The ornamental plant sector is characterized by the production of a large variety of genera, species and cultivars that are much more numerous than those of other agricultural production sectors. Many countries throughout the world are involved in an intensive exchange of potted plants, cut flowers and propagation material. This intense trade exchange favors the introduction of the causal agents of new diseases on farms, in parks, along tree-lined avenues and in city gardens. Global warming can favor plant pathogens that thrive under high temperatures. Moreover, the interaction between the ongoing increase in temperature and in the CO2 concentration has caused a significant increase in the disease severity of many pathosystems. The numerous reports of new plant pathogens on ornamental plants in Italy in recent years fall into this context. In plant pathology research, living labs incorporate the complexities and variability of natural conditions, and they can thus be used to conduct experiments and test hypotheses. A private garden, located in the hamlet of Bariola (Piedmont, Biella province, northern Italy), has become an ideal living lab that is used to monitor the evolution of the phytosanitary situation of ornamental plants. The results obtained in this living lab are reported hereafter. Moreover, new trends in disease prevention and management, such as the adoption of appropriate prevention practices, water and fertilization management and use of environmentally friendly methods to reduce pesticide use as part of an integrated pest management approach, are also examined.

Climate change is having a significant impact on global agriculture, particularly on vegetable crops, which play a critical role in global nutrition. Recently, increasing research has concentrated on the impact of climate change on vegetable crop diseases, with several studies being conducted in phytotrons, which have been used to explore the effects of increased temperatures and CO2 concentrations to simulate future scenarios. This review focuses on the combined effects of temperature and carbon dioxide increases on foliar and soilborne vegetable diseases, as evaluated under phytotron conditions. The influence of climate change on mycotoxin production and disease management strategies is also explored through case studies. The results offer valuable information that can be used to guide both seed and agrochemical industries, as well as to develop disease-resistant varieties and innovative control measures, including biocontrol agents, considering the diseases that are likely to become prevalent under future climatic scenarios. Recommendations on how to manage vegetable diseases under ongoing climate change are proposed to facilitate plants' adaptation to and enhanced against the changing conditions. A proactive and comprehensive response to climate-induced challenges in vegetable farming is imperative to ensure food security and sustainability.

Abstract Vegetable crops are economically important throughout the world and they all share some common features, such as high value, globalisation of the seed market, continuous intensification and innovation of their production systems, the presence of a high number of crops and varieties, and a limited availability of chemical pesticides for their disease management. In this review, we focus on fungal plant pathogens, although several diseases caused by bacteria are becoming important. Many diseases caused by soilborne pathogens, such as Fusarium oxysporum (different formae speciales ), Sclerotinia sclerotiorum , Rhizoctonia solani, Pythium spp. and Phytophthora spp., become more severe over the last few years. Many of these diseases can be considered the consequence of the profound changes that soil disinfestation has undergone since the use of methyl bromide was prohibited in 2005. In the meantime, new hosts have been detected for diseases caused by foliar pathogens ( Alternaria spp., Stemphylium spp. Fusarium equiseti , Albifimbria verrucaria , Paramyrothecium roridum ), often as a consequence of climate change. The phytopathological situations of vegetable crops is discussed hereafter, with special emphasis on Italy, which is one of the most important vegetable production countries in Europe (not worldwide). The evolution of some diseases as a possible consequence of the current limitations in the use of chemicals, of the globalisation of the markets and/or of climate change is critically discussed. The disease management options that are currently available (e.g. the use of healthy planting material, host resistance, soil health, soilless systems, biological control, and integrated pest management) are discussed.

inoculation and B. cinerea was reisolated from symptomatic tissues with the same method described above.Control branches remained symptomless.B. cinerea is reported on a large number of hosts, among which also the genus Rododendron (Coyier and Roane 2001).This is the first report of B. cinerea on R. arboreum hybrids in Italy.The control of B. cinerea on Rhododendron could become a serious problem for the production of rooted cuttings, increasing the costs in the production sector of this genus.

