Spanish Melon Landraces: Revealing Useful Diversity by Genomic, Morphological, and Metabolomic Analysis.

Spain is a secondary centre of the diversification of the melon (Cucumis melo L.), with high diversity represented in highly appreciated landraces belonging to the Flexuosus and Ibericus groups. A collection of 47 accessions of Flexuosus, Chate, Piel de Sapo, Tendral, Amarillo, Blanco, and Rochet was analysed using a genotyping-by-sequencing (GBS) approach. A total of 66,971 quality SNPs were identified. Genetic analysis differentiated Ibericus accessions and exotic materials (Ameri, Momordica, Kachri, and Agrestis), while Flexuous accessions shared ancestry between them. Within the Ibericus group, no clear genomic distinction could be identified for the different landraces evaluated, with accessions of different landraces showing high genetic similarity. The morphological characterization confirmed that the external colour and fruit shape had been used as recognition patterns for Spanish melon landraces, but variability within a landrace exists. Differences were found in the sugars and acid and volatile profiles of the materials. Flexuosus and Chate melons at the immature commercial stage accumulated malic acid and low levels of hexoses, while Ibericus melons accumulated high contents of sucrose and citric acid. Specific trends could be identified in the Ibericus landraces. Tendral accumulated low levels of sugars and citric acid and high of malic acid, maintaining higher firmness, Rochet reached higher levels of sugars, and Amarillo tended to lower malic acid contents. Interestingly, high variability was found within landraces for the acidic profile, offering possibilities to alter taste tinges. The main volatile organic compounds (VOCs) in Flexuosus and Chate were aldehydes and alcohols, with clear differences between both groups. In the Ibericus landraces, general trends for VOC accumulation could be identified, but, again, a high level of variation exists. This situation highlights the necessity to develop depuration programs to promote on-farm in situ conservation and, at the same time, offers opportunities to establish new breeding program targets and to take advantage of these sources of variation.

Comparative transcriptome analysis uncovers regulatory roles of long non-coding RNAs involved in resistance to powdery mildew in melon.

BACKGROUND: Long non-coding RNAs (lncRNAs) are a class of non-coding RNAs with more than 200 nucleotides in length, which play vital roles in a wide range of biological processes. Powdery mildew disease (PM) has become a major threat to the production of melon. To investigate the potential roles of lncRNAs in resisting to PM in melon, it is necessary to identify lncRNAs and uncover their molecular functions. In this study, we compared the lncRNAs between a resistant and a susceptible melon in response to PM infection. RESULTS: It is reported that 11,612 lncRNAs were discovered, which were distributed across all 12 melon chromosomes, and > 85% were from intergenic regions. The melon lncRNAs have shorter transcript lengths and fewer exon numbers than protein-coding genes. In addition, a total of 407 and 611 lncRNAs were found to be differentially expressed after PM infection in PM-susceptible and PM-resistant melons, respectively. Furthermore, 1232 putative targets of differently expressed lncRNAs (DELs) were discovered and gene ontology enrichment (GO) analysis showed that these target genes were mainly enriched in stress-related terms. Consequently, co-expression patterns between LNC_018800 and CmWRKY21, LNC_018062 and MELO3C015771 (glutathione reductase coding gene), LNC_014937 and CmMLO5 were confirmed by qRT-PCR. Moreover, we also identified 24 lncRNAs that act as microRNA (miRNA) precursors, 43 lncRNAs as potential targets of 22 miRNA families and 13 lncRNAs as endogenous target mimics (eTMs) for 11 miRNAs. CONCLUSION: This study shows the first characterization of lncRNAs involved in PM resistance in melon and provides a starting point for further investigation into the functions and regulatory mechanisms of lncRNAs in the resistance to PM.

Genetic architecture of fruit size and shape variation in cucurbits: a comparative perspective.

