Type="Italic">murina</Emphasis> Infection

Studying Pneumocystis has proven to be a challenge from the perspective of propagating a significant amount of the pathogen in a facile manner. The study of several fungal pathogens has been aided by the use of invertebrate model hosts. Our efforts to infect the invertebrate larvae Galleria mellonella with Pneumocystis proved futile since P. murina neither caused disease nor was able to proliferate within G. mellonella. It did, however, show that the pathogen could be rapidly cleared from the host.     

Inoculation of<Emphasis Type="Italic">Rhododendron</Emphasis> cv. Belle-Heller with two strains of<Emphasis Type="Italic">Phialocephala fortinii</Emphasis> in two different substrates

The growth response of an ornamentalRhododendron hybrid to the inoculation withPhialocephala fortinii was studied in two pot experiments in order to decide about the effectiveness of the inoculation of young rhododendron microplants. Two different substrates were used in both experiments, either sterilized or non-sterilized: a horticultural substrate and a soil collected from a field site with dominant ericoid vegetation. Two fungal isolates were used for an inoculation:P. fortinii strain P (UAMH 8433) andP. fortinii strain F, a dark septate endophyte (DSE) previously isolated from naturally-infected roots ofVaccinium myrtillus. BothPhialocephala strains successfully colonized the roots of the host plants forming typical DSE (=pseudomycorrhizal) colonization pattern including the formation of intracellular microsclerotia. However, pseudomycorrhizal colonization did not affect the growth parameters of the host rhododendrons. The results from both experiments indicate a neutral effect of the inoculation with DSE fungi on the growth ofRhododendron cv. Belle-Heller.     

Latent infections of <Emphasis Type="Italic">Fomes fomentarius</Emphasis> in the xylem of European beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis>)

Fungal colonisation originating from endophytic thalli in wood of healthy European beech trees (Fagus sylvatica) was studied. Fungi were isolated from wood immediately after felling and after incubation for 8, 16 and 24 weeks under two different drying regimes. Two media were used to isolate fungi: malt extract agar with and without thiabendazol. Thiabendazol was added to inhibit non-basidiomycetes. The two drying regimes had no influence on the species composition of the recovered mycobiota and the frequency of isolation of these species. Mycelia of basidiomycetes except Coniophora puteana emerged only from wood samples inoculated onto malt extract agar containing thiabendazol. Only a few isolates were obtained from freshly cut wood, but a great number of isolates was recovered already after eight weeks of wood incubation. Four taxa accounted for 88 % of the total number of isolates: Hypoxylon fragiforme, Trichoderma spp., and the basidio-mycetes Coniophora puteana and Fomes fomentarius. The latter had not been considered an endophyte before. The isolates of F. fomentarius were made exclusively from the stem and some large diameter branches, which are the locations of its basidiocarps on dying trees. Every isolate of F. fomentarius was genetically different as revealed by tests for somatic compatibility. Advantages of the presumed endophytic strategy of F. fomentarius are discussed. Microscopic investigations showed a great number of hyphae within the cell lumina of vessels and a distinct wood degradation already after eight weeks of wood incubation.     

Physiological responses to water stress in<Emphasis Type="Italic"> Eucalyptus cloeziana</Emphasis> and<Emphasis Type="Italic"> E. argophloia</Emphasis> seedlings

Effects of water stress duration and intensity on gas exchange and leaf water potential were investigated in 7-month-old seedlings of a humid coastal provenance (Gympie) and a dry inland (Hungry Hills) provenance of E. cloeziana F. Muell. and in a dry inland (Chinchilla) provenance of E. argophloia Blakely supplied with 100% (T₁₀₀), 70% (T₇₀), 50% (T₅₀) of their water requirements, or were watered only after they were wilted at dawn (T₀). Seedlings of E. argophloia had the highest midday net photosynthetic rate (A), stomatal conductance (g _s), stomatal density and predawn leaf water potential (_pd) in all treatments. The E. cloeziana provenances did not differ in these attributes. The T₇₀ and T₅₀ treatments caused reductions in A of 30% in E. argophloia, and 55% in the E. cloeziana provenances. Under the T₀ treatment, E. argophloia maintained higher rates of gas exchange at all levels of water stress than E. cloeziana provenances. The estimates of _pd and midday water potential (_md) at which plants remained wilted overnight were respectively: –2.7 and –4.1 MPa for E. cloeziana (humid), –2.8 and –4.0 MPa for E. cloeziana (dry) and, –3.7 and –4.9 MPa for E. argophloia. Following stress relief, both A and g _s recovered more quickly in E. argophloia and in the dry provenance of E. cloeziana than in the humid provenance. We conclude that E. argophloia is more drought tolerant and has a potential for cultivation in the humid and semi humid climates, whilst E. cloeziana has greater potential in the humid subtropical climates.     

