Fungal Planet description sheets: 1182-1283.

Novel species of fungi described in this study include those from various countries as follows: Algeria, Phaeoacremonium adelophialidum from Vitis vinifera. Antarctica, Comoclathris antarctica from soil. Australia, Coniochaeta salicifolia as endophyte from healthy leaves of Geijera salicifolia, Eremothecium peggii in fruit of Citrus australis, Microdochium ratticaudae from stem of Sporobolus natalensis, Neocelosporium corymbiae on stems of Corymbia variegata, Phytophthora kelmanii from rhizosphere soil of Ptilotus pyramidatus, Pseudosydowia backhousiae on living leaves of Backhousia citriodora, Pseudosydowia indooroopillyensis, Pseudosydowia louisecottisiae and Pseudosydowia queenslandica on living leaves of Eucalyptus sp. Brazil, Absidia montepascoalis from soil. Chile, Ilyonectria zarorii from soil under Maytenus boaria. Costa Rica, Colletotrichum filicis from an unidentified fern. Croatia, Mollisia endogranulata on deteriorated hardwood. Czech Republic, Arcopilus navicularis from tea bag with fruit tea, Neosetophoma buxi as endophyte from Buxus sempervirens, Xerochrysium bohemicum on surface of biscuits with chocolate glaze and filled with jam. France, Entoloma cyaneobasale on basic to calcareous soil, Fusarium aconidiale from Triticum aestivum, Fusarium juglandicola from buds of Juglans regia. Germany, Tetraploa endophytica as endophyte from Microthlaspi perfoliatum roots. India, Castanediella ambae on leaves of Mangifera indica, Lactifluus kanadii on soil under Castanopsis sp., Penicillium uttarakhandense from soil. Italy, Penicillium ferraniaense from compost. Namibia, Bezerromyces gobabebensis on leaves of unidentified succulent, Cladosporium stipagrostidicola on leaves of Stipagrostis sp., Cymostachys euphorbiae on leaves of Euphorbia sp., Deniquelata hypolithi from hypolith under a rock, Hysterobrevium walvisbayicola on leaves of unidentified tree, Knufia hypolithi and Knufia walvisbayicola from hypolith under a rock, Lapidomyces stipagrostidicola on leaves of Stipagrostis sp., Nothophaeotheca mirabibensis (incl. Nothophaeotheca gen. nov.) on persistent inflorescence remains of Blepharis obmitrata, Paramyrothecium salvadorae on twigs of Salvadora persica, Preussia procaviicola on dung of Procavia sp., Sordaria equicola on zebra dung, Volutella salvadorae on stems of Salvadora persica. Netherlands, Entoloma ammophilum on sandy soil, Entoloma pseudocruentatum on nutrient poor (acid) soil, Entoloma pudens on plant debris, amongst grasses. New Zealand, Amorocoelophoma neoregeliae from leaf spots of Neoregelia sp., Aquilomyces metrosideri and Septoriella callistemonis from stem discolouration and leaf spots of Metrosideros sp., Cadophora neoregeliae from leaf spots of Neoregelia sp., Flexuomyces asteliae (incl. Flexuomyces gen. nov.) and Mollisia asteliae from leaf spots of Astelia chathamica, Ophioceras freycinetiae from leaf spots of Freycinetia banksii, Phaeosphaeria caricis-sectae from leaf spots of Carex secta. Norway, Cuphophyllus flavipesoides on soil in semi-natural grassland, Entoloma coracis on soil in calcareous Pinus and Tilia forests, Entoloma cyaneolilacinum on soil semi-natural grasslands, Inocybe norvegica on gravelly soil. Pakistan, Butyriboletus parachinarensis on soil in association with Quercus baloot. Poland, Hyalodendriella bialowiezensis on debris beneath fallen bark of Norway spruce Picea abies. Russia, Bolbitius sibiricus on à moss covered rotting trunk of Populus tremula, Crepidotus wasseri on debris of Populus tremula, Entoloma isborscanum on soil on calcareous grasslands, Entoloma subcoracis on soil in subalpine grasslands, Hydropus lecythiocystis on rotted wood of Betula pendula, Meruliopsis faginea on fallen dead branches of Fagus orientalis, Metschnikowia taurica from fruits of Ziziphus jujube, Suillus praetermissus on soil, Teunia lichenophila as endophyte from Cladonia rangiferina. Slovakia, Hygrocybe fulgens on mowed grassland, Pleuroflammula pannonica from corticated branches of Quercus sp. South Africa, Acrodontium burrowsianum on leaves of unidentified Poaceae, Castanediella senegaliae on dead pods of Senegalia ataxacantha, Cladophialophora behniae on leaves of Behnia sp., Colletotrichum cliviigenum on leaves of Clivia sp., Diatrype dalbergiae on bark of Dalbergia armata, Falcocladium heteropyxidicola on leaves of Heteropyxis canescens, Lapidomyces aloidendricola as epiphyte on brown stem of Aloidendron dichotomum, Lasionectria sansevieriae and Phaeosphaeriopsis sansevieriae on leaves of Sansevieria hyacinthoides, Lylea dalbergiae on Diatrype dalbergiae on bark of Dalbergia armata, Neochaetothyrina syzygii (incl. Neochaetothyrina gen. nov.) on leaves of Syzygium chordatum, Nothophaeomoniella ekebergiae (incl. Nothophaeomoniella gen. nov.) on leaves of Ekebergia pterophylla, Paracymostachys euphorbiae (incl. Paracymostachys gen. nov.) on leaf litter of Euphorbia ingens, Paramycosphaerella pterocarpi on leaves of Pterocarpus angolensis, Paramycosphaerella syzygii on leaf litter of Syzygium chordatum, Parateichospora phoenicicola (incl. Parateichospora gen. nov.) on leaves of Phoenix reclinata, Seiridium syzygii on twigs of Syzygium chordatum, Setophoma syzygii on leaves of Syzygium sp., Starmerella xylocopis from larval feed of an Afrotropical bee Xylocopa caffra, Teratosphaeria combreti on leaf litter of Combretum kraussii, Teratosphaericola leucadendri on leaves of Leucadendron sp., Toxicocladosporium pterocarpi on pods of Pterocarpus angolensis. Spain, Cortinarius bonachei with Quercus ilex in calcareus soils, Cortinarius brunneovolvatus under Quercus ilex subsp. ballota in calcareous soil, Extremopsis radicicola (incl. Extremopsis gen. nov.) from root-associated soil in a wet heathland, Russula quintanensis on acidic soils, Tubaria vulcanica on volcanic lapilii material, Tuber zambonelliae in calcareus soil. Sweden, Elaphomyces borealis on soil under Pinus sylvestris and Betula pubescens. Tanzania, Curvularia tanzanica on inflorescence of Cyperus aromaticus. Thailand, Simplicillium niveum on Ophiocordyceps camponoti-leonardi on underside of unidentified dicotyledonous leaf. USA, Calonectria californiensis on leaves of Umbellularia californica, Exophiala spartinae from surface sterilised roots of Spartina alterniflora, Neophaeococcomyces oklahomaensis from outside wall of alcohol distillery. Vietnam, Fistulinella aurantioflava on soil. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Cowan DA, Maggs-Kölling, et al. 2021. Fungal Planet description sheets: 1182-1283. Persoonia 46: 313-528. https://doi.org/10.3767/persoonia.2021.46.11.

Phytophthora Species Are Common on Nursery Stock Grown for Restoration and Revegetation Purposes in California.