The Cucurbitaceae family hosts many economically important fruit vegetables (cucurbits) such as cucumber, melon, watermelon, pumpkin/squash, and various gourds. The cucurbits are probably best known for the diverse fruit sizes and shapes, but little is known about their genetic basis and molecular regulation. Here, we reviewed the literature on fruit size (FS), shape (FSI), and fruit weight (FW) QTL identified in cucumber, melon, and watermelon, from which 150 consensus QTL for these traits were inferred. Genome-wide survey of the three cucurbit genomes identified 253 homologs of eight classes of fruit or grain size/weight-related genes cloned in Arabidopsis, tomato, and rice that encode proteins containing the characteristic CNR (cell number regulator), CSR (cell size regulator), CYP78A (cytochrome P450), SUN, OVATE, TRM (TONNEAU1 Recruiting Motif), YABBY, and WOX domains. Alignment of the consensus QTL with candidate gene homologs revealed widespread structure and function conservation of fruit size/shape gene homologs in cucurbits, which was exemplified with the fruit size/shape candidate genes CsSUN25-26-27a and CsTRM5 in cucumber, CmOFP1a in melon, and ClSUN25-26-27a in watermelon. In cucurbits, the andromonoecy (for 1-aminocyclopropane-1-carboxylate synthase) and the carpel number (for CLAVATA3) loci are known to have pleiotropic effects on fruit shape, which may complicate identification of fruit size/shape candidate genes in these regions. The present work illustrates the power of comparative analysis in understanding the genetic architecture of fruit size/shape variation, which may facilitate QTL mapping and cloning for fruit size-related traits in cucurbits. The limitations and perspectives of this approach are also discussed.

QTL mapping of melon fruit quality traits using a high-density GBS-based genetic map.

BACKGROUND: Melon shows a broad diversity in fruit morphology and quality, which is still underexploited in breeding programs. The knowledge of the genetic basis of fruit quality traits is important for identifying new alleles that may be introduced in elite material by highly efficient molecular breeding tools. RESULTS: In order to identify QTLs controlling fruit quality, a recombinant inbred line population was developed using two commercial cultivars as parental lines: "Védrantais", from the cantalupensis group, and "Piel de Sapo", from the inodorus group. Both have desirable quality traits for the market, but their fruits differ in traits such as rind and flesh color, sugar content, ripening behavior, size and shape. We used a genotyping-by-sequencing strategy to construct a dense genetic map, which included around five thousand variants distributed in 824 bins. The RIL population was phenotyped for quality and morphology traits, and we mapped 33 stable QTLs involved in sugar and carotenoid content, fruit and seed morphology and major loci controlling external color of immature fruit and mottled rind. The median confidence interval of the QTLs was 942 kb, suggesting that the high density of the genetic map helped in increasing the mapping resolution. Some of these intervals contained less than a hundred annotated genes, and an integrative strategy combining gene expression and resequencing data enabled identification of candidate genes for some of these traits. CONCLUSION: Several QTLs controlling fruit quality traits in melon were identified and delimited to narrow genomic intervals, using a RIL population and a GBS-based genetic map.

The genetic basis of fruit morphology in horticultural crops: lessons from tomato and melon.

Fruits represent an important part of the human diet and show extensive variation in size and shape between and within cultivated species. The genetic basis of such variation has been studied most extensively in tomato, where currently six quantitative trait loci (QTLs) involving these traits have been fine-mapped and the genes underlying the QTLs identified. The genes responsible for the cloned QTLs belong to families with a few to many members. FASCIATED is encoded by a member of the YABBY family, CNR/FW2.2 by a member of the Cell Number Regulator family, SlKLUH/FW3.2 by a cytochrome P450 of the 78A class (CYP78A), LOCULE NUMBER by a member of the WOX family including WUSCHEL, OVATE by a member of the Ovate Family Proteins (OFP), and SUN by a member of the IQ domain family. A high portion of the history and current diversity in fruit morphology among tomato cultivars can be explained by modifications at four of these cloned QTLs. In melon, a number of QTLs involved in fruit morphology have been mapped, but the molecular basis for these QTLs is unknown. In the present review, we examine the current knowledge on the molecular basis of fruit morphology in tomato and transfer that information in order to define candidate genes of melon fruit shape and size QTLs. We hypothesize that different members of the gene families identified in tomato may have a role in the regulation of fruit morphology in other species. We anchored the published melon QTL map on the genome sequence and identified the melon family members of the six cloned tomato QTLs in the genome. We investigated the co-localization of melon fruit morphology QTLs and the candidate genes. We found that QTLs for fruit weight co-localized frequently with members of the CNR/FW2.2 and KLUH/FW3.2 families, as well as co-localizations between OFP family members and fruit-shape QTLs, making this family the most suitable to explain fruit shape variation among melon accessions.