HomePlant DiseaseVol. 108, No. 3First Report of Botrytis Blight Caused by Botrytis cinerea on Plectranthus scutellarioides in Italy PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Botrytis Blight Caused by Botrytis cinerea on Plectranthus scutellarioides in ItalyA. Garibaldi, D. Bertetti, I. Martino, and M. L. GullinoA. GaribaldiCentre of Competence AGROINNOVA, University of Torino, Largo Braccini 2 10095, Grugliasco, Italy, D. BertettiCentre of Competence AGROINNOVA, University of Torino, Largo Braccini 2 10095, Grugliasco, Italy, I. Martinohttps://orcid.org/0000-0001-8045-240XCentre of Competence AGROINNOVA, University of Torino, Largo Braccini 2 10095, Grugliasco, Italy, and M. L. Gullino†Corresponding author: M. L. Gullino; E-mail Address: [email protected]https://orcid.org/0000-0002-7706-1915Centre of Competence AGROINNOVA, University of Torino, Largo Braccini 2 10095, Grugliasco, ItalyAffiliationsAuthors and Affiliations A. Garibaldi D. Bertetti I. Martino M. L. Gullino † Centre of Competence AGROINNOVA, University of Torino, Largo Braccini 2 10095, Grugliasco, Italy Published Online:26 Feb 2024https://doi.org/10.1094/PDIS-09-23-1932-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Plectranthus scutellarioides (syn. Solenostemon scutellarioides), Lamiaceae family, is an herbaceous perennial bedding plant appreciated for its colorful, variegated leaves. In March 2023, symptoms of an unknown blight were observed on ten 5-month-old potted plants of P. scutellarioides grown in a glasshouse belonging to the Agroinnova Centre in Grugliasco (Torino province, Northern Italy). Symptoms appeared at the base of stems in which infected tissues rotted and turned brown. Affected leaves and petioles wilted and fell off. In some cases, the plant broke at the base and collapsed. A soft, gray mycelium appeared on affected tissues. Five affected stems were immersed in a solution of sodium hypochlorite (1%) for 30 s, and then they were washed in sterilized water. Small fragments were excised from the margin of rotted tissues and plated on potato dextrose agar (PDA) medium added with streptomycin sulfate (25 mg/l). Plates were incubated at temperatures ranging from 22 to 25°C under a light/dark regime (12 h/12 h). Gray soft fungal colonies developed and produced branched conidiophores that supported unicellular, elliptical to ovoid conidia measuring 8.8 to 14.3 × 7.1 to 10.0 (mean: 11.3 × 8.4) μm (n = 50). These characteristics were similar to those of Botrytis cinerea (Ellis 1971). The DNA of the isolate DB23MAR01 was extracted from a pure culture with the E.Z.N.A. Fungal DNA Mini Kit (Omega Bio-Tek). The G3PDH, NEP1, and NEP2 regions were examined (primers: G3PDHfor+/G3PDHrev+, NEP1(−207)for/NEP1(+1,124)rev, and NEP2(−200)for/NEP2(+1,147)rev) (Staats et al. 2005, 2007). Three sequences of 871 (gpdh3), 1,103 (NEP1), and 680 (NEP2) base pairs were obtained (GenBank accession nos. OR355007, OR355008, and OR355009, respectively). A BLASTn search showed 100% (gpdh3), 99.64% (NEP1), and 100% (NEP2) identity with the B. cinerea isolate B05.10 (accession nos. OR355007, OR355008, and OR355009, respectively). In the pathogenicity test, the isolate DB23MAR01 was inoculated on three 5-month-old plants of P. scutellarioides. Mycelial discs (10 mm in diameter) obtained from cultures grown on PDA were applied on stems (10 discs per plant). Three control plants were treated with PDA discs without the pathogen. All plants were maintained in a moistened chamber for 8 days at temperatures ranging from 19 to 30°C. The first symptoms of infection appeared on inoculated stems 3 days after the inoculation. B. cinerea was reisolated from symptomatic stems. The pathogenicity test was carried out also by spraying approximately 15 leaves of 3.5-month-old plants of P. scutellarioides with a conidial and mycelium suspension at the concentration of 1 × 105 CFU/ml. Control plants were treated with sterile water. The plants were maintained in a moistened chamber for 8 days at temperatures ranging from 18 to 23°C. First, necrotic spots appeared on inoculated leaves approximately 13 days after the inoculation. B. cinerea was reisolated from symptomatic tissues. The control plants remained symptomless. B. cinerea has been reported on P. scutellarioides in the United States (Harlan and Hausbeck 2016). To the best of our knowledge, this is the first report of B. cinerea on P. scutellarioides in Italy, as well as in Europe. The cultivation of P. scutellarioides is increasing in Italy because of the ease of reproducing this species and its expanding use as a bedding plant. The control of B. cinerea on this host could become a serious problem for greenhouse cultivation, increasing the production costs.The author(s) declare no conflict of interest.References:Ellis, M. B. 1971. Page 507 in: Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, England.Crossref, Google ScholarHarlan, B. R., and Hausbeck, M. K. 2016. Diseases of Coleus. In: Handbook of Florists' Crops Diseases. R. J. Mc Govern and W. H. Elmer, eds. Springer International Publishing, Cham, Switzerland.Google ScholarStaats, M., et al. 2005. Mol. Biol. Evol. 22:333. https://doi.org/10.1093/molbev/msi020Crossref, ISI, Google ScholarStaats, M., et al. 2007. Fungal Genet. Biol. 44:52. https://doi.org/10.1016/j.fgb.2006.07.003Crossref, ISI, Google ScholarFunding: The authors thank the AGROINNOVA Diagnostic Lab for supporting this work.The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 108, No. 3 March 2024SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Cover Image Metrics Article History Issue Date: 28 Mar 2024Published: 26 Feb 2024Accepted: 8 Dec 2023 Page: 805 Information© 2024 The American Phytopathological SocietyFundingAGROINNOVA Diagnostic LabKeywordsepidemiologyfungiornamentalsThe author(s) declare no conflict of interest.PDF download