Phytophthora tentaculata was detected for the first time in North America in 2012 in a nursery on sticky monkeyflower plant (Diplacus aurantiacus) and again in 2014 on outplanted native plants. At that time, this species was listed as a federally actionable and reportable pathogen by the USDA. As a result of these detections, California native plant nurseries were surveyed to determine the prevalence of Phytophthora species on native plant nursery stock. A total of 402 samples were collected from 26 different native plant nurseries in California between 2014 and 2016. Sampling focused on plants with symptoms of root and crown rot. Symptomatic tissue was collected and tested by immunoassay, culture, and molecular techniques (PCR). Identifications were made using sequences from the internal transcribed spacer (ITS) rDNA region, a portion of the trnM-trnP-trnM, or the atp9-nad9 mitochondrial regions. Phytophthora was confirmed from 149 of the 402 samples (37%), and from plants in 22 different host families. P. tentaculata was the most frequently detected species in our survey, followed by P. cactorum and members of the P. cryptogea complex. Other species include P. cambivora, P. cinnamomi, P. citricola, P. hedraiandra, P. megasperma, P. multivora, P. nicotianae, P. niederhauserii, P. parvispora, P. pini, P. plurivora, and P. riparia. A few Phytophthora sequences generated from mitochondrial regions could not be assigned to a species. Although this survey was limited to a relatively small number of California native plant nurseries, Phytophthora species were detected from three quarters of them (77%). In addition to sticky monkeyflower, P. tentaculata was detected from seven other hosts, expanding the number of associated hosts. During this survey, P. parvispora was detected for the first time in North America from symptomatic crowns and roots of the nonnative Mexican orange blossom (Choisya ternata). Pathogenicity of P. parvispora and P. nicotianae was confirmed on this host. These findings document the widespread occurrence of Phytophthora spp. in native plant nurseries and highlight the potential risks associated with outplanting infested nursery-grown stock into residential gardens and wildlands.

Phylogeny and taxonomy of the genus Tubakia s. lat.

The genus Tubakia is revised on the basis of morphological and phylogenetic data. The phylogenetic affinity of Tubakia to the family Melanconiellaceae (Diaporthales) was recently postulated, but new analyses based on sequences retrieved from material of the type species of Tubakia, T. dryina, support a family of its own, viz. Tubakiaceae fam. nov. Our phylogenetic analyses revealed the heterogeneity of Tubakia s. lat. which is divided into several genera, viz., Tubakia s. str., Apiognomonioides gen. nov. (type species: Apiognomonioides supraseptata), Involutiscutellula gen. nov. (type species: Involutiscutellula rubra), Oblongisporothyrium gen. nov. (type species: Oblongisporothyrium castanopsidis), Paratubakia gen. nov. (type species: Paratubakia subglobosa), Racheliella gen. nov. (type species: Racheliella wingfieldiana sp. nov.), Saprothyrium gen. nov. (type species: Saprothyrium thailandense) and Sphaerosporithyrium gen. nov. (type species: Sphaerosporithyrium mexicanum sp. nov.). Greeneria saprophytica is phylogenetically closely allied to Racheliella wingfieldiana and is therefore reallocated to Racheliella. Particular emphasis is laid on a revision and phylogenetic analyses of Tubakia species described from Japan and North America. Almost all North American collections of this genus were previously referred to as T. dryina s. lat., which is, however, a heterogeneous complex. Several new North American species have recently been described. The new species Sphaerosporithyrium mexicanum, Tubakia melnikiana and T. sierrafriensis, causing leaf spots on several oak species found in the North-Central Mexican state Aguascalientes and the North-Eastern Mexican state Nuevo León, are described, illustrated, and compared with similar species. Several additional new species are introduced, including Tubakia californica based on Californian collections on various species of the genera Chrysolepis, Notholithocarpus and Quercus, and T. dryinoides, T. oblongispora, T. paradryinoides, and Paratubakia subglobosoides described on the basis of Japanese collections. Tubakia suttoniana nom. nov., based on Dicarpella dryina, is a species closely allied to T. californica and currently only known from Europe. Tubakia dryina, type species of Tubakia, is epitypified, and the phylogenetic position and circumscription of Tubakia are clarified. A revised, supplemented key to the species of Tubakia and allied genera on the basis of conidiomata is provided.

Detection of Phytophthora ramorum in Nurseries and Forest Lands in California in 2004 to 2009.

From December 2004 through May 2009, samples were collected from California nurseries and wild lands to survey for Phytophthora ramorum and comply with federal regulations of nursery stock. Samples were prescreened by an enzyme-linked immunosorbent assay (ELISA) that detects Phytophthora spp. and tested by culture, P. ramorum-specific real-time polymerase chain reaction (PCR), and nested PCR. Yearly percentages of infected samples ranged from 0.6 to 2.3%. Camellia spp., Rhododendron spp., Magnolia spp., Pieris spp., and Laurus nobilis tested positive the most frequently in the nurseries and Lithocarpus densiflorus, Umbellularia californica, and Quercus agrifolia tested positive most often from wild lands. Of the 118,410 samples isolated onto PARP media, 0.8% was identified as P. ramorum. Of 115,056 samples tested by ELISA, 5.9% tested positive for Phytophthora spp. Of the 6,520 samples tested by PCR, 12.4% tested positive for P. ramorum. The false-negative, positive, and internal control failure rates of the assays are discussed. After removing the seasonal effect of sampling strategy, isolation of the pathogen into culture was found to be seasonally dependent whereas detectability by PCR and ELISA was not. To our knowledge, this is the first evaluation of a regulatory testing program for a plant pathogen on this scale using standardized assays.

Leaf Spot of Arugula, Caused by Alternaria japonica, in California.

Arugula (Eruca vesicaria subsp. sativa (Mill.) Thell. is a Cruciferous plant used for culinary purposes. From 2012 to 2013, a foliar disease seriously impacted the growth and quality of about 0.1 ha of hydroponically grown arugula at a Santa Barbara County nursery. Samples of affected arugula seedlings exhibited adaxial and abaxial symptoms of mottling with circular to oval, water soaked, dark green leaf spots, each 1 to 3 mm in diameter, and some of which coalesced. Conidia of an Alternaria sp. were observed on the foliage. Symptomatic leaf pieces were disinfested with 0.6% NaOCl, blotted dry, and plated on acidified potato dextrose agar (APDA). Cultures were incubated under near-UV lights for 24 h/day. Olivaceous-grey colonies of the same Alternaria species observed on the leaves grew after 7 days. After 21 days on carrot-piece agar (3), the fungus produced beakless conidia with longitudinal and constricted transverse septa that measured 30.0 to 69.0 × 12.5 to 20.0 µm and were borne singly or in short chains of 2 to 3 conidia. In addition, knots of dark, thick-walled micro-chlamydospores were produced by the hyphae. The fungus was identified morphologically as Alternaria japonica Yoshii (2), and the species confirmed by sequence analysis. A portion of the internal transcribed spacer (ITS) region of ribosomal DNA (rDNA) was amplified using ITS1 and ITS4 primers (4). The sequence (GenBank Accession No. KJ126846) was 100% identical to the ITS rDNA sequence of an isolate of A. japonica (KC584201) using a BLASTn query. A. japonica was also detected in seeds of the lot used to grow the affected arugula crop. Pathogenicity of a single isolate was tested by inoculating four 37-day-old plants each of arugula, cabbage (Brassica oleracea L. var. capitata), and broccoli (B. oleracea L. var. botrytis L.). Inoculum was obtained from 11-day-old cultures of the isolate grown at 24°C on half-strength APDA. Half of a 2.5 cm diameter agar plug containing hyphae and conidia was ground in 2 ml of sterilized water, and the volume of water increased to 45 ml. Leaves of four plants/host species were sprayed with 3.5 to 4.0 ml of inoculum. The inoculated plants and four control plants of each species treated similarly with sterilized water were immediately incubated in a dark dew chamber at 23°C. After 72 h in the dew chamber, inoculated plants of all three hosts produced similar symptoms of wilting, water soaking, and dark green leaf spotting as the original symptomatic field plants. Conidia formed in the leaf spots on both sides of inoculated leaves. A. japonica was re-isolated from all of the inoculated plants but from none of the symptomless control plants using the method previously described. Pathogenicity tests were repeated, with similar results. Although reported in Italy in 2013 (1), to our knowledge, this is the first report of A. japonica on arugula in the United States. References: (1) G. Gilardi et al. Acta Hort. 1005:569, 2013. (2) E. G. Simmons. Page 368 in: Alternaria, An Identification Manual. CBS Fungal Biodiversity Centre, Utrecht, 2007. (3) S. Werres et al. Z. Planzenkr. Pflanzensh. 108:113, 2001. (4) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990.

