Is haemodynamic depression during carotid stenting a predictor of peri-procedural complications?

OBJECTIVE: The clinical significance of Haemodynamic Depression (HD) during carotid stenting (CAS) remains unclear. The aim of this study was to analyze the frequency and predictors of HD during CAS in a single centre experience. METHODS: A prospective protocol for CAS was applied in a 15-month interval. Patients with restenosis, on betablockers, or with arrhythmias were excluded. A standardized dose of atropine (0.4mg) was given prior to stent deployment. Changes in heart rate, blood pressure, and neurological status were monitored and recorded. HD was defined as systolic pressure <90mmHg and/or heart rate <50 beats/min. Fifteen potential predictors of HD (age, gender, hypertension, smoking, diabetes, coronary artery disease, previous myocardial infarction, symptoms, degree of carotid stenosis contralateral CEA or CAS, calcified/hyperechoic plaque, plaque length, stent oversizing and type of stent) were tested in multivariate analysis. RESULTS: Two hundred and twenty three consecutive patients were enrolled. HD occurred in 98 cases (44%): in 68 cases HD required additional pharmacological support. At 30 days, any stroke rate was 3.1% (3 major and 4 minor), TIA rate 1.8%, myocardial infarction rate 0.4%. No deaths were recorded. No difference in complication rates were found in patients with or without HD. From regression analysis only the presence of calcified plaque (HR 9.5; 95% CI 5.0 to 18.2; p<0.0001) and the plaque length (HR 1.77; 95% CI 1.03 to 3.06; p=0.038) were associated significantly with HD. CONCLUSIONS: HD during CAS is a common, relatively benign event, without increased risk of peri-operative complications. Careful pharmacological treatment is necessary to decrease HD and the potential complications, especially in patients with more severe calcified lesions. These results require confirmation in a separate, larger cohort.

First Report of Zucchini Collapse by Fusarium solani f. sp. cucurbitae Race 1 and Plectosporium tabacinum in Italy.

Zucchini plant collapse has been often associated with Fusarium solani f. sp. cucurbitae race 1, which is the causal agent of Fusarium crown and foot rot disease of cucurbits. In Italy, F. solani f. sp. cucurbitae race 1 has been reported on zucchini (Cucurbita pepo) in a greenhouse in the Tuscany Region (4). In spring 2005, a severe outbreak was observed on zucchini in a vast area of cultivation in the province of Venice. Isolations from necrotic vessels gave more than 20 single-spore cultures. On the basis of morphological characteristics, they were identified as F. solani (2) and Plectosporium tabacinum (3). The internal transcribed spacer (ITS) region of rDNA was amplified and sequenced. A fragment of 454 and 531 bp was 99% homologous with sequence PSU66732 and AF150472 of F. solani f. sp. cucurbitae race 1 and P. tabacinum, respectively, in the NCBI database. The nucleotide sequences have been assigned Accession No. AM408782 for F. solani f. sp. cucurbitae race 1 and AM408781 for P. tabacinum. Pathogenicity tests were conducted with four isolates of each species on 15-day-old zucchini plants and on fruit. Plants were inoculated by dipping the roots in a conidial suspension of 106 spores ml-1 for 10 min. Control plants were dipped in sterile water. Five replicates for the inoculated and control plants were used. All plants were maintained in a greenhouse at approximately 24°C. After 14 days, inoculations with F. solani f. sp. cucurbitae race 1 gave symptoms of a cortical rot at the base of the stem with a progressive yellows and wilting of leaves, while plants inoculated with P. tabacinum displayed a moderate wilting. Fruit were washed under running water, disinfected with a solution of 3% sodium hypochlorite and 5% ethanol for 1 min, and inoculated with 6-mm-diameter mycelial plugs cut from the margin of 10-day-old cultures grown on PDA. Plugs were inserted into holes (approximately 2 mm deep) made with a sterile 7-mm-diameter cork borer. Five replicates per isolate were used. Fruit were kept at room temperature (22 to 24°C) in a moist chamber. All isolates induced symptoms of fruit rotting 10 days after inoculation. All controls remained healthy. The colonies reisolated from the inoculated plants and fruit were morphologically identical to the original isolates. The results obtained proved that F. solani f. sp. cucurbitae race 1 can be considered the major pathogen in zucchini collapse, at the same time P. tabacinum may play a role in this syndrome as reported for other cucurbits (1). To our knowledge, this is the first report of zucchini plant collapse caused by F. solani f. sp. cucurbitae race 1 and P. tabacinum, and the first report of P. tabacinum on zucchini in Italy. References: (1) V. J. Garcia-Jimenez et al. EPPO Bull. 30:169, 2000. (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University, University Park, 1983. (3) M. E. Palm et al. Mycologia 87:397, 1995. (4) G. Vannacci and P. Gambogi. Phytopathol. Mediterr. 19:103, 1980.