This study involves simulating climate changes under phytotron conditions, providing novel insights into the combined impact of elevated temperature (20–24 °C, 24–28 °C, 28–32 °C) and CO2 levels (800–850 ppm) compared to standard CO2 concentrations on calcium oxide, potassium phosphite, Streptomyces griseoviridis, Trichoderma asperellum and Beauveria bassiana. The study focuses specifically on their effects in the lettuce-Fusarium oxysporum f. sp. lactucae (race 1) pathosystem. Temperature was the main factor that influenced Fusarium wilt severity in the inoculated and untreated controls and the efficacy provided by the tested products. Potassium phosphite generally provided consistent disease reduction under all the tested conditions, and it resulted to be more effective at 20–24 °C× 400–450 ppm of CO2 (76

HomePlant DiseaseVol. 107, No. 7First Report of Root Rot Caused by Globisporangium sylvaticum on Anemone japonica in Italy PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Root Rot Caused by Globisporangium sylvaticum on Anemone japonica in ItalyA. Garibaldi, D. Bertetti, G. Tabone, I. Luongo, and M. L. GullinoA. GaribaldiCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, D. BertettiCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, G. TaboneCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, I. LuongoDISAFA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, and M. L. Gullino†Corresponding author: M. L. Gullino; E-mail Address: [email protected]https://orcid.org/0000-0002-7706-1915Centre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this authorAffiliationsAuthors and Affiliations A. Garibaldi1 D. Bertetti1 G. Tabone1 I. Luongo2 M. L. Gullino1 † 1Centre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, Italy 2DISAFA, University of Torino, 10095 Grugliasco, Italy Published Online:8 Jul 2023https://doi.org/10.1094/PDIS-08-22-1757-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Japanese anemone (Anemone japonica, syn. A. hupehensis; Ranunculaceae family) is a perennial herbaceous ornamental plant with prolonged flowering used in borders. During the summer of 2021, 5 out of 20 3-year-old plants of A. japonica grown in a private garden in San Paolo Cervo, Biella province, northern Italy, showed leaf chlorosis and wilting, followed by the collapse of affected plants that finally dried out. Roots showed brown discoloration and were characterized by the presence of a soft rot. Affected roots were dipped in sodium hypochlorite (1%) for 1 min, then washed in sterile water. Small pieces of root tissues (about 2 mm2) were excised from the margins of lesions and plated on the selective medium for oomycetes BNPRA-HMI (Masago et al. 1977). Plates were incubated at 25 ± 1°C, 12/24 h light. Colonies of oomycete-like organisms were observed under an optical microscope. Pure isolates with the same morphological features were grown on corn meal agar (CMA) on which they produced a whitish aerial mycelium with globose intercalary and terminal hyphal swellings that were 13.6 to 33.0 × 12.5 to 31.5 (average 23.2 × 22.5) μm (n = 30). Oospores were not observed. The isolate 21/163-4 was grown on PDA and the DNA was extracted using the E.Z.N.A. Fungal DNA Mini Kit (Omega Bio-Tek, Darmstadt, Germany). A PCR reaction was performed using primers for the cytochrome oxidase 1 (COX1) gene region (Robideau et al. 2011). A sequence with 615 base pairs was obtained (GenBank accession number OP562266) whose BLASTn analysis showed 100% identity with the ex-type C12-94 of Globisporangium sylvaticum (GenBank accession number KT692836). Therefore, the causal agent of the disease observed on A. japonica was identified as G. sylvaticum (syn. Pythium sylvaticum). In a pathogenicity test, five 6-month-old plants of A. japonica were transplanted in pots containing 1 liter of a steam-disinfested substrate consisting of peat moss/pomix/pine bark cortex/clay (50:20:20:10). The inoculum consisted of wheat and hemp kernels colonized by the isolate 21/163-4 and incubated for 10 days, at 25 ± 1°C. The inoculum was mixed to the substrate at a rate of 2 g/liter. Five control plants of A. japonica were grown in a steam-disinfested substrate infested with uninoculated wheat and hemp kernels. All plants were grown in a greenhouse at 20 to 32°C. First symptoms consisting of chlorosis appeared on inoculated plants about 10 days after the inoculation. Five to 7 days later, inoculated plants wilted and collapsed and roots rotted. On CMA, colonies of G. sylvaticum reisolated from affected roots were identical to those described above and produced hyphal swellings measuring 16.6 to 31.2 × 16.3 to 29.5 (average 23.8 × 23.1) μm (n = 30). No symptoms appeared on control plants. The pathogenicity test was carried out twice, providing the same results. G. sylvaticum and P. sylvaticum have been reported on several hosts (Farr and Rossman 2022), including Rhododendron sp. in Pacific Northwest nurseries (Weiland et al. 2020). In Italy, Phytophthora cactorum has been described on Anemone coronaria (Garibaldi and Gullino 1974). This is the first report of G. sylvaticum on Japanese anemone in Italy, as well as worldwide. This disease may become important because the cultivation of A. japonica is increasing in Italy, due to the rusticity of this species that makes it particularly suitable in the landscape, in particular for low maintenance gardens.The author(s) declare no conflict of interest.References:Farr, D. F., and Rossman, A. Y. 2022. Fungal Databases, Syst. Mycol. Microbiol. Lab., USDA-ARS. Retrieved 1 August 2022 from https://nt.ars-grin.gov/fungaldatabases/ Google ScholarGaribaldi, A., and Gullino, G. 1974. Informatore Fitopatologico 24:13. Google ScholarMasago, H., et al. 1977. Phytopathology 67:425. https://doi.org/10.1094/phyto-67-425 Crossref, ISI, Google ScholarRobideau, G. P., et al. 2011. Mol. Ecol. Resour. 11:1002. https://doi.org/10.1111/j.1755-0998.2011.03041.x Crossref, ISI, Google ScholarWeiland, J. E., et al. 2020. Plant Dis. 104:1841. https://doi.org/10.1094/PDIS-08-19-1672-RE Link, ISI, Google ScholarFunding: This work was supported by AGROINNOVA Diagnostics, Grugliasco (TO), Italy.The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 7 July 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 26 Jul 2023Published: 8 Jul 2023Accepted: 19 Dec 2022 Page: 2267 Information© 2023 The American Phytopathological SocietyFundingAGROINNOVA Diagnostics, Grugliasco (TO), ItalyKeywordsepidemiologyoomycetesornamentalsThe author(s) declare no conflict of interest.PDF download

