Six-year follow-up study of bone mineral density in patients with systemic lupus erythematosus.

UNLABELLED: Long-term bone mineral density (BMD) changes and the associated factors in systemic lupus erythematosus (SLE) patients were assessed. Despite the remarkably low overall bone loss, significant spine bone loss was associated with the use of glucocorticoids, use of antimalarials, and lower 25-hydroxyvitamin D levels, stressing the importance of prevention of osteoporosis and vitamin D deficiency in SLE patients. INTRODUCTION: The aim of this study is to assess the BMD changes in patients with SLE and to identify the associated factors. METHODS: Demographic and clinical data of 126 SLE patients were collected, and BMD measurements of the lumbar spine and the total hip were performed by dual-energy X-ray absorptiometry at baseline and follow-up. Statistical analyses were performed using independent Mann-Whitney U tests and linear regression analyses. RESULTS: At baseline, 39.7 % of the patients (90 % female, mean age 39 ± 12.2 years) had osteopenia, and 6.3 % had osteoporosis. The median follow-up duration was 6.7 years (range 1.9-9.3 years). Mean changes in BMD at the lumbar spine (-0.08 %/year) and the hip (-0.20 %/year) were not significant. During follow-up, 70 % of the patients used glucocorticoids. The mean ± SD daily glucocorticoid dose was 5.0 ± 5.0 mg. In multiple regression analysis, BMD loss at the spine was significantly associated with higher daily glucocorticoid dose and lower baseline 25-hydroxyvitamin D levels. BMD loss at the hip was associated with lower 25-hydroxyvitamin D levels at baseline, reduction of body mass index, and baseline use of antimalarials. CONCLUSIONS: In this 6-year follow-up study, bone loss was remarkably low. A dose-dependent relationship between glucocorticoid use and spinal bone loss was found. In addition, the use of antimalarials and lower 25-hydroxyvitamin D levels at baseline were associated with BMD loss. These findings underline the importance of prevention and treatment of vitamin D deficiency and osteoporosis in SLE, especially in patients using glucocorticoids or antimalarials.

Strobilurin (QoI) Resistance in Populations of Erysiphe necator on Grapes in Michigan.

Powdery mildew, caused by Erysiphe necator, is the most common and destructive disease of grapes (Vitis spp.) worldwide. In Michigan, it is primarily controlled with fungicides, including strobilurins (quinone outside inhibitors [QoIs]). Within the United States, resistance to this class of fungicides has been reported in E. necator populations in some east coast states. Among 12 E. necator isolates collected from five Michigan vineyards in 2008, one carried the G143A single-nucleotide mutation responsible for QoI resistance. This isolate was confirmed to be resistant in a conidium germination assay on water agar amended with trifloxystrobin at 0.001, 0.01, 0.1, 1, 10, or 100 µg/ml and salicylhydroxamic acid (100 mg/liter). The mutant isolate was able to germinate on media amended with 100 µg/ml trifloxystrobin, whereas a representative wild-type isolate did not germinate at concentrations higher than 0.1 µg/ml. In 2009, 172 isolates were collected from a total of 21 vineyards (juice and wine grapes): three vineyards with no fungicide application history (baseline sites), six research vineyards, and 12 commercial vineyards. QoI resistance was defined as the effective concentration that inhibited 50% of conidial germination (EC50) > 1 µg/ml. Isolates from baseline sites had EC50 values mostly below 0.01 µg/ml, while isolates that were highly resistant to trifloxystrobin (EC50 > 100 µg/ml) occurred in five research and three commercial wine grape vineyards at frequencies of 40 to 100% and 25 to 75% of the isolates, respectively. The G143A mutation was detected in every isolate with an EC50 > 1 µg/ml. These results suggest that fungicide resistance may play a role in suboptimal control of powdery mildew observed in some Michigan vineyards and emphasizes the need for continued fungicide resistance management.

First Report of Blueberry Leaf Rust Caused by Thekopsora minima on Vaccinium corymbosum in Michigan.