Reactive oxygen species (ROS) and antioxidative enzyme status in <Emphasis Type="Italic">Solanum lycopersicum</Emphasis> on priming with fluorescent <Emphasis Type="Italic">Pseudomonas</Emphasis> spp. against <Emphasis Type="Italic">Fusarium oxysporum</Emphasis>

In plants, ROS signaling and increase in activities of antioxidants are among defense responses. The present study describes the oxidative stress profiling in model host plant tomato (Solanum lycopersicum L.), during an invasion of the wilt pathogen Fusarium oxysporum f. sp. lycopersici with or without seed priming with Pseudomonas isolates M80, M96 and T109. Tomato seeds were primed with known Pseudomonas isolates M80, M96 and T109 and the forty-day- old plants were challenged with spores of F. oxysporum under greenhouse conditions. Leaf samples were collected at 0, 24, 48 72 and 96 h post fungal challenge and analysed for systemic level of oxidative stress parameters including total phenolics, proline, hydrogen peroxide, lipid peroxidation and enzymatic antioxidants. Disease incidence in the plants under greenhouse conditions was also calculated. Results revealed that priming with Pseudomonas isolates resulted in reduced oxidative stress in the host, during pathogen invasion. M80-priming showed highest antioxidative protection to the host plants during F. oxysporum invasion. The observed reduction in hydrogen peroxide and lipid peroxidation in primed plants was in agreement with the increased activities of the corresponding antioxidant enzymes. Greenhouse results showed that the highest wilt disease symptoms were with M80-priming followed by M96 and T109. The present study gives substantial evidences on the oxidative stress mitigation in response to Pseudomonas-priming on the model tomato-Fusarium interaction system.     

<Emphasis Type="Italic">Ty</Emphasis>1<Emphasis Type="Italic">/copia</Emphasis>- and <Emphasis Type="Italic">Ty</Emphasis>3<Emphasis Type="Italic">/gypsy</Emphasis>-like DNA sequences in <Emphasis Type="Italic">Helianthus </Emphasis>species

Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.     

Characterisation of members of the <Emphasis Type="Italic">Fusarium incarnatum</Emphasis>-<Emphasis Type="Italic">equiseti</Emphasis> species complex from undisturbed soils in South Africa

The genus Fusarium hosts a large number of economically significant phytopathogens with a global distribution. Surprisingly, only a limited number of studies have tried to identify the natural distribution of members of this genus in undisturbed soils. Members of the Fusarium incarnatum-equiseti species complex (FIESC) are increasingly associated with plant disease, and human and animal health problems. Recently, an outbreak of kikuyu poisoning of cattle was attributed to the F. incarnatum-equiseti species complex. Thus, it is of importance to identify the natural distribution of members of the FIESC from the environment. The aim of this study was to use the phylogenetic signal within the TEF 1α gene region to characterise 54 F. incarnatum-equiseti isolates obtained from undisturbed soils from the grassland biome of South Africa. These isolates were further compared with members of the FIESC previously associated with kikuyu poisoning of cattle. The phylogenetic analysis indicated a high level of variation within this species complex. Several members were closely related to isolates implicated in the death of cattle from infected kikuyu grass.     

Diversity and recombination in <Emphasis Type="Italic">Wolbachia</Emphasis> and <Emphasis Type="Italic">Cardinium</Emphasis> from <Emphasis Type="Italic">Bryobia</Emphasis>spider mites

