Efficacy of an individual-tailored smoking cessation intervention APP among Chinese smokers: study protocol for a randomized controlled trial.

BACKGROUND AND AIMS: Tobacco use has posed a tremendous public health problem for China. The Chinese government has taken great efforts to curb the tobacco epidemic. However, the existing smoking cessation services available in China are underused and have some limitations. Our research team intends to develop a smartphone smoking cessation application (SSC APP) and integrate it with the existing smoking cessation services. This study aims to assess the efficacy of the SSC APP developed by our research team through a randomized controlled trial (RCT). METHODS: Current smokers who are motivated to quit within 1 month (n = 1000) will be recruited both online and offline, and all potential participants will register and complete the prescreening assessment online. Participants will be randomly assigned to either the intervention group (receiving the SSC APP and a self-help smoking cessation manual) or the control group (receiving a self-help smoking cessation manual only) using a block randomization method. This study will be a two-arm, single-blind, parallel-group RCT. Participants will be followed up after enrollment through online questionnaires or by phone call. The primary outcome is self-reported 6-month continuous abstinence. The main secondary outcomes include self-reported 7-day point-prevalence abstinence at each follow-up; self-reported 3-month continuous abstinence; reduction in the number of cigarettes smoked per day; and the number of recent quit attempts. DISCUSSION: If this SSC APP proves to be effective, it could be integrated with the existing smoking cessation services and further facilitate smoking cessation at the population level in China. TRIAL REGISTRATION: Chinese Clinical Trial Registry: ChiCTR2200062097, Registered July 22, 2022.

Colletotrichum caladii sp. nov. Causing Anthracnose Leaf Spot of Caladium × hortulanum (Araceae) in Florida, U.S.A.

Caladium (Caladium × hortulanum) is an ornamental plant popular for its variable and colorful foliage. In 2020, plants showing leaf spots and blight, typical of anthracnose, were found in a field trial at the University of Florida's Gulf Coast Research and Education Center in Wimauma, Florida, U.S.A. Leaf samples consistently yielded a Colletotrichum-like species with curved conidia and abundant setae production in the acervuli. The internal transcribed spacer (ITS), partial sequences of the glyceraldehyde-3-phosphate dehydrogenase gene (gapdh), actin gene (act), chitin synthase 1 gene (chs-1), beta-tubulin gene (tub2), and histone3 gene (his3) were amplified and sequenced. BLASTN searches in the NCBI GenBank database revealed similarities to species of the Colletotrichum truncatum species complex. Phylogenetic analyses using multilocus sequence data supports a distinct species within this complex, with the closest related species being C. curcumae. Based on morphological and phylogenetic analyses, a new species of Colletotrichum, named C. caladii, is reported. Pathogenicity assays and subsequent isolation confirmed that this species was the causal agent of the disease.

The Role and Mechanism of Paeoniae Radix Alba in Tumor Therapy.

Tumors have a huge impact on human life and are now the main cause of disease-related deaths. The main means of treatment are surgery and radiotherapy, but they are more damaging to the organism and have a poor postoperative prognosis. Therefore, we urgently need safe and effective drugs to treat tumors. In recent years, Chinese herbal medicines have been widely used in tumor therapy as complementary and alternative therapies. Medicinal and edible herbs are popular and have become a hot topic of research, which not only have excellent pharmacological effects and activities, but also have almost no side effects. Therefore, as a typical medicine and food homology, some components of Paeoniae Radix Alba (PRA, called Baishao in China) have been shown to have good efficacy and safety against cancer. Numerous studies have also shown that Paeoniae Radix Alba and its active ingredients treat cancer through various pathways and are also one of the important components of many antitumor herbal compound formulas. In this paper, we reviewed the literature on the intervention of Paeoniae Radix Alba in tumors and its mechanism of action in recent years and found that there is a large amount of literature on its effect on total glucosides of paeony (TGP) and paeoniflorin (PF), as well as an in-depth discussion of the mechanism of action of Paeoniae Radix Alba and its main constituents, with a view to promote the clinical development and application of Paeoniae Radix Alba in the field of antitumor management.

Anti-Tumor Effects and Toxicity Reduction Mechanisms of Prunella vulgaris: A Comprehensive Review.