Leaf rust symptoms have been noticed sporadically on northern highbush blueberry plants (Vaccinium corymbosum L.) in Michigan for the past 8 years. In 2009, leaf rust was seen in several cultivated blueberry fields and on greenhouse-grown blueberry plants in southwest Michigan. In 2010, leaf rust was widespread throughout western Michigan and particularly evident in the fall, sometimes resulting in premature defoliation. Cultivars Rubel, Jersey, Elliott, Liberty, and Brigitta were most commonly affected. Both the 2009 and 2010 growing seasons were characterized by above-average precipitation in early to mid-summer. Early symptoms on the adaxial leaf surface consisted of roughly circular yellow spots that later developed brown, necrotic centers. Older lesions were more angular and sometimes surrounded by a purplish border. In the fall, a "green island" effect was sometimes apparent around the lesions. On the abaxial side, numerous yellow-to-orange rust pustules (uredinia) were visible. Uredinia were dome shaped, erumpent, 100 to 400 µm in diameter, clustered, and sometimes coalescing. Urediniospores were broadly obovate with dark yellowish content and measured 19 to 25 × 16 to 20 µm (average 22 × 18 µm, n = 30). Spore walls were hyaline, echinulate, and 1.0 to 1.5 µm thick with obscure germ pores. Uredinia were examined with light and scanning electron microscopy for the presence of conspicuous ostiolar cells characteristic of Naohidemyces vaccinii (Wint.) Sato, Katsuya et Y. Hiratsuka, but none were observed. No telia or teliospores were observed. On the basis of morphology, the pathogen was identified as Thekopsora minima P. Syd. & Syd. (3,4) and a sample was deposited in the U.S. National Fungus Collection (BPI 881107). Genomic DNA was extracted from urediniospores of rust isolates from six different locations, and a 267-bp fragment of the ITS2 region was amplified and sequenced using the primers ITS3 and ITS4 (GenBank Accession No. HQ661383). All sequences were identical to each other and shared 99% identity (232 of 234 bp) with a T. minima isolate from South Africa (GenBank Accession No. GU355675). The alternate host, hemlock (mostly Tsuga canadensis L.) is a common and valuable conifer in the Michigan landscape. Hemlock trees were not examined for the presence of aecia but are assumed to play a role in the epidemiology of the disease in Michigan because leaf rust tends to be more severe near hemlock trees. Pucciniastrum vaccinii (G. Wint.) Jorst. was considered the causal agent of blueberry leaf rust until Sato et al. (1,4) identified three unique species. While T. minima has been reported on black huckleberry (Gaylussacia baccata [Wangenh.] K. Koch) in Michigan (4), to our knowledge, this is the first report of T. minima on highbush blueberry in the state. T. minima has been reported on highbush blueberry in Delaware and New York (4), Japan (2), and South Africa (3). The severity of the outbreak in 2010 warrants further research into economic losses, epidemiology, and management of the disease. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Botany and Mycology Laboratory, ARS, UDSA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , 2010. (2) T. Kobayashi. Page 1227 in: Index of Fungi Inhabiting Woody Plants in Japan. Host, Distribution and Literature. Zenkoku-Noson-Kyoiku Kyokai Publishing Co., Tokyo, 2007. (3) L. Mostert et al. Plant Dis. 94:478, 2010. (4) S. Sato et al. Trans. Mycol. Soc. Jpn. 34:47, 1993.

First Report of Juneberry Rust Caused by Gymnosporangium nelsonii on Juneberry in Michigan.