HomePlant DiseaseVol. 107, No. 5First Report of Leaf Spot Caused by Alternaria alternata on Melissa officinalis in Italy PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Leaf Spot Caused by Alternaria alternata on Melissa officinalis in ItalyA. Garibaldi, D. Bertetti, G. Tabone, and M. L. GullinoA. GaribaldiCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, D. BertettiCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, G. TaboneCentre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this author, and M. L. Gullino†Corresponding author: M. L. Gullino; E-mail Address: [email protected]https://orcid.org/0000-0002-7706-1915Centre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, ItalySearch for more papers by this authorAffiliationsAuthors and Affiliations A. Garibaldi D. Bertetti G. Tabone M. L. Gullino † Centre of Competence AGROINNOVA, University of Torino, 10095 Grugliasco, Italy Published Online:18 May 2023https://doi.org/10.1094/PDIS-06-22-1360-PDNAboutSectionsPDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat Lemon balm (Melissa officinalis), in the Lamiaceae family, is a perennial herbaceous species commonly used as an ornamental and aromatic plant for the lemon scent of the leaves. In Italy, the cultivation of lemon balm as an aromatic plant produces 72 tons of product per year (ISMEA 2013). During the summer of 2021, brown, irregularly shaped, necrotic spots, up to 2 to 3 mm in size, were observed on 40 6-month-old M. officinalis plants in a garden in Biella province (Northern Italy). The disease incidence was about 90%. Affected leaves were disinfected in sodium hypochlorite (1%) for 30 s and washed in sterile water. Small pieces of leaf tissue were taken from the margins of necrotic spots, plated on potato dextrose agar (PDA), and incubated at 25°C, obtaining slow-growing fungal colonies with greenish cottony mycelium after 7 days. Ten isolates from hyphal tips of these colonies were grown on PDA under a light/dark regime of 14 h/10 h. After about 10 days, colonies produced ovoid to obclavate conidia that were 18 to 45 × 9 to 20 (average 28 × 15) μm (n = 50). Conidia had one to five transverse and zero to five longitudinal or oblique septa. When present, beaks on the apical cells were 2 to 10 (average 4) μm long (n = 50). Based on these morphological characteristics, the fungus was identified as Alternaria sp. (Simmons 2007). The DNA of a representative isolate (coded 22/18) was extracted using the E.Z.N.A. Fungal DNA Mini Kit (Omega Bio-Tek, Darmstadt, Germany). A PCR reaction was performed using primers for the rpb2, tef1, and endoPG genomic regions (Woudenberg et al. 2015). Three sequences with 502 (rpb2), 240 (tef1), and 412 (endoPG) base pairs were obtained (GenBank accession nos. ON710882, ON710884, and ON710886). Using BLASTn, the rpb2 and tef1 sequences matched 99.4% (499/502 bp) and 100% (240/240 bp) to the CBS 916.96 of Alternaria alternata (KC584375; KC584634 respectively) and the endoPG sequence matched 100% (412/412 bp) to the CBS 117130 (KP124055). Pathogenicity testing was also performed with isolate 22/18. A mycelium and spore suspension in sterile deionized water containing 105 CFU/ml was obtained from fungal cultures grown on PDA using a sterile spreader and sprayed onto leaves of three healthy plants of M. officinalis (10 ml per plant). Three control plants were sprayed with sterile water. All plants were covered with moistened plastic bags for 7 days to maintain high relative humidity. Plants were kept in a shaded greenhouse at 18 to 25°C. Leaf spots appeared on inoculated plants about 8 days after the inoculation, then symptoms similar to those described above developed on inoculated leaves. A. alternata was reisolated and identified by the amplification of the rpb2, tef1, and endoPG genes (GenBank accession nos. ON710883, ON710885, and ON710887, respectively). No symptoms appeared on the control plants. The pathogenicity test was carried out twice with the same result. A. alternata has been previously reported on M. officinalis in Poland (Machowicz-Stefaniak et al. 2002). To our knowledge, this is the first report of A. alternata infecting M. officinalis in Italy. This disease is important because M. officinalis is a very common species and the production of aromatic plants from the Lamiaceae family is steadily increasing in Italy. A. alternata may be a seedborne pathogen (Rotem 1994), and this aspect should be investigated for A. alternata on M. officinalis.The author(s) declare no conflict of interest.References:ISMEA 2013. Piante Efficinali in Italia: Un’Istantanea Della Filiera E Dei Rapporti Tra I Diversi Attori. https://www.ismea.it/flex/files/9/f/a/D.d6718fbd2fd0094a2bab/Rapporto_Osservatorio_Piante_Officinali_def.pdf Google ScholarMachowicz-Stefaniak, Z., et al. 2002. Pl. Protect. Sci. 38:347. https://doi.org/10.17221/10487-pps Crossref, Google ScholarRotem, J. 1994. The Genus Alternaria: Biology, Epidemiology, and Pathogenicity. American Phytopathological Society, St. Paul, MN. Google ScholarSimmons, E. G. 2007. Alternaria: An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, the Netherlands. Google ScholarWoudenberg, J. H. C., et al. 2015. Stud. Mycol. 82:1. https://doi.org/10.1016/j.simyco.2015.07.001 Crossref, ISI, Google ScholarFunding: Funding was provided by Fondazione Cassa Risparmio Cuneo (SFIDA) Agroalimentare 4.0, SFIDA Project ‘Low environmental impact management strategies for the horticultural sector.’The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 5 May 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 31 May 2023Published: 18 May 2023Accepted: 20 Oct 2022 Page: 1634 Information© 2023 The American Phytopathological SocietyFundingFondazione Cassa Risparmio Cuneo (SFIDA)KeywordsepidemiologyfungiornamentalsThe author(s) declare no conflict of interest.PDF download

