Characterization of Botryosphaeria dothidea Isolates Collected from Pistachio and Other Plant Hosts in California

ABSTRACT Eighty-six isolates of Botryosphaeria dothidea, the causal agent of Botryosphaeria panicle and shoot blight of pistachio, were collected from pistachio and other plant hosts in California. The isolates were characterized by microsatellite-primed polymerase chain reaction (MP-PCR), sequences of the nuclear ribosomal DNA internal transcribed spacer region (ITS1, 5.8S gene, and ITS2), morphological and cultural characters, osmotic and fungicide sensitivity, and pathogenicity on pistachio. Three groups of these isolates were identified based upon analysis of MP-PCR data and ITS sequences. Group I contained 43 pycnidiospore-derived isolates collected from pistachio and other hosts. Group II consisted of 20 ascosporic isolates obtained from a single sequoia plant. Group III consisted of 20 ascosporic isolates from three shoots on a single blackberry plant, two pycnidiospore-derived isolates from incense cedar, and one from pistachio. Group I predominated over the other two groups in California pistachio orchards. B. dothidea isolates of group III grew faster on acidified potato dextrose agar (APDA) than the isolates of groups I and II. Isolates of group III produced pycnidia on both APDA and autoclaved pistachio shoots, but the isolates of the other two groups produced pycnidia on only autoclaved pistachio shoots. Additionally, significant differences in osmotic and fungicide sensitivities were observed among these three groups. Results from lathhouse inoculations demonstrated that the representative isolates for each of the three groups were all capable of infecting pistachio and producing characteristic disease symptoms of Botryosphaeria blight. The virulence of group II isolates on pistachio was, however, significantly lower than that of group I isolates.     

Spatiotemporal Changes in the Population Structure of Botryosphaeria dothidea from California Pistachio Orchards

ABSTRACT Spatiotemporal changes in the population structure of Botryosphaeria dothidea, causal agent of panicle and shoot blight of pistachio, were analyzed by using microsatellite-primed polymerase chain reaction (MPPCR), partial sequences of the RNA polymerase II (RPB2) gene, and vegetative compatibility groups (VCGs). We examined 390 isolates, 378 recovered from pistachio in seven counties of California from 1990 to 2001 and 12 recovered from peach, apple, and sycamore in Georgia, North Carolina, South Carolina, Illinois, and Pennsylvania. Six microsatellite primers generated 116 polymorphic bands. Based on MP-PCR data, we observed very high (>98%) levels of genetic identity among populations of B. dothidea collected from the commercial pistachio orchards in California. The near identity of these populations was supported by VCGs and partial sequences of the RBP2 gene. These findings suggest that populations of B. dothidea from commercial pistachio orchards are spatially and temporally stable, at least in the past 5 years.     

Effects of Single-Drop Impactions and Natural and Simulated Rains on the Dispersal of Botryosphaeria dothidea Conidia

ABSTRACT Laboratory and field experiments were conducted to study the dispersal of Botryosphaeria dothidea conidia using single-drop impactions and natural and simulated precipitations. For laboratory studies, 200 single drops were released from a height of 1 m on infected pistachio nuts. On pieces of photographic film, 50% of the droplets were collected within 20 mm (average droplet travel distance) of the target area, and the droplets ranged from 0.041 to 3.19 mm in diameter, with an average of 0.3 mm. Each droplet carried an average of 23 B. dothidea conidia. In 3 years of field experiments, rainwater was collected in funnels connected to bottles positioned at different heights inside the tree canopy and at different distances away from the edge of tree canopy in three commercial pistachio orchards in San Joaquin, Yolo, and Glenn counties in California. Numbers of conidia in rainwater varied among and within sampling seasons by sampling dates and orchards. Up to 67,000 conidia/ml were obtained in rainwater samples collected from an orchard in Yolo County. Rainwater from orchards in Yolo and Glenn counties contained a consistently higher number of conidia than rainwater collected from the orchard in San Joaquin County. Variation in numbers of conidia also existed among heights where bottles were located. There were significantly more conidia in rainwater collected inside than outside tree canopies. Inside tree canopies, bottles located at 100 and 150 cm above ground collected more B. dothidea conidia than those placed at 50 and 200 cm. Conidia were collected as far as 1 m from the tree canopy edge. Based on data from the Glenn County orchard, a linear relationship between number of conidia (Y) and rainfall amount (X) in millimeters was determined as Y = 240X - 3,867, with r(2) = 0.91, which meant that a minimum of 16.1 mm of rain was needed to disperse conidia of B. dothidea. The power law model best described the dispersal gradients of B. dothidea propagules in the 1999-2000 and 2001-02 sampling seasons, with r(2) values of >/=0.73, whereas the exponential law model fit best for the 2000-01 data, with r(2) values of >/=0.81. In a rain simulation experiment, the intensity of the rain generated by a nozzle at 138 kPa of pressure inside the tree canopy was approximately five times higher than rain recorded outside the tree canopy. Rain removed up to 65% of conidia from infected fruit. These results confirmed that B. dothidea is a splash-dispersed pathogen with relatively short distances of spore dispersal within pistachio orchards. Only pycnidia are present in pistachio orchards; therefore, the results also indicate that inoculum of B. dothidea should be entirely splashed dispersed.     