BACKGROUND: Wolbachia and Cardinium are endosymbiotic bacteria infecting many arthropods and manipulating host reproduction. Although these bacteria are maternally transmitted, incongruencies between phylogenies of host and parasite suggest an additional role for occasional horizontal transmission. Consistent with this view is the strong evidence for recombination in Wolbachia, although it is less clear to what extent recombination drives diversification within single host species and genera. Furthermore, little is known concerning the population structures of other insect endosymbionts which co-infect with Wolbachia, such as Cardinium. Here, we explore Wolbachia and Cardinium strain diversity within nine spider mite species (Tetranychidae) from 38 populations, and quantify the contribution of recombination compared to point mutation in generating Wolbachia diversity. RESULTS: We found a high level of genetic diversity for Wolbachia, with 36 unique strains detected (64 investigated mite individuals). Sequence data from four Wolbachia genes suggest that new alleles are 7.5 to 11 times more likely to be generated by recombination than point mutation. Consistent with previous reports on more diverse host samples, our data did not reveal evidence for co-evolution of Wolbachia with its host. Cardinium was less frequently found in the mites, but also showed a high level of diversity, with eight unique strains detected in 15 individuals on the basis of only two genes. A lack of congruence among host and Cardinium phylogenies was observed. CONCLUSIONS: We found a high rate of recombination for Wolbachia strains obtained from host species of the spider mite family Tetranychidae, comparable to rates found for horizontally transmitted bacteria. This suggests frequent horizontal transmission of Wolbachia and/or frequent horizontal transfer of single genes. Our findings strengthens earlier reports of recombination for Wolbachia, and shows that high recombination rates are also present on strains from a restrictive host range. Cardinium was found co-infecting several spider mite species, and phylogenetic comparisons suggest also horizontal transmission of Cardinium among hosts.     

Evaluation of <Emphasis Type="Italic">Streptomyces</Emphasis> spp. for biological control of <Emphasis Type="Italic">Sclerotium</Emphasis> root and stem rot and <Emphasis Type="Italic">Ralstonia</Emphasis> wilt of chili pepper

The objective of this study was to screen Streptomyces spp. for biological control of root and stem rot (Sclerotium rolfsii) and bacterial wilt (Ralstonia solanacearum), the very destructive diseases of chili pepper in Thailand. About 265 isolates of Streptomyces spp. were tested for their inhibitory effects on S. rolfsii mycelial growth on dual culture plates. Then, 14 promising isolates were further tested for their effects on R. solanacearum growth. Three effective isolates further identified as S. mycarofaciens SS-2-243, S.philanthi RL-1-178 and S. philanthi RM-1-138 were selected and proved to produce both antifungal and antibacterial substances in the culture medium. S. philanthi RM-1-138 strongly inhibited seed germination and seedling growth of chili pepper in laboratory tests. Therefore, it was not used in the following studies. When tested in greenhouse conditions, the efficacy of S. philanthi RL-1-178 in suppressing Sclerotium root and stem rot of chili pepper was approximately equal to that of Trichoderma harzianum NR-1-52 or that of carboxin treatment. S. mycarofaciens SS-2-243 and S. philanthi RL-1-178 suppressed Ralstonia wilt of chili pepper in a way that was similar to streptomycin sulfate treatment and it was observed that T. harzianum NR-1-52 had no effect on the bacterial wilt. Under field conditions where the soil was inoculated with two pathogens, the results showed that S. philanthi RL-1-178 could protect the chili pepper plants from S. rolfsii and R. solanacearum infection better than S. mycarofaciens SS-2-243 or T. harzianum NR-1-52. S. philanthi RL-1-178 treatment resulted in 58.75% survival of chili pepper plants and its efficacy was not significantly different from the carboxin-and-streptomycin sulfate treatment.     

<Emphasis Type="Italic">Diaporthe</Emphasis> from walnut tree (<Emphasis Type="Italic">Juglans regia</Emphasis>) in China,with insight of the <Emphasis Type="Italic">Diaporthe eres</Emphasis> complex

Species of Diaporthe are important plant pathogenic fungi that commonly occur on a wide range of hosts. They are relatively difficult to identify due to their extreme similarity in morphology and confusing multigene phylogeny, especially in the Diaporthe eres complex. In the present study, isolates were collected from diseased branches of Juglans regia in China. Most strains were clustered into the D. eres species complex based on the combined internal transcribed spacer (ITS) region, partial calmodulin (CAL), histone H3 (HIS), translation elongation factor 1-alpha (TEF1-α) and beta-tubulin (TUB) genes. To focus on this complex, CAL, TEF1-α and TUB were selected in further phylogenetic analyses that showed a better topology compared with combined five-gene phylogeny. Results revealed that all strains which clustered in the Diaporthe eres complex from Juglans regia in China were Diaporthe eres. Results suggested a revised species criterion in the Diaporthe eres complex. The current study uncovered a new species here described as Diaporthe. tibetensis.