Detection and Identification of a 16SrII Group Phytoplasma Causing Clover Little Leaf Disease in Iran

White clover plants showing little leaf and leaf reddening symptoms were observed in Isfahan Province in central Iran. Restriction fragment length polymorphism analyses of nested PCR‐amplified fragments from Iranian clover little leaf phytoplasma isolates and representative phytoplasmas from other phytoplasma groups using AluI, CfoI, KpnI and RsaI restriction enzymes indicated that the clover phytoplasma isolates are related to the peanut WB group. Sequence analyses of partial 16S rRNA fragments showed that Iranian clover little leaf phytoplasma has 99% similarity with soybean witches'‐broom phytoplasma, a member of the peanut WB (16SrII) phytoplasma group. This is the first report of clover infection with a phytoplasma related to the 16SrII group.     

Detection and identification of ‘Candidatus Phytoplasma asteris’ in Brassica rapa subsp. pekinensis in Poland

Severe growth abnormalities, including leaf yellowing, sprout proliferation and flower virescence and phyllody, were found on Brassica rapa subsp. pekinensis plants in Poland. The presence of phytoplasma in naturally infected plants was demonstrated by polymerase chain reaction assay employing phytoplasma universal P1/P7 followed by R16F2n/R16R2 primer pairs. The detected phytoplasma was identified using restriction fragment length polymorphism analysis (RFLP) of the 16S rRNA gene fragment with AluI, HhaI, MseI and RsaI endonucleases. After enzymatic digestion, all tested samples showed restriction pattern similar to that of ‘Candidatus phytoplasma asteris’. Nested PCR‐amplified products, obtained with primers R16F2n/R16R2, were sequenced. Sequences of the 16S rDNA gene fragment of analysed phytoplasma isolates were nearly identical. They revealed high nucleotide sequence identity (>98%) with corresponding sequences of other phytoplasma isolates from subgroup 16SrI‐B, and they were classified as members of ‘Candidatus phytoplasma asteris’. This is the first report of the natural occurrence of phytoplasma‐associated disease in plants of Chinese cabbage.     

A rapid assay for simultaneous detection of Spiroplasma eriocheiris and white spot syndrome virus in Procambarus clarkii by multiplex PCR

Aims: To establish a multiplex PCR method for simultaneous and rapid detection of Spiroplasma eriocheiris and white spot syndrome virus (WSSV) in Procambarus clarkii with recommendations for application to other crustacea. Methods and Results: Three primer sets were mixed at a ratio of 1 : 3 : 1 to amplify specific fragments of the S. eriocheiris, WSSV, P. clarkii crayfish (control organism) genomes, respectively. S. eriocheiris and WSSV were used to challenge the susceptible crustacea in the experimental groups. Total DNA of the samples was purified and detected by multiplex PCR. The PCR‐amplified products produced four groups of results as follows. One fragment of 1195 bp, amplified by the primer set ITS‐crayfish/28S‐crayfish, served as an internal control, showed no pathogen detection, thus confirming the specificity of our positive tests. Two groups represented by: (i) samples challenged by S. eriocheiris alone, or (ii) challenged by WSSV alone, yielded two fragments each; i.e. those from S. eriocheiris (271 bp) plus the internal control and those from WSSV (530 bp) plus the internal control. Finally, for the fourth group, in cases of double challenged treatments, all three amplified products were detected simultaneously. Conclusions: Simultaneous and rapid detection of two pathogens in P. clarkii is important to maintain productive and healthy crayfish in aquaculture. The direct detection of S. eriocheiris and WSSV from P. clarkii is practicable with multiplex PCR. Significance and Impact of the Study: This study shows that the two pathogens are simultaneously and rapidly detected in P. clarkii by multiplex PCR, thus increasing the efficiency of pathogen detection.     