山核桃干腐病菌对7种杀菌剂的敏感性比较及其 对苯醚甲环唑敏感基线的建立

测定了甲基硫菌灵、百菌清、腐霉利、戊唑醇、啶酰菌胺、苯醚甲环唑和醚菌酯对山核桃干腐病菌Botryosphaeria dothidea的离体抑菌活性。结果表明,上述7种杀菌剂抑制该病原菌菌丝生长的活性依次为苯醚甲环唑＞戊唑醇＞腐霉利＞甲基硫菌灵＞百菌清＞醚菌酯＞啶酰菌胺。进一步研究表明,苯醚甲环唑对采自安徽和浙江两省从未使用过甾醇脱甲基抑制剂类(DMIs)杀菌剂的150株山核桃干腐病菌菌丝生长的平均EC50值为0.43( ±0.11) μ g/mL,可作为其敏感基线用于以后的抗药性监测。     

Botryosphaeriaceae occurring on native Syzygium cordatum in South Africa and their potential threat to Eucalyptus

Eight species of the Botryosphaeriaceae (canker and dieback pathogens) were identified on native Syzygium cordatum in South Africa, based on anamorph morphology, ITS rDNA sequence data and PCR-RFLP analysis. The species identified were Neofusicoccum parvum, N. ribis, N. luteum, N. australe, N. mangiferae , Botryosphaeria dothidea, Lasiodiplodia gonubiensis and L. theobromae . Their pathogenicity on S. cordatum seedlings and a Eucalyptus grandis  ×  camaldulensis clone was determined in glasshouse inoculation trials. Isolates of all identified species, except one of N. mangiferae , were more pathogenic on the Eucalyptus clone than on S. cordatum . Some of the species that cross-infected these hosts, such as N. ribis, N. parvum and L. theobromae , were amongst the most pathogenic on the Eucalyptus clone, while B. dothidea and L. gonubiensis were the least pathogenic. Results of this study illustrate that species of the Botryosphaeriaceae from native hosts could pose a threat to introduced Eucalyptus spp., and vice versa .     

32份木薯种质对疫霉根腐病的抗性评价和农艺性状分析

通过田间自然发病和室内离体接种方法对32份木薯种质进行了棕榈疫霉根腐病抗病性评价,结果表明,供试的32份木薯种质中,高抗种质7份,抗病种质7份,中感种质8份,感病种质7份,高感种质3份。其中高抗种质为‘H360’、‘华南11号’、‘华南8号’、‘H588’、‘桂热3号’、‘H873’和‘H971’;抗病种质为:‘F556’、‘H502’、‘GR911’、‘C-4’、‘F10’、‘南植188’和‘H47’。对其中14份抗棕榈疫霉根腐病木薯种质的农艺性状进行了鉴定和评价,结果表明‘华南8号’、‘GR911’、‘F556’、‘C-4’、‘H360’可以进一步加以利用。     

Contrasting genetic structure between Magnaporthe grisea populations associated with the golf course turfgrasses Lolium perenne (perennial ryegrass) and Pennisetum clandestinum (kikuyugrass)