First Report of Phytophthora cambivora Causing Bleeding Cankers and Dieback on Beech (Fagus sylvatica) in Italy.

European beech (Fagus sylvatica) is an important forest tree species common in northern and central Europe. In Italy, this species is typical in mountain areas over 1,000 m above sea level. In the last decade, decline and death was reported on European beech caused by several Phytophthora species (2), and P. pseudosyringae was recently reported in Italy (3). During 2004 and 2005, seven declining and dying F. sylvatica trees, older than 20 years, were observed in the Veneto Region of Italy with symptoms of bleeding cankers at the base of trunks and on branches. Cankers on the collar showed tongue-shaped necroses of the inner bark and cambium tissues. Four trees were in a public park of Mestre and three were in a forest stand in the province of Belluno. Samples were taken from declining trees, one in the park and two in the forest. Inner bark and cambium tissue pieces were cut from the canker margins, cultured on CARPBHy-agar (corn meal agar amended with 250 µg ml-1 ampicillin, 10 µg ml-1 rifampicin, 10 µg ml-1 pimaricin, 15 µg ml-1 benomyl, 50 µg ml-1 hymexazol), and incubated at 20°C. Ten morphologically similar isolates were subcultured as single hyphal tips and characterized. These isolates produced nonpapillate sporangia that were ovoid, obpyriform or ellipsoid, and exhibited predominately internal proliferation in soil extract. Hyphal swellings with outgrowths were present under those conditions. The morphological characteristics were consistent with those of P. cambivora (1). Base sequences of the ITS region of rDNA were determined for six of the isolates, and an 832-bp fragment was amplified for each isolate and that sequence was 100% homologous with sequences DQ396418 and AY880985 of P. cambivora in the NCBI database ( http://www.ncbi.nlm.nih.gov/BLAST/ ). The sequence of one isolate, ISPaVe 1950, was deposited in GenBank (Accession No. AM269752). Pathogenicity tests were conducted with 2-year-old potted beech seedlings. Inoculum of representative isolates was grown for 4 weeks on sterilized millet seeds moistened with V8 broth and added to soil at 3% (wt/vol). Control plants received sterilized inoculum only. The soil was flooded for 48 h. Inoculations were performed during May 2005 at 15 to 35°C with six replicates for the inoculated and control plants. The plants were maintained outdoors and assessed after 3 months. Wilt, root rot, and dark brown lesions at the collar developed on inoculated plants, but not on the controls. Symptoms were similar to those on naturally infected trees. The pathogen reisolated from the inoculated plants was morphologically identical to the original isolates, which confirmed P. cambivora as the causal agent. To our knowledge, this is the first report of P. cambivora on beech in Italy. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) T. Jung et al. Mycologist, 19:159, 2005. (3) E. Motta et al. Plant Dis. 87:1005, 2003.

First Report of Twig Canker of Hazelnut Caused by Fusarium lateritium in Italy.