ITS-RFLP fingerprinting and molecular marker for detection of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="Italic">ciceris</Emphasis>

Genetic diversity of 11 representative isolates of Fusarium oxysporum f.sp. ciceris causing chickpea wilt was determined through internal transcribed spacer (ITS) region of the ribosomal DNA-restriction fragment length polymorphism (ITS-RFLP). ITS1+5.8s+ITS2 regions of the isolates were amplified with a set of primers ITS1 and ITS4 and amplified products were digested with 4 restriction enzymes (AluI, MboI, RsaI, MseI). Six different kinds of ITS-RFLP patterns were obtained. The ITS region of these isolates was sequenced and deposited to NCBI GeneBank. The nucleotide sequence homology of ITS region grouped the isolates into 5 categories. Primers were designed with sequence information using Primer 3 software. F. oxysporum f.sp. ciceris specific markers (FOC F2 and FOC R2) based on ITS region were developed for the first time for detection of the pathogen. The markers produced an amplicon of 292 bp; they were validated against the isolates of the pathogen collected from different locations of India.     

Identification of three RFLPs at the HCK locus on chromosome 20

New HindIII, RsaI and TaqI restriction fragment length polymorphisms (RFLPs) within the haemopoietic cell kinase gene in chromosome band 20q11.2 are described. These RFLPs provide a useful marker for linkage analysis in proximal 20q.     

Marine Amebae From Clean and Stressed Bottom Sediments of the Atlantic Ocean and Gulf of Mexico*,†,‡

SYNOPSIS Amebae isolated from sediments of the Atlantic Ocean and Gulf of Mexico were maintained in continuous culture and most were identified to genus and species. Twenty-six species representing 12 genera were recognized from existing literature and several others (Flabellula, Mastigamoeba, Cochliopododium) were identified only to genus. One ameboflagellate and several small limax-type amebae which require further study also were isolated. Other sarcodmids belonging to the Heliozoida, Testocida, Leptomyxida, and Proteomyxida were identified only tentatively. the distribution of the amebae and ameba-like organisms was tabulated for the following geographic areas: Atlantic Ocean near Long Island, New York: Atlantic Ocean 16-65 miles offshore from New York and New Jersey: Atlantic Ocean 1-50 miles offshore from Maryland and Delaware: and the Gulf of Mexico 3.5-41 miles offshore from the southeastern United States. Amebae present in shellfish holding trays at Lewis. Delaware, were isolated, and identified to compare the distribution of species in laboratory tanks with those present in natural ocean bottoms. Published accounts of each collection site were reviewed to obtain specific data on contamination with sewage wastes, acid wastes, dredge spoils, and petroleum hydrocarbons. Two previously undescribed amebae were found to represent new genera and species and are described herein, one from the Delaware mariculture facility, and the other from the digestive tract of the blue crab, Callinectes sapidus, and the gill surface of the lady crab, Ovalipes ocellatus. Sarcodinids present in clean or stressed environments were listed, and genera and species that were widespread or apparently geographically restricted were recorded.     

Application of New Primer-Enzyme Combinations to Terminal Restriction Fragment Length Polymorphism Profiling of Bacterial Populations in Human Feces

New primer-enzyme combinations for terminal restriction fragment length polymorphism (T-RFLP) targeting of the 16S rRNA gene were constructed by using the T-RFLP analysis program (designated TAP T-RFLP) located at the Ribosomal Database Project website, and their performance was examined empirically. By using the fluorescently labeled 516f primer (Escherichia coli positions 516 to 532) and 1510r primer (positions 1510 to 1492), the 16S rRNA gene was amplified from human fecal DNA. The resulting amplified product was digested with RsaI plus BfaI or with BslI. When the T-RFLP was carried out with fecal DNAs from eight individuals, eight predominant operational taxonomic units (OTUs) were detected with RsaI and BfaI digestion and 14 predominant OTUs were detected with BslI digestion. The distribution of the OTUs was consistent with the results of the computer simulations with TAP T-RFLP. The T-RFLP analyses of the fecal DNAs from individuals gave characteristic profiles, while the variability of the T-RFLP profiles between duplicate DNA preparations from the same samples were minimal. This new T-RFLP method made it easy to predict what kind of intestinal bacterial group corresponded to each OTU on the basis of the terminal restriction fragment length compared with the conventional T-RFLP and, moreover, made it possible to identify the bacterial species that an OTU represents by cloning and sequencing.     