Gray leaf spot (GLS) disease of perennial ryegrass (Lolium perenne) and kikuyugrass (Pennisetum clandestinum) in golf courses in California was first noted in 2001 and 2003, respectively, and within 5 years had become well established. The causal agent of the disease is the fungus Magnaporthe grisea, which is known to consist primarily of clonal lineages that are highly host specific. Therefore, our objective was to investigate host specificity and population dynamics among isolates associated primarily from perennial ryegrass and kikuyugrass since the disease emerged at similar times in California. We also obtained isolates from additional hosts (tall fescue, St. Augustinegrass, weeping lovegrass, and rice) and from the eastern United States for comparative purposes. A total of 38 polymorphic amplified fragment length polymorphism makers were scored from 450 isolates which clustered by host with high bootstrap support (71 to 100%). Genetic structure between kikuyugrass and perennial ryegrass isolates differed significantly. Isolates from kikuyugrass were genotypically diverse (n = 34), possessed both mating types, and some tests for random mating could not be rejected, whereas isolates from perennial ryegrass were less genotypically diverse (n = 10) and only consisted of a single mating type. Low genotypic diversity was also found among the other host specific isolates which also only consisted of a single mating type. This is the first study to document evidence for the potential of sexual reproduction to occur in M. grisea isolates not associated with rice (Oryza sativa). Moreover, given the significant host specificity and contrasting genetic structures between turfgrass-associated isolates, the recent emergence of GLS on various grass hosts in California suggests that potential cultural practices or environmental changes have become conducive for the disease and that the primary inoculum may have already been present in the state, despite the fact that two genotypes associated with perennial ryegrass and St. Augustinegrass in California were the same as isolates collected from the eastern United States.     

长期施药果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性

为了监测果园中苹果轮纹病菌对戊唑醇和甲基硫菌灵敏感水平的变化,采用菌丝生长速率法测定了采集自山东烟台地区和北京市昌平区,有较长施药史苹果园中的苹果轮纹病菌对戊唑醇和甲基硫菌灵的敏感性。结果表明:戊唑醇对连续施用戊唑醇5年、每年施药1~2次的果园中苹果轮纹病菌的EC_(50)为0.017 4~0.114 3μg/mL,即该类果园中苹果轮纹病菌对此药的敏感性仍然保持在较高水平,与野生菌株的敏感性非常接近,没有出现敏感性分化的抗药亚群体;甲基硫菌灵对连续施用甲基硫菌灵10年、每年施药2次的果园中苹果轮纹病菌的EC_(50)为0.846 4~4.677 4μg/mL,果园中苹果轮纹病菌与野生菌株相比EC_(50)平均值约上升3.15倍,最低值和最高值分别是已报道敏感性基线的1.19倍和6.59倍,没有出现敏感性发生显著分化的抗药性亚群体。     

桉树溃疡病病原菌的鉴定

 随着桉树人工纯林的面积扩大,桉树病害也日趋加重,严重影响和制约桉树产业的发展。2008年至今,在云南省石林县和红河州桉树种植区发生一种病害,主要为害嫩枝、枝条和主干,发病初期,感病枝条和主干上产生红褐色圆或椭圆形坏死斑,以后逐渐扩大成椭圆或不规则溃疡斑,病变扩展到木质部后,常造成枝条生长畸形,易引起刮风断裂。主干树皮下明显呈黑褐色坏死,并造成感染面周围树皮开裂,溃疡处一般可看到流胶,严重时造成整株干枯死亡。调查发现,该病发病率通常在 10％～25％,重者可达 40％ 以上,引起桉树溃疡和枯萎死亡。本文通过病原菌分离、致病性测定及传统、分子鉴定明确了该病的病原,以期为病害防治提供理论依据。     

Taxonomy, phylogeny and identification of Botryosphaeriaceae associated with pome and stone fruit trees in South Africa and other regions of the world