Strawberry (Fragaria × ananassa Duch.) is widely cultivated in Italy. During May-June 2022, mild symptoms of an unknown leaf spot disease appeared on 5-10% of June-bearing strawberry (cv. Elodì) plants transplanted in July 2021 in a commercial farm located in the province of Cuneo, North Italy. During September-November 2022, the symptoms appeared also on 10-15% of the plants transplanted in July 2022. The disease was scattered throughout the field, large 600 m2, both on new and senescent leaves. Fungicides (sulphur, Tiovit Jet; penconazole, Topas 10 EC) were applied to the plants according to integrated pest management during the growing period. The disease symptoms were purplish to brown necrotic leaf spots up to 1-3 mm in diameter and chlorotic leaf margins. Black lesions were occasionally observed on the petioles, appearing as small necrotic or larger elongated lesions causing leaf death. Peritechia were observed in planta after about 4 months from sampling and measured (144 to 239 μm and 200 to 291 μm, n = 10). Diseased leaves and petioles from about 10 plants were surface disinfested for 1 min in 1% NaClO, rinsed with sterile water and plated on potato dextrose agar (PDA) amended with 25 mg streptomycin sulphate/liter. A fungus with white cottony colonies was repeatedly recovered and maintained in pure culture on PDA. Biguttulate conidia with rounded ends were measured (4.3 to 8.0 μm and 1.2 to 2.9 μm, average 6.1× 2.3 μm, n = 50) from 21-day old colonies grown in PDA at 22°C and 12 h photoperiod. According to colony and conidia morphology, the isolate was identified as Gnomoniopsis sp. (Walker et al., 2010). The fungal DNA was extracted from a pure culture of one isolate selected as a representative (code FR2-22), by using the E.Z.N.A. Fungal DNA Mini Kit (Omega Bio-Tek, Darmstadt, Germany). The identification was carried out by amplifying and sequencing the internal transcribed spacer (ITS) region and the partial translation elongation factor 1-α (TEF) gene using the primers ITS1/ITS4 and EF-728F/EF2 (Udayanga et al., 2021), respectively. The purified PCR products were sequenced at the BMR Genomics Centre (Padova, Italy) obtaining 551bp (ITS) and 652bp (TEF) sequences deposited in GenBank (Accession nos. OQ179950 and OQ190173, respectively). A BLASTn search of both sequences revealed to be 100% identical to the ITS and TEF loci of Gnomoniopsis fructicola sequences of the isolates VPRI_15547 and CBS 275.51 deposited in GenBank with accession Nos. MT378345 and MT383092. The pathogenicity of the isolate FR2-22 was assessed in two trials by biological tests (3 replicates with 1 plant per replicate/pot) in two greenhouse compartments, kept at temperature 20-24°C and at humidity 80-90%. Healthy leaves of forty-day-old strawberry plants (cv. Elodì) were sprayed with 1-5 x106 conidia/ml obtained from the FR2-22 isolate grown on PDA at 25°C for 20 days. The control (water-sprayed plants) was kept in the same conditions. Small leaf spots similar to the symptoms previously observed in the farm were observed 15 days post inoculation. Furthermore, 30 to 40% of leaves developed symptoms similar to those observed in the field after 25-40 days, while the control remained health. The same fungal isolate was repeatedly reisolated from the affected leaves and petioles and identified based on TEF sequencing. Gnomoniopsis fragariae comb. nov., designed as new name for Gnomoniopsis fructicola (Udayanga et al., 2021), has previously been reported on Fragaria × ananassa plants in Australia and in the USA (Farr and Rossman, 2023). To the best of our knowledge, this is the first report of G. fragariae on strawberry in Italy. The impact of the disease caused by this pathogen could be of high importance in the future of strawberry production in Italy. Healthy propagation material and strict disease management practices in nurseries is a requirement to avoid disease epidemics.