First Detection of Puccinia ballotiflora on Salvia greggii.

Salvia greggii, autumn sage, is grown for its bright red to white flowers that bloom in late summer and fall. In February of 2008, a rust sample was sent to the CDFA plant pathology diagnostics laboratory in Sacramento from a nursery in Santa Barbara County, CA. Pustules were abundant on older leaves causing moderate defoliation of containerized stock. Only the varieties with entirely red or pink flowers were affected. S. greggii 'Hotlips,' a popular white/red bicolor, was unaffected. Amphigenous uredinia were cinnamon brown, round, powdery, and sometimes surrounded by yellow halos. Pustules were found primarily on the leaves, although a few were on the stems. Urediniospores were broadly obovoid, subglobose to broadly ellipsoid, echinulate, and 22 to 27 × 24 to 32 µm (24.9 × 26.9 µm average) with one apical pore and 2 to 3 equatorial pores. Urediniospore walls were cinnamon brown in color and measured 1.0 to 2.0 µm (1.5 µm average). No telia were observed. After the initial detection, this rust was found in additional nursery sites in Santa Cruz, Santa Clara, Santa Barbara, and Ventura counties in 2008 and 2009. In November of 2011, a sample from a landscape planting in Santa Barbara County of a similar rust with telia and teliospores was submitted. Urediniospores and teliospores were present in the same lesions. Lesions with teliospores were located primarily on the stems. Mature teliospores were two-celled, verrucose, chocolate brown, and 25 to 31 × 32 to 40 µm (28.6 × 35.3 µm average) with a pedicel ranging from 8 to 12 × 38 to 104 µm, sometimes attached obliquely. The rust matched the morphological characteristics of Puccinia ballotiflora (Syn = P. ballotaeflora Long) (2). To confirm pathogenicity, three 20-cm-tall plants of S. greggii 'Navajo Red' in 3.8-liter pots were spray inoculated with 10 ml of a 2.5 × 103 urediniospores per ml suspension and incubated in a dew chamber at 23°C for 2 days in the dark. Plants were transferred to a growth chamber maintained at 22°C with a 12-h photoperiod. Three plants were sprayed with sterile distilled water as controls. Uredinial pustules (1 to 2 mm) appeared on the abaxial surface of the leaves after 3 weeks. The pathogenicity test was repeated with similar results. The internal transcribed spacer region of rDNA and a portion of the 28S rDNA were amplified with primer pairs ITS5 (5'-GGAAGTAAAAGTCGTAACAAGG-3'), Rust1 (5'-GCTTACTGCCTTCCTCAATC-3'), and Rust2inv (5'-GATGAAGAACACAGTGAAA-3'), LR6 (5'-CGCAGTTCTGCTTACC-3') as described by Aime (1) and sequenced using the amplification primers, Rust2 (5'-TTTCACTGTGTTCTTCATC-3') and Rust3 (5'-GAATCTTTGAACGCACCTTG-3'). BLAST query of the assembled sequence, GenBank KF381491, was 91% identical to P. acroptili, JN204194, its closest match of similar length. P. ballotiflora has been found in Colombia on S. cataractarum, S. petiolaris, and S. mayori (3), and in Texas and Mexico on S. ballotiflora (4). To the best of our knowledge, this is the first detection of P. ballotiflora on S. greggii worldwide. P. ballotiflora is already widespread in the nursery trade in California and frequent fungicide applications are necessary to keep plants marketable. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) J. W. Baxter and G. B. Cummins. Lloydia 14:201, 1951. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Botany and Mycology Laboratory, Online publication http://nt.ars-grin.gov/fungaldatabases ARS, USDA, 2014 (4) F. D. Kern et al. Mycologia 25:448, 1933.

First Published Report of Rust on White Alder Caused by Melampsoridium hiratsukanum in the United States.

White alder (Alnus rhombifolia) is a fast-growing tree native to the western United States and is planted frequently in landscapes. In September 2010, mature leaves of white alder with small, orange-yellow pustules were collected in a commercial nursery in Santa Cruz County, CA. Approximately 25 white alder trees were affected. Collected leaves were sent to the California Department of Food and Agriculture Plant Pest Diagnostics Laboratory. Young uredinial pustules were bullate, with urediniospores emerging from a single pore in the pustule. Spiny cells lined the ostiole. With age, pustules broke open to release more spores. Urediniospores were obovate to oval and measured from 14 to 20 × 27 to 41 µm (17.1 × 32.2 µm average, n = 62). Spores were uniformly echinulate and contained a nearly hyaline cell wall measuring from 1 to 2 µm (1.5 µm average) in thickness. A portion of the 28S ribosomal subunit (GenBank Accession No. KC313888) and the internal transcribed spacer regions (KC313889) were amplified and sequenced from DNA extracted from urediniospores using primers LR6 and rust2inv (1) and ITS1-F and ITS4-B (2), respectively. Our ITS sequence had 99% identity to GenBank accession EF564164, Melampsoridium hiratsukanum. In September 2011, white alder leaves with similar symptoms were collected from a commercial nursery in Santa Barbara County, CA. The spore morphology matched the white alder sample previously collected in Santa Cruz County, CA, in 2010. At that time, pathogenicity assays were conducted on three 1-year-old, 61-cm white alder trees planted in 3.8-liter pots. Six detached leaves with visible rust pustules were rubbed gently onto both the apical and distal side of moistened leaves of the healthy alders. Each infected leaf was used to inoculate a total of 6 to 10 healthy leaves by rubbing two leaves per tree before moving to the next tree. Leaves on three additional white alder trees were rubbed with healthy leaves as controls. Trees were incubated in a dew chamber for 3 days in darkness at 24°C, then placed in a growth chamber at 22°C with a 12-h photoperiod. Twelve days after inoculation, small lesions were visible on a few of the leaf undersides of each inoculated tree. Not all inoculated leaves developed pustules. No lesions developed on the control trees. M. hiratsukanum has been reported in Canada, Europe, and eastern Asia (3). There are no published reports of this rust in the United States, but there is an unpublished specimen from white alder in the USDA Systematic Mycology Herbarium (BPI 028048) collected from California in 1931, which was identified as M. hiratsukanum by G. B. Cummins using morphological criteria. We are unaware if older specimens of this rust exist because we were unable to search other herbaria in the United States. To the best of our knowledge, this rust has been present in California since 1931, but has only recently been found causing disease in nursery plants. There have been no reports of the serious foliar disease symptoms on trees in California wild lands as have been reported in Europe, presumably due to dry summer and fall seasons in white alder's natural habitat. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) M. Gardes and T. D. Bruns. Mol. Ecol. 2:113, 1993. (3) J. Hatula et al. Mycologia 101:622, 2009.

