Molecular and Alkaloid Characterization of Claviceps purpurea Sensu Lato From Grass Seed Production Areas of the U.S. Pacific Northwest.

Ergot, caused by Claviceps purpurea sensu lato, is an economically important seed replacement disease of Kentucky bluegrass (Poa pratensis) and perennial ryegrass (Lolium perenne) seed crops. C. purpurea sensu stricto is considered the primary Claviceps species responsible, but genetic diversity and cryptic species within C. purpurea sensu lato have previously been reported. Fifty-six C. purpurea sensu lato isolates collected from P. pratensis (n = 21) and L. perenne (n = 35) in Oregon and Washington between 2010 and 2014 were characterized via random amplified polymorphic DNA (RAPD), partial internal transcribed spacer (ITS), ß-tubulin and elongation factor-1α (EF-1α) sequences, conidial size, and ergot alkaloid chemotype. Based on RAPD analysis, seven isolates from P. pratensis and 33 isolates from L. perenne collected in Oregon corresponded to C. purpurea sensu stricto, and 13 isolates collected from P. pratensis in Washington and Oregon were identified as C. humidiphila. Partial ITS, ß-tubulin, and EF-1α sequences identified 10 isolates from P. pratensis as C. humidiphila, and seven isolates from P. pratensis and 33 isolates from L. perenne were identified as C. purpurea sensu stricto. Several isolates generated ambiguous RAPD bands or sequences that prevented identification. Ergot alkaloid chemotype profiling found that ergocornine and its epimer were predominant in sclerotia from P. pratensis, whereas ergotamine and its epimer were most abundant in sclerotia from L. perenne. This study confirms the presence of the C. purpurea sensu lato species complex in the U.S. Pacific Northwest and suggests that more research is needed to characterize and mitigate Claviceps spp. infection of grass seed crops in North America.

Detection and Quantification of Airborne Claviceps purpurea sensu lato Ascospores from Hirst-Type Spore Traps using Real-Time Quantitative PCR.

The U.S. Pacific Northwest states of Oregon and Washington are major producers of cool-season grass seed. Ergot, caused by fungi in the Claviceps purpurea sensu lato group, is an important seed replacement disease of grass worldwide. Microscopic methods that are currently used to quantify airborne Claviceps ascospores captured by spore traps are not currently rapid enough to allow for detecting and reporting of spore numbers in a timely manner, hindering growers from using this information to help manage ergot. We developed a SYBR Green real-time quantitative polymerase chain reaction (qPCR)-based assay for fast and efficient detection and quantification of C. purpurea sensu lato ascospores from Hirst-type spore traps. Species-specificity of the qPCR assay was confirmed against 41 C. purpurea sensu lato isolates collected from six hosts and six other Claviceps spp. Significant relationships were observed between cycle threshold (Ct) values and standard curves of serial dilutions of DNA ranging from 1 pg to 10 ng (R2 = -0.99; P = 0.0002) and DNA extracted from a conidial suspension representing 8 to 80,000 conidia (R2 = -0.99; P = 0.0004). Ct values from qPCR were significantly correlated with results from microscopic examination of spore trap samples from the field (r = -0.68; P < 0.0001) and the procedure was able to detect a single ascospore from spore trap tape samples. The qPCR procedure developed in this study provided a means for quantifying airborne Claviceps ascospores that was highly specific and useful over a wide range of spore densities, and could be performed in a matter of hours instead of days. The qPCR assay developed in this study could be part of an integrated pest management approach to help grass seed growers make risk-based fungicide application decisions for ergot management in grass grown for seed.

Maternal mental health priorities, help-seeking behaviors, and resources in post-conflict settings: a qualitative study in eastern Uganda.