Species of Botryosphaeria are well-recognized pathogens of pome and stone fruit trees. The taxonomy of these fungi, however, has been confused in the past. Recent taxonomic changes to the Botryosphaeriaceae further influence the literature pertaining to these fungi. This study reviews the taxonomic status of Botryosphaeriaceae associated with fruit tree diseases, identifies them in South Africa and elsewhere, and develops a reliable identification technique for them. Comparisons were made using DNA sequence data from the nuclear ITS rRNA operon and anamorph morphology. These analyses distinguished six clades amongst isolates associated with fruit tree diseases, corresponding to Neofusicoccum ribis (=  B. ribis ), N. parvum (=  B. parva ), N. australe (=  B. australis ), B. dothidea , Diplodia mutila (=  B. stevensii ) and ' Botryosphaeria ' obtusa (the genus Botryosphaeria is no longer available for the fungus known as B. obtusa , but a new name has not been proposed yet). Isolates from fruit trees in South Africa were grouped in the N. australe and ' Botryosphaeria' obtusa clades. This is the first report of N. australe from fruit trees. PCR-RFLP analysis using the restriction endonucleases Cfo I and Hae III distinguished the major clades. However, two groups of closely related species, N. ribis and N. parvum , and N. australe and N. luteum (=  B. lutea ), had identical RFLP profiles. Using RFLP, it was shown that ' Botryosphaeria ' obtusa is the dominant species on fruit trees in the Western Cape Province of South Africa. These results and methods will be useful in future epidemiological studies and disease management of Botryosphaeriaceae from fruit trees.     

苹果轮纹病菌抗戊唑醇突变体UV-TS1-10的生理生化特性

利用苹果轮纹病菌敏感菌株TS1和抗戊唑醇突变体UV-TS1-10进行了苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)活力、可溶性蛋白含量及酯酶同工酶图谱等生理生化特性的测定。经不同浓度药剂处理0~24h,抗性突变体UV-TS1-10体内PAL活性一直高于敏感菌株TS1,两者都呈现先上升后下降的趋势,并在1.5h达到最高值;抗药突变体UV-TS1-10体内POD活力也高于TS1,一直处于上升趋势,24h达到最高值时两菌株活力差异最大;UV-TS1-10体内可溶性蛋白含量为TS1的1.3倍,同一菌株在不同浓度戊唑醇处理后可溶性蛋白含量差异不大,稳定性好;抗药突变体UV-TS1-10比敏感菌株TS1的酯酶同工酶图谱少了一条Rf=0.33的谱带,多了Rf=0.14的特征性谱带,表明抗戊唑醇突变体UV-TS1-10其生理生化特性发生了较大变化。本文以研究敏、抗菌株间生理生化特性的差异为基础,探讨苹果轮纹病菌对戊唑醇可能的抗性机制,为科学地指导生产用药提供理论依据。     

红瑞木溃疡病病原菌的鉴定

为了明确近年来引起上海辰山植物园红瑞木上枝干溃疡病的病原菌种类,首先对病原菌分离并依据柯赫氏法则进行了致病性测定和病原菌验证,然后进行了形态学特征观察、rDNA-ITS序列分析和系统发育树构建。病原菌形态学特征与葡萄座腔菌(Botryosphaeria dothidea)一致,其rDNA-ITS序列(已提交GenBank,登录号:JN638454)与GenBank中葡萄座腔菌相似性达到99%,在系统发育树上与葡萄座腔菌处于同一分支。将辰山植物园红瑞木枝干溃疡病的病原菌鉴定为葡萄座腔菌(B.dothidea)。     

Morphological, pathogenic, and molecular characterization of alternaria isolates associated with alternaria late blight of pistachio

ABSTRACT Alternaria isolates were obtained from various pistachio tissues collected in five orchards in California. For all isolates, morphological characteristics of the colony and sporulation apparatus were determined and compared with those of representative isolates of A. alternata, A. tenuissima, A. arborescens, and A. infectoria. A selection of the pistachio isolates and the representative Alternaria isolates were evaluated for pathogenicity to pistachio. Molecular characteristics of these isolates were determined using random amplified polymorphism DNA (RAPD) analysis, polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis of nuclear intergenic spacer rDNA, and sequence analysis of nuclear internal transcribed spacer (ITS) rDNA. Based on morphological characteristics, the pistachio isolates were grouped as identical or very similar to either A. alternata, A. tenuissima, A. arborescens, or A. infectoria. Isolates from the alternata, tenuissima, and arborescens species-groups were pathogenic to pistachio and no significant differences in pathogenicity were observed. Isolates from the infectoria species-group were only weakly pathogenic to pistachio. Based on cluster analysis of RAPD and PCR-RFLP data, three distinct clusters were evident; the infectoria cluster, the arborescens cluster, and a combined alternata/tenuissima cluster. Based on analysis of ITS sequence data, the infectoria species-group was phylogenetically distinct from the other species-groups. Isolates of the alternata, tenuissima, and arborescens species-groups comprised a monophyletic clade in which the three species-groups could not be further resolved.     