Amelanchier alnifolia (Nutt.) Nutt. ex M. Roem., commonly known as juneberry or Saskatoon serviceberry, was historically a widely used prairie fruit that is native to the Northern Great Plains, southern Yukon and Northwest Territories (4). While juneberry is an important fruit crop in the prairie provinces of Canada, small commercial plantings also occur throughout the northern United States (2), including Michigan. On July 18, 2009, severe rust symptoms were observed on plants in a 2-year-old field of A. alnifolia 'Northline' in Northport, MI. The plants had been sourced as seedlings from a nursery in Alberta, Canada in 2007. Signs and symptoms were present on fruits and leaves on virtually all of the plants. Symptomatic fruit were still immature, and on average, more than 70% of the fruit surface was covered with tubular, whitish aecia with conspicuous orange aeciospores. Portions of twigs also showed fusiform swellings (1 to 3 cm long) covered with aecia. Aecia were hypophyllous, fructicolous and caulicolous, roestelioid, and 2 to 4 mm high. The peridium was cylindric and tapering toward the apex, dehiscent at the apex, retaining a tubular shape for a long time and at times becoming lacerated on the sides with age. Peridial cells were linear rhomboidal, 50 to 105 µm long, hyaline to brownish, outer walls smooth, inner walls with small papillae, and side walls delicately verrucose-rugose with elongate papillae having variable lengths. Aeciospores were globoid, 20 to 35 × 25 to 38 µm (average 30.7 × 32.5 µm), orange to cinnamon brown, and densely verrucose with walls 2.5 to 3.5 µm thick. On the basis of these morphological characters, the host, and comparison with a reference specimen (BPI 122010), the pathogen was identified as Gymnosporangium nelsonii Arthur (1,3). The 5' region of the 28S rDNA was sequenced (GenBank Accession No. HM591299.1), confirming the identification as a species of Gymnosporangium, one distinct from previously sequenced specimens available in GenBank. The specimen has been deposited at the U.S. National Fungus Collections (BPI 880671 and 880709). Four other species found previously on Amelanchier spp. in the Midwest differ as follows: G. clavipes and G. clavariiforme have verrucose peridial cells and different 28S rDNA sequences; G. nidus-avis has rugose peridial cells; and G. corniculans has cornute peridia that dehisce from lateral slits while apices remain intact and verrucose peridial walls with verrucae on the side walls (1). The infection was likely caused by basidiospores originating from telia on Juniperus spp. in the area surrounding the field. However, no telia of G. nelsonii were found on junipers in the immediate vicinity. To our knowledge, this is the first report of G. nelsonii on juneberry in Michigan and the Midwest. Because of the devastating impact of this disease on fruit quality, fungicide programs have been devised for disease control and were effective in 2010. Juneberry growers in the Midwest need to be aware of this disease and monitor their crop carefully for symptoms and signs. References: (1) F. D. Kern. A Revised Taxonomic Account of Gymnosporangium. Pennsylvania State University Press, University Park, 1973. (2) K. Laughlin et al. Juneberry for Commercial and Home Use on the Northern Great Plains. North Dakota State University, Fargo 1996. (3) S. K. Lee and M. Kakishima. Mycoscience 40:121, 1999. (4) G. Mazza and C. G. Davidson. Page 516 in: New Crops. Wiley, New York, 1993.

First Report of Pythium sterilum Causing Root Rot of Blueberry in the United States.