BACKGROUND: Limited knowledge exists to inform the selection and introduction of locally relevant, feasible, and effective mental health interventions in diverse socio-cultural contexts and health systems. We examined stakeholders' perspectives on mental health-related priorities, help-seeking behaviors, and existing resources to guide the development of a maternal mental health component for integration into non-specialized care in Soroti, eastern Uganda. METHODS: We employed rapid ethnographic methods (free listing and ranking; semi-structured interviews; key informant interviews and pile sorting) with community health workers (n = 24), primary health workers (n = 26), perinatal women (n = 24), traditional and religious healers (n = 10), and mental health specialists (n = 9). Interviews were conducted by trained Ateso-speaking interviewers. Two independent teams conducted analyses of interview transcripts following an inductive and thematic approach. Smith's Salience Index was used for analysis of free listing data. RESULTS: When asked about common reasons for visiting health clinics, the most salient responses were malaria, general postnatal care, and husbands being absent. Amongst the free listed items that were identified as mental health problems, the three highest ranked concerns were adeka na aomisio (sickness of thoughts); ipum (epilepsy), and emalaria (malaria). The terms epilepsy and malaria were used in ways that reflected both biomedical and cultural concepts of distress. Sickness of thoughts appeared to overlap substantially with major depression as described in international classification, and was perceived to be caused by unsupportive husbands, intimate partner violence, chronic poverty, and physical illnesses. Reported help-seeking for sickness of thoughts included turning to family and community members for support and consultation, followed by traditional or religious healers and health centers if the problem persisted. CONCLUSION: Our findings add to existing literature that describes 'thinking too much' idioms as cultural concepts of distress with roots in social adversity. In addition to making feasible and effective treatment available, our findings indicate the importance of prevention strategies that address the social determinants of psychological distress for perinatal women in post-conflict low-resource contexts.

Identification of Environmental Factors Related to Claviceps purpurea Ascospore Production in Perennial Ryegrass Seed Fields and Development of Predictive Models.

Claviceps purpurea, the causal agent of ergot of perennial ryegrass seed crops, overwinters as sclerotia in the soil and releases airborne ascospores in the spring that infect flower ovaries and replace seed with sclerotia. Burkard spore traps were used to quantify the dispersal phenology and concentration of ascospores in perennial ryegrass seed fields in the Columbia Basin of Oregon. Weather factors were measured concurrently with spore trapping. Nonparametric regression, box-and-whisker plots, and univariate analysis were used to visualize and identify trends between ascospore concentrations and weather variables. Most ascospores (75.4%) were trapped when minimum soil temperatures were between 16.2 and 20.4°C. Over 67% of the total ascospores trapped were observed when minimum air temperatures were between 6.8 and 12.4°C and 64% of ascospores were trapped when daily mean dew point was between 3.7 and 8.2°C. Environmental favorability index (EFI) models were developed and validated based on their ability to predict ascospore occurrence. The EFI models were able to predict ascospore occurrence with an accuracy of 71.7 to 87.5% depending on the year. The models were up to 79.8% accurate when validated using three years of historical spore trap data not used in the EFI model development. Ninety-four percent of ascospores were trapped when cumulative air degree days, using lower and upper thresholds of 10 and 25°C, respectively, were between 230 and 403. These results suggest that weather parameters can be used to model C. purpurea ascospore occurrence and potentially improve the timing and efficacy of fungicide applications by identifying when plant protection is most needed.

Mental health and psychosocial support for South Sudanese refugees in northern Uganda: a needs and resource assessment.

BACKGROUND: Since December 2013, an armed conflict in South Sudan has resulted in the displacement of over 2.2 million people, more than 270,000 of whom are presently in refugee settlements located throughout Uganda. Existing literature suggests that refugees are at increased risk for a range of mental health and psychosocial problems. There is international consensus on the importance of needs and resource assessments to inform potential mental health and psychosocial support (MHPSS) interventions. METHODS: We conducted a MHPSS needs and resource assessment in Rhino Camp refugee settlement in northern Uganda, between June and August 2014. We followed World Health Organization (WHO) and United Nations High Commissioner for Refugees (UNHCR) guidelines for MHPSS needs assessments in humanitarian settings. The assessment used a range of methodologies including: 1) a desk (literature) review to understand the context for mental health service provision; 2) an analysis of data from existing health information systems (HIS); 3) an assessment of the current infrastructure for service provision using a shortened version of a Who does What Where until When (4Ws); and 4) semi-structured individual and group interviews (total n = 86) with key informants (n = 13) and general community members (individual interviews n = 28, four focus groups with n = 45). RESULTS: Data from the HIS indicated that visits to health centers in refugee settlements attributable to psychotic disorders, severe emotional disorders, and other psychological complaints increased following the refugee influx between 2013 and 2014, but overall help-seeking from health centers was low compared to estimates from epidemiological studies. In semi-structured interviews the three highest ranked mental health and psychosocial problems included "overthinking", ethnic conflict, and child abuse. Other concerns included family separation, drug abuse, poverty, and unaccompanied minors. The 4Ws assessment revealed that there were very limited MHPSS services available in Rhino Camp. CONCLUSIONS: The types of MHPSS problems among South Sudanese refugees in northern Uganda are diverse and the burden appears to be considerable, yet there are currently few available services. The assessment indicates the need for a range of services addressing social concerns as well as varied types of mental conditions. The idiom of "overthinking" may form a useful starting point for intervention development and mental health communication.

