Schrödinger cat states of a 16-microgram mechanical oscillator.

According to quantum mechanics, a physical system can be in any linear superposition of its possible states. Although the validity of this principle is routinely validated for microscopic systems, it is still unclear why we do not observe macroscopic objects to be in superpositions of states that can be distinguished by some classical property. Here we demonstrate the preparation of a mechanical resonator in Schrödinger cat states of motion, where the ∼1017 constituent atoms are in a superposition of two opposite-phase oscillations. We control the size and phase of the superpositions and investigate their decoherence dynamics. Our results offer the possibility of exploring the boundary between the quantum and classical worlds and may find applications in continuous-variable quantum information processing and metrology with mechanical resonators.

Excitonic Spin-Coherence Lifetimes in CdSe Nanoplatelets Increase Significantly with Core/Shell Morphology.

We report spin-polarized transient absorption for colloidal CdSe nanoplatelets as functions of thickness (2-6 monolayer thickness) and core/shell motif. Using electro-optical modulation of co- and cross-polarization pump-probe combinations, we sensitively observe spin-polarized transitions. Core-only nanoplatelets exhibit few-picosecond spin lifetimes that weakly increase with layer thickness. The spectral content of differenced spin-polarized signals indicate biexciton binding energies that decrease with increasing thickness and smaller values than previously reported. Shell growth of CdS with controlled thicknesses, which partially delocalize the electron from the hole, significantly increases the spin lifetime to ∼49 ps at room temperature. Implementation of ZnS shells, which do not alter delocalization but do alter surface termination, increased spin lifetimes up to ∼100 ps, bolstering the interpretation that surface termination heavily influences spin coherence, likely due to passivation of dangling bonds. Spin precession in magnetic fields both confirms long coherence lifetime at room temperature and yields the excitonic g factor.

Spore Dispersal Patterns of Colletotrichum fioriniae in Orchards and the Timing of Apple Bitter Rot Infection Periods.

Bitter rot is a major disease of apple fruit in warm and humid regions. It is caused by various species in the Colletotrichum gloeosporioides and C. acutatum species complexes, of which C. fioriniae of the C. acutatum species complex is most common in the Mid-Atlantic region of the United States. While bitter rot management begins with good cultural practices, fungicides are generally used for consistent control. Fungicides should be applied before or during infection periods, but the timing of infection is unclear due to the hemibiotrophic lifestyle of the causal species. To determine when infection periods occur, we quantified C. fioriniae spore dispersal throughout three growing seasons and compared the temporal susceptibility of apples in two seasons of field trials. Spores were detected in rainwater from bud break to leaf drop, with the highest spore quantities in the summer and early fall correlating with optimal temperatures for C. fioriniae. Late-season-inoculated fruit had more bitter rot than early-season-inoculated fruit, but this was also positively correlated with periods of optimal temperatures and moisture for infection. In the context of previous experiments, these results suggest that infection periods are primarily determined by temperature and moisture rather than apple fruit phenology. Based on the relative numbers of spores and biotrophic and necrotrophic infections, only a tiny proportion of spores establish viable biotrophic infections, but a relatively high proportion of biotrophic infections switch to necrotrophy. We suggest bitter rot management should focus on preventing initial biotrophic infections by protecting apples during weather conditions that favor infection.

Characterizations of an Emerging Disease: Apple Blotch Caused by Diplocarpon coronariae (syn. Marssonina coronaria) in the Mid-Atlantic United States.