PURPOSE: To investigate and systematically describe the mechanism of action of Prunella vulgaris (P. vulgaris) against digestive system tumors and related toxicity reduction. METHODS: This study briefly describes the history of medicinal food and the pharmacological effects of P. vulgaris, focusing on the review of the anti-digestive tumor effects of the active ingredients of P. vulgaris and the mechanism of its toxicity reduction. RESULTS: The active ingredients of P. vulgaris may exert anti-tumor effects by inducing the apoptosis of cancer cells, inhibiting angiogenesis, inhibiting the migration and invasion of tumor cells, and inhibiting autophagy. In addition, P. vulgaris active ingredients inhibit the release of inflammatory factors and macrophages and increase the level of indicators of oxidative stress through the modulation of target genes in the pathway to achieve the effect of toxicity reduction. CONCLUSION: The active ingredients in the medicine food homology plant P. vulgaris not only treat digestive system tumors through different mechanisms but also reduce the toxic effects. P. vulgaris is worthy of being explored more deeply.

Synergistic Approaches in the Design and Applications of UCST Polymers.

This review summarizes recent progress in the synergistic design strategy for thermoresponsive polymers possessing an upper critical solution temperature (UCST) in aqueous systems. To achieve precise control of the responsive behavior of the UCST polymers, their molecular design can benefit from a synergistic effect of hydrogen bonding with other interactions or modification of the chemical structures. The combination of UCST behavior with other stimuli-responsive properties of the polymers may yield new functional materials with potential applications such as sensors, actuators, and controlled release devices. The advances in this area provide insight or inspiration into the understanding and design of functional UCST polymers for a wide range of applications.

Pseudocercospora pancratii Causing Leaf Spots on Commercial Blackberry (Rubus sp.) in Florida.

Blackberry (Rubus L. subgenus Rubus Watson) is a deciduous berry crop that is the fourth most economically important berry crop, and its production is expanding in the southeastern United States. However, since most commercially available cultivars were bred under temperate conditions, they are not always well adapted and could be threatened by new pathogen populations inhabiting subtropical areas. In 2017, plants showing purple or brown leaf spots and angular-to-irregular lesions on both leaf surfaces, with clusters of black conidiophores at the center, were observed in a field trial at the University of Florida's Gulf Coast Research and Education Center (UF/GCREC) in Wimauma, FL. A fungus resembling Cercospora/Pseudocercospora was isolated from the lesions. The ribosomal DNA internal transcribed spacers, the translation elongation factor 1-alpha, and the actin genes were amplified and sequenced. Based on the phylogenetic analysis, the closest related species was Pseudocercospora pancratii. Pathogenicity assays and subsequent reisolation confirmed that this species is the causal agent of the disease. Among eight cultivars screened, no complete resistance was found. However, 'Osage' was the least susceptible, and 'Kiowa' was the most susceptible. This study is the first report of P. pancratii causing leaf spots on blackberry worldwide, and it may help shape future research into disease epidemiology and management for a crop that is rapidly expanding but has very limited disease information currently available for Florida growers.

The Potential of Glycyrrhiza from "Medicine Food Homology" in the Fight against Digestive System Tumors.

Glycyrrhiza has a long history of applications and a wide range of pharmacological effects. It is known as the "king of all herbs". Glycyrrhiza is effective in clearing heat, detoxifying, relieving cough, and tonifying qi and has good bioactivity in multiple inflammatory, immune, and tumor diseases. This review aims to summarize the origin, distribution, and anti-digestive system tumor mechanism of glycyrrhiza and its homologous applications in medicine and food. The active compounds include triterpenoids, flavonoids, and coumarins, which are widely used in clinical treatments, disease prevention, and daily foods because of their "enhancement of efficacy" and "reduction of toxicity" against digestive system tumors. This paper reviews the use of glycyrrhiza in digestive system tumors and provides an outlook on future research and clinical applications.

The Role and Mechanism of Perilla frutescens in Cancer Treatment.

Perilla frutescens is an annual herb of the Labiatae family and is widely grown in several countries in Asia. Perilla frutescens is a plant that is used medicinally in its entirety, as seen in its subdivision into perilla seeds, perilla stalks, and perilla leaves, which vary more markedly in their chemical composition. Several studies have shown that Perilla frutescens has a variety of pharmacological effects, including anti-inflammatory, antibacterial, detoxifying, antioxidant, and hepatoprotective. In the absence of a review of Perilla frutescens for the treatment of cancer. This review provides an overview of the chemical composition and molecular mechanisms of Perilla frutescens for cancer treatment. It was found that the main active components of Perilla frutescens producing cancer therapeutic effects were perilla aldehyde (PAH), rosmarinic acid (Ros A), lignan, and isoestrogen (IK). In addition to these, extracts of the leaves and fruits of Perilla frutescens are also included. Among these, perilla seed oil (PSO) has a preventive effect against colorectal cancer due to the presence of omega-3 polyunsaturated fatty acids. This review also provides new ideas and thoughts for scientific innovation and clinical applications related to Perilla frutescens.