novae-verbascicola, synonym of H. verbasci-densiflori, has been reported on V. nigrum (Garibaldi et al., 2013) and V. blattaria whereas this is the first report of the pathogen on V. chaixii in Italy.Although the economic importance of this disease is at present limited, but the spread of H. verbascidensiflori on V. chaixii could cause management problems in low maintenance gardens.

inoculated leaves showed first necrotic spots and A. alternata was reisolated from symptomatic leaves.No symptoms appeared on controls.On H. paniculata, A. alternata has been reported in China (Liu et al. 2017).To our knowledge, this is the first report of A. alternata on H. paniculata in Italy, as well as in Europe.

HomePlant DiseaseVol. 107, No. 8First Report of Neofusicoccum parvum Causing Stem Cankers and Woody Rot on Eucalyptus globulus in France PreviousNext DISEASE NOTE OPENOpen Access licenseFirst Report of Neofusicoccum parvum Causing Stem Cankers and Woody Rot on Eucalyptus globulus in FranceD. Bertetti, A. Rettori, R. Martinis, V. Guarnaccia, G. Tabone, A. Garibaldi, and M. L. GullinoD. BertettiCentre of Competence AGROINNOVA, Grugliasco, Italy, A. RettoriANT-NET s.r.l., Torino, TO, Italy, R. MartinisStudio Associato Planta, Rosta 10090, TO, Italy, V. Guarnacciahttps://orcid.org/0000-0003-3188-7743Centre of Competence AGROINNOVA, Grugliasco, Italy, G. TaboneUniversity of Torino, Grugliasco 10095, Italy, A. GaribaldiUniversity of Torino, Grugliasco 10095, Italy, and M. L. Gullino†Corresponding author: M. L. Gullino; E-mail Address: [email protected]https://orcid.org/0000-0002-7706-1915University of Torino, Grugliasco 10095, ItalyAffiliationsAuthors and Affiliations D. Bertetti1 A. Rettori2 R. Martinis3 V. Guarnaccia1 G. Tabone4 A. Garibaldi4 M. L. Gullino4 † 1Centre of Competence AGROINNOVA, Grugliasco, Italy 2ANT-NET s.r.l., Torino, TO, Italy 3Studio Associato Planta, Rosta 10090, TO, Italy 4University of Torino, Grugliasco 10095, Italy Published Online:3 Aug 2023https://doi.org/10.1094/PDIS-12-22-2808-PDNAboutSectionsView articlePDFSupplemental ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmailWechat View articleTasmanian blue gum (Eucalyptus globulus), belonging to the family Myrtaceae, is a tree used as ornamental in the Mediterranean climates. During the 2020 summer, three 50-year-old trees of E. globulus growing in two public parks in Hyères (Toulon Province, South of France; 43.117748°N, 6.142687°E) exhibited numerous cortical cankers and injuries, 1 to 10 cm long and 0.1 to 1 cm wide, that produced copious brown exudates. The sapwood underneath the cankers showed brown discoloration and was rotted. Symptoms spread up to 70% of the canopy. Affected plants showed some branch dieback. Small cankers were present on young stem sprouts. The disease incidence was 5% of 60 plants monitored in Hyères. Symptomatic tissue samples were collected, surface sterilized in 1% NaClO for 1 min, and then washed in sterile water. Small fragments of sapwood tissue underlying the bark canker margin were plated onto potato dextrose agar (PDA) medium. Plates were incubated at 25°C. The multiple isolates obtained from each symptomatic tree were first whitish and then dark grayish and formed aerial mycelium. A single representative isolate (28-20-O) was used to identify the putative pathogen. The isolate was grown on pine needle agar medium at 26 ± 1°C. Colonies produced unicellular, hyaline, fusoid conidia measuring 10.4 to 21.8 × 4.6 to 7.0 μm (average 18.3 × 6.1 μm, n = 50). The DNA of the isolate 28-20-O was extracted, and the partial translation elongation factor 1-alpha (tef-1α) and the β-tubulin (tub2) genes were amplified using the EF1-728F/EF1-986R (Carbone and Kohn 