Apple orchards with minimal or reduced fungicide inputs in the Mid-Atlantic region of the United States have experienced outbreaks of severe premature defoliation with symptoms that matched those of apple blotch disease (ABD) caused by Diplocarpon coronariae. Fungal isolates obtained from symptomatic apple leaves and fruit produced uniform slow-growing, dark-gray colonies on peptone potato dextrose agar and had conidia. Internal transcribed spacer DNA sequences matched with D. coronariae and Koch's postulates were fulfilled when typical ABD symptoms occurred when reinoculated onto apple leaves and fruit. Spore dispersal in nonfungicide-treated orchards detected with quantitative PCR was low in early spring and dropped to undetectable levels in late May and early June before rising exponentially to highs in July and August, which coincided with symptom development. Only low spore numbers were detected in fungicide-treated orchards and nearby forests. In preliminary fungicide tests, fluxapyroxad, thiophanate methyl, and difenoconazole effectively inhibited mycelial growth of isolates in vitro. When apple cultivars Fuji and Honeycrisp were inoculated with D. coronariae, Honeycrisp showed delayed onset of symptoms and lower disease severity, and the transcription profile of seven host defense-related genes showed that PR-2, PR-8, LYK4, and CERK1 were highly induced in Honeycrisp at 2 and 5 days postinoculation. This is the first report of ABD in the Mid-Atlantic United States, which includes studies of seasonal D. coronariae spore dispersal patterns, preliminary fungicide efficacy, and host defense-related gene expression to assist development of best ABD management practices.

'Should I stay or should I go?': A mixed methods study on nurse retention during challenging times.

Background: The World Health Organization estimates that between 80,000 and 180,000 medical personnel perished as a result of COVID-19. Although studies about nurses' organizational commitment during the COVID-19 pandemic have been conducted, the sources of motivations and resilience strategies of nurses in providing a quality healthcare service amidst the COVID-19 pandemic have yet to be explored. Objective: This study aimed to investigate how motivation and resilience influence nurses to serve and cater to patients during the COVID-19 pandemic. Methods: A sequential exploratory mixed approach was used in this study between July and August 2022. The Connor-Davidson Resilience Scale (CD-RISC-10), Work Extrinsic and Intrinsic Motivations scale (WEIMS), and Garbee and Killacky's Intent to Stay Scale (GKISS) were used to measure resilience, motivation, and intention to stay, among 50 nurses within Metro Manila. Quantitative data were analyzed using quantile regression, while qualitative data from eight participants were analyzed using thematic analysis. Results: The majority of the nurses were working 12 hours and above (52%) and earning a bi-weekly income of PHP 15,001 to 20,000 (96%). The GKISS scores of most respondents indicated their likelihood of remaining in their current profession was moderately low (Mdn = 12.5; IQR = 12-14). It was also found that there was no sufficient statistical evidence to conclude that intention to stay was associated with resilience (p = 0.914) and work motivation (p = 0.560). The qualitative strand of this study explored the significant influences of motivation, resilience strategies, and sources of intention to stay among Filipino nurses while facing the COVID-19 pandemic. The primary motivations of nurses lie in family, passion for work, and career development, while the resilience strategies include adaptiveness, time management skills, and self-fulfillments. On the other hand, the intent to stay greatly lies in serving the people and the country. Conclusion: This study concludes that positive and negative resilience and motivations from different facets of the social life of Filipino nurses, including passion, familial ties, patient care, and faith are the antecedents influencing the intention to serve in the healthcare service. In terms of staying for an extended period in a nursing career, the study found that institutionalized interventions, adequate compensation and benefits, and a good workplace are determinants of staying longer in the Philippines as Filipino nurses.

Performance validity in the dementia clinic: Specificity of validity tests when used individually and in aggregate across levels of cognitive impairment severity.