First Report of Root and Stem Rot Caused by Phytophthora tentaculata on Mimulus aurantiacus in North America.

Sticky monkey flower plant, Mimulus aurantiacus (Phrymaceae), is a small, perennial shrub that is widely distributed throughout California, especially in coastal and disturbed habitats. It is also found in native plantings in parks and landscapes. In October 2012, nearly all the M. aurantiacus plants grown in a Monterey County, CA nursery for a restoration project were stunted and had dull, yellowish leaves. Roots and stem collars had necrotic, sunken lesions with few feeder roots. Thirty percent of the plants had died. Samples of diseased plants were sent to the CDFA-PPDC Lab and tested positive for Phytophthora sp. using the Agdia ELISA Phytophthora kit (Agdia, Elkhart, IN). A Phytophthora sp. was consistently isolated from the tissue on corn meal agar-PARP (CMA-PARP) (2). Sporangia were spherical to ovoid, papillate to bipapillate and 17 to 42.5 (avg. 27.5) × 12 to 35 (avg. 22.9) µm, with a length/breadth ratio of 1.2:1. Chlamydospores, which were spherical, terminal to intercalary, thin walled and 27.5 to 40 µm, and hyphal swellings formed on CMA-PARP. Spherical oospores, 25 to 36 µm, with primarily paragynous antheridia formed readily on V8 juice agar. rDNA sequences of the internal transcribed spacer (ITS) region of the isolates (GenBank KF667505), amplified using primers ITS1 and ITS4, were 100% identical to Phytophthora tentaculata (CBS 552.96, GenBank AF266775) by a BLAST query (1,3). To assess pathogenicity, exposed root crowns of three 3.78-liter potted M. aurantiacus plants were inoculated with 20 ml of zoospore suspension (2 × 104 ml-1). Plants were maintained in a 23°C growth chamber with a 12-h photoperiod and watered daily. Sterile water was applied to the exposed crowns of three control plants. At 2 weeks, all inoculated plants were wilted with chlorotic foliage. After 3 weeks, the cortical tissue of the crowns and roots was discolored and sloughing and P. tentaculata was recovered on CMA-PARP. P. tentaculata did not grow from the asymptomatic control plants. Inoculations were repeated with similar results. P. tentaculata is a homothallic species in Phytophthora clade 1 that causes crown, root, and stalk rot of nursery plants in Europe and China (1,4). A USDA PERAL analysis lists it as one of the top 5 Phytophthora species of concern to the United States (4). Genera infected with P. tentaculata include Apium, Aucklandia, Chicorium, Chrysanthemum, Delphinium, Gerbera, Lavandula, Santolina, Origanum, and Verbena (4). To our knowledge, this is the first report of P. tentaculata in North America. The source of inoculum of P. tentaculata in California remains unknown. The nursery used seed and cuttings of M. aurantiacus from nearby native areas for propagation, and P. tentaculata was not found in neighboring plant hosts or by baiting soil and water at the nursery. All infected M. aurantiacus material was destroyed. The presence of P. tentaculata in California nurseries could have serious economic impacts on the nursery industry and environmental impacts on susceptible native hosts, if spread into the wildlands. References: (1) D. E. L. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) S. N. Jeffers and S. B. Martin. Plant Dis. 70:1038, 1986. (3) H. Krober and R. Z. Marwitz. Pflanzenkrankh. Pflanzenschutz 100:250, 1993. (4) U.S. Department of Agriculture, Animal and Plant Health Inspection Services (APHIS). Phytophthora species in the Environment and Nursery Settings New Pest Response Guidelines, USDA-APHIS-PPQ-Emergency and Domestic Programs-Emergency Management, Riverdale, MD, 2010.

First Report of Camphor Tree (Cinnamomum camphora) as a Host of Phytophthora ramorum.

Cinnamomum camphora (Lauraceae) is an evergreen shade tree grown in many parts of the United States, including California. From 2007 to 2011, an arborist working in a residential neighborhood in Mill Valley (Marin Co.) noticed several camphor trees with branch dieback and decline. Affected trees had patchy, irregular cankers on the branches and shoot blight. Cankers were black and most had horizontal fissures. Cankers were most abundant in the inside and lower portions of the canopies. In 2011, samples sent to Bartlett Tree Laboratory tested positive for Phytophthora sp. using the Agdia ELISA Phytophthora kit (Agdia, Elkhart, IN). In February 2009 and April 2011, camphor leaf samples were collected by Sacramento Co. inspectors during an annual nursery inspection for Phytophthora ramorum and submitted to CDFA. The normally bright green leaves were reddish with small necrotic spots surrounded by green halos. Camphor samples from Marin Co. were also collected and sent to CDFA in September 2011. An organism with coralloid coenocytic hyphae, chlamydospores, and ellipsoidal semi-papillate sporangia grew on CMA-PARP (4) from both Marin and Sacramento Co. samples. Morphologically, it matched the description of P. ramorum (3). rDNA sequences of the internal transcribed spacer (ITS) region of the Marin (GenBank KC473521) and Sacramento (KC473522) isolates, amplified using primers ITS1 and ITS4 (4), were 100% identical to P. ramorum by a BLAST query (AY038058). Microsatellite loci placed the Marin isolate in the NA1 clonal lineage, while the Sacramento isolate belonged to the NA2 lineage (2). Pathogenicity of both isolates was tested on 5 trees grown in 18.93-liter pots. Three leaves on each tree were inoculated with 6-mm agar plugs taken from the margin of 7-day-old cultures grown on V8 juice agar (V8). Leaves were wounded with a sterile pushpin and two colonized plugs of each isolate were covered with a freezer tube cap filled with sterile dH2O and attached to the leaves with a pin-curl clip (4). Three branches of the same plants were wounded and inoculated with a 3-mm colonized agar plug for each isolate and secured with Parafilm. An equal number of leaves and stems were treated with uncolonized V8 plugs as controls. Plants were sprayed with dH2O, covered in large plastic bags, and placed in a growth chamber at 18°C. After 4 days, the bags, caps, and plugs were removed from the leaves. Black lesions were seen 7 days after inoculation on most leaves and 10 to 14 days on inoculated branches. After 32 days, P. ramorum was isolated from leaf lesions and canker margins onto CMA-PARP. No Phytophthora spp. grew from the controls. The experiment was repeated once with similar results. Overall, leaf and stem lesions were larger with the NA2 lineage isolate than the NA1 lineage isolate, which is consistent with previous research (1). Leaf abscission was seen in 30% of the leaves inoculated with the NA2 lineage isolate but none of the NA1 or control leaves. To our knowledge, this is the first report of P. ramorum on camphor in nursery and landscape settings. Mill Valley is known for its mild temperatures and abundant summer fog. Optimal weather conditions likely led to the spread of P. ramorum from infected neighboring forest hosts to camphor in Mill Valley, rather than from an introduction of infected nursery plants. References: (1) E. Elliott et al. For. Pathol. 41:7, 2011. (2) E. M. Goss et al. Phytopathology 101:166, 2011. (3) S. Werres et al. Mycol. Res. 105:1155, 2001. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

First Report of Candidatus Liberibacter asiaticus Associated with Citrus Huanglongbing in California.