Characterization of the indigenous PAH-degrading bacteria of <Emphasis Type="Italic">Spartina</Emphasis> dominated salt marshes in the New York/New Jersey Harbor

The aerobic polyaromatic hydrocarbon (PAH) degrading microbial communities of two petroleum-impacted Spartina-dominated salt marshes in the New York/New Jersey Harbor were examined using a combination of microbiological, molecular and chemical techniques. Microbial isolation studies resulted in the identification of 48 aromatic hydrocarbon-degrading bacterial strains from both vegetated and non-vegetated marsh sediments. The majority of the isolates were from the genera Paenibacillus and Pseudomonas. Radiotracer studies using ¹⁴C-phenanthrene and ¹⁴C-pyrene were used to measure the PAH-mineralization activity in salt marsh sediments. The results suggested a trend towards increased PAH mineralization in vegetated sediments relative to non-vegetated sediments. This trend was supported by the enumeration of PAH-degrading bacteria in non-vegetated and vegetated sediment using a Most Probable Numbers (MPN) technique, which demonstrated that PAH-degrading bacteria existed in non-vegetated and vegetated sediments at levels ranging from 10² to 10⁵ cells/g sediment respectively. No difference between microbial communities present in vegetated versus non-vegetated sediments was found using terminal restriction fragment length polymorphism (of the 16S rRNA gene) or phospholipid fatty acid analysis. These studies provide information on the specific members and activity of the PAH-degrading aerobic bacterial communities present in Spartina-dominated salt marshes in the New York/New Jersey Harbor estuary.     

PCR-RFLP of the ribosomal DNA internal transcribed spacers (ITS) provides markers for the A and B genomes in<Emphasis Type="Italic"> Musa</Emphasis> L.

Musa acuminata Colla (AA genomes) and Musa balbisiana Colla (BB genomes) are the diploid ancestors of modern bananas that are mostly diploid or triploid cultivars with various combinations of the A and B genomes, including AA, AAA, BB, AAB and ABB. The objective of this study was to identify molecular markers that will facilitate discrimination of the A and B genomes, based on restriction-site variations in the internal transcribed spacers (ITS) of the nuclear ribosomal RNA genes. The ITS regions of seven M. acuminata and five M. balbisiana accessions were each amplified by PCR using specific primers. All accessions produced a 700-bp fragment that is equivalent in size to the ITS of most plants. This fragment was then digested with ten restriction enzymes (AluI, CfoI, DdeI, HaeIII, HinfI, HpaII, MspI, RsaI, Sau3AI and TaqI) and fractionated in 2% agarose gels, stained with ethidium bromide and visualized under UV light. The RsaI digest revealed a single 530-bp fragment unique to the A genome and two fragments of 350-bp and 180-bp that were specific to the B genome. A further 56 accessions representing AA, AAA, AAB, AB and ABB cultivars, and synthetic hybrids, were amplified and screened with RsaI. All accessions with an exclusively A genome showed only the 530-bp fragment, while accessions having only the B-genome lacked the 530-bp fragment but had the 350-bp and 180-bp fragments. Interspecific cultivars possessed all three fragments. The staining intensity of the B-genome markers increased with the number of B-genome complements. These markers can be used to determine the genome constitution of Musa accessions and hybrids at the nursery stage, and, therefore, greatly facilitate genome classification in Musa breeding.Communicated by H.F. Linskens     

Screening for nonsense mutations in patients with severe hemophilia A can provide rapid,direct carrier detection

Summary Despite marked genetic heterogeneity in families with hemophilic patients, transition mutations in CG dinucleotides occur frequently. Of 71 CG dinucleotides in the factor VIII cDNA, a C-to-T transition in 12 would lead to a new Stop codon (CGA to TGA). Using restriction enzyme digestion of 11 amplified DNA fragments, seven point mutations were localized among 60 patients with severe hemophilia A. Five were detected as loss of a natural or introduced TaqI site at codons -5, 583, 1941, 2116, and 2209 and were confirmed as CGA (Arg) to TGA (Stop) nonsense mutations by DNA sequencing. A novel C-to-T nonsense mutation was detected as loss of the RsaI site at codon 1966 and confirmed by sequence in two unrelated individuals. Two partial gene deletions were detected as selective failure to amplify exon 1 and exons 15–22, respectively. In an additional (61st) patient who was subsequently found to have mild (instead of severe) hemophilia, digests suggested a mutation in codon 1696. Upon sequencing, this codon contained a novel missense mutation, a C-to-G transversion changing CGA (Arg 1696) to GGA (Gly). In four families with women available for testing, carrier status was rapidly determined by direct screening for the point mutation. In two of three with sporadic occurrences, the mother was a carrier as were two of four sisters. In the other family, the mother and a sister were homozygous for the TaqI cleavage site in their amplified exon 24 fragment, indicating a de novo C-to-T transition in codon 2209 in the patient's factor VIII gene. This final patient's sister was a noncarrier even though by linkage analysis she inherited the same factor VIII gene as her brother.These results have already been published in part in abstract form: Reiner AP, Thompson AR (1990) Circulation Research 82:304     