In September 2009, ~40 declining blueberry plants (Vaccinium corymbosum L. 'Jersey') were observed in a poorly drained area of a 30-year-old field near Fennville, MI. The stunted bushes had yellow leaves and defoliation; others were completely dead. The grower reported that the bushes had been declining over several years. Root samples tested positive in a Phytophthora ELISA test (Agdia Inc., Elkhart IN). Twenty root pieces (2 cm long and 2 to 3 mm in diameter) were surface disinfested and plated on Rye A agar; five yielded fungal-like colonies that were subcultured on potato dextrose agar (PDA). One isolate was white and grew slowly (3 to 4 mm/day at 22 to 24°C). Three isolates were white and grew faster (10 to 12 mm/day at 22 to 24°C) in a chrysanthemal pattern. The fifth was a Fusarium sp. DNA of the white colonies was extracted and the internal transcribed spacer (ITS) region was sequenced using ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3') primers. The slow-growing morphotype had 99% identity to Phytophthora sp. isolate 92-209C (Accession No. EU106591) in GenBank but failed to induce symptoms in multiple inoculation tests. The fast-growing morphotype (Accession No. HQ398249) had 98% identity to Pythium sterilum UASWS0265 from declining alder stands in Poland (Accession No. DQ525089). Sequencing of the COXII gene using the FM66/FM58 primer set (3) yielded a product (Accession No. HQ721468) with 100% identity to P. sterilum GD32a from forest soil in Poland (Accession No. EF421185). Hyphae were hyaline, coenocytic, and 4 to 7 µm wide with some swellings at the tips (7 to 9 µm wide). No sporangia, oogonia, or antheridia were observed. Mycelium tested positive in the ELISA test described above. According to Agdia Inc., 10 of 19 tested Pythium spp. have shown similar cross reactivity. Pythium spp. are known to cause root rot of blueberries in Oregon (2). In British Columbia, P. sterilum was commonly isolated from roots of declining blueberry bushes (4). P. sterilum Belbahri & Lefort only reproduces asexually (1). Our isolate was similar but did not produce sporangia in water or on PDA, V8 juice agar, Rye A agar, or water agar. Roots of 10 2-month-old 'Bluecrop' cuttings were placed in an aqueous suspension of rinsed mycelium (0.1 g/ml) from 21-day-old cultures grown in V8 broth or in sterile deionized water (control). After 1 h, plants were potted in peat moss/perlite (2:1) or autoclaved sand (five each) and placed in a glasshouse at 25°C. After 7 days, inoculated plants in both soil types had wilted or collapsed with significant necrosis on the roots and primary shoot. Control plants showed no symptoms. In a similar experiment with 6-month-old plants in sand, symptoms appeared after 10 to 12 days. The pathogen was recovered from surface-disinfested root and stem sections of all inoculated plants but not control plants and its identity was confirmed by sequencing of the ITS region. To our knowledge, this is the first report of P. sterilum on blueberries in the United States. While this disease appears to be uncommon in Michigan, it is a potential cause of plant decline, the diagnosis of which may be complicated by cross reactivity in ELISA testing. References: (1) L. Belbahri et al. FEMS Microbiol. Lett. 255:209, 2006. (2) D. R. Bryla and R. G. Linderman. HortScience 43:260, 2008. (3) F. N. Martin. Mycologia 92:711, 2000. (4) S. Sabaratnam. BC Plant Health Fund Final Report. B.C. Retrieved from http://www.agf.gov.bc.ca/cropprot/phf_final_report.pdf , 2008.

First Report of Stem Blight Caused by Calonectria colhounii (Anamorph Cylindrocladium colhounii) on Greenhouse-Grown Blueberries in the United States.

Necrotic stems and leaves were observed on 2- to 4-month-old, rooted microshoot plants (Vaccinium corymbosum L. 'Liberty' and 'Bluecrop', V. angustifolium Aiton 'Putte', and V. corymbosum × V. angustifolium 'Polaris') in a Michigan greenhouse in 2008 and 2009. As the disease progressed, leaves fell off and 80 to 100% of the plants died in some cases. Root rot symptoms were also observed. A fungus was isolated from stem lesions. On potato dextrose agar (PDA), cultures first appeared light tan to orange, then rusty brown and zonate with irregular margins. Chains of orange-brown chlamydospores were abundant in the medium. Macroconidiophores were penicillately branched and had a stipe extension of 220 to 275 × 2.5 µm with a narrowly clavate vesicle, 3 to 4 µm wide at the tip. Conidia were hyaline and cylindrical with rounded ends, (1-)3-septate, 48 to 73 × 5 to 7 (average 60 × 5.5) µm and were held together in parallel clusters. Perithecia were globose to subglobose, yellow, 290 to 320 µm high, and 255 to 295 µm in diameter. Ascospores were hyaline, 2- to 3-septate, guttulate, fusoid with rounded ends, slightly curved, and 30 to 88 × 5 to 7.5 (average 57 × 5.3) µm. On the basis of morphology, the fungus was identified as Calonectria colhounii Peerally (anamorph Cylindrocladium colhounii Peerally) (1,2). The internal transcribed spacer region (ITS1 and ITS2) of the ribosomal DNA and the ß-tubulin gene were sequenced (GenBank Accession Nos. HQ909028 and JF826867, respectively) and compared with existing sequences using BLASTn. The ITS sequence shared 99% maximum identity with that of Ca. colhounii CBS 293.79 (GQ280565) from Java, Indonesia, and the ß-tubulin sequence shared 97% maximum identity with that of Ca. colhounii CBS 114036 (DQ190560) isolated from leaf spots on Rhododendron sp. in North Carolina. The isolate was submitted to the Centraalbureau voor Schimmelcultures in the Netherlands (CBS 129628). To confirm pathogenicity, 5 ml of a conidial suspension (1 × 105/ml) were applied as a foliar spray or soil drench to four healthy 'Bluecrop' plants each in 10-cm plastic pots. Two water-sprayed and two water-drenched plants served as controls. Plants were misted intermittently for 2 days after inoculation. After 7 days at 25 ± 3°C, drench-inoculated plants developed necrotic, sporulating stem lesions at the soil line, while spray-inoculated plants showed reddish brown leaf and stem lesions. At 28 days, three drench-inoculated and one spray-inoculated plant had died, while others showed stem necrosis and wilting. No symptoms were observed on control plants. Fungal colonies reisolated from surface-disinfested symptomatic stem, leaf, and root segments appeared identical to the original isolate. Cy. colhounii was reported to cause a leaf spot on blueberry plants in nurseries in China (3), while Ca. crotalariae (Loos) D.K. Bell & Sobers (= Ca. ilicicola Boedijn & Reitsma) causes stem and root rot of blueberries in North Carolina (4). To our knowledge, this is the first report of Ca. colhounii causing a disease of blueberry in Michigan or the United States. Because of its destructive potential, this pathogen may pose a significant threat in blueberry nurseries. References: (1) P. W. Crous. Taxonomy and Pathology of Cylindrocladium (Calonectria) and Allied Genera. The American Phytopathological Society, St. Paul, MN, 2002. (2) L. Lombard et al. Stud. Mycol. 66:31, 2010. (3) Y. S. Luan et al. Plant Dis. 90:1553, 2006. (4) R. D. Milholland. Phytopathology 64:831, 1974.