Simple sequence repeat markers that identify Claviceps species and strains.

BACKGROUND: Claviceps purpurea is a pathogen that infects most members of Pooideae, a subfamily of Poaceae, and causes ergot, a floral disease in which the ovary is replaced with a sclerotium. When the ergot body is accidently consumed by either man or animal in high enough quantities, there is extreme pain, limb loss and sometimes death. RESULTS: This study was initiated to develop simple sequence repeat (SSRs) markers for rapid identification of C. purpurea. SSRs were designed from sequence data stored at the National Center for Biotechnology Information database. The study consisted of 74 ergot isolates, from four different host species, Lolium perenne, Poa pratensis, Bromus inermis, and Secale cereale plus three additional Claviceps species, C. pusilla, C. paspali and C.fusiformis. Samples were collected from six different counties in Oregon and Washington over a 5-year period. Thirty-four SSR markers were selected, which enabled the differentiation of each isolate from one another based solely on their molecular fingerprints. Discriminant analysis of principle components was used to identify four isolate groups, CA Group 1, 2, 3, and 4, for subsequent cluster and molecular variance analyses. CA Group 1 consisting of eight isolates from the host species P. pratensis, was separated on the cluster analysis plot from the remaining three groups and this group was later identified as C. humidiphila. The other three groups were distinct from one another, but closely related. These three groups contained samples from all four of the host species. These SSRs are simple to use, reliable and allowed clear differentiation of C. humidiphila from C. purpurea. Isolates from the three separate species, C. pusilla, C. paspali and C.fusiformis, also amplified with these markers. CONCLUSIONS: The SSR markers developed in this study will be helpful in defining the population structure and genetics of Claviceps strains. They will also provide valuable tools for plant breeders needing to identify resistance in crops or for researchers examining fungal movements across environments.

Spatial Patterns of Ergot and Quantification of Sclerotia in Perennial Ryegrass Seed Fields in Eastern Oregon.

Ergot, caused by Claviceps purpurea, is a major disease of perennial ryegrass grown for seed in eastern Oregon. The objective of this research was to quantify and describe the spatial patterns of ergot severity in each of three 50-ha commercial fields of perennial ryegrass grown for seed in 2012 and 2013. In total, 1,433 and 1,405 quadrats were sampled among the three fields in 2012 and 2013, respectively, and the percentage of quadrats with ergot ranged from 59 to 90%. The mean incidence of infected seed heads in each quadrat ranged between 13 and 29%, while mean severity in each quadrat ranged from 0.2 to 0.5 sclerotia per seed head. Significant autocorrelation and clustering were observed in all three fields in both years, as indicated by Moran's I and spatial analysis by distance indices of aggregation. The mean number of ergot sclerotia collected from each field after harvest ranged between 4 and 15 sclerotia m-2 in 2012 and 18 and 119 sclerotia m-2 in 2013. Sclerotia left in perennial fields after harvest are a significant source of inoculum that should be targeted for control. This is the first study to quantify spatial patterns of ergot in perennial ryegrass and provides insights into possible mechanisms that contribute to ergot etiology and epidemiology.