1999) and T1/Bt2b primers (Glass and Donaldson 1995), respectively, as reported by Bezerra et al. (2021). Two sequences were obtained (GenBank accession nos. OP810556 and OP810557) that showed 99.3 and 99.8% identity, respectively, with tef-1α and tub2 sequences of the Neofusicoccum parvum (syn. Fusicoccum parvum) strain CMW 9081 (ON568671 and ON568670). The morphological characteristics of this pathogen (Crous et al. 2006) matched the description reported above. In the pathogenicity test, 1.5-cm-deep wounds were made through the bark tissues of nine branches on three 8-year-old plants of E. globulus. Fungus-colonized PDA disks (8 mm in diameter) of the isolate 28-20-0 were placed on the wound surface, sterile water-moistened gauze was placed over the disk, and both were secured to the branch with Parafilm. Control plants were treated with PDA disks. Plants were maintained outdoors, in the shade, at temperatures ranging from 19 to 36°C. Seven months after inoculation, blackish cankers, 5 to 8.5 cm long and 2.5 to 5 cm wide, appeared near the wounds on inoculated branches, and the internal woody tissues showed dark brown discoloration. Grayish fungal colonies producing conidia coinciding in shape and size with N. parvum were consistently reisolated from cankers. Controls remained healthy and exhibited healthy callus tissues. The pathogenicity test was repeated once, with the same results. N. parvum has been reported on E. globulus in many countries including Australia (Burgess et al. 2019), China (Li et al. 2020), and Portugal (Barradas et al. 2016). In France, N. parvum has been reported on Vitis vinifera (Larignon et al. 2015). This is the first report of N. parvum on E. globulus in France. The presence of N. parvum may become a significant problem for the management of public parks and tree-lined avenues in countries with a Mediterranean climate in which E. globulus and several potential ornamental hosts of this pathogen are grown.The author(s) declare no conflict of interest.References:Barradas, C., et al. 2016. Eur. J. Plant Pathol. 146:245. https://doi.org/10.1007/s10658-016-0910-1 Crossref, ISI, Google ScholarBezerra, J. D. P., et al. 2021. Plants 10:492. https://doi.org/10.3390/plants10030492 Crossref, Google ScholarBurgess, T. I., et al. 2019. Australas. Plant Pathol. 48:35. https://doi.org/10.1007/s13313-018-0577-5 Crossref, ISI, Google ScholarCarbone, I., and Kohn, L. M. 1999. Mycologia 91:553. https://doi.org/10.2307/3761358 Crossref, ISI, Google ScholarCrous, P. W., et al. 2006. Stud. Mycol. 55:235. https://doi.org/10.3114/sim.55.1.235 Crossref, ISI, Google ScholarGlass, N. L., and Donaldson, G. C. 1995. Appl. Environ. Microbiol. 61:1323. https://doi.org/10.1128/AEM.61.4.1323-1330.1995 Crossref, ISI, Google ScholarLarignon, P., et al. 2015. Plant Dis. 99:1859. https://doi.org/10.1094/pdis-03-15-0280-pdn Link, ISI, Google ScholarLi, G., et al. 2020. IMA Fungus 11:22. https://doi.org/10.1186/s43008-020-00043-x Crossref, Google ScholarFunding: The authors thank the “Direction des Espaces Verts de l’Antenne d’Hyères de la Métropole Toulon Provence Méditerranée (MTPM)” and AGROINNOVA Diagnostic Lab for supporting this work.The author(s) declare no conflict of interest.DetailsFiguresLiterature CitedRelated Vol. 107, No. 8 August 2023SubscribeISSN:0191-2917e-ISSN:1943-7692 Download Metrics Article History Issue Date: 29 Aug 2023Published: 3 Aug 2023Accepted: 3 Mar 2023 Page: 2548 Information© 2023 The American Phytopathological SocietyFundingDirection des Espaces Verts de l’Antenne d’Hyères de la Métropole Toulon Provence Méditerranée (MTPM)AGROINNOVA Diagnostic LabKeywordsepidemiologyfungitreesThe author(s) declare no conflict of interest.PDF download