First Report of Grape Root Rot Caused by Roesleria subterranea in Michigan.

In September of 2008, declining grapevines were observed in two vineyards (Vitis interspecific hybrids 'Canada Muscat' and 'Chardonel') in Fennville, MI. Affected vines were stunted with shortened internodes and yellow leaves; others had dead cordons or were entirely dead. The grower reported that vines were losing vigor and collapsing during a period of 2 years. Renewal trunks would collapse during the second season of growth. Several symptomatic vines showed signs of root decay. On one vine, distinctive fruiting bodies (mazaedia) were apparent on the roots below the soil line and resembled those of Roesleria subterranea (Weinm.) Redhead (2,3,4). The mazaedia were 4 to 5 mm tall and 1 mm in diameter with white-to-tan stipes and powdery, gray-to-greenish hemispherical heads. Ascospores were hyaline to light grayish green, disk shaped, and 4 to 6 µm in diameter. This fungus, also known as R. hypogaea Thüm & Pass., has been previously reported to cause grape root rot, vine decline, and replant problems in North America and Europe (2,3,4). The fungus was cultured from ascospores on potato dextrose agar (PDA). Colonies grew slowly (approximately 2 mm per day at 22 to 24°C) and were green in the center. No spores were produced. DNA was extracted, and internal transcribed spacer (ITS) sequences obtained by PCR were compared with known sequences using BLASTn (1). Our isolate had 100% ITS sequence homology to an isolate from Germany, Roesleria subterranea strain IB (Accession No. EF060304.1). To test for pathogenicity, the fungus was grown in potato dextrose broth for 14 days at 22 to 24°C. An aqueous suspension (0.1 g of fungus per ml) was prepared by blending mycelia with sterile deionized water (SDW) in a food processor. Five two-node, rooted 'Chardonnay' cuttings (45 days old) were placed in the suspension. Five other cuttings were placed in SDW (control). After 3 h, plants were removed and repotted in fresh BACTO soil (Michigan Peat Company, Houston, TX) and kept in a growth chamber at 23°C with a 16/8-h light/dark cycle. After 25 days, inoculated plants were, on average, 63% smaller with 77% lower fresh-root weight and fewer fine roots than the control plants. The pathogen was recovered from surface-disinfested roots of all five inoculated plants but not from the control plants. Cultures appeared similar to the original isolate and their identity was confirmed by ITS sequencing. To our knowledge, this is the first report of R. subterranea on grapes in Michigan and the Midwest. This fungus needs to be recognized as a potential cause of vine decline and replant problems in Midwestern vineyards. References: (1) S. F. Altschul et al. J. Mol. Biol. 215:403, 1990. (2) W. Gärtel. Page 40 in: Compendium of Grape Diseases. R. C. Pearson and A. C. Goheen, eds. The American Phytopathological Society, St. Paul, MN, 1988. (3) M. Kirchmair et al. Mycol. Res. 112:1210, 2009. (4) J. R. Liberato et al. Pest and Diseases Image Library. Online publication, 2009.