Group support psychotherapy for depression treatment in people with HIV/AIDS in northern Uganda: a single-centre randomised controlled trial.

BACKGROUND: Group support psychotherapy (GSP) is a culturally sensitive intervention that aims to treat depression by enhancing social support, teaching coping skills, and income-generating skills. We compared GSP with group HIV education (GHE) for treatment of depression in people with HIV in Uganda. METHODS: In this open-label randomised controlled trial, we included men and women with HIV, aged 19 years or older, who met the Mini International Neuropsychiatric Interview criteria for major depression from an urban HIV care centre in Kitgum district, northern Uganda. Participants were randomly assigned to receive eight weekly sessions of either GSP or GHE. Randomisation was achieved by urn (men and women separately picked a paper containing the intervention allocation from a basket; ratio 1:1), and the intervention sessions were given to gender-specific groups. Participants were followed up immediately after the intervention and 6 months after the end of treatment. The primary outcomes were change in depressive symptom scores (measured with the Self-Reporting Questionnaire) and in function scores (measured with a locally developed method), analysed by intention to treat using cluster-adjusted t tests and permutation tests. This trial is registered with The Pan African Clinical Trials Registry, number PACTR201402000742370. FINDINGS: Between Jan 6, and Jan 20, 2014, we assessed 150 individuals, of whom 109 were randomly assigned to receive eight weekly sessions of either GSP (n=57) or GHE (n=52). Change in mean depression scores immediately after intervention did not differ between groups (mean difference -0·19, 95% CI -1·77 to 1·39, p=0·78). Mean function scores did not differ between groups either (0·24, -0·41 to 0·88; p=0·41). At 6 months after end of treatment, participants in the GSP group had lower mean depression scores than did those in the GHE group (-2·50, -3·98 to 1·02, p value=0·005), and higher function scores (0·74, -0·17 to 1·65, p=0·09) than did participants in the GHE group. No adverse events were reported. INTERPRETATION: The benefits of existing HIV educational interventions in HIV care services could be improved by the addition of GSP content. Potential benefits of the integration of GSP into existing HIV interventions, such as adherence counselling or group HIV educational programmes, should be addressed in future studies. FUNDING: Grand Challenges Canada.

Afternoon Ascospore Release in Claviceps purpurea Optimizes Perennial Ryegrass Infection.

In Kentucky bluegrass (Poa pratensis), Claviceps purpurea, the causal agent of ergot, typically releases ascospores during the early-morning hours, between about midnight and 10:00 a.m., corresponding to time of flowering, when the unfertilized ovaries are most susceptible to infection. During aeromycology studies of C. purpurea in perennial ryegrass (Lolium perenne) in northeastern Oregon during 2008 to 2010 and 2013, a strain of C. purpurea was found that released ascospores in the afternoon, coinciding with flowering in perennial ryegrass. Under controlled environmental conditions, sclerotia from perennial ryegrass and Kentucky bluegrass released spores in the afternoon and morning, respectively, consistent with timing of spore release under field conditions. Internal transcribed spacer (ITS) sequences of single sclerotial isolates from Kentucky bluegrass and perennial ryegrass were consistent with C. purpurea, although minor variations in ITS sequences among isolates were noted. Differences between Kentucky bluegrass and perennial ryegrass isolates were observed in random amplified polymorphic DNA. Evidence is provided for adaptation of C. purpurea to perennial ryegrass by means of delayed spore release that coincides with afternoon flowering in perennial ryegrass.

Enhanced oxidative stress resistance through activation of a zinc deficiency transcription factor in Brachypodium distachyon.

Identification of viable strategies to increase stress resistance of crops will become increasingly important for the goal of global food security as our population increases and our climate changes. Considering that resistance to oxidative stress is oftentimes an indicator of health and longevity in animal systems, characterizing conserved pathways known to increase oxidative stress resistance could prove fruitful for crop improvement strategies. This report argues for the usefulness and practicality of the model organism Brachypodium distachyon for identifying and validating stress resistance factors. Specifically, we focus on a zinc deficiency B. distachyon basic leucine zipper transcription factor, BdbZIP10, and its role in oxidative stress in the model organism B. distachyon. When overexpressed, BdbZIP10 protects plants and callus tissue from oxidative stress insults, most likely through distinct and direct activation of protective oxidative stress genes. Increased oxidative stress resistance and cell viability through the overexpression of BdbZIP10 highlight the utility of investigating conserved stress responses between plant and animal systems.