Huanglongbing (HLB), also known as citrus greening, is one of the most destructive citrus diseases worldwide and is seen as a major threat to the multimillion dollar citrus industry in California. The vector of the two bacterial species associated with this disease, Candidatus Liberibacter asiaticus and Ca. L. americanus, is the Asian citrus psyllid (ACP), Diaphorina citri (4). ACP was detected in California in August of 2008 and has since been detected in nine counties in southern California. As part of a long term survey and testing program for the ACP carrying the HLB associated bacteria, groups of ACP nymphs and adults were submitted to the Jerry Dimitman Citrus Research Board/Citrus Pest and Disease Prevention Program Laboratory in Riverside, CA. In March 2012, DNA extracted using the Qiagen MagAttract 96 DNA plant kit (QIAGEN Inc., 27220 Turnberry Lane, Suite 200, Valencia, CA 91355) from a group of three ACP adults tested positive for Ca. L. asiaticus with the real-time PCR assay developed by Li et al. (4). ACP adults were collected from a residential citrus tree located in the Hacienda Heights area of Los Angeles County, California. The approximately 1.8 meter tall lemon tree had 23 graft unions, primarily of lemon (Citrus × meyeri) and pomelo (Citrus maxima) varieties. The tree was unthrifty, with yellow shoots and chlorotic leaves. Symptoms on the lemon and pomelo leaves included asymmetrical blotchy mottling, yellowing, and corking of the leaf veins, with the blotchy mottle more prominent in the pomelo leaves. Pomelo leaves appeared crinkled along the thickened veins. Lemon leaves had yellow veins and a few had islands of green tissue completely surrounded by yellow tissue. The entire tree was removed, cut into sections, bagged, and transported to the CDFA Plant Pest Diagnostics Lab for analysis. Two hundred milligrams of petiole and midrib tissue from leaves apical to each graft union was collected, and DNA from each sample was extracted using the Qiagen DNeasy plant mini kit. DNA extracted from both lemon and pomelo leaves tested positive for Ca. L. asiaticus using real-time PCR (4). A 1,160-bp fragment of the 16S ribosomal RNA gene was amplified from the insect and plant DNA extracts using conventional PCR with primers Ol1 and OI2c (2). A 703-bp fragment of the ß-operon gene was amplified from the insect and plant extracts with primers A2 and J5 (1). The 16S rDNA fragments from the insect and plant respectively (GenBank Accession Nos. JX430434 and JX455745) and the ß-operon fragments (JX430435 and JX455746) showed 100% identity with the corresponding regions of Ca. L. asiaticus (CP001677) strain psy 62. Our 16S rDNA sequence showed 98% identity with Ca. L. africanus (EU921620), 97% identity with Ca. L. solanacearum (HM246509), and 96% with Ca. L. americanus (FJ036892). In response to the detection of HLB, a 241 km2 quarantine area around the detection site was established. Surveys for ACP and symptomatic host plants within the HLB quarantine area are ongoing. To date, there have been no additional positive detections. In the United States, HLB was first detected in Florida in 2005 (4) and in Texas in January of 2012 (3). To our knowledge, this is the first confirmed report of Ca. L. asiaticus associated with HLB in California. References: (1) A. Hocquellet et al. Mol. Cell. Probes 13:373, 1999. (2) S. Jagoueix et al. Mol. Cell. Probes 10:43, 1996. (3) M. Kunta et al. Phytopathology 102:S4.66, 2012. (4) W. Li et al. J. Microbiol. Methods 66:104, 2006.

First Report of Colletotrichum phormii Causing Anthracnose on New Zealand Flax in the United States.

Phormium colensoi Hook.f. (syn. P. cookianum), New Zealand flax, (family Xanthorrhoeaceae) is popular in ornamental landscapes in the United States because of its sturdy blade-like foliage available in diverse colors. In February 2012, the Oregon State University Plant Clinic received three potted plants of P. colensoi 'Black Adder' from a commercial nursery in Santa Cruz County, California. The margins and midribs of several leaves had brown lesions that were variable in size, and fusiform to ellipsoidal in shape. Embedded in the lesions were black acervuli without setae that exuded salmon-colored spore masses under moist conditions. Conidia were hyaline, cylindrical to fusiform, straight to slightly curved, and 22.4 to 35.2 × 4.0 to 6.4 (average 24.7 × 4.9) µm. Based on morphology, the fungus was confirmed by USDA-APHIS National Identification Services to be Colletotrichum phormii (Henn.) D.F. Farr & Rossman (2). In March 2012, the California Department of Food and Agriculture Plant Pest Diagnostic Lab received additional samples from the same nursery lot (25% disease incidence) from which a similar fungus was recovered. rDNA sequences of the internal transcribed spacer (ITS) region from the California isolate (GenBank KC122681), amplified using primers ITS1 and ITS4 (2), were 100% identical to multiple species of Colletotrichum, including C. phormii by a BLAST query (JQ948446 through JQ948453). ITS sequence similarity alone is not sufficient to address Colletotrichum taxonomy and must be used in combination with host range and morphology (1). Pathogenicity of C. phormii (isolate CDFA986) was tested on three 'Black Adder' plants, which were inoculated with 6-mm agar plugs from a 14-day-old culture grown on half strength potato dextrose agar (PDA). Leaves were wound-inoculated along the midrib using colonized plugs (4). Five leaves per plant were inoculated with C. phormii plugs and five leaves per plant were treated with uncolonized PDA agar plugs as controls. Plants were sprayed with water and incubated in plastic bags at 22°C with a 12-h photoperiod. After 48 h, the bags and caps were removed and plants were kept under the same conditions. Two weeks later, water-soaked lesions had developed on the inoculated leaves. Lesions expanded along the midrib and became fusiform in shape after 21 to 28 days. C. phormii was isolated from lesion margins of all the inoculated leaves, but not from control leaves. This experiment was repeated once with similar results. Another Colletotrichum species, C. gloeosporiodes, also occurs on Phormium spp., but differs from C. phormii in morphology and symptom expression. Subsequent nursery and landscape surveys showed that anthracnose caused by C. phormii occurs on several P. colensoi cultivars as well as on P. tenax in five California counties including Santa Cruz, Yolo, Sacramento, San Luis Obispo, and Solano. C. phormii is also reported to infect P. colensoi and P. tenax in New Zealand, Europe, the United Kingdom, Australia, and South Africa (2,3). To our knowledge, this is the first report of C. phormii causing anthracnose on Phormium in North America. This disease could impact the American nursery trade and New Zealand flax production due to crop loss and increased production costs for pest management. References: (1) J. Crouch et al. Mycologia 101:648, 2009. (2) D. F. Farr et al. Mycol. Res. 110:1395, 2006. (3). H. Golzar and C. Wang. Australas. Plant Pathol. 5:110, 2010. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

First Report of Phytophthora ramorum Causing a Leafspot on Loropetalum chinense, Chinese Fringe Flower in California.