Detection of Eutypa lata and Eutypella vitis in Grapevine by Nested Multiplex Polymerase Chain Reaction.

ABSTRACT Two fungi were isolated from grapevines in Michigan vineyards with Eutypa dieback symptoms: Eutypa lata and Eutypella vitis. These fungi are difficult to distinguish morphologically but are genetically distinct as determined by sequencing of the internal transcribed spacer (ITS) regions. The ITS regions of 25 Eutypa lata and 15 Eutypella vitis isolates were sequenced. Eutypa lata sequences were more variable than those of Eutypella vitis. Polymerase chain reaction (PCR) primers were designed for each species and evaluated against isolates of both fungi as well as 11 closely related Diatrypaceous fungi and 23 isolates of other fungi representing various pathogenic, saprophytic, and endophytic genera on grape and other small fruit crops. The primers were specific for their intended species. A nested multiplex PCR protocol was developed and used to successfully detect these fungi in wood samples from cankers with and without stromata from naturally infected vines as well as in artificially inoculated, potted canes. The primers developed in this study will assist in our abilities to diagnose and study the roles of Eutypa lata and Eutypella vitis in Eutypa dieback development.

First Report of Anthracnose Caused by Elsinoë ampelina on Grapes in Michigan.

In 2001, dark brown-to-purple, sunken lesions were observed on shoots and berries of 5-year-old 'Mars' and 'Marquis' table grapes (Vitis spp.) in Onondaga, MI. The disease affected >90% of the vines. Many leaves were curled and distorted and some shoot tips had died back. Older wood showed crater-like indentations. No fruit was harvested due to poor fruit quality. Lesions (at least 10 per sample) were surface-disinfested with 1% sodium hypochlorite, placed on potato dextrose agar (PDA), and kept at 23 to 25°C under ambient light. Sphaceloma ampelinum de Bary (teleomorph Elsinoë ampelina Shear) was isolated from shoots, leaves, and clusters (4). Colonies appeared as slow-growing, dark red mounds. Conidia were hyaline, ovoid, and measured 2.5 to 5 × 5 to 12.5 µm (average 3.5 × 7.4 µm). While grape anthracnose is usually considered a southern disease, occasional outbreaks have been reported in Ohio (1) and it appears to have become more common in Michigan in recent years. Several old herbarium specimens and records of the fungus on grapes in Michigan exist (2,3), but pathogenicity was not proven. In 2004, the disease was confirmed in eight table grape vineyards (three 'Marquis', two 'Concord Seedless', two 'Mars', and one unknown variety), one juice grape ('Niagara'), and one wine grape vineyard ('Vidal') in various locations in Michigan. To determine pathogenicity, shoots of two potted 'Mars' plants were sprayed until runoff with a suspension of 106 conidia/ml of an isolate from 'Marquis' grapes in Lawton, MI. The plants were covered with clear plastic bags for 48 h and kept at 23 to 25°C on the lab bench for 2 weeks. Shoots sprayed with water served as controls. After 4 days, numerous brown spots appeared on inoculated young leaves, petioles, internodes, and tendrils. Lesions continued to enlarge and coalesce into large necrotic areas. The fungus was successfully reisolated on PDA using the procedure described above. ITS1F/ITS4 amplification of three isolates from 'Marquis' vineyards in St. Joseph, Lawton, and Onondaga, MI produced a product of approximately 1,040 bp. The sequences most closely matched that of E. banksiae I. Pascoe & P. Crous from Banksia prionotes Lindl. in GenBank, but no E. ampelina sequences were available for comparison. The sequences of the three isolates in this study were submitted to GenBank (Accession Nos. AY826762, AY826763, and AY826764). The disease in the vineyard in Onondaga may have been present on the plants which originated in Arkansas. Additional evidence for nursery stock as a source of inoculum was the discovery of anthracnose on 'Concord Seedless' plants at a retailer in Okemos, MI in 2004. Anthracnose was also found on riverbank grape (Vitis riparia Michx.) in Holland, MI, indicating the potential of wild hosts to be an inoculum source. However, nothing is known about the ability of isolates from wild grapes to infect cultivated grapes. Control methods, such as the use of disease-free plants, pruning, and effective fungicides are necessary to avoid serious losses in susceptible varieties, particularly in years with heavy rainfall. References: (1) M. A. Ellis and O. Erincik. Anthracnose of grape. Ohio State Univ. Ext. Fact Sheet. HYG-3208-02, 2002. (2) D. F. Farr et al. Fungal Databases. Systematic Botany and Mycology Laboratory, On-line publication. ARS, USDA, 2005. (3) A. E. Jenkins and A. A. Bitancourt. Nos. 1-550, Myrangiales Selecti Exsiccati, 1940-1963. (4) R. C. Pearson and A. C. Goheen, eds. Compendium of Grape Diseases. The American Phytopathological Society, St. Paul, MN, 1995.