Cucurbits depicted in Byzantine mosaics from Israel, 350-600 ce.

BACKGROUND AND AIMS: Thousands of floor mosaics were produced in lands across the Roman and Byzantine empires. Some mosaics contain depictions of agricultural produce, potentially providing useful information concerning the contemporary presence and popularity of crop plants in a particular geographical region. Hundreds of floor mosaics produced in Israel during the Byzantine period have survived. The objective of the present work was to search these mosaics for Cucurbitaceae in order to obtain a more complete picture of cucurbit crop history in the eastern Mediterranean region. RESULTS AND CONCLUSIONS: Twenty-three mosaics dating from 350-600 ce were found that had images positively identifiable as cucurbits. The morphological diversity of the cucurbit fruits in the mosaics of Israel is greater than that appearing in mosaics from any other Roman or Byzantine provincial area. The depicted fruits vary in shape from oblate to extremely long, and some are furrowed, others are striped and others lack definite markings. The cucurbit taxa depicted in the mosaics are Cucumis melo (melon), Citrullus lanatus (watermelon), Luffa aegyptiaca (sponge gourd) and Lagenaria siceraria (bottle gourd). Cucumis melo is the most frequently found taxon in the mosaics and is represented by round dessert melons and long snake melons. Fruits of at least two cultivars of snake melons and of watermelons are represented. To our knowledge, images of sponge gourds have not been found in Roman and Byzantine mosaics elsewhere. Indeed, the mosaics of Israel contain what are probably the oldest depictions of Luffa aegyptiaca in Mediterranean lands. Sponge gourds are depicted often, in 11 of the mosaics at eight localities, and the images include both mature fruits, which are useful for cleaning and washing, and immature fruits, which are edible. Only one mosaic has images positively identifiable as of bottle gourds, and these were round-pyriform and probably used as vessels.

Archaeobotanical evidence supports indigenous cucurbit long-term use in the Mesoamerican Neotropics.

The squash family (Cucurbitaceae) contains some of the most important crops cultivated worldwide and has played an important ecological, economic, and cultural role for millennia. In the American tropics, squashes were among the first cultivated crop species, but little is known about how their domestication unfolded. Here, we employ direct radiocarbon dating and morphological analyses of desiccated cucurbit seeds, rinds, and stems from El Gigante Rockshelter in Honduras to reconstruct human practices of selection and cultivation of Lagenaria siceraria, Cucurbita pepo, and Cucurbita moschata. Direct radiocarbon dating indicates that humans started using Lagenaria and wild Cucurbita starting ~ 10,950 calendar years before present (cal B.P.), primarily as watertight vessels and possibly as cooking and drinking containers. A rind directly dated to 11,150-10,765 cal B.P. represents the oldest known bottle gourd in the Americas. Domesticated C. moschata subsequently appeared ~ 4035 cal B.P., followed by domesticated C. pepo ~ 2190 cal B.P. associated with increasing evidence for their use as food crops. Multivariate statistical analysis of seed size and shape show that the archaeological C. pepo assemblage exhibits significant variability, representing at least three varieties: one similar to present-day zucchini, another like present-day vegetable marrow, and a native cultivar without modern analogs. Our archaeobotanical data supports the hypothesis that Indigenous cucurbit use started in the Early Holocene, and that agricultural complexity during the Late Holocene involved selective breeding that encouraged crop diversification.

Identification and characterization of ten new water gaps in seeds and fruits with physical dormancy and classification of water-gap complexes.