WSSV对锯缘青蟹的致病性及血清酶指标影响

锯缘青蟹(Scylla serrata)俗称青蟹,是我国重要的海水养殖蟹类.近年来,浙江、福建、广东等青蟹主要养殖地区出现了严重的青蟹病害.对浙江省养殖青蟹的发病原因和流行病学调查发现,白斑综合征病毒(white spotsyndrome virus,WSSV)与青蟹发病存在较大相关性.为进一步研究WSSV对青蟹的致病性和发病机理,作者采用白斑综合征病毒的除菌过滤液,以1:10-1:10000稀释度注射感染青蟹,结果表明1:10、1:100感染组的青蟹死亡率达100%,1:1000感染组死亡率为66.7%,1:10000感染组死亡率为38.9%.根据攻毒悬液的病毒浓度计算出WSSV对青蟹的LD50为1.19×104拷贝/只(7.93×103拷贝/g组织);取WSSV感染青蟹血淋巴进行PCR检测,攻毒死亡青蟹的WSSV检出率为100%,表明WSSV对青蟹有很强的致病力.分析病毒感染濒死蟹的血清酚氧化酶(PO)、过氧化物酶(POD)、超氧化物歧化酶(SOD)、碱性磷酸酶(ALP)、谷丙转氨酶(GPT)、符草转氨酶(GOT)等主要酶指标,发现病毒感染青蟹的PO、POD和SOD活力明显低于对照组,而ALP、GPT和GOT的活力则明显高于对照组;用WSSV单克隆抗体对感染蟹进行免疫组化分析,发现WSSV主要侵染青蟹的鳃、甲壳下表皮、心脏、肠、胃等组织的上皮细胞,尤其以鳃上皮细胞损害最为严重.     

Decarboxylase activity involved in methyl ketone production by Staphylococcus carnosus 833, a strain used in sausage fermentation

Outbreaks of Vibrio parahaemolyticus gastroenteritis in the United States (Texas, New York and Pacific Northwest) in 1997-98 emphasized the need to develop molecular methods for identification and differentiation of these organisms. When outbreak isolates were analyzed for the enterobacterial repetitive intergenic consensus sequences, the Texas and New York outbreak isolates had a specific 850-bp DNA fragment that was absent in Pacific Northwest isolates. The 850-bp polymerase chain reaction (PCR) product was found in isolates of serovar O3:K6, which have an unusual potential to spread and cause infections. To develop a specific molecular detection method for serovar O3:K6, the nucleotide sequence of the 850-bp product was determined. The GenBank blast analysis did not show homology with any known Vibrio spp. gene sequences. Two PCR primers were designed to specifically amplify the unique sequences from serovar O3:K6 isolates. Genomic DNA from 10 Texas, eight New York, and seven Pacific Northwest outbreak isolates of V. parahaemolyticus was assayed by PCR. Texas and New York isolates were positive in the PCR assay, giving a 327-bp PCR product as predicted; however, Pacific Northwest isolates were negative, indicating the absence of the target gene. Texas and New York isolates were all serovar O3:K6; the Pacific Northwest isolates were not. The primers were tested with other Vibrio spp. and other closely related species and no amplification of the 327-bp PCR product was found. The PCR method can be used to specifically identify O3:K6 V. parahaemolyticus isolates in less than 6 h.     