Characterization of Phomopsis spp. Infecting Grapevines in the Great Lakes Region of North America.

Seventy-five isolates of Phomopsis were obtained from grapes (Vitis spp.) with Phomopsis cane and leaf spot symptoms in Ohio, Michigan, New York, Pennsylvania, Maryland, and Ontario (Canada). Four isolates from California and one from Europe were also included in the study. Isolates were grouped on the basis of DNA sequences from intron regions in the translation elongation factor 1-α and calmodulin genes. According to DNA sequence comparisons with the type isolate, all isolates except two (OH-48 and CAL-5) were determined to be P. viticola, confirming the etiology of this disease in the Great Lakes region. Thirty representative isolates were evaluated for mycelial growth rate in vitro, conidial size, and pathogenicity on grapevine (Vitis interspecific hybrid 'Seyval') leaves and internodes. A subsample of 13 isolates was also evaluated for pathogenicity on fruit and rachises. All isolates of P. viticola caused disease on grape but differed in virulence. Among P. viticola isolates, virulence on leaves and internodes was positively correlated, and virulence on fruit and rachises was positively correlated, but there was no relationship between ratings on vegetative versus reproductive grape tissues. Some isolates that were not virulent on leaves or internodes were highly virulent on fruit and rachises and vice versa, indicating some specialization with respect to host tissues. However, differences were mostly of a quantitative nature, which makes it difficult if not impossible to assign biotypes. Among P. viticola isolates, virulence on fruit and rachises was positively correlated with mycelial growth rate in vitro. For the two isolates that were not P. viticola, the internal transcribed spacer regions of the nuclear ribosomal DNA were sequenced for identification purposes. Based on the best match available in GenBank, CAL-5 was determined to be close to Diaporthe phaseolorum, while the sequence of OH-48 matched that of Phomopsis sp. from Eucommia ulmoides in China. Both isolates had shorter alpha conidia and significantly higher mycelial growth rates than the P. viticola isolates, and were not or only slightly pathogenic to Vitis interspecific hybrid 'Seyval'.

Incidence and Causes of Postharvest Fruit Rot in Stored Michigan Cranberries.