Pharmacological Mechanisms and Adjuvant Properties of Licorice Glycyrrhiza in Treating Gastric Cancer.

Licorice is a remarkable traditional Chinese medicine obtained from the dried root and rhizomes of the Glycyrrhiza genus, and t has been utilized in China for many centuries. It consists of more than 300 compounds that are mainly divided into triterpene saponins, flavonoids, polysaccharides, and phenolic components. The active compounds of licorice have been found to possess multiple biological activities, including antitumor, anti-inflammatory, antiviral, antimicrobial, immunoregulatory, cardioprotective, and neuroprotective functions. In addition to providing a brief overview of licorice's adjuvant properties, this review describes and analyzes the pharmacological mechanisms by which licorice components function to treat gastric cancer. Furthermore, licorice compounds are also found to be potent adjuvant chemotherapy agents, as they can improve the quality of life of cancer patients and alleviate chemotherapy-induced adverse effects.

Exploring the Role of Lycium barbarum Polysaccharide in Corneal Injury Repair and Investigating the Relevant Mechanisms through In Vivo and In Vitro Experiments.

Lycium barbarum polysaccharide (LBP) is the main active component of Fructus Lycii, exhibiting various biological activities. This study aims to explore the protective effects of LBP on human corneal epithelial cells (HCEC) and a rat corneal injury model. Potential target points for LBP improving corneal injury repair were screened from public databases, and functional and pathway enrichment analyses of core targets were conducted using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Rat corneal alkali burns and HCEC oxidative stress injury models were established, and the results were validated through slit lamp examination, HE staining, TUNEL assay, immunofluorescence, CCK-8 assay, flow cytometry, scratch assay, and qRT-PCR methods. In the context of database retrieval, identification of 10 LBP monosaccharide components and 50 corneal injury repair-related targets was achieved. KEGG pathway analysis suggested that LBP might regulate the IL-17 and TNF signaling pathways through targets such as JUN, CASP3, and MMP9, thereby improving corneal damage. In vivo and in vitro experimental results indicated that LBP could reduce the increase of inflammation index scores (p < 0.05), inflammatory cell density (p < 0.01), TUNEL-positive cells (p < 0.01), corneal opacity scores (p < 0.01), and expression of corneal stromal fibrosis-related proteins α-SMA, FN, and COL (p < 0.01) caused by chemical damage to rat corneas. LBP inhibited oxidative stress-induced decreases in cell viability (p < 0.001) and migration healing ability (p < 0.01) in HCECs, reducing apoptosis rates (p < 0.001), ROS levels (p < 0.001), and the expression of inflammatory factors TNF-α and IL-6 (p < 0.01). qRT-PCR results demonstrated that LBP intervention decreased the mRNA levels of JUN, CASP3, and MMP9 in H2O2-induced alkaline-burned corneas and HCECs (p < 0.01).The integrated results from network pharmacology and validation experiments suggest that the inhibitory effects of LBP on apoptosis, inflammation, and fibrosis after corneal injury may be achieved through the suppression of the TNF and IL-17 signaling pathways mediated by JUN, CASP3, and MMP9.

Awareness and prevalence of e-cigarette use among Chinese adults: policy implications.

OBJECTIVE: To assess the awareness and prevalence of electronic cigarettes (e-cigarettes) and associated factors among Chinese adults (15 years and older). METHOD: This study examined data from Global Adults Tobacco Survey China Project, which was nationally representative and used stratified multiphase cluster randomised sampling design. Data were collected in 2018 through a household survey with in-person interviews using tablet computers. Complex sampling weighted analysis method was used. RESULTS: 48.5% of Chinese adults had heard of e-cigarettes. The proportions of Chinese adults who had ever used, had used in the last 12 months, and currently used e-cigarettes were 5.0%, 2.2% and 0.9%, respectively; people in the 15-24 years group showed the highest rates of ever use, last 12-month use and current use at 7.6%, 4.4%, and 1.5%, respectively. Among males, higher e-cigarette use was associated with 15-24 years age group, college/university or above education, and daily use of combustible cigarettes. Among all e-cigarette users, 90.6% also used combustible cigarettes. The most common reason for e-cigarette use was smoking cessation (46.2%) while among ever smokers, 9.5% of ever e-cigarette users had quit smoking and 21.8% of never e-cigarette users had quit smoking (adjusted OR 0.454, 95% CI 0.290 to 0.712). CONCLUSION: Prevalence of e-cigarettes among Chinese adults had increased since 2015, especially among young people aged 15-24. The high level of dual use and lower quit rate among e-cigarette users indicated e-cigarettes had not shown cessation utility at the population level in China. Regulation of e-cigarettes is needed to protect youth and minimise health risks.