Population structure of Cercospora kikuchii, the causal agent of Cercospora leaf blight and purple seed stain in soybean

Random amplified polymorphic DNA (RAPD) and microsatellite-primed polymerase chain reaction (MP-PCR) were used to characterize 164 isolates of Cercospora kikuchii, most of which were collected from Louisiana. Plant tissue (seeds versus leaves), but not host cultivar, had a significant impact on pathogen population differentiation. Cluster analysis showed that the Louisiana population was dominated by a primary lineage (group I) with only a few Louisiana isolates belonging to the minor lineage that also included the non-Louisiana isolates (group II). A previous study showed that isolates could be differentiated according to vegetative compatibility groups (VCGs). However, RAPD and MP-PCR data demonstrated that isolates of C. kikuchii were not generally clustered according to these VCGs. Furthermore, genetic relationships within and between VCGs were examined using sequences of the intergenic spacer region of rDNA. These analyses showed that VCG is not an indicator of evolutionary lineage in this fungus. Our results suggest the likely existence of a cryptically functioning sexual stage in some portion of the C. kikuchii population.     

葡萄座腔菌(Botryosphaeria dothidea)全基因组分泌蛋白的预测及功能分析

 葡萄座腔菌(Botryosphaeria dothidea)是引起多种果树和林木枝干溃疡病和果实腐烂病的重要病原菌。为明确葡萄座腔菌的致病机理,采用SignalP、WoLF PSORT、TMHMM、GPI-SOM等软件,对葡萄座腔菌全基因组14 998条蛋白序列进行了分泌蛋白预测和功能分析。结果表明B.dothidea全基因组编码蛋白中有851条序列具有典型的分泌蛋白特征,占蛋白总数的5.67%,其长度主要分布在100~700个氨基酸范围内。信号肽的分析结果表明,以19个氨基酸为信号肽的分泌蛋白数目最多,非极性氨基酸丙氨酸(A)在信号肽中的使用频率最高,而有带电侧链的天冬氨酸(D)和谷氨酸(E)使用频率最低,信号肽-3和-1位置的氨基酸相对保守,其切割位点属于典型的A-X-A型。对分泌蛋白功能预测结果表明,578个分泌蛋白获得了功能注释,其功能主要涉及碳水化合物的运输、代谢过程,蛋白翻译后修饰和氨基酸代谢、运输过程。分泌蛋白中效应蛋白(effector)预测结果表明,B. dothidea分泌蛋白中共有119个潜在的效应蛋白,其中11个可被PHI数据库注释到,其与引起其他植物病原菌致病力变化的致病效应蛋白具有较高的相似性。碳水化合物活性酶类(CAZymes)的预测结果表明,B. dothidea分泌蛋白组中共有279个CAZymes,其中GHs家族最多。这些结果的获得为今后进一步筛选B. dothidea的效应蛋白,明确B. dothidea的致病机理,以及筛选寄主新的抗性基因提供了必要的基础。     

Canker and die-back of Eucalyptus in South Africa caused by Botryosphaeria dothidea

Die-back and canker of several Eucalyptus species and clones were observed during a survey of the most important forestry areas of South Africa. Disease was often associated with extreme environmental conditions such as drought, hot winds and frost. Botryosphaeria dothidea , which is well known as a cause of canker and die-back of Eucalyptus in other countries, was consistently isolated from symptomatic trees. Artificial inoculations of Eucalyptus nitens resulted in lesion development, confirming the pathogenicity of 5. dothidea to Eucalyptus in South Africa. This is the first report of this disease in South Africa.     