Outcomes, feasibility and acceptability of a group support psychotherapeutic intervention for depressed HIV-affected Ugandan adults: a pilot study.

BACKGROUND: Psychotherapy is the recommended first line treatment for mild to moderate depression. However, its availability in low resource settings is limited. We developed a manualized culturally sensitive group support psychotherapeutic intervention for depressed HIV affected Ugandan adults. In this study, we aimed to assess its feasibility, acceptability and impact on depression, functioning, social support and self-esteem. METHODS: A total of 77 depressed individuals were assigned to the group intervention (n=48) and a wait-list control group (n=29), and assessed before, during and at the end of the intervention. The self-reporting questionnaire, a locally relevant function assessment instrument, the Rosenberg self-esteem scale, and the multiple dimensions perceived social support scale were administered to assess depression symptoms, functioning, self-esteem and social support at three assessment periods. Multivariate longitudinal regression models were used to determine change in outcomes over time between the two groups. Participants were asked to evaluate the intervention. RESULTS: Post -intervention assessments indicate that, in comparison to the wait-list control group, the intervention group had a faster reduction in depression symptom scores [OR=0.00,95% CI, 0.00-0.003] and faster increase in functioning scores [OR=4.82, 95% CI, 2.39 to 9.75], social support scores [OR=2.68, 95% CI, 1.50-4.78] and self-esteem [OR=1.90, 95% CI 1.48-2.44]. Sixty-three percent of participants strongly agreed that the intervention had reduced their depression and would recommend it to other depressed individuals. LIMITATIONS: Inadequate study power due to small sample sizes may result in imprecise confidence intervals even when there are significant differences. The use of non-random samples could have resulted in selection bias. CONCLUSIONS: This intervention appears feasible, acceptable and promising in treating depression and restoring function, enhancing social support and self-esteem. Larger and randomized evaluations are warranted.

Developing a culturally sensitive group support intervention for depression among HIV infected and non-infected Ugandan adults: a qualitative study.

BACKGROUND: Depression is ranked first among neuropsychiatric diseases that contribute to the burden of disease in low- and middle-income countries. However, access to antidepressants is limited and there is a dearth of locally developed psychotherapeutic interventions targeted to treat depression. AIM: We aimed to obtain information on the cultural understanding of depression symptoms, complications and treatment methods used in post-conflict communities in northern Uganda in order to inform the development of an indigenous group support intervention to treat depression. METHODS: Focus group discussions (FGDs) were conducted with a total of 110 men and women aged 19-68 years. FDGs took place in a private space, lasted about 2-3h and were conducted in the local language for patients and their caregivers and in English for health workers. Interview transcripts from the FGDs were reviewed for accuracy, translated into English and transcribed. QRS Nvivo 10 qualitative data analysis software was used for coding and thematic analysis. RESULTS: Our study revealed community misperceptions about etiology, presentation and treatment of depression. Regardless of HIV status, most FGD participants who were not health workers linked depression symptoms to HIV infection. Although there were concerns about confidentiality of issues disclosed, many FGD participants were supportive of a group support intervention, tailored to their gender and age, that would not only focus on treating depression but also provided them with skills to improve their livelihoods. Simple CBT techniques were deemed culturally appropriate and acceptable. LIMITATION: Generalizability of study findings may be limited given that the sample was primarily of Luo ethnicity yet there are different ethnic populations in the region. CONCLUSION: Local communities can directly inform intervention content. The participants׳ preferences confirmed the need for a gender-specific intervention for depression that extends beyond medications and empowers them emotionally, socially and economically.

The impact of group counseling on depression, post-traumatic stress and function outcomes: a prospective comparison study in the Peter C. Alderman trauma clinics in northern Uganda.