OBJECTIVE: This study examined the specificity of both individual PVTs and three different PVT batteries in individuals undergoing neuropsychological evaluation for dementia in order to establish both appropriate individual test cutoffs and multiple-PVT failure criterion. METHODS: Participants were 311 validly performing patients with no cognitive impairment (n = 24), mild cognitive impairment (MCI; n = 115), mild dementia (n = 122), or moderate dementia (n = 50). Cutoffs associated with ≥90% specificity were established for 11 individual PVTs across impairment severity groups. Aggregate false positive rates according to number of PVTs failed were examined for two 4-PVT batteries and one 7-PVT battery. One-way ANOVAs with post-hoc comparisons were conducted for each PVT. RESULTS: Performance on 9 of 11 PVTs significantly differed according to impairment severity. PVT cutoffs achieving ≥90% specificity also generally varied by group. For PVTs previously validated in non-dementia samples, slight adjustments from established cutoffs were generally required to maintain adequate specificity in MCI and mild dementia groups, with greater modifications required in the moderate dementia group. A criterion of ≥2 PVT failures resulted in ≥90% specificity in both 4-PVT batteries across groups. In the 7-PVT battery, adequate specificity was achieved with ≥2 failures in MCI and ≥3 failures in the mild dementia group. CONCLUSIONS: The incorporation and interpretation of several easily assimilated multiple-PVT batteries in dementia evaluations are explored. Additionally, data regarding individual PVT performance according to cognitive impairment severity are provided to aide validity assessment of both patients undergoing dementia evaluation and examinees who are less impaired.

Base rates of invalidity when patients undergoing routine clinical evaluations have social security disability as an external incentive.

Objective: Social Security Disability is a common external incentive in neuropsychological evaluations. This study determined base rates of invalidity when patients referred for routine clinical evaluations have Social Security Disability as an external incentive. Method: Patients (n = 242) were grouped as validly or invalidly performing based on the use of multiple performance validity tests. Frequency analyses were then conducted. Results: As a whole, 46.0% of clinically referred patients with Social Security Disability as an external incentive produced invalid data. When divided by disability pursuit status, 58.6% of individuals already receiving Social Security Disability, 44.6% of individuals actively seeking Social Security Disability, and 39.3% of individuals considering seeking Social Security Disability produced invalid data. By comparison, only 8.5% of clinically referred patients without known external incentives produced invalid data. Conclusions: Beyond establishing base rates, these data indicate that the external incentive, not necessarily the evaluation setting, increases the rate of invalidity, as obtained base rates mirror those observed in independent medical examinations. In addition, this study highlights that even patients who report that they are considering but have not committed themselves to pursuing an external incentive frequently invalidate testing.

Prodromal Dementia With Lewy Bodies: Evolution of Symptoms and Predictors of Dementia Onset.

BACKGROUND: Research criteria for prodromal dementia with Lewy bodies (DLB) were published in 2020, but little is known regarding prodromal DLB in clinical settings. METHODS: We identified non-demented participants without neurodegenerative disease from the National Alzheimer's Coordinating Center Uniform Data Set who converted to DLB at a subsequent visit. Prevalence of neuropsychiatric and motor symptoms were examined up to 5 years prior to DLB diagnosis. RESULTS: The sample included 116 participants clinically diagnosed with DLB and 348 age and sex-matched (1:3) Healthy Controls. Motor slowing was present in approximately 70% of participants 3 years prior to DLB diagnosis. In the prodromal phase, 50% of DLB participants demonstrated gait disorder, 70% had rigidity, 20% endorsed visual hallucinations, and over 50% of participants endorsed REM sleep behavior disorder. Apathy, depression, and anxiety were common prodromal neuropsychiatric symptoms. The presence of 1+ core clinical features of DLB in combination with apathy, depression, or anxiety resulted in the greatest AUC (0.815; 95% CI: 0.767, 0.865) for distinguishing HC from prodromal DLB 1 year prior to diagnosis. The presence of 2+ core clinical features was also accurate in differentiating between groups (AUC = 0.806; 95% CI: 0.756, 0.855). CONCLUSION: A wide range of motor, neuropsychiatric and other core clinical symptoms are common in prodromal DLB. A combination of core clinical features, neuropsychiatric symptoms and cognitive impairment can accurately differentiate DLB from normal aging prior to dementia onset.

Fungicide Sensitivity of Colletotrichum Species Causing Bitter Rot of Apple in the Mid-Atlantic U.S.A.