Multilocus Phylogenetic Analyses of Colletotrichum gloeosporioides Species Complex Causing Crown Rot on Strawberry in Florida.

Colletotrichum gloeosporioides is the causal agent of Colletotrichum crown rot of strawberry in the southern United States. Recent multigene studies defined C. gloeosporioides as a complex species comprised of 37 species. In our study, we phylogenetically characterized C. gloeosporioides isolates from strawberry and other noncultivated plants around strawberry fields. One hundred fifteen strawberry isolates and 38 isolates from noncultivated hosts were sequenced for five genomic regions: internal transcribed spacer, actin, calmodulin, chitin synthase, and glyceraldehyde-3-phosphate dehydrogenase. Phylogenetic analysis using the maximum likelihood and Bayesian inference methods, based on partition-specific models, revealed that most of the isolates in Florida (86%) were closely related to C. siamense, whereas 14 isolates were closely related to C. theobromicola (syn. C. fragariae), four isolates were C. fructicola, and three isolates were C. clidemiae. However, only the first three species were pathogenic to strawberry. Morphological characteristics evaluated show that mycelial growth of all species is approximately 5 mm/day, but colony morphology varies by species and incubation conditions. In vitro mating of the isolates demonstrated that C. fructicola is homothallic whereas C. siamense and C. theobromicola isolates are heterothallic. The biological importance of these different Colletotrichum species is currently being investigated to determine whether different management strategies are needed in strawberry production fields.

Development of a Multiplex High-Throughput Diagnostic Assay for the Detection of Strawberry Crown Rot Diseases Using High-Resolution Melting Analysis.

Rapid and accurate disease diagnosis is a prerequisite for an effective disease management program in strawberry production. In Florida, Colletotrichum spp., Phytophthora spp., and Macrophomina phaseolina are the primary microorganisms causing strawberry crown rot. Even though the diseases can be caused by different pathogens, symptoms are indistinguishable and equally devastating. To inform strawberry growers in a timely fashion of diagnostic results for effective deployment of chemical control practices, we developed a multiplex high-resolution melting (HRM) assay to rapidly and accurately detect the abovementioned pathogens. The multiplex HRM assays using three predesigned primer pairs showed high specificity for individual species by generating specific melting peaks without cross-reaction between primers or with other common strawberry pathogens. The amplification limit of the assay was 1 pg of Colletotrichum and Phytophthora and 100 pg of M. phaseolina DNA per 10-µl reaction. However, the presence of different melting peaks was observed in mixed DNA samples and was concentration and target DNA dependent. A crude DNA extraction protocol was developed to allow high-throughput screening by minimizing the inhibitory effects. Moreover, we applied the HRM assay to 522 plant samples and found high correlations between conventional pathogen isolation and HRM and between singleplex and multiplex assays. Altogether, this multiplex HRM assay is specific, cost effective, and reliable for the timely detection of strawberry crown rot pathogens.

First Report of Diaporthe phaseolorum Causing Stem Canker of Hemp (Cannabis sativa).