BACKGROUND: The effectiveness of group interventions for adults with mental distress in post-conflict settings is less clear in sub-Saharan Africa. AIM: To assess the impact of group counseling intervention on depression, post-traumatic stress and function outcomes among adults attending the Peter C. Alderman Foundation (PCAF) trauma clinics in northern Uganda. METHODS: 631 War affected adults were enrolled into PCAF trauma clinics. Using a quasi-experimental design, assessments were conducted at baseline, at 3 and 6 months following initiation of care. Multivariate longitudinal regression models were used to determine change in depression, post-traumatic stress and function scores over time among group counseling participants and non-participants. RESULTS: In comparison to non-participants, participants had faster reduction in depression scores during the 6-month follow-up period [ß=-1.84, 95%CI (-3.38 to -0.30), p=0.019] and faster reduction in post-traumatic stress scores during the 3-month follow-up period [ß=-2.14, 95%CI (-4.21 to -0.10), p=0.042]. At 3-month follow up, participants who attended two or more sessions had faster increase in function scores [ß=3.51, 95%CI (0.61-6.40), p=0.018] than participants who attended only one session. LIMITATIONS: Selection bias due to the use of non-random samples. Substantial attrition rates and small sample sizes may have resulted in insufficient statistical power to determine meaningful differences. CONCLUSION: The group counseling intervention offered in the PCAF clinics may have considerable mental health benefits over time. There is need for more research to structure, standardize and test the efficacy of this intervention using a randomized controlled trial.

Implementation and scale-up of psycho-trauma centers in a post-conflict area: a case study of a private-public partnership in northern Uganda.

As one article in an ongoing series on Global Mental Health Practice, Etheldreda Nakimuli-Mpungu and colleagues describe a private-public partnership that implemented and scaled psycho-trauma centers in Northern Uganda.

Infection of Brachypodium distachyon by formae speciales of Puccinia graminis: early infection events and host-pathogen incompatibility.

Puccinia graminis causes stem rust, a serious disease of cereals and forage grasses. Important formae speciales of P. graminis and their typical hosts are P. graminis f. sp. tritici (Pg-tr) in wheat and barley, P. graminis f. sp. lolii (Pg-lo) in perennial ryegrass and tall fescue, and P. graminis f. sp. phlei-pratensis (Pg-pp) in timothy grass. Brachypodium distachyon is an emerging genetic model to study fungal disease resistance in cereals and temperate grasses. We characterized the P. graminis-Brachypodium pathosystem to evaluate its potential for investigating incompatibility and non-host resistance to P. graminis. Inoculation of eight Brachypodium inbred lines with Pg-tr, Pg-lo or Pg-pp resulted in sporulating lesions later accompanied by necrosis. Histological analysis of early infection events in one Brachypodium inbred line (Bd1-1) indicated that Pg-lo and Pg-pp were markedly more efficient than Pg-tr at establishing a biotrophic interaction. Formation of appressoria was completed (60-70% of germinated spores) by 12 h post-inoculation (hpi) under dark and wet conditions, and after 4 h of subsequent light exposure fungal penetration structures (penetration peg, substomatal vesicle and primary infection hyphae) had developed. Brachypodium Bd1-1 exhibited pre-haustorial resistance to Pg-tr, i.e. infection usually stopped at appressorial formation. By 68 hpi, only 0.3% and 0.7% of the Pg-tr urediniospores developed haustoria and colonies, respectively. In contrast, development of advanced infection structures by Pg-lo and Pg-pp was significantly more common; however, Brachypodium displayed post-haustorial resistance to these isolates. By 68 hpi the percentage of urediniospores that only develop a haustorium mother cell or haustorium in Pg-lo and Pg-pp reached 8% and 5%, respectively. The formation of colonies reached 14% and 13%, respectively. We conclude that Brachypodium is an apt grass model to study the molecular and genetic components of incompatiblity and non-host resistance to P. graminis.

Survival, Germination, and Growth of Epichloë typhina and Significance of Leaf Wounds and Insects in Infection of Orchardgrass.