Apple growers in the Mid-Atlantic region of the U.S.A. have reported increased losses to bitter rot of apple. We tested the hypothesis that this increase is because the Colletotrichum population has developed resistance to commonly used single-mode-of-action (single-MoA) fungicides. We screened 220 Colletotrichum isolates obtained from 38 apple orchards in the Mid-Atlantic region for resistance to 11 fungicides in Fungicide Resistance Action Committee (FRAC) groups 1, 7, 9, 11, 12, and 29. Eleven (5%) of these isolates were resistant to FRAC group 1 with confirmed ß-tubulin E198A mutations, and two (<1%) were also resistant to FRAC group 11 with confirmed cytochrome-b G143A mutations. Such low frequencies of resistant isolates indicate that fungicide resistance is unlikely to be the cause of any regional increase in bitter rot. A subsample of isolates was subsequently tested in vitro for sensitivity to every single-MoA fungicide registered for apple in the Mid-Atlantic U.S.A. (22 fungicides; FRAC groups 1, 3, 7, 9, 11, 12, and 29), and 13 fungicides were tested in field trials. These fungicides varied widely in efficacy both within and between FRAC groups. Comparisons of results from our in vitro tests with results from our field trials and other field trials conducted across the eastern U.S.A. suggested that EC25 values (concentrations that reduce growth by 25%) are better predictors of fungicide efficacy in normal field conditions than EC50 values. We present these results as a guideline for choosing single-MoA fungicides for bitter rot control in the Mid-Atlantic U.S.A.

Methodology for Single Bee and Bee Brain 1H-NMR Metabolomics.

The feasibility of metabolomic 1H NMR spectroscopy is demonstrated for its potential to help unravel the complex factors that are impacting honeybee health and behavior. Targeted and non-targeted 1H NMR metabolic profiles of liquid and tissue samples of organisms could provide information on the pathology of infections and on environmentally induced stresses. This work reports on establishing extraction methods for NMR metabolic characterization of Apis mellifera, the European honeybee, describes the currently assignable aqueous metabolome, and gives examples of diverse samples (brain, head, body, whole bee) and biologically meaningful metabolic variation (drone, forager, day old, deformed wing virus). Both high-field (600 MHz) and low-field (80 MHz) methods are applicable, and 1H NMR can observe a useful subset of the metabolome of single bees using accessible NMR instrumentation (600 MHz, inverse room temperature probe) in order to avoid pooling several bees. Metabolite levels and changes can be measured by NMR in the bee brain, where dysregulation of metabolic processes has been implicated in colony collapse. For a targeted study, the ability to recover 10-hydroxy-2-decenoic acid in mandibular glands is shown, as well as markers of interest in the bee brain such as GABA (4-aminobutyrate), proline, and arginine. The findings here support the growing use of 1H NMR more broadly in bees, native pollinators, and insects.

How Much Education and Training Do Residents Across Specialties Receive in Neuropsychology?

INTRODUCTION: Neuropsychologists play an important role on multidisciplinary teams with physicians from multiple specialties. The extent of residency training on the use of neuropsychological services is unclear. Medical residents across multiple specialties throughout the United States were surveyed to assess resident education, training, and understanding of neuropsychological services, along with their intent to consult neuropsychologists in the future. METHODS: A survey was sent to residents in accredited psychiatry, neurology, family medicine, and internal medicine programs. After data were collected, chi-square group level analyses with post-hoc pairwise comparisons were used to analyze the data. RESULTS: A total of 434 residents took the survey. The proportion of residents exposed to neuropsychology during residency varied significantly according to specialty (χ2 (3, N = 419) = 51.4, p < 0.001), with more psychiatry and neurology residents reporting exposure than residents in family medicine or internal medicine. Similarly, the proportion of psychiatry and neurology residents who 'agree' or 'strongly agree' that they understand the nature of neuropsychological services differed significantly from family medicine and internal medicine residents (χ2 (3, N = 415) = 40.4, p < 0.001). The majority of residents across all specialties (85.7%) reported they are likely to consult/order neuropsychological services in future practice. CONCLUSIONS: The majority of residents in all specialties reported exposure to neuropsychological services in some manner, but forms of exposure varied. Results indicated a need for increased education and training in neuropsychological services, especially within family medicine and internal medicine programs.