Hemp is an annual herbaceous plant that is used for its fiber and oil in a variety of commercial and industrial products. In Florida, it is currently being explored as a new specialty crop. During a field trial from October to January 2019 in Wimauma, FL, a stem canker was observed on up to 60% of three-month-old plants of 'Eletta Campana', 'Carmagnola Selezionata', and 'Tygra'. Symptoms started on the main stems with light-to-dark brown lesions of different sizes and shapes. Over time, the lesions coalesced into large necrotic areas and bore pycnidia. Isolations were made from diseased stem tissues on General Isolation medium (Amiri et al. 2018) after surface disinfestation (Marin et al. 2020). The plates were placed in a growth chamber at 25°C under a 12/12 photoperiod. A fungus with white, floccose, aerial mycelium and pycnidia producing alpha and beta conidia was consistently isolated. Three single spore isolates were chosen for identification and pathogenicity tests. Pycnidia on PDA were globose to irregular and ranged from 170 to 250 µm long (210 ± 2.5, n = 50) and 140 to 220 µm wide (180 ± 2.7, n = 50). The alpha conidia were unicellular, hyaline, ellipsoidal to fusiform and ranged from 5.3 to 7.7 µm long (6.5 ± 1.6, n = 50) and 1.5 to 4.6 µm wide (2.8 ± 1.8, n = 50). The beta conidia were hyaline, elongated, filiform, straight or curved and ranged from 10.2 to 17.7 µm long (16.1 ± 2.2, n = 50) and 0.5 to 1.8 µm wide (0.8 ± 0.2, n = 50). Perithecia were not observed. Based on morphological features, the fungus was similar to anamorphs of Diaporthe spp. (Santos et al. 2011; Udayanga et al. 2015). DNA from the same three isolates was extracted using the FastDNA kit, and the ribosomal internal transcribed spacer (ITS), ß-tubulin (TUB), and calmodulin (CAL) regions were amplified following Udayanga et al. (2014), and Sanger sequenced by Genewiz. Sequences were deposited in GenBank (accession no. MT497039 to MT497047 for ITS, TUB, and CAL). BLASTn searches revealed isolates 20-58, 20-59, and 20-60 were 96.34% identical to the epitype isolate D. phaseolorum AR4203 for ITS (KJ590738.1, 527 bp out of 547 bp), 100% for TUB (KJ610893.1, 459 bp out of 459 bp), and 100% for CAL (KJ612135.1, 522 bp out of 522 bp) (Udayanga et al. 2015). Their identity was confirmed by phylogenetic analyses using maximum likelihood and Bayesian inference methods. To complete Koch's postulates, pycnidia of the same three isolates were harvested and crushed in 2 mL Eppendorf tubes containing 0.01% Tween 20. Conidia suspensions were adjusted to 106 spores/mL. Three 5-week-old potted plants of 'Eletta Campana' and 'Carmagnola Selezionata' per isolate were inoculated using a 1 mL syringe with a needle by injecting 200 µL of the suspension into the stem. Plants were placed inside clear plastic bags for 48 h and maintained in the greenhouse. Control plants were injected with sterile deionized water and kept under the same conditions. The pathogenicity test was repeated once. Four weeks after inoculation, inoculated plants developed stem cankers from which the same pathogen was isolated, whereas controls remained healthy. To our knowledge, this is the first report of D. phaseolorum causing stem canker on hemp. This pathogen has been reported causing canker on sunflower and Phaseolus spp. (Gomzhina and Gannibal 2018; Udayanga et al. 2015; Vrandecic et al. 2009). This discovery may help shape future research into disease epidemiology and management for a crop in which very limited disease information is available at the moment.

Outbreak of Leaf Spot and Fruit Rot in Florida Strawberry Caused by Neopestalotiopsis spp.

Pestalotiopsis-like species have been reported affecting strawberry worldwide. Recently, severe and unprecedented outbreaks have been reported in Florida commercial fields where leaf, fruit, petiole, crown, and root symptoms were observed, and yield was severely affected. The taxonomic status of the fungus is confusing because it has gone through multiple reclassifications over the years. Morphological characteristics, phylogenetic analyses, and pathogenicity tests were evaluated for strawberry isolates recovered from diseased plants in Florida. Phylogenetic analyses derived from the combined internal transcribed spacer, ß-tub, and tef1 regions demonstrated that although there was low genetic diversity among the strawberry isolates, there was a clear separation of the isolates in two groups. The first group included isolates recovered over a period of several years, which was identified as Neopestalotiopsis rosae. Most isolates recovered during the recent outbreaks were genetically different and may belong to a new species. On potato dextrose agar, both groups produced white, circular, and cottony colonies. From the bottom, colonies were white to pale yellow for Neopestalotiopsis sp. and pale luteous to orange for N. rosae. Spores for both groups were five-celled with three median versicolored cells. Mycelial growth and spore production were higher for the new Neopestalotiopsis sp. isolates. Isolates from both groups were pathogenic to strawberry roots and crowns. However, the new Neopestalotiopsis sp. proved more aggressive in fruit and leaf inoculation tests, confirming observations from the recent outbreaks in commercial strawberry fields in Florida.