Genetic divergence between Atlantic and Indo-Pacific stocks of bigeye tuna (Thunnus obesus) and admixture around South Africa

Two mitochondrial DNA segments of the bigeye tuna (Thunnus obesus) were amplified by polymerase chain reaction (PCR), and restriction fragment length polymorphism (RFLP) analyses of these segments were used for the genetic stock study. The variation in a segment flanking the ATPase and COIII genes was low; only two genotypes (α and β) were detected by RsaI digestion. Yet a large difference in the genotype distribution was observed between ocean basin samples. The α type predominated in four Atlantic samples, where 178 of 244 individuals were the α type. In contrast, only one of 195 individuals collected in the Indo‐Pacific was the α type? The frequency of the α type varied considerably from 0 to 80% among seven samples collected off the Cape of Good Hope. The variation found in the other segment, containing the D‐loop region, was much higher; two endonucleases (DpnII and RsaI) detected five genotypes each and 15 composite genotypes. A highly significant difference in genotype frequencies was observed between the Atlantic and Indo‐Pacific samples, but no heterogeneity was observed among the four Atlantic or among four Indo‐Pacific samples. These results clearly indicate that not only gene flow, but also fish migration, between the Atlantic and Indian Oceans are severely restricted, and that fishes from these distinct stocks are intermingling around South Africa. The simple and diagnostic genetic marker found in this study can be used to estimate mixing ratios between Atlantic and Indian stocks around South Africa.     

Genetic differentiation of Colletotrichum gloeosporioides and C. truncatum associated with Anthracnose disease of papaya (Carica papaya L.) and bell pepper (Capsium annuum L.) based on ITS PCR-RFLP fingerprinting

Members of the genus Colletotrichum include some of the most economically important fungal pathogens in the world. Accurate diagnosis is critical to devising disease management strategies. Two species, Colletotrichum gloeosporioides and C. truncatum, are responsible for anthracnose disease in papaya (Carica papaya L.) and bell pepper (Capsicum annuum L.) in Trinidad. The ITS1–5.8S–ITS2 region of 48 Colletotrichum isolates was sequenced, and the ITS PCR products were analyzed by PCR-RFLP analysis. Restriction site polymorphisms generated from 11 restriction enzymes enabled the identification of specific enzymes that were successful in distinguishing between C. gloeosporioides and C. truncatum isolates. Species-specific restriction fragment length polymorphisms generated by the enzymes AluI, HaeIII, PvuII, RsaI, and Sau3A were used to consistently resolve C. gloeosporioides and C. truncatum isolates from papaya. AluI, ApaI, PvuII, RsaI, and SmaI reliably separated isolates of C. gloeosporioides and C. truncatum from bell pepper. PvuII, RsaI, and Sau3A were also capable of distinguishing among the C. gloeosporioides isolates from papaya based on the different restriction patterns that were obtained as a result of intra-specific variation in restriction enzyme recognition sites in the ITS1–5.8S–ITS2 rDNA region. Of all the isolates tested, C. gloeosporioides from papaya also had the highest number of PCR-RFLP haplotypes. Cluster analysis of sequence and PCR-RFLP data demonstrated that all C. gloeosporioides and C. truncatum isolates clustered separately into species-specific clades regardless of host species. Phylograms also revealed consistent topologies which suggested that the genetic distances for PCR-RFLP-generated data were comparable to that of ITS sequence data. ITS PCR-RFLP fingerprinting is a rapid and reliable method to identify and differentiate between Colletotrichum species.     

Direct Evidence for Mendelian Inheritance of the Variations in the Ribosomal Protein Gene Introns in Yellowfin Tuna (Thunnus albacares)

Restriction fragment length polymorphism found in the S7 ribosomal protein gene introns of yellowfin tuna (Thunnus albacares) was compared between a single pair of parents and their offspring. The sizes of the first intron (RP1) and second intron (RP2) amplified by polymerase chain reaction were 810 bp and 1400 bp, respectively. The dam and sire had different restriction types from one another in HhaI and RsaI digestions for RP1 and in DdeI, HhaI, and ScrFI digestions for RP2. Putative genotypes in both introns of 64 larvae were found to be segregated in Mendelian proportions. Genotype distributions in a wild yellowfin tuna sample (n= 34) were in Hardy-Weinberg proportions, and observed heterozygosity ranged from 0.149 to 0.388. This study presents novel Mendelian markers, which are feasible for tuna population genetic study and pedigree analysis. Received December 8, 1999; accepted April 11, 2000.     