BACKGROUND AND AIMS: Physical dormancy (PY) occurs in seeds or fruits of 18 angiosperm families and is caused by a water-impermeable palisade cell layer(s) in seed or fruit coats. Prior to germination, the seed or fruit coat of species with PY must become permeable in order to imbibe water. Breaking of PY involves formation of a small opening(s) (water gap) in a morpho-anatomically specialized area in seeds or fruits known as the water-gap complex. Twelve different water-gap regions in seven families have previously been characterized. However, the water-gap regions had not been characterized in Cucurbitaceae; clade Cladrastis of Fabaceae; subfamilies Bombacoideae, Brownlowioideae and Bythnerioideae of Malvaceae; Nelumbonaceae; subfamily Sapindoideae of Sapindaceae; Rhamnaceae; or Surianaceae. The primary aims of this study were to identify and describe the water gaps of these taxa and to classify all the known water-gap regions based on their morpho-anatomical features. METHODS: Physical dormancy in 15 species was broken by exposing seeds or fruits to wet or dry heat under laboratory conditions. Water-gap regions of fruits and seeds were identified and characterized by use of microtome sectioning, light microscopy, scanning electron microscopy, dye tracking and blocking experiments. KEY RESULTS: Ten new water-gap regions were identified in seven different families, and two previously hypothesized regions were confirmed. Water-gap complexes consist of (1) an opening that forms after PY is broken; (2) a specialized structure that occludes the gap; and (3) associated specialized tissues. In some species, more than one opening is involved in the initial imbibition of water. CONCLUSIONS: Based on morpho-anatomical features, three basic water-gap complexes (Types-I, -II and -III) were identified in species with PY in 16 families. Depending on the number of openings involved in initial imbibition, the water-gap complexes were sub-divided into simple and compound. The proposed classification system enables understanding of the relationships between the water-gap complexes of taxonomically unrelated species with PY.

[Studies on biological characteristics and germination conditions of Thladiantha dubia seeds].

OBJECTIVE: To study the biological characteristics and find out the optimum condition for germination of seed of Thladiantha dubia Bunge for its standardized culturing. METHOD: The weight per 1 000 seeds, seed moisture content and seed viability were determined. The biological characteristics were studied and germination conditions of seed of T. dubia were tested under following conditions: different seed soaking time, different temperatures (15, 20, 25, 30, 35 degrees C) and different irradiation time (0, 5, 10, 15, 20 min). RESULT: The average length, width and thickness of T. Dubia seed were 4.96, 3.25 and 1.08 mm, respectively. The weight per 1 000 seeds was 14.03 g; the seed moisture content was 10.10%; the seed viability was 90.33%. Under the same condition of light, temperature and other factors, the seed germination percentage and germination energy were the highest after seed soaking 24 h. The suitable temperature range of seeds was form 25 degrees C to 35 degrees C. Under different irradiation time, the seed germination percentage and germination energy were the highest after irradiation 10 min. In different germinating beds, the seeds germination percentage and germination energy were the highest on paper (TP), which was 89.33%. CONCLUSION: The optimum condition for the germination of the seed of T. dubia is seed soaking 12 h, irradiation 10 min, 25-30 degrees C on filter paper.

Introduction, adaptation and characterization of monk fruit (Siraitia grosvenorii): a non-caloric new natural sweetener.

Siraitia grosvenorii, an herbaceous perennial plant, native to the southern parts of China, is commonly used as a low-calorie natural sweetener. It contains cucurbitane-type triterpene glycosides known as mogrosides. The extract from monk fruit is about 300 times sweeter than sucrose. In spite of its immense importance and International demand, Siraitia grosvenorii (Swingle) is not commercially cultivated outside China since scientific information for cultivation of this species is lacking. Planting material of monk fruit plant was not available in India. Thus, the seeds of monk fruit were introduced in India from China after following International norms. Then the experiments were conducted on different aspects such as seed germination, morphological and anatomical characterization, phenology, flowering and pollination behaviors, and dynamic of mogroside-V accumulation in fruit. The hydropriming at 40 °C for 24 h was found effective to reduce the germination time and to increase the germination rate (77.33%). The multicellular uniseriate trichomes were observed in both the leaf surfaces, however, higher trichomes density was observed in the ventral surface of males compared to females. The microscopic view revealed that the ovary was trilocular (ovary consists three chambers) having two ovules in each chamber or locule. Most of the fruits were globose or oblong type with 5-7 cm in length and 4-7 cm diameter. Mogroside-V content in fruit at 80 days after pollination was 0.69% on dry weight basis. The rate of increase of mogroside-V accumulation from 50 to 70 days was very slow, whereas a sharp increase was observed from 70 to 80 days. The higher receptivity of stigma was observed with fully open flowers. The floral diagram and formula have also been developed for both male and female flowers. Our results highlighted that monk fruit can be grown in Indian conditions.

Shaping melons: agronomic and genetic characterization of QTLs that modify melon fruit morphology.