The incidence of postharvest fruit rot and associated fungi was studied in stored cranberries in Michigan in 2000 and 2001. Ripe cranberries were harvested from eight commercial farms in southwest and northeast Michigan, including the Upper Peninsula. Eight cranberry cultivars were represented: Stevens, Searles, Le Munyon, Pilgrim, Ben Lear, Bergman, Beckwith, and WSU 61. Fruit rot incidence was assessed within 1 week after harvest. Remaining sound fruit was stored for 2 months at 5°C, and fungi were isolated from rotted fruit after 1 and 2 months of storage. Year and region, but not cultivar, significantly affected the overall rate of rot development in storage. Storage rot levels generally were lower in 2001 than in 2000, particularly in southern Michigan. A high incidence of field rot at harvest did not necessarily lead to a high incidence of storage rot. Storage rot tended to be more severe in the northern than in the southern growing region. Fungi most frequently associated with storage rot were Fusicoccum putrefaciens, Colletotrichum acutatum, Coleophoma empetri, Phomopsis vaccinii, and Phyllosticta elongata. F. putrefaciens was the predominant storage rot fungus in northern Michigan in both years and caused up to 80% fruit rot in storage. C. empetri and P. elongata also were isolated more frequently from beds in northern than southern Michigan in 2001. The cvs. Pilgrim and Stevens were more susceptible to storage rot caused by Colletotrichum acutatum, and Bergman and WSU 61 were more susceptible to storage rot caused by Phomopsis vaccinii than some of the other cultivars.

First Report of Tobacco ringspot virus in Table Grapes in Michigan.

In 1998, several 10-year-old 'Marquis' and 'Vanessa' (Vitis sp.) table grapevines at the Southwest Michigan Research and Extension Center in Benton Harbor started showing decline symptoms such as stunted shoots with small leaves and berries. Vines eventually stopped producing fruit and died. In 1999, symptomatic vines were indexed on cucumber (Cucumis sativus L. 'National Pickling') cotyledons, which developed chlorotic local lesions. Symptomatic cucumber tissue was tested using Ouchterlony double diffusion with polyclonal antibodies for Tomato ringspot virus (ToRSV) and Tobacco ringspot virus (TRSV) provided by D. Ramsdell. Samples tested positive for TRSV. 'Marquis' vines (9 of 45) in the affected area also tested positive in double-antibody sandwich enzyme-linked immunosorbent assay with polyclonal antibodies for TRSV (Agdia, Inc., Elkhart, IN). Analysis of soil samples from the site in 1989 yielded five dagger nematodes (Xiphinema americanum Cobb) per g of soil, confirming the potential for virus spread by nematodes (1). TRSV reportedly infects Vitis vinifera L. but not V. labrusca L. (1). 'Marquis' and 'Vanessa' have V. vinifera heritage. The detection of TRSV has led to the establishment of a program for the production of virus-tested table grape planting stock, as well as research on the utility of nematode-resistant rootstocks for growing table grapes at the infested site. Reference: (1) R. C. Pearson and A. C. Goheen, eds. Compendium of Grape Diseases, The American Phytopathological Society, St. Paul, MN, 1995.

A First Assessment of the Cranberry Fruit Rot Complex in Michigan.

Samples of ripe fruit were taken at harvest from all eight commercial cranberry farms in Michigan over a 3-year period to determine the distribution and incidence of fruit rot diseases and the fungal pathogens associated with rotted fruit. Totals of 23, 33, and 28 beds were sampled in 1999, 2000, and 2001, respectively. Fruit rot incidence varied widely among beds and farms and ranged from 5 to 97% (mean 33.4%) in 1999, 1 to 91% (mean 26.3%) in 2000, and 1 to 67% (mean 12.8%) in 2001. Differences in fruit rot incidence were observed among cultivars, but rankings differed among farms. In general, cultivars Ben Lear, Bergman, and Pilgrim tended to have lower and Beckwith and WSU61 higher fruit rot incidence than other cultivars grown in the same location. Colletotrichum acutatum, Pestalotia vaccinii, and Phyllosticta vaccinii were the fungi most frequently recovered from rotted fruit. Fusicoccum putrefaciens, Phomopsis vaccinii, Physalospora vaccinii, Allantophomopsis lycopodina, Coleophoma empetri, and Botrytis cinerea were isolated occasionally in 1999. The isolation frequency of Physalospora vaccinii, Phomopsis vaccinii, and C. empetri increased markedly in 2000. Glomerella cingulata was first detected in 2001. Fusicoccum putrefaciens was most common in the northern and Glomerella cingulata in the southern growing areas. A comparison of sound and rotted fruit from selected beds showed that Phyllosticta elongata predominated in sound fruit, whereas G. cingulata predominated in rotted fruit.