Cultivation of hazelnut (Corylus avellana L.) has considerable economic potential in Italy, in particular, in the northern Lazio Region. Since early summer of 2000, cankered twigs have been observed on hazelnut trees that were severely affected by gray necrosis, which is a disease complex causing fruit drop (1). In subsequent years, sunken areas were observed on 1-year-old shoots from late April through May. The resulting cankers had reddish brown margins and the death of the cambium in the infected area and produced an L-shaped malformation of twigs. Girdling of the twig by the canker resulted in death of the foliage. Yellow-to-orange sporodochia were evident on cankers by early June. Isolations were made from the margins of young cankers from 20 twigs collected from 10 trees. Tissue pieces were plated onto potato dextrose agar (PDA) after surface disinfection with 1% sodium hypochlorite. Slow-growing, cream-to-reddish brown colonies with sparse aerial mycelium emerged from 80% of diseased tissue pieces within 10 days of incubation at 20 to 22°C. Conidial production was induced by keeping pure cultures at 22 to 25°C under natural light but out of direct sunlight. Within 1 month, sporodochia bearing ellipsoidal, spindle-shaped, commonly 1 to 3 septate macroconidia developed. Intercalary chlamydospores were often present in chains. Single conidia were subcultured on carnation leaf agar (CLA). On the basis of morphological and cultural characteristics, the fungus was identified as Fusarium lateritium Nees. (2). Pathogenicity tests were conducted outdoors on the current year's shoots of hazelnut trees with four isolates derived from single conidia of F. lateritium. Inocula used were either mycelial plugs cut from the margin of actively growing cultures or small (10 × 10 mm) pieces of sterile cheesecloth soaked in 1 × 106 conidia per ml suspension. The mycelial plugs were placed under the bark, while the soaked cheesecloth pieces were wrapped around an area that had been wounded by gently scraping off a length of the bark (approximately 10 mm) with a sterile needle. All the inoculations were wrapped with Parafilm to prevent desiccation. Six inoculations per isolate were performed. In a similar manner, controls were inoculated with agar plugs or water only. After 3 months, the length and width of each canker were measured. For both inoculation methods, cankers were similar to those observed in nature and averaged 20.6 × 5 mm, while the controls did not show any symptoms. F. lateritium was consistently reisolated from the canker margins of the inoculated shoots. To our knowledge, this is the first report of F. lateritium causing twig cankers on hazelnut. The fungus has been reported to cause cankers on several tree species, including Malus domestica (apple), Morus spp. (mulberry), Sophora japonica (Japanese pagoda tree), Robinia pseudoacacia (black locust), Citrus spp., and Pyrus pyrifolia (Asian pear). References: (1) A. Belisario et al. Inf. Agrario 59(6):71, 2003. (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University, University Park, 1983.

First Report of Alternaria Species Groups Involved in Disease Complexes of Hazelnut and Walnut Fruit.

During the last 5 years, two new diseases, brown apical necrosis (BAN) and gray necrosis (GN), were observed on English walnut (Juglans regia) and hazelnut (Corylus avellana), respectively (2,3). Both diseases caused severe fruit drop resulting in yield loss often exceeding 30%. Previous work demonstrated that BAN and GN are disease complexes caused by several fungi (Alternaria spp., Fusarium spp., and a Phomopsis sp.) (2,3). In both diseases, preliminary identification of Alternaria spp. revealed they were a complex of small-spored catenulate taxa related to A. alternata. To further characterize these taxa, additional pathogenicity tests and morphological examinations were conducted with isolates obtained from each host. Single-spored isolates were prescreened for pathogenicity by inoculating detached, surface-disinfested hazelnut leaves or walnut leaflets (1). Only isolates that produced foliar lesions after 5 days were used in subsequent fruit inoculations. From this screening, 35 isolates were selected (19 from walnut and 16 from hazelnut). For each isolate, attached fruit of respective hosts were inoculated at bloom by placing 10 µl of a conidial suspension (1 × 106 conidia per ml of H2O + 0.26% agar) onto the stigmas (150 fruit per isolate). Controls (150 fruit) were treated with agar solution only. After 15 days, fruit were examined for development of disease symptoms, and examination continued until fruit maturation (late July). Approximately 20 to 50% of the inoculated fruit displayed discoloration or necrosis of internal tissue, particularly the pericarp and the embryo, although symptoms were more limited than those typically seen in fully expressed BAN and GN. No differences in symptoms were evident among the isolates tested. The controls showed no symptom development initially, although 5% began to develop discoloration at fruit maturity. Fungal isolates used as inoculum were reisolated from all symptomatic fruit by surface disinfesting tissue from the margins of necrotic lesions. For each isolate, the conidial characteristics were described from cultures grown under defined conditions (4). Three distinct groups of isolates were identified. Alternata sp. group isolates produced conidial chains (8 to 20 spores) with numerous secondary and occasionally tertiary chains branching from apical and median cells. Conidia were typically ovate and often possessed a one-celled apical extension. Tenuissima sp. group isolates developed conidial chains (10 to 22 spores) with occasional branching forming secondary chains from apical and median cells. Conidia were ovate to obclavate, often with long apical extensions (10 to 35 µm). Arborescens sp. group isolates developed conidial chains (5 to 12 spores) with numerous secondary, tertiary, and quaternary short chains branching from apical cells. Conidia were typically ovate with minimal apical extensions. Of the walnut isolates, 12, 4, and 3 were from the arborescens, alternata, and tenuissima sp. groups, respectively. Of the hazelnut isolates, 7, 6, and 3 were from the arborescens, alternata, and tenuissima sp. groups, respectively. The finding that Alternaria from several distinct sp. groups can cause similar disease on a single host is consistent with previous work on pistachio, almond, and pear (4). References: (1) A. Belisario et al. Plant Dis. 83:696, 1999. (2) A. Belisario et al. Plant Dis. 86:599, 2002. (3) A. Belisario et al. Inf. Agrario 59:71, 2003. (4) B. M. Pryor et al. Phytopathology 92:406, 2002.