[Progress in research and development of Xanthoceras sorbifolia].

Xanthoceras sorbifolia, an excellent oil-rich woody species, has high comprehensive economic value in edible, medicinal, and ornamental fields. The chemical composition, pharmacological effect, and quality control of X. sorbifolia were introduced, and its development and application were reviewed in this study. As revealed by the previous research, the main chemical constituents of X. sorbifolia were triterpenoids, flavonoids, fatty acids, phenylpropanoids, steroids, phenolic acids, organic acids, etc. It possesses pharmacological effects, such as neuroprotection, bacteriostasis, anti-oxidation, anti-tumor, anti-inflammation, analgesia, anti-HIV, and anti-coagulation. X. sorbifolia is widely applied in medical, food, chemical industry, and other fields, and deserves in-depth research and development.

Electrolyte Structure of Lithium Polysulfides with Anti-Reductive Solvent Shells for Practical Lithium-Sulfur Batteries.

The lithium-sulfur (Li-S) battery is regarded as a promising secondary battery. However, constant parasitic reactions between the Li anode and soluble polysulfide (PS) intermediates significantly deteriorate the working Li anode. The rational design to inhibit the parasitic reactions is plagued by the inability to understand and regulate the electrolyte structure of PSs. Herein, the electrolyte structure of PSs with anti-reductive solvent shells was unveiled by molecular dynamics simulations and nuclear magnetic resonance. The reduction resistance of the solvent shell is proven to be a key reason for the decreased reactivity of PSs towards Li. With isopropyl ether (DIPE) as a cosolvent, DIPE molecules tend to distribute in the outer solvent shell due to poor solvating power. Furthermore, DIPE is more stable than conventional ether solvents against Li metal. The reactivity of PSs is suppressed by encapsulating PSs into anti-reductive solvent shells. Consequently, the cycling performance of working Li-S batteries was significantly improved and a pouch cell of 300 Wh kg-1 was demonstrated. The fundamental understanding in this work provides an unprecedented ground to understand the electrolyte structure of PSs and the rational electrolyte design in Li-S batteries.

First report of sour rot of strawberry caused by Geotrichum candidum in the United States.

Strawberry (Fragaria x ananassa) is an important crop in the U.S., and Florida is the second major producer in the country. In January 2020, an unknown fruit rot was observed in two strawberry fields in Dover (seedling selection) and Plant City (cultivar Florida127), Florida. Disease incidence varied from less than 1% in one field to up to 15% in the second field during some harvests where over-ripe fruit were present. Affected fruit had a water-soaked soft rot with a sour smell, and sometimes with white mycelium on the fruit surface. Direct isolation was performed from symptomatic fruit from each area by touching the surface of a lesion with a sterile needle and streaking the fungus over general isolation medium (Amiri et al. 2018). The fungus was incubated at 25°C and 12-h photoperiod for five days. Four single-spore isolates (20-46 and 20-47 from Plant City; 20-49 and 20-50 from Dover) obtained from different colonies were grown on potato dextrose agar (PDA). Colonies were white to cream, flat, with a powdery surface, and had a characteristic sour odor. Hyphae were hyaline, septate, growing in a dichotomous pattern and often disarticulating into arthroconidia, which were unicellular, spherical to cylindrical, measuring 4.8 to 9.5 × 3.5 to 5.6 µm (n = 50). Based on the morphological characteristics, the fungus was identified as Geotrichum candidum (De Hoog et al. 1986). To confirm the identity of the isolates, the ribosomal internal transcribed spacer (ITS-rDNA) and the translation elongation factor 1-alpha (TEF1-α) gene regions were amplified and sequenced using the primers ITS1/ITS4 (White et al. 1990), and EF1-728F/EF1-1567R (Carbone and Kohn 1999), respectively. Consensus sequences were deposited in the GenBank (accession numbers MT353975 to MT353978 for ITS-rDNA, and MT346367 to MT346370 for TEF1-α). The BLASTn analysis revealed 99% identity with reference sequences of G. candidum for ITS-rDNA (KU373122) and TEF1-α (MK397513). Phylogenetic analysis, including ITS sequences of G. candidum and other spp., obtained from GenBank, was performed using maximum likelihood and Bayesian inference methods, implemented in MEGA-X and MrBayes, respectively. The isolates were grouped within the G. candidum clade. The pathogenicity of the fungus (isolate 20-46) was evaluated in ripe and green strawberry fruit (cultivar Florida127). Non-wounded and superficially wounded (with a sterilized needle) fruit were inoculated with 20 µl of a spore suspension (1 × 107 spore/ml), prepared by washing the surface of a 5-day-old colony on PDA, with sterile deionized water (SDW) plus 0.01% (v/v) Tween 20. Wounded and non-wounded control fruit were treated with SDW. Fruit were maintained in moist containers at 25°C. Each treatment consisted of 12 fruit (three replicates, each containing four fruit) and was evaluated daily for 10 days. Symptoms of sour rot were visible as soon as 48 hr after inoculation, but only on ripe (100% incidence) and green (58% incidence) wounded fruit. Symptoms progressed to an intense water-soaking with the presence of a typical white mycelium on the surface. Control fruit remained symptomless. The fungus was successfully recovered from symptomatic fruit, fulfilling Koch's postulates. Although strawberry fruit rots caused by G. candidum have already been reported in Pakistan and China (Hussain et al. 2016; Ma et al. 2018), this is the first report of this species causing sour rot on strawberry in the U.S. The disease may be a minor problem on damaged or over-ripe fruit, but further studies might be needed to determine its importance, distribution, and potential strategies for control.