Genetic differentiation between hosts and locations in populations of latent Botrytis cinerea in southern England

This study tested the hypothesis that aggressive, localized infections and asymptomatic systemic infections were caused by distinct specialized groups of Botrytis cinerea, using microsatellite genotypes at nine loci of 243 isolates of B. cinerea obtained from four hosts (strawberry (Fragaria×ananassa), blackberry (Rubus fruticosus agg.), dandelion, (Taraxacum officinale agg.) and primrose (Primula vulgaris)) in three regions in southern England (in the vicinities of Brighton, Reading and Bath). The populations were extremely variable, with up to 20 alleles per locus and high genic diversity. Each host in each region had a population of B. cinerea with distinctive genetic features, and there were also consistent host and regional distinctions. The B. cinerea population from strawberry was distinguished from that on other hosts, including blackberry, most notably by a common 154‐bp amplicon at locus 5 (present in 35 of 77 samples) that was rare in isolates from other hosts (9/166), and by the rarity (3/77) of a 112‐bp allele at locus 7 that was common (58/166) in isolates from other hosts. There was significant linkage disequilibrium overall within the B. cinerea populations on blackberry and strawberry, but with quite different patterns of association among isolates from the two hosts. No evidence was found for differentiation between populations of B. cinerea from systemically infected hosts and those from locally infected fruits.     

河北省苹果主要病虫害发生现状调查

在2007-2009年对河北省唐山、保定、邢台、石家庄、沧州、衡水、秦皇岛、张家口、廊坊、承德共10个地市200余个苹果园进行了问卷调查、实地重点考察和现场访谈,调查内容包括品种名称、树龄结构以及各种病虫害发生情况。结果表明:河北省苹果以‘富士’品种为主,占调查果园面积的58%,其次为‘元帅’;从树龄结构上看,树龄超过15年的果园占69%,说明河北省苹果园老化现象比较严重。苹果上常发生的病虫害有枝干轮纹病、腐烂病、斑点落叶病、褐斑病、锈病、苹果黄蚜、山楂叶螨、金纹细蛾、苹果绵蚜、桑天牛、枣尺蠖和黑蚱蝉共12种。其中枝干轮纹病、腐烂病和山楂叶螨是全省苹果产区发生普遍且较严重的病虫害。唐山市枝干轮纹病病株率高达92%,张家口市腐烂病病株率为72.67%,苹果黄蚜、锈病、褐斑病和金纹细蛾在不同地区发生程度不同。苹果绵蚜在河北省已普遍发生。品种以及地形对病虫害发生的影响也存在不同程度差异。本文根据对河北省苹果病虫害发生状况的调查结果,提出了通过加强栽培管理、病虫害预测预报、选用抗性品种与砧木以及化学防治为手段的病虫害防治对策。     

Pathogenicity,Morpho-Species and Mating Types of <Emphasis Type="Italic">Alternaria</Emphasis> spp. causing Alternaria blight in <Emphasis Type="Italic">Pistacia</Emphasis> spp. in Turkey

Alternaria genus includes many plant pathogens on numerous hosts, causing leaf spots, rots and blights. Alternaria blight has been observed as one of the important fungal diseases of pistachio (Pistacia vera L.) as well as its wild relatives (P. terebinthus, P. lentiscus, P. khinjuk, P. atlantica, P. mutica) in Turkey. Alternaria species were sampled from Pistacia spp. hosts from different geographic regions in Turkey during field trips in late spring to early fall of 2013. Alternaria blight symptoms were observed mainly on fruits and rarely on leaves. Four hundred and twenty two of the isolates were morphologically defined as A. alternata, A. tenuissima, A. arborescens and also intermediate morpho-species between A. alternata/A. arborescens. Pathogenicity of the isolates was confirmed with host inoculations on detached fruits. Mating types of 270 isolates of Alternaria spp. from the collection were identified using a PCR-based mating type assay that amplifies either a MAT1-1 or a MAT1-2 fragment from the mating locus. Although a strongly clonal population structure was expected due to the putative asexual reproduction of these fungi, both idiomorphs were detected at equal frequencies at several different spatial scales. The distribution of mating types within each geographic region, within host species as well as in overall collection was not significantly different from 1:1. Amplified fragments of partial idiomorph sequences were obtained for representative isolates. Parsimony trees were depicted based on sequence data of mating type genes for these representative isolates as well as some other Alternaria species obtained by Genebank. Several point mutations presented a few clusters which are supported by high bootsrapped values. The Alternaria blight disease agents both from cultivated and wild hosts were pathogenic on pistachio which may cause difficulties to control the disease because of extensity of pathogen sources. Besides, equal mating type distribution of the pathogen at both geographic and host species levels suggests a potential for sexual reproduction of Alternaria spp. in Turkey.