First Report of Wilt and Dieback on Pokeweed (Phytolacca decandra) Caused by Phytophthora nicotianae.

Pokeweed (Phytolacca decandra, synonym Phytolacca americana) is a root perennial plant that produces a succulent annual stem. In late June 2001, a severe dieback occurred on a group of pokeweed plants being grown as ornamentals in a garden in Rome. Disease symptoms consisted of leaf wilting followed by collapse of the plant. Stem collars and roots had dark brown-to-black water-soaked lesions. A wet rot was observed on plants with advanced disease symptoms. Isolations, from sections of roots and stems previously washed in running tap water, were made on PARBhy selective medium (10 mg of pimaricin, 250 mg of ampicillin [sodium salt], 10 mg of rifampicin, 50 mg of hymexazol, 15 mg of benomyl, 15 g of malt extract, and 20 g of agar in 1,000 ml of H2O) (2), followed by incubation at 20°C. A species of Phytophthora identified based on morphological and cultural characteristics (1) was isolated consistently from rotted roots and collars of diseased plants. All isolates produced papillate, spherical, ovoid to obturbinate, noncaducous sporangia and terminal and intercalary chlamydospores. Hyphal swellings with hyphal outgrowths were present. Observed characteristics were similar to those described for P. nicotianae. Isolates were mating type A2 with amphigynous antheridia in paired cultures with the A1 tester isolate of P. nicotianae. Identification was confirmed by comparing restriction fragment length polymorphism patterns of the internal transcribed spacer region of ribosomal DNA with those obtained from previously identified Phytophthora species. Pathogenicity tests were conducted on 10 2-month-old potted pokeweed plants. Inoculum was prepared by inoculating sterilized millet seeds moistened with V8 broth with plugs of mycelium and growing for 4 weeks. The inoculum was added to potting soil at 3% (wt/vol), and sporulation was induced by flooding the soil for 48 h. Five uninoculated plants were used as controls. Plants were maintained outdoors and assessed for symptoms within 2 months after inoculation. Wilting, root rot, and dark brown lesions on the collar developed on inoculated plants. The pathogen was reisolated from the inoculated plants and morphologically identical to the original isolates, which confirmed P. nicotianae as the causal agent of the disease. Few diseases have been reported on Phytolacca decandra. This species is not only an invasive weed, but is also cultivated as an ornamental and medicinal plant. In addition, antiviral (PAP) and antifungal (Pa-AFP) proteins that are used as a remedy for several human and plant infections have been extracted from the plant. To our knowledge, this is the first report of P. nicotianae on pokeweed. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) A. M.Vettraino et al. Plant Pathol. 50:90, 2001.

First Report of Phytophthora nicotianae and P. citricola Associated with English Walnut Decline in Europe.