The Effects of Nutrition and Environmental Factors on Conidial Germination and Appressorium Formation of Phyllosticta citricarpa, the Causal Agent of Citrus Black Spot.

Citrus black spot, caused by Phyllosticta citricarpa, has been identified in Florida since 2010 and can reduce fruit yield and marketability. The conditions required for conidial germination have been poorly understood for P. citricarpa, limiting further biological studies. In this study, the effects of citrus juices, concentration, pH, various carbon and nitrogen sources, and environmental conditions were evaluated in vitro. All tested juices, especially 'Valencia' (>85%, P < 0.05), favored germination and appressorium formation, whereas sterile water rarely stimulated germination (<1%). The 'Valencia' juice effect was concentration and pH dependent, and the maximum rate was reached in 1.5% juice with pH of 3.4. Most carbon, nitrogen, or complex sources did not favor germination or appressorium formation, with the exception of potato dextrose broth. An incubation period of 18 to 24 h at 24°C was required for peak germination and appressorium formation. The further analysis of critical juice components using synthetic citrus juice revealed that sugars, salts, citric acid, and thiamine were most important for germination and appressorium formation (>80%, P > 0.05). These results provide a better understanding of fungal biology of P. citricarpa and a robust and convenient system for further applications such as screening for efficacious fungicides.

Anthracnose Fruit and Root Necrosis of Strawberry Are Caused by a Dominant Species Within the Colletotrichum acutatum Species Complex in the United States.

Strawberry anthracnose fruit rot and root necrosis, caused by Colletotrichum acutatum, are primary limiting factors in fruit production fields in the United States. Recent research focusing on the phenotypic and genetic characteristics of this species has shed light on the diversity of the C. acutatum species complex. In this study, we performed multilocus sequence analysis of four genetic loci to characterize 217 C. acutatum isolates collected over a 23-year period from symptomatic plant tissues of strawberry from six different states. The results revealed two Colletotrichum spp. (C. nymphaeae and C. fioriniae), with 97.7% of the isolate collection (212 of 217) belonging to C. nymphaeae as a dominant clonal linage, regardless of the isolation source. No correlation between species groups and geographical origins of the isolates was observed. Further sequence comparison between historical and contemporary isolates showed the same populations being widely distributed throughout the strawberry nurseries and production fields in the United States and Canada. Subsequently, a subset of 12 isolates representing different quinone-outside inhibitor fungicide resistance profiles from root or fruit tissue of strawberry was selected for comparison of pathogenicity on strawberry. In this test, isolates of different resistance groups or different isolation sources exhibited a similar degree of aggressiveness and caused indistinguishable symptoms on strawberry crowns (P = 0.9555 and 0.7873, respectively) and fruit (P = 0.1638 and 0.1141, respectively), although a significant difference among individual isolates was observed in detached-fruit assays (P = 0.0123). Separate pathogenicity tests using isolates of the two species revealed C. nymphaeae being more aggressive than C. fioriniae in infecting strawberry roots and crowns (P = 0.0073). Therefore, given the occurrence and pathogenicity of C. nymphaeae, this species is likely the sole cause responsible for strawberry anthracnose in the United States.