Opportunities and Possibilities of Developing an Advanced Precision Spraying System for Tree Fruits.

Reducing risk from pesticide applications has been gaining serious attention in the last few decades due to the significant damage to human health, environment, and ecosystems. Pesticide applications are an essential part of current agriculture, enhancing cultivated crop productivity and quality and preventing losses of up to 45% of the world food supply. However, inappropriate and excessive use of pesticides is a major rising concern. Precision spraying addresses these concerns by precisely and efficiently applying pesticides to the target area and substantially reducing pesticide usage while maintaining efficacy at preventing crop losses. This review provides a systematic summary of current technologies used for precision spraying in tree fruits and highlights their potential, briefly discusses factors affecting spraying parameters, and concludes with possible solutions to reduce excessive agrochemical uses. We conclude there is a critical need for appropriate sensing techniques that can accurately detect the target. In addition, air jet velocity, travel speed, wind speed and direction, droplet size, and canopy characteristics need to be considered for successful droplet deposition by the spraying system. Assessment of terrain is important when field elevation has significant variability. Control of airflow during spraying is another important parameter that needs to be considered. Incorporation of these variables in precision spraying systems will optimize spray decisions and help reduce excessive agrochemical applications.

Normal cognitive test scores cannot be interpreted as accurate measures of ability in the context of failed performance validity testing: A symptom- and detection-coached simulation study.

Introduction: While use of performance validity tests (PVTs) has become a standard of practice in neuropsychology, there are differing opinions regarding whether to interpret cognitive test data when standard scores fall within normal limits despite PVTs being failed. This study is the first to empirically determine whether normal cognitive test scores underrepresent functioning when PVTs are failed.Method: Participants, randomly assigned to either a simulated malingering group (n = 50) instructed to mildly suppress test performances or a best-effort/control group (n = 50), completed neuropsychological tests which included the North American Adult Reading Test (NAART), California Verbal Learning Test - 2nd Edition (CVLT-II), and Test of Memory Malingering (TOMM).Results: Groups were not significantly different in age, sex, education, or NAART predicted intellectual ability, but simulators performed significantly worse than controls on the TOMM, CVLT-II Forced Choice Recognition, and CVLT-II Short Delay Free Recall. The groups did not significantly differ on other examined CVLT-II measures. Of simulators who failed validity testing, 36% scored no worse than average and 73% scored no worse than low average on any of the examined CVLT-II indices.Conclusions: Of simulated malingerers who failed validity testing, nearly three-fourths were able to produce cognitive test scores that were within normal limits, which indicates that normal cognitive performances cannot be interpreted as accurately reflecting an individual's capabilities when obtained in the presence of validity test failure. At the same time, only 2 of 50 simulators were successful in passing validity testing while scoring within an impaired range on cognitive testing. This latter finding indicates that successfully feigning cognitive deficits is difficult when PVTs are utilized within the examination.

Transcriptomic Responses of the Honey Bee Brain to Infection with Deformed Wing Virus.