Eighteen trials were carried out in a closed soilless system to evaluate the effectiveness of different strains of experimental non-pathogenic Fusarium oxysporum and Fusarium solani, commercial biocontrol agents (Streptomyces griseoviridis, Bacillus subtilis and Beauveria bassiana), as well as products based on calcium oxide (CaO) and potassium phosphite on race 1 of Fusarium oxysporum f. sp. lactucae, the causal agent of the Fusarium wilt of lettuce. The treatments were applied to lettuce seedlings, which had been grown for 2 days in a peat medium before being artificially inoculated with the pathogen, and were repeated five times at 7-day intervals. The experimental non-pathogenic F. oxysporum MSA35 and FC3 strains provided a greater disease severity reduction (54%-83% efficacy) than the commercial B. subtilis (29%-31% efficacy), S. griseoviridis (22%-52% efficacy) and B. bassiana (39%-63% efficacy) formulations. The highest fresh weight value was provided by the non-pathogenic F. oxysporum MSA35 and FC3 strains, thereby generally reflecting the observed disease reduction. Calcium oxide and potassium phosphite generally resulted in disease protection, but a great variability in efficacy was observed. The obtained results showed good possibilities for the non-pathogenic Fusarium oxysporum strain against the pathogen in soilless systems.

This feature article tracks 100 years of soil disinfestation, from the goal of eradicating soilborne pathogens and pests to much milder approaches, aimed at establishing a healthier soil, by favoring or enhancing the beneficial soil microflora and introducing biological control agents. Restrictions on the use of many chemical fumigants is favoring the adoption of nonchemical strategies, from soilless cultivation to the use of physical or biological control measures, with more focus on maintaining soil microbial diversity, thus enhancing soil and plant health. Such approaches are described and discussed, with special focus on their integrated use.

through the base of the branch tissues of three 8-year-old plants of S. molle (three branches for plant).The wounds were covered with gauze wetted with sterile water and protected with parafilm.Three control plants were treated with sterile PDA disks.Plants were maintained at temperatures ranging from 18 to 34 °C.One month after the inoculation, internal tissues of inoculated branches showed brown discoloration, and N. parvum was reisolated and identified through tef-1α sequencing.Control plants remained healthy.To our knowledge, this is the first report of N. parvum on S. molle in France (Farr and Rossman, 2022).At present, the economic importance of this disease is limited, but it may become a more significant problem due to the extent of the cultivation of S. molle in Mediterranean countries.The isolate 22-20-O has been deposited at the AGROINNOVA Collection, University of Torino, Italy.

inoculated plants, while controls remained healthy.Pathogenicity was repeated showing the same results.Reisolated colonies were morphologically identical to the original ones and sequences of tef1 and actin genes of one representative reisolate 22/04-20 (OP144209; OP144210) showed 99.6% and 100% identity with the isolate CPC 11,120 and CPC 13,669 (HM148258; HM148522) of C. cladosporioides.