English (Persian) walnut (Juglans regia), among the most widely cultivated species of Juglans worldwide, is cultivated primarily for fruit production but also for timber. In the last 10 years, walnut decline causing leaf yellowing, sparse foliage, overall decline, and plant death has increased in Italian commercial orchards. In Italy, Phytophthora cactorum, P. cambivora, P. cinnamomi, and P. cryptogea are associated with this disease (1,4). Over the last 5 years, P. cinnamomi was the most widely isolated and destructive species (1). Recently, a different species of Phytophthora was isolated from diseased roots and soil from around lateral roots of 10 declining trees in two orchards in the Veneto Region of northern Italy. Another species of Phytophthora was isolated consistently from rotted roots of declining walnut trees in two orchards in the Campania Region of southern Italy. Phytophthora spp. were isolated directly from plant material or Rhododendron spp. leaf baiting on soil samples with PARBhy selective medium (10 mg of pimaricin, 250 mg of ampicillin [sodium salt], 10 mg of rifampicin, 50 mg of hymexazol, 15 mg of benomyl, 15 g of malt extract, 20 g of agar in 1,000 ml of H2O). Two species of Phytophthora were identified based on morphological and cultural characteristics (2). The species from trees in the Veneto Region was identified as P. nicotianae. All isolates produced papillate, spherical to obturbinate, occasionally caducous sporangia with short pedicels, terminal and intercalary chlamydospores, and were mating type A2. The species isolated from trees in the Campania Region was identified as P.citricola. Isolates were homothallic, produced semipapillate, persistent, obclavate to obpyriform sporangia, occasionally with two apices, and antheridia paragynous. Identifications were confirmed by comparing restriction fragment length polymorphism patterns of the internal transcribed spacer region of rDNA with those obtained from previously identified species of Phytophthora. Pathogenicity of two isolates each of P. citricola and P. nicotianae was tested on 2-year-old potted walnut seedlings. Inocula were prepared by inoculating sterilized millet seeds moistened with V8 broth with plugs of mycelium and incubated for 4 weeks at 20°C in the dark. Infested seeds were added to potting soil at a rate of 3% (wt/vol). One day later, pots were flooded for 48 h to promote sporulation. Ten noninoculated seedlings were used as the control. Symptoms were assessed 2 months after inoculation. Seedlings inoculated with P. nicotianae developed necrosis of feeder and lateral roots, but only limited infection of taproots. Seedlings inoculated with P. citricola developed necroses at the insertion points of lateral roots. All four isolates produced visible damage to lateral roots on inoculated plants. P. nicotianae and P. citricola were reisolated from respectively infected roots. Results from these inoculations confirmed P. nicotianae and P. citricola as root pathogens of English walnut. Both species were associated with walnut decline as reported in the United States (3). To our knowledge, this is the first report of P. nicotianae and P. citricola on J. regia in Europe. References: (1) A. Belisario et al. Petria 11:149. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (3) M. E. Matheron and S. M. Mircetich. Phytopathology 75:977, 1985. (4) A. M. Vettraino et al. Plant Dis. 86:328, 2002.

First Report of Phytophthora cryptogea in Walnut Stands in Italy.

English (Persian) walnut (Juglans regia L.) is among the most widely cultivated species in pure and mixed plantations of broadleaved trees in Italy. A decline of walnut of increasing occurrence has been reported recently in new plantations in central and northern Italy. Symptoms of the decline were typically characterized by yellowing of the foliage, defoliation, and plant death. Dark, flame-shaped necroses were often present at the collar. Phytophthora cactorum, P. cambivora, and P. cinnamomi were among the species associated with necrotic tissues of the collar and main roots (1). Furthermore, a Phytophthora sp. was isolated from soil removed from the lateral root zone of 6 of 15 declining trees in 3 walnut plantations, 2 in northern Italy and 1 in central Italy. Isolations were made by baiting with Rhododendron leaves and plating on PARBhy selective medium (3). The species isolated was identified as P. cryptogea on the basis of morphological and cultural characteristics (2). All isolates produced oval to obpyriform, nonpapillate sporangia and were mating type A2. Identification of the isolates was confirmed by comparing the restriction fragment length polymorphism patterns of the internal transcribed spacer region of ribosomal DNA with those obtained from previously identified Phytophthora species. Pathogenicity tests on potted 2-year-old walnut seedlings were conducted using two isolates of P. cryptogea. Inoculum was prepared by growing isolates on sterilized millet seeds added to soil at 2.5% (wt/vol). Sporulation was induced by 24-h flooding of the soil. Symptoms were assessed 1 month after inoculation. Ten uninoculated seedlings were used as controls. Inoculated seedlings showed no symptoms on the tap root, but there were extensive necroses of lateral roots ranging from 14 to 75% (average 38.6 ± 6.7 SE) of total lateral root (dry weight) compared with values of 0 to 11% (average 3 ± 1.5 SE) for uninoculated seedlings. P. cryptogea was easily reisolated from infected lateral roots and from the soil of inoculated pots. The inoculation trials confirmed P. cryptogea as a feeder-root pathogen of walnut in Italy. To our knowledge, this is the first report of P. cryptogea on English walnut in Italy. This species often has been associated with walnut decline in the United States (2) and on other woody plants in Italy (3). References: (1) A. Belisario et al. Petria 11:127, 2001. (2) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Association, St. Paul, MN, 1996. (3) A. M. Vettraino et al. Plant Pathol. 50:90, 2001.

Resistance to Fusarium oxysporum f. sp. melonis Race 1,2 in Muskmelon Lines Nad-1 and Nad-2.