Managed colonies of European honey bees (Apis mellifera) are under threat from Varroa destructor mite infestation and infection with viruses vectored by mites. In particular, deformed wing virus (DWV) is a common viral pathogen infecting honey bees worldwide that has been shown to induce behavioral changes including precocious foraging and reduced associative learning. We investigated how DWV infection of bees affects the transcriptomic response of the brain. The transcriptomes of individual brains were analyzed using RNA-Seq after experimental infection of newly emerged adult bees with DWV. Two analytical methods were used to identify differentially expressed genes from the ~15,000 genes in the Apis mellifera genome. The 269 genes that had increased expression in DWV infected brains included genes involved in innate immunity such as antimicrobial peptides (AMPs), Ago2, and Dicer. Single bee brain NMR metabolomics methodology was developed for this work and indicates that proline is strongly elevated in DWV infected brains, consistent with the increased presence of the AMPs abaecin and apidaecin. The 1361 genes with reduced expression levels includes genes involved in cellular communication including G-protein coupled, tyrosine kinase, and ion-channel regulated signaling pathways. The number and function of the downregulated genes suggest that DWV has a major impact on neuron signaling that could explain DWV related behavioral changes.

Bitter Rot of Apple in the Mid-Atlantic United States: Causal Species and Evaluation of the Impacts of Regional Weather Patterns and Cultivar Susceptibility.

Apple growers in the Mid-Atlantic region of the United States have been reporting an increase in losses to bitter rot of apple and are requesting up-to-date management recommendations. Management is complicated by variations in apple cultivar susceptibility, temperature, rainfall, and biology of the Colletotrichum spp. that cause bitter rot. Over 500 apple fruit with bitter rot were obtained from 38 orchards across the Mid-Atlantic and the causal species were identified as Colletotrichum fioriniae and C. nymphaeae of the C. acutatum species complex and C. chrysophilum, C. noveboracense, C. siamense, C. fructicola, C. henanense, and C. gloeosporioides sensu stricto of the C. gloeosporioides species complex, the latter two being first reports. Species with faster in vitro growth rates at higher temperatures were more abundant in warmer regions of the Mid-Atlantic, while those with slower growth rates at higher temperatures were more abundant in cooler regions. Regional bloom dates are earlier and weather data show a gradual warming trend that likely influenced but was not necessarily the main cause of the recent increase in bitter rot in the region. A grower survey of apple cultivar susceptibility showed high variation, with the increase in acres planted to the highly susceptible cultivar Honeycrisp broadly corresponding to the increase in reports of bitter rot. These results form a basis for future studies on the biology and ecology of the Colletotrichum spp. responsible, and suggest that integrated bitter rot management must begin with selection of less-susceptible apple cultivars.

80 questions for UK biological security.

Multiple national and international trends and drivers are radically changing what biological security means for the United Kingdom (UK). New technologies present novel opportunities and challenges, and globalisation has created new pathways and increased the speed, volume and routes by which organisms can spread. The UK Biological Security Strategy (2018) acknowledges the importance of research on biological security in the UK. Given the breadth of potential research, a targeted agenda identifying the questions most critical to effective and coordinated progress in different disciplines of biological security is required. We used expert elicitation to generate 80 policy-relevant research questions considered by participants to have the greatest impact on UK biological security. Drawing on a collaboratively-developed set of 450 questions, proposed by 41 experts from academia, industry and the UK government (consulting 168 additional experts) we subdivided the final 80 questions into six categories: bioengineering; communication and behaviour; disease threats (including pandemics); governance and policy; invasive alien species; and securing biological materials and securing against misuse. Initially, the questions were ranked through a voting process and then reduced and refined to 80 during a one-day workshop with 35 participants from a variety of disciplines. Consistently emerging themes included: the nature of current and potential biological security threats, the efficacy of existing management actions, and the most appropriate future options. The resulting questions offer a research agenda for biological security in the UK that can assist the targeting of research resources and inform the implementation of the UK Biological Security Strategy. These questions include research that could aid with the mitigation of Covid-19, and preparation for the next pandemic. We hope that our structured and rigorous approach to creating a biological security research agenda will be replicated in other countries and regions. The world, not just the UK, is in need of a thoughtful approach to directing biological security research to tackle the emerging issues.

Feedback with patients who produce invalid testing: Professional values and reported practices.