Chinese fringe flower is a popular landscape plant in California for its red evergreen foliage and its showy red flowers in the spring. In April 2007, a sample was submitted to the California Department of Food and Agriculture diagnostic laboratory from Sacramento County as part of an inspection of a nursery for Phytophthora ramorum. A sample was taken from Loropetalum chinense because the inspector noticed very small spots and defoliation in the crop, even though P. ramorum was not detected in previous samples sent to the lab with similar symptoms. Six 5-mm2 pieces of the leaves were placed on CMA-PARP (1) medium as part of our standard nursery screening, even though no lesions were seen. An organism with coralloid coenocytic hyphae, chlamydospores, and ellipsoidal semi-papillate sporangia matching the description of P. ramorum (2) grew into a snowflake-shaped colony from two pieces. On closer inspection of the leaves, small green lesions of approximately 3 to 5 mm wide were visible, especially when the leaves were backlit. For sporangial production, a 6-mm plug was transferred from the colony margin of the isolate onto V8 juice agar (V8). Sporangia, produced on V8 plugs incubated in dH20 for 2 days, were from 41 to 61 × 23 to 32 µm (48.7 × 29.3 µm average) with a length to breadth ratio from 1.3 to 2.0 (average 1.7). Chlamydospores on CMA-PARP were 36.7 to 60.1 µm (49.1 µm diameter average). From 2008 to 2011, similar symptoms were found on L. chinense from Contra Costa, San Joaquin, and Los Angeles Counties. The same organism was isolated from these infected plants. To confirm pathogenicity on L. chinense, five nursery-grown plants in 3.78-L pots were inoculated with three isolates each. Plants were inoculated with 6-mm plugs taken from the margin of a 7- to 10-day old culture grown on V8. Plant leaves were wounded with a sterile pushpin and two colonized plugs were covered with a freezer tube cap filled with sterile dH2O and attached to the underside of the leaves with a sterile pin-curl clip (4). Inoculated plants were sprayed with water, covered with plastic bags, and incubated for 2 days, when bags and plugs were removed. Four leaves per isolate were inoculated on each plant and four leaves per plant were treated similarly with uncolonized V8 plugs as a control. Plants were incubated for 12 to 14 days at 18°C (16-h photoperiod) when lesions were visible and some of the leaves began to abscise. P. ramorum grew from each lesion produced on inoculated leaves and no Phytophthora spp. grew from the control leaves when isolated onto CMA-PARP. Inoculations were repeated with similar results. The internal transcribed spacer region (ITS) of rDNA was amplified and sequenced from the isolates using ITS1 and ITS4 primers as described by White et al. (3). BLAST analysis of the sequenced amplicons (GenBank JQ361743 through JQ361745) showed 100% identity with the ITS sequence of P. ramorum (GenBank AY594198). P. ramorum is a quarantine pathogen with many hosts (2,4). Leaf spots on L. chinense caused by P. ramorum are inconspicuous and missing this disease during nursery inspections could lead to unintended spread to neighboring host plants. References: (1) S. N. Jeffers and S. B. Martin. Plant Dis. 70:1038, 1986. (2) S. Werres et al. Mycol. Res. 105:1155, 2001. (3) T. J. White et al. Page 315 in: PCR Protocols. A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

First Report of Neofusicoccum nonquaesitum Causing Branch Cankers on Giant Sequoia (Sequoiadendron giganteum) in North America.

Between 2001 and 2007, samples from three California native plants showing canker symptoms were submitted to the California Department of Food and Agriculture's Plant Pest Diagnostics laboratory. Giant sequoia (Sequoiadendron giganteum) and coast redwood (Sequoia sempervirens) showed branch cankers and dieback, whereas tanoak (Lithocarpus densiflora) had bleeding bole cankers. Samples were collected from mature trees in private landscapes in El Dorado, Sacramento, and Alameda counties in California. A fungus was isolated on one-half strength acidified potato dextrose agar (APDA) from the canker margins of all three hosts. Colonies were moderately fast growing, initially white, later turning olivaceous black. Pycnidia developed singly or in small groups and contained conidia that measured 18 to 29 × 6 to 8 µm (average 21.5 × 6.8 µm). Conidia were aseptate, hyaline, and fusiform, with truncate bases. rDNA sequences of the internal transcribed spacer (ITS) region of the isolates (GenBank JQ282157 through JQ282159), amplified using primers ITS1 and ITS4 (2), were 100% identical to the holotype isolate of Neofusicoccum nonquaesitum Inderb., Trouillas, Bostock & Michailides (1) by a BLAST query (GenBank GU251163). Pathogenicity of the N. nonquaesitum isolate from giant sequoia (CDFA4) was tested on five saplings using cultures grown on APDA for 14 days. A single wound was made approximately 2 cm above the soil line on the cambium of each plant using a 3-mm cork borer. One 3-mm colonized agar plug was placed on each wound and secured with Parafilm. Plugs of APDA were placed onto wounds of five plants as controls. All plants were kept in a growth chamber at 23°C with a 12-h photoperiod. After 4 days, Parafilm was removed to reveal dark brown cankers measuring 12 to 43 mm long on the inoculated plants. Fourteen days after inoculation, cankers were black, sunken, and measured 79 to 117 mm (average 91.4 mm) long. Most of the inoculated plants were wilted with chlorotic to necrotic foliage. Mature pycnidia with cirri developed in most of the cankers. N. nonquaesitum was reisolated on APDA from all of the cankers. No symptoms developed on the control plants. The experiment was repeated once with similar results. Botryosphaeria dothidea, also in the Botryosphaeriaceae, has been reported to cause similar cankers on giant sequoia and coast redwood in California (3). However, rDNA sequencing of the ITS region of this isolate obtained from the American Type Culture Collection (ATCC 60344) (GenBank JQ284384) showed it matched the type specimen of Neofusicoccum australe (GenBank GU251219), not our isolate. To our knowledge, this is the first report of N. nonquaesitum as a pathogen of giant sequoia in North America. This study expands the host range of N. nonquaesitum from almond (Prunus dulcis), California bay (Umbellularia californica), and blueberry (Vaccinium spp.) (1) to include giant sequoia, coast redwood, and tanoak, which are economically important trees in California forests and landscapes. References: (1) P. Inderbitzin et al. Mycologia 102:1350, 2010. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA, 1990. (3) J. J. Worrall et al. Plant Dis. 70:757, 1986.

First Report of Leaf Spot Caused by Phytophthora taxon Pgchlamydo on Evergreen Nursery Stock in California.