Molecular Characterization of Phytoplasmas Associated with Potato Purple Top Disease in Iran

Potato plants with symptoms suggestive of potato purple top disease (PPTD) occurred in the central, western and north‐western regions of Iran. Polymerase chain reaction (PCR) and nested PCR assays were performed using phytoplasma universal primer pair P1/P7 followed by primer pairs R16F2n/R16R2 and fU5/rU3 for phytoplasma detection. Using primer pairs R16F2n/R16R2 and fU5/rU3 in nested PCR, the expected fragments were amplified from 53% of symptomatic potatoes. Restriction fragment length polymorphism (RFLP) analysis using AluI, CfoI, EcoRI, KpnI, HindIII, MseI, RsaI and TaqI restriction enzymes confirmed that different phytoplasma isolates caused PPTD in several Iranian potato‐growing areas. Sequences analysis of partial 16S rRNA gene amplified by nested PCR indicated that ‘Candidatus Phytoplasma solani’, ‘Ca. Phytoplasma astris’ and ‘Ca. Phytoplasma trifolii’ are prevalent in potato plants showing PPTD symptoms in the production areas of central, western and north‐western regions of Iran, although ‘Ca. Phytoplasma solani’ is more prevalent than other phytoplasmas. This is the first report of phytoplasmas related to ‘Ca. Phytoplasma astris’, ‘Ca. Phytoplasma solani’ and ‘Ca. Phytoplasma trifolii’ causing PPTD in Iran.     

Genetic diversity study of Chromobacterium violaceum isolated from Kolli Hills by amplified ribosomal DNA restriction analysis (ARDRA) and random amplified polymorphic DNA (RAPD)

Aim: Chromobacterium are saprophytes that cause highly fatal opportunistic infections. Identification and strain differentiation were performed to identify the strain variability among the environmental samples. We have evaluated the suitability of individual and combined methods to detect the strain variations of the samples collected in different seasons. Methods and Results: Amplified ribosomal DNA restriction analysis (ARDRA) and random amplified polymorphic DNA (RAPD) profiles were obtained using four different restriction enzyme digestions (AluI, HaeIII, MspI and RsaI) and five random primers. A matrix of dice similarity coefficients was calculated and used to compare these restriction patterns. ARDRA showed rapid differentiation of strains based on 16S rDNA, but the combined RAPD and ARDRA gave a more reliable differentiation than when either of them was analysed individually. Conclusion: A high level of genetic diversity was observed, which indicates that the Kolli Hills’C. violaceum isolates would fall into at least three new clusters. Significance and Impact of the Study: Results showed a noteworthy bacterial variation and genetic diversity of C. violaceum in the unexplored, virgin forest area.     

Detection of genetic variation among single-spore isolates and identification of genets ofArmillaria ostoyae by AFLP analysis with Texas RedTM-labeled selective primer

AFLP (amplified fragment length polymorphism) analysis was applied toArmillaria ostoyae isolates (single-spore isolates and field isolates from the same forest). For detection of AFLP, we have developed a modified method using DNA sequencer with Texas Red-labeled selective primer. In analysis of single-spore isolates, this technique provided large numbers of highly polymorphic DNA markers, which can be used to identify genets. The results suggested that outbreeding might be common inA. ostoyae.     

Molecular Characterization of Aster Yellows Phytoplasma Associated with Valerian and Sowthistle Plants by PCR–RFLP Analyses

In Alberta, Canada, valerian grown for medicinal purposes and sowthistle, a common weed, showed typical aster yellows symptoms. Molecular diagnosis was made using a universal primer pair (P1 / P7) designed to amplify the entire 16S rRNA gene and the 16 / 23S intergenic spacer region in a direct polymerase chain reaction (PCR) assay. This primer pair amplified the DNA samples from valerian and sowthistle and reference controls (AY‐27, CP, PWB, AY of canola, LWB). They produced the expected PCR products of 1.8 kb, which were diluted and used as templates in a nested PCR. Two primer pairs R16F2n / R2 and P3 / P7 amplified the DNA templates giving PCR products of 1.2 and 0.32 kb, respectively. No PCR product was obtained with either set of primers and DNA isolated from healthy plants. Restriction fragment length polymorphism (RFLP) was used to analyse the partial 16S rDNA sequences (1.2 kb) of all phytoplasma DNA samples after restriction with four endonucleases (AluI, HhaI, MseI and RsaI). The restriction patterns of these strains were found to be identical with the RFLP pattern of the AY phytoplasma reference control (AY‐27 strain). Based on the RFLP data, the two strains are members of subgroup A of the AY 16Sr1 group. We report here the first molecular study on the association of AY phytoplasmas with valerian and sowthistle plants.