Epichloë typhina is an important stroma-producing endophytic ascomycete that is responsible for significant yield loss in orchardgrass (Dactylis glomerata) seed production fields. Infection is presumed to occur through leaves or stems, although details of the infection process and conditions that favor leaf infection are not well understood. The primary objectives of this study were to investigate the early stages of infection, including the effect of temperature or water potential on ascospore germination and subsequent growth of E. typhina, the tolerance of ascospores to desiccation, the requirement of leaf wounds for infection of orchardgrass by E. typhina, and the potential for insects to facilitate infection. Ascospores tolerated dry conditions, with at least 40% surviving 12 days under desiccation. Germination and growth of E. typhina was greatest at 25°C, with little to no growth at 5 and 35°C. Mycelial growth decreased with decreasing water potential from -0.3 to -10 MPa. Ascospore germination on leaves was predominantly hyphal at wound sites and iterative (conidiogenous) at sites without wounds. E. typhina typically entered leaves through wounds. Direct penetration was rarely observed and appeared to be associated with ascospore clusters. Germ tubes were significantly longer at sites with honeydew deposits from the bird cherry-oat aphid than at sites without honeydew. Growth of E. typhina was also observed at feeding sites of eriophyid mites, suggesting that leaf-wounding or sap-excreting insects support epiphyllous growth of E. typhina on leaves.

A Reevaluation of the Host Range and Geographical Distribution of Claviceps Species in the United States.

A listing of host and state reports and distribution maps for 11 taxa of Claviceps occurring in the United States, including C. africana, C. cinerea, C. grohii, C. nigricans, C. paspali, C. pusilla, C. purpurea var. purpurea and var. spartinae, C. tripsaci, C. yanagawensis, and C. zizaniae, was prepared based on literature citations and examination of specimens from herbaria. The occurrence of C. ranunculoides is questioned based on examination of conidia and sclerotia from archived specimens. Collections of C. purpurea var. purpurea from grasses in the Pani-coideae were referred to other Claviceps spp. based on occurrence of macroconidia and micro-conidia. C. purpurea var. purpurea was found on 165 grass species within the continental United States and Alaska. The size of conidia of C. purpurea var. purpurea was found to be relatively stable across host and geographical regions. However, conidia of C. purpurea var. purpurea from hosts in the Aveneae and Meliceae (generally associated with wet habitats) were more variable in size and generally larger than those from other tribes in the Pooideae. Claviceps spp. in the continental United States occurred in diverse habitats, including temperate grasslands of the middle to northern latitudes (C. purpurea var. purpurea, C. nigricans) to the middle to southern latitudes (C. pusilla), coastal habitats (C. purpurea var. spartinae, C. ziza-niae), northern wetlands (C. grohii), southern temperate to subtropical grasslands (C. africana, C. paspali, C. tripsaci, C. yanagawensis), and arid southwestern grasslands (C. cinerea).

Occurrence and Distribution of Ergot and Estimates of Seed Loss in Kentucky Bluegrass Grown for Seed in Central Oregon.

In 1991 to 1993, ergot was detected in 36, 44, and 62%, respectively, of fields of Kentucky bluegrass grown for seed in central Oregon. Relatively few fields (2 to 13%) had a high (more than 20 sclerotia/gm seed) level of ergot. Ergot severity (percent sclerotia by weight) in 1991 to 1993 was estimated at 0.85, 0.07, and 0.34%, respectively. Percent seed replaced by ergot in 1991 to 1993 was estimated at 0.22, 0.02, and 0.08, respectively. Recleaning of seed to reduce ergot contamination and to meet purity standards resulted in a 7.8% reduction in marketable seed weight. Estimated value of seed replaced by ergot in 1991, 1992, and 1993, was $75,625, $4,758, and $17,076, respectively. Estimated value of seed lost during recleaning in 1991, 1992, and 1993, was $37,669, $8,171, and $21,964, respectively. Weed grasses supporting ergot at the time of harvest of Kentucky bluegrass were species of Bromus, Secale, Festuca, and Poa. However, very few seed heads of weed grasses were infected, and they appeared to contribute little to ergot development in central Oregon. Most infested fields (with more than one sclerotium/gm seed prior to recleaning) or weed grass sites with ergot were located in the southern range of the area of study.