As part of the Phytophthora ramorum testing program from 2005 through 2007, a Phytophthora sp. was isolated on PARP-CMA medium (4) at the CDFA lab in Sacramento, CA, from the margin of necrotic spots and tissue suffering from dieback on Arctostaphylos sp. (manzanita), Camellia spp., Laurus nobilis (bay), Buxus sempervirens (boxwood), Rhododendron sp., Arbutus unedo (strawberry tree), and Sequoia sempervirens (coast redwood). Isolates were collected from Shasta, Contra Costa, San Diego, Solano, Santa Cruz, Alameda, Sacramento, San Joaquin, Monterey, and Los Angeles Counties. Isolates from A. unedo tissue on PARP medium produced apapillate, obovate sporangia 25 to 80 × 15 to 40 µm (48.0 × 26.9 µm average) and a few isolates produced intercalary and terminal chlamydospores at 22°C (30 to 46 µm diameter, 38.9 µm average). The internal transcribed spacer region (ITS) of rDNA was amplified from four isolates using ITS1 and ITS4 primers as described by White et al. (3) and the amplicons sequenced (GenBank Accession Nos. JQ307188 through JQ307191). BLAST analysis of the amplicons showed 99 to 100% identity with the ITS sequence of Phytophthora taxon Pgchlamydo from forest streams in Oregon (GenBank Accession No. HM004224) (1). Pathogenicity tests were performed on B. sempervirens, C. sasanqua, L. nobilis, and A. unedo. Five plants of each species were inoculated with 6-mm plugs taken from the margin of a 7- to 10-day-old culture grown on V8 juice agar. Plant leaves were wounded with a sterile pushpin and two agar plugs were covered with a freezer tube cap filled with sterile dH2O and clipped to the underside of the leaves with a sterile pin-curl clip (4). Inoculated plants were sprayed with water, covered with plastic bags, and incubated for 2 days, when bags and plugs were removed. Five leaves of each isolate plus five control plugs using V8 juice agar alone were inoculated on each plant. Plants were incubated for 12 days at 18°C (16-h photoperiod). Lesions formed on all inoculated plants, ranging in size from approx. 1 mm on B. sempervirens to 9.2 × 10.9 mm average on A. unedo. The lesions on A. unedo grew into and caused the mid-vein to blacken. The lesion sizes on camellia and bay were larger than those formed on B. sempervirens and smaller than those formed on A. unedo, with most lesions surrounded by a dark ring. Phytophthora taxon Pgchlamydo is associated with leaf lesions on rhododendron and dieback of yew in Minnesota (2). To our knowledge, this is the first report of Phytophthora taxon Pgchlamydo causing disease in camellia, bay, strawberry tree, and boxwood in California. Phytophthora taxon Pgchlamydo causes damage that is indistinguishable from the quarantine pest, P. ramorum (4). References: (1) P. W. Reeser et al. Mycologia 103:22, 2011. (2) B. W. Schwingle and R. A. Blanchette. Plant Dis. 92:642, 2008. (3) T. J. White et al. PCR Protocols: A Guide to Methods and Applications. M. A. Innis et al., eds., Academic Press, San Diego, 1990. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.

First Report of Ramularia didyma Causing a Leaf Spot on Ranunculus (Ranunculus asiaticus) Hybrids in California.

Ranunculus or Persian buttercups (Ranunculus asiaticus) are colorful, cool-season perennials or annuals grown as landscape bedding plants and for field-grown bulb and cut flower production in mild winter climates. In March of 2008, tan-to-brown lesions were observed on the foliage of containerized ranunculus growing in a greenhouse at a production and retail nursery in coastal San Mateo County, CA. Approximately 15% of the approximately 150 cv. Bloomingdale mixed shade ranunculus plants had leaf spot symptoms. Symptomatic plants were generally clustered together on two benches, with a double-flowered purple cultivar with picotee markings having the highest disease incidence and severity. Angular to round, necrotic lesions ranged between 0.25 and 1.0 cm in diameter and were often surrounded by chlorotic tissue. Whitish sporulation was observed on abaxial and adaxial sides of the larger lesions. Conidiophores were hyaline, aseptate, measured 45 to 75 × 3 to 5 µm (56 × 3.7 µm average), and were produced in fascicles on the leaf surface. One-celled fusiform to cylindrical conidia measured 22.5 to 30.0 × 9.0 to 15 µm (25.4 × 11.9 µm average) and two-celled conidia measured 26.0 to 47.5 × 10 to 14 µm (35.3 × 12.1 µm average). Most conidia were hyaline, although a few were pale brown. Morphologically, the fungus matched the description of Ramularia didyma Unger (1). Small (3-mm2) pieces were taken from the margin of the lesion, disinfested with 0.6% sodium hypochlorite for 2 min, and placed at room temperature on carrot piece agar. Colonies were white and grew slowly to approximately 3.5 cm in 25 days. No conidia were produced in culture. To conduct pathogenicity tests, the foliage of nine mixed-color ranunculus plants grown from tubers for 7 weeks at 16°C in a growth chamber were sprayed with an aqueous suspension of mycelia. Inoculum was produced by grinding five, 3.5-cm colonies on carrot piece agar in 120 ml of water with a mortar and pestle. The foliage of an equal number of plants was sprayed with water. Plants were incubated in a dew chamber at 20°C for 48 h in the dark and then moved into a growth chamber with a 12-h photoperiod where relative humidity was maintained at ~95% by placing plants over a tray of water and covering each plant group with a plastic tent. Small, angular spots developed on approximately half of the inoculated plants 20 days later when the fungus was reisolated from the lesions. No symptoms were observed on the noninoculated control plants. Sporulation was observed on diseased lesions following misting of plants and incubation in sealed plastic bags for an additional week. Pathogenicity tests were repeated with mycelia with similar results. Sequence of the internal transcribed spacer regions of the rDNA was deposited into GenBank (Accession No. HQ442297). The sequence matched R. coleosporii and R. carthami with 96% identity. R. didyma has been reported to cause a leaf spot on Ranunculus spp. in the United States (Delaware, Iowa, Indiana, Maryland, New York, and Vermont). To our knowledge, this is the first confirmed report of R. didyma on Ranunculus asiaticus in California. Introduction of this pathogen into commercial production fields could cause significant economic loss. The closest large-scale production fields are located approximately 430 miles south of San Mateo County near Carlsbad, CA where more than 50 acres of ranunculus are grown for cut flower and tuber production. Reference: (1) J. B. Ellis and B. M. Everhart. J. Mycol. 1:79, 1885.

First Report of Fusarium Wilt Caused by Fusarium oxysporum f. sp. passiflorae on Passion Fruit in North America.

Passiflora edulis Sims f. edulis, known as purple passion fruit, is a woody, perennial vine that is grown for its attractive two-part flower and its purple, edible fruit (4). In November 2009, passion fruit vines were collected during a regulatory nursery inspection in Santa Barbara County and submitted to the California Department of Food and Agriculture Plant Pest Diagnostics Laboratory. Nearly 100% of the plants inspected, all of which were approximately 1.25 m tall, appeared stunted, defoliated, and severely wilted. Dark brown vascular discoloration was present in the roots and lower stems of the plants. A pinkish violet Fusarium oxysporum colony containing chlamydospores, multiseptate macroconidia, and microconidia formed on monophialidic conidiophores was consistently isolated from roots and stems onto half-strength acidified potato dextrose agar (aPDA). All further experiments were done with an isolate obtained from a single conidium. A portion of the translation elongation factor gene (TEF-1α) was amplified and sequenced with primers ef1 and ef2 from our isolate (GenBank No. JF332039) (3). BLAST analysis of the 615-bp amplicon with the FUSARIUM-ID database showed 99% similarity with a F. oxysporum passion fruit isolate from Australia (NRRL 38273) (3). To confirm pathogenicity, washed roots of four-leaf stage seedlings approximately 10 cm tall were submerged in a conidial spore suspension (106 spores/ml) for 15 min. The conidial suspension was prepared by flooding 10-day-old cultures grown on aPDA medium with sterile distilled water. Seven seedlings were inoculated and planted in 10-cm2 pots and kept in a 25°C growth chamber with a 12-h photoperiod. Seven seedlings were mock inoculated with sterile water. After 3 weeks, four of the seven inoculated plants had leaves with yellow veins and discolored roots and had partially defoliated. Two of the four symptomatic plants also had brown stem cankers. F. oxysporum grew from the isolated roots and stems of all the inoculated plants. F. oxysporum did not grow from root and stem pieces from the water-dipped plants and the plants remained asymptomatic. Inoculations were repeated on plants approximately 15 cm tall with F. oxysporum growing from roots and stem pieces of all inoculated plants. Symptoms of yellow veins and root necrosis were not observed until 4 weeks after inoculation. Fusarium wilt caused by F. oxysporum f. sp. passiflorae is a significant disease of P. edulis f. edulis in Australia. The disease has also been reported in South Africa, Malaysia, Brazil, Panama, and Venezuela; but it is unclear as to whether the symptoms were caused by Fusarium wilt or Haematonectria canker (1). Banana poka (P. mollissima), P. ligularis, and P. foetida are also susceptible hosts (2). To our knowledge, this is the first report of Fusarium wilt caused by F. oxysporum f. sp. passiflorae on passion fruit in North America. Passion fruit is not commercially produced for consumption in California so the economic importance of this disease appears to be limited to nursery production and ornamental landscapes. The grower of the California nursery stated that the infected passion fruit plants had been propagated on site from seed. The source of inoculum at this nursery remains unknown. References: (1) I. H. Fischer and J. A. M. Rezende. Pest Tech. 2:1, 2008 (2) D. E. Garder. Plant. Dis. 73:476, 1989. (3) D. M. Geiser et al. Eur. J. Plant Pathol. 110:473, 2004. (4) F. W. Martin et al. Econ. Bot. 24:333, 1970.