OBJECTIVE: Providing feedback to clinical patients who produce invalid neuropsychological test data presents with several potential challenges. Given the limited guidance available on the topic, neuropsychologists most likely utilize approaches that idiosyncratically incorporate professional values related to both assessment and patient care to address overarching feedback goals. The current article discusses professional values believed to inform feedback decisions and presents survey results regarding how neuropsychologists would approach feedback across various clinical scenarios where testing is invalid. METHOD: Participants were 209 adult-focused clinical neuropsychologists recruited via professional listservs, the majority of whom reported being board certified. Respondents were provided three case vignettes of clinical patients who produced invalid test data and were asked how they would provide feedback to each patient. Open-ended responses were coded to determine the relative frequency of feedback approaches, explicit statements, and implied goals. RESULTS: Nearly all respondents (98%) indicated that feedback would include some description of the invalid findings, and most respondents indicated that they would provide explanations for the reasons of invalidity (67%) and statements regarding the impact of invalidity on test interpretation (75%). There was little agreement across respondents, however, regarding specific feedback approach. Feedback goals included to Inform, Investigate, Treat, Educate, and Correct, with the presence of these implied goals also varying across respondents. CONCLUSIONS: The findings indicate that there is minimal consensus regarding feedback approaches provided to patients who produce invalid test data and underscore a need for further development and validation of specific feedback methods. The results are discussed within the context of the potentially competing professional values of evidence-based assessment, patient-doctor collaboration, and aspirational principles of beneficence and fidelity.

Cross-validation of the Invalid Forgetting Frequency Index (IFFI) from the Test of Memory Malingering.

OBJECTIVE: To increase sensitivity of the Test of Memory Malingering (TOMM), adjustments have been proposed, including adding consistency indices. The Invalid Forgetting Frequency Index (IFFI) is the most recently developed consistency index. While strong classification accuracy rates were originally reported, it currently lacks cross-validation. METHOD: A sample of 184 outpatients was utilized. Valid performers passed all criterion performance validity tests (PVTs) and invalid performers failed two or more PVTs. Classification accuracy statistics were calculated. RESULTS: AUC for the IFFI was 0.80, demonstrating adequate discrimination between valid and invalid groups. A score of 3 or more inconsistent responses resulted in sensitivity and specificity rates of 63% and 92%, respectively. CONCLUSIONS: This is the first article to cross-validate the IFFI. In both the original IFFI study and the current study, the same cut-off was found to maintain at least 90% specificity while producing higher sensitivity rates than those achieved by traditional TOMM indices.

Quantification of Colletotrichum fioriniae in Orchards and Deciduous Forests Indicates It Is Primarily a Leaf Endophyte.

Colletotrichum fioriniae of the C. acutatum species complex is an important hemibiotrophic pathogen of vegetables and fruits in temperate regions worldwide. In apple, it is one of the primary species responsible for bitter rot disease. Understanding the disease cycle is complicated because many broadleaf plants can be hosts of C. fioriniae. By detecting and quantifying rain-splashed C. acutatum species complex conidia in more than 500 samples from heavily bitter-rot-infected apple orchards and nearby forested woodlots over two summers, we show that conidial quantities were higher in the woodlots than in the orchards. Testing of more than 1,000 surface-disinfected leaves of apple and 24 different forest plant species showed that overall C. fioriniae was an abundant leaf endophyte, with high variation in leaf colonization area. Endophytic isolates from leaves were pathogenic on apples, and multilocus sequence analysis showed 100% identity between most isolates from leaves and diseased fruits. Apple leaves endophytically infected with C. fioriniae were present in a conventionally managed orchard and abundant in an untreated orchard. These lines of evidence, in the context of previously published research, lead us to hypothesize that the main ecological role of C. fioriniae is that of a leaf endophyte, which we present as a generalized C. fioriniae infection cycle that provides an updated framework for its integrated management in agricultural systems.

Author Correction: Identification and characterization of Colletotrichum species causing apple bitter rot in New York and description of C. noveboracense sp. nov.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.