Of seven doubled-haploid melon lines parthenogenetically originated using irradiated pollen, two lines, Nad-1 and Nad-2, were selected for resistance to Fusarium wilt after successive inoculations with F. oxysporum f. sp. melonis race 1,2w virulent isolate. Nad-1 and Nad-2 were compared with the commercial hybrids and with the parent cvs. Isabelle and Giallo di Paceco. Evaluation of germplasm extended over a 2-year period showed a higher resistance of Nad-1 and Nad-2 plants to Fusarium oxysporum f. sp. melonis race 1,2 than other genotypes tested in this study. The resistance expressed in the two doubled-haploid lines could be due to their homozygous state that maximizes the expression of the genes for resistance already present in the parental line Isabelle. The use of this source of resistance may be exploited commercially either in rootstocks or to facilitate breeding for F1 hybrids. Future research will concentrate on the identification of genetic markers associated with resistance to race 1,2 using these doubledhaploid lines.

Occurrence of Pink Patch of Perennial Ryegrass Caused by Limonomyces roseipellis in Italy.

In March 1999, an unusual pink gelatinous mycelium was observed on several cultivars of perennial ryegrass (Lolium perenne L.) turf grown in experimental plots in Saint Andrea d'Agliano, Perugia (central Italy). Approximately 50% of the turf area showed symptoms on susceptible varieties. The same symptoms, although with lower severity, were observed during the following year in two experimental fields in northern Italy. The presence of mycelium on infected leaf blades was extensive during periods of high relative humidity and high temperature. The disease decreased progressively when weather conditions became dry and cold. A fungus, characterized by pink colonies, was consistently isolated from leaves of affected plants on potato dextrose agar (pH 5.5). On the basis of the presence of clamp connections and binucleate hyphal cells, the fungus was identified as Limonomyces roseipellis Stalpers & Loerakker, the causal agent of pink patch of turfgrass (1,3). For the pathogenicity test, one isolate of L. roseipellis was grown on maize flour and sand medium (2) at 22 ± 2°C for 14 days. Inoculum (20 g) was added to a sterile mixture of sand and peat moss (1:1; 640 g). Two hundred seeds of L. perenne (cv. Amadeus) were sown in boxes containing infested or noninfested soil as a control. Boxes were kept in a greenhouse at 22 ± 2°C, 80% relative humidity, and 14 h of sunlight per day. Four to five weeks after sowing, typical lesions resembling natural symptoms were observed only on plants grown in inoculum-infested soil, and L. roseipellis was consistently reisolated from diseased plants. Pink patch is probably underestimated in turf since the symptoms are less severe compared with red thread caused by Laetisaria fuciformis (McAlpine) Burdsall, and the development of mycelium of Limonomyces roseipellis is slower. References: (1) J. D. Kaplan and N. Jackson. Plant Dis. 67:159, 1983. (2) Y. L. Nene et al. ICRISAT Inf. Bull. 10:1, 1981. (3) J. A. Stalpers and W. M. Loerakker. Can. J. Bot. 60:529, 1982.

Occurrence and Etiology of Brown Apical Necrosis on Persian (English) Walnut Fruit.

In 1998, a severe fruit drop was observed in Italy, principally on cv. Lara Persian (English) walnut (Juglans regia). Dropped fruit showed a brown patch at the blossom end and blackening and rot of inner tissues. The disease, called brown apical necrosis (BAN), was investigated on fruit collected in Italy and France in 1999. In 2000, studies were carried out in three walnut orchards located in Italy and in France to substantiate the etiology of BAN. Isolations performed from inner diseased fruit tissues yielded several fungi, in decreasing frequency of isolation: species of Fusarium and Alternaria, and one species each of Cladosporium, Colletotrichum, and Phomopsis. However, only Fusarium spp. were recovered from stigmas of BAN-affected fruit. The fungi associated with BAN-diseased fruit and species composition differed among locations and over time, confirming results obtained in previous investigations. The species of Fusarium used in pathogenicity tests reproduced BAN-disease symptoms when inoculated on fruit, whereas an Alternaria alternata isolate caused only limited necrosis of the style. However, the role of the other fungi commonly isolated from BAN-diseased fruit remains to be defined. The walnut blight pathogen, Xanthomonas arboricola pv. juglandis, occasionally was isolated from BAN-diseased fruit. No correlation was found between the extent of external brown patches and the size of inner lesions. Repeated isolations from and inoculations of fruit demonstrated that BAN can be considered a complex disease, and the inner infections originate from the style of the fruit.