First Report of Botrytis hyacinthi on Pineapple Lily in California.

Pineapple lily (Eucomis vandermerwei) is grown for its exotic-looking flower spike that looks like a small pineapple. It is used as an accent plant in the garden or for its long-lasting cut flowers. In late November 2007, plant foliage was submitted to the California State Diagnostic Laboratory by a commercial grower for phytosanitary inspection before shipment of bulbs to Europe. Leaves had wet, brown, elliptical spots of 1 to 2 cm long, some with yellow halos. The interior of the older spots was pale brown and papery. Conidiophores typical of Botrytis spp. were observed on the abaxial side of the leaf in the interior of the older spots. Isolations on half-strength acidified potato dextrose agar (APDA) yielded a grayish mycelium with conidiophores developing on the plant tissue only. The agar was grayish yellow, especially when viewed from the underside. Conidiophores measured 275 to 650 µm × 15 to 20 µm (411.2 × 15.5 µm average). Conidia were light brown, subglobose to broadly ellipsoidal, and measuring 10 to 15 × 13 to 20 µm (11.8 × 16.2 µm average). Scattered, black sclerotia measuring 335 to 1,007 × 518 to 1,079 µm (668.9 × 743.9 µm average) formed on the medium after approximately 7 days. Pathogenicity was confirmed by inoculating four Eucomis spp. plants with one inoculation per leaf, four leaves per plant. Each leaf was wounded with a sterile pushpin and three agar plugs from 4-day-old cultures were placed in a plastic screw-cap lid filled with sterile water and clipped onto each wound. Plants were misted with water, covered with a plastic bag, and placed in a growth chamber at 16°C (12-h photoperiod) for 48 h after which the agar plugs and caps were removed. An equal number of plants were wounded and mock inoculated with APDA. Pathogenicity experiments were repeated. After 14 days, all inoculated leaves had lesions and the fungus was reisolated. No Botrytis spp. were isolated from the mock-inoculated plants. Our sequence of the intergenic spacer regions of one isolate, GenBank FJ10809, matched Botrytis hyacinthi sequence AJ716297 with 99.8% identity. Using molecular (3) and morphological characters (1,4), the pathogen was identified as B. hyacinthi, the cause of fire disease in hyacinths. This pathogen was described previously on hyacinths in Washington State (2), the Netherlands (4), and the United Kingdom (2). The importance and economic impact of this disease appears to be limited because it has only been observed on mature or senescing foliage and not bulbs. To our knowledge, this is the first report of B. hyacinthi causing a leaf spot on pineapple lily. References: (1) C. J. Gould et al. Plant Dis. Rep. 42:534, 1958. (2) W. C. Moore. Page 14 in: Diseases of Bulbs. Bull. No. 117. Minist. Agric. Fish. London, 1939. (3) M. Staats et al. Mol. Biol. Evol. 22:333, 2005. (4) J. Westerdijk and F. H. Van Beyma Thoe Kingma. Meded. Phytopathol. Lab. "Willie Commelin Scholten" 12:15, 1928.

First Report of Embellisia hyacinthi Causing a Leaf Spot and Bulb Skin Spot Disease on Scilla peruviana in California.

The genus Scilla (Hyacinthaceae) includes more than 50 species of perennial, flowering bulbs grown in landscapes worldwide. In December 2000 and May 2009, an unknown leaf spot disease on Scilla peruviana was submitted to the California Department of Food and Agriculture Plant Pest Diagnostic Lab. Samples were collected during routine phytosanitary inspections of production fields in Santa Cruz County in 2000 and Monterey County in 2009. The disease was detected before plants flowered in one field at each location each year and appeared to have a scattered distribution. Foliar spots were large, elliptical to oblong with grayish black centers and brown margins. Yellow halos surrounded many of the spots. Examination of the bulb material revealed small necrotic patches on the outer bulb scales. A rapidly growing fungus was isolated on one-half-strength acidified potato dextrose agar (APDA) from the sporulating leaf spots and necrotic patches on the bulbs. The colonies were greenish gray and became dark olivaceous with age. Dictyospores, which formed on simple to branched, geniculate conidiophores, were oblong, fusiform or obclavate and usually had a triangular apical cell. They were initially hyaline, turning olivaceous brown with age. Conidia measured 14 to 39 × 8 to 13 µm (average 24.6 × 9.9 µm) typically with two to four (but up to seven) thick, transverse septa and one to two longitudinal septa. Morphologically, the fungus matched the description of Embellisia hyacinthi de Hoog & Miller (1,3). To confirm pathogenicity, four leaves of four S. peruviana plants were inoculated by taking colonized mycelial plugs from 2-week-old cultures and placing them in a plastic screw-cap lid filled with sterile water. The water plus mycelial plug suspension in the lid was then clipped to the adaxial side of a pushpin-wounded leaf (4). Plants were placed in a dark dew chamber at 20°C for 48 h and then moved to a growth chamber at 20°C with a 12-h photoperiod. After 48 h, the clips, caps, and plugs were removed. An equal number of control plants were wounded and mock inoculated with noncolonized APDA agar plugs and the experiment was repeated. Leaf lesions were visible 3 days after clip removal and expanded to an average of 26 × 10 mm, 14 days after inoculation. Sporulation was observed in the lesions after 5 to 7 days and the fungus was isolated from all inoculated leaves. No symptoms developed on the control leaves. DNA sequencing of the internal transcribed spacer region of the isolate (GenBank Accession No. HQ425562) using primers ITS1 and ITS4 matched the identity of E. hyacinthi (2,4). E. hyacinthi has been reported as a foliar and bulb pathogen on Hyacinthus, Freesia, and Scilla in Japan and Europe including Great Britain. Bulbs infected with E. hyacinthi are generally less sound and less valuable than noninfected bulbs (1). To our knowledge, this is the first report of the disease on S. peruviana in California. References: (1) G. S. de Hoog and P. J. Muller. Neth. J. Plant Pathol. 79:85, 1973. (2) B. Pryor and D. M. Bigelow. Mycologia 95:1141, 2003. (3) E. Simmons. Mycotaxon 17:216, 1983. (4) L. E. Yakabe et al. Plant Dis. 93:883, 2009.