The consistency of quantitative trait locus (QTL) effects among genetic backgrounds is a key factor for introgressing QTLs from initial mapping experiments into applied breeding programs. We have selected four QTLs (fs6.4, fw4.3, fw4.4 and fw8.1) involved in melon fruit morphology that had previously been detected in a collection of introgression lines derived from the cross between a Spanish cultivar, "Piel de Sapo," and the Korean accession PI161375 (Songwan Charmi). Introgression lines harboring these QTLs were crossed with an array of melon inbred lines representative of the most important cultivar types. Hybrids of the introgression and inbred lines, with the appropriate controls, were evaluated in replicated agronomic trials. The effects of the QTLs were consistent among the different genetic backgrounds, demonstrating the utility of these QTLs for applied breeding programs in modifying melon fruit morphology. Three QTLs, fw4.4, fs6.4 and fs12.1 were subjected to further study in order to map them more accurately by substitution mapping using a new set of introgression lines with recombination events within the QTL chromosome region. The position of the QTLs was narrowed down to 36-5 cM, depending on the QTL. The results presented in the current study set the basis for the use of these QTLs in applied breeding programs and for the molecular characterization of the genes underlying them.

Comprehensive characterization of natural cellulosic fiber from Coccinia grandis stem.

The anatomical, physico-chemical, mechanical, thermal and surface characteristics of Coccinia grandis fiber (CGF) were studied for a potential substitute to the harmful synthetic fibers. The anatomical analysis of Coccinia grandis stem reveals the presence of high strength xylem fibers. Polarized light microscopy and scanning electron microscopy of CGF shows a hierarchical cell structure composed of a primary and a secondary cell wall, cell lumen and the middle lamellae. The average cross-sectional area and density of the CGF were 0.0111 mm2 and 1.5175 ± 0.005 g/cm3 respectively. The x-ray diffraction and Fourier transform infrared analyses of the fiber indicates the presence of cellulose Iß with a crystallinity index of 46.09%. The mean Young's modulus and tensile strength of the CGF were 124 GPa and 775 MPa respectively, which is sufficient enough for the reinforcement in polymer composites. The thermogravimetric analysis confirms the thermal stability of CGF up to 250 °C, which is well within the polymerization process temperature.

Improved de novo genome assembly and analysis of the Chinese cucurbit Siraitia grosvenorii, also known as monk fruit or luo-han-guo.

Background: Luo-han-guo (Siraitia grosvenorii), also called monk fruit, is a member of the Cucurbitaceae family. Monk fruit has become an important area for research because of the pharmacological and economic potential of its noncaloric, extremely sweet components (mogrosides). It is also commonly used in traditional Chinese medicine for the treatment of lung congestion, sore throat, and constipation. Recently, a single reference genome became available for monk fruit, assembled from 36.9x genome coverage reads via Illumina sequencing platforms. This genome assembly has a relatively short (34.2 kb) contig N50 length and lacks integrated annotations. These drawbacks make it difficult to use as a reference in assembling transcriptomes and discovering novel functional genes. Findings: Here, we offer a new high-quality draft of the S. grosvenorii genome assembled using 31 Gb (∼73.8x) long single molecule real time sequencing reads and polished with ∼50 Gb Illumina paired-end reads. The final genome assembly is approximately 469.5 Mb, with a contig N50 length of 432,384 bp, representing a 12.6-fold improvement. We further annotated 237.3 Mb of repetitive sequence and 30,565 consensus protein coding genes with combined evidence. Phylogenetic analysis showed that S. grosvenorii diverged from members of the Cucurbitaceae family approximately 40.9 million years ago. With comprehensive transcriptomic analysis and differential expression testing, we identified 4,606 up-regulated genes in the early fruit compared to the leaf, a number of which were linked to metabolic pathways regulating fruit development and ripening. Conclusions: The availability of this new monk fruit genome assembly, as well as the annotations, will facilitate the discovery of new functional genes and the genetic improvement of monk fruit.

The cucurbits of mediterranean antiquity: identification of taxa from ancient images and descriptions.

BACKGROUND: A critical analysis was made of cucurbit descriptions in Dioscorides' De Materia Medica, Columella's De Re Rustica and Pliny's Historia Naturalis, works on medicine, agriculture and natural science of the 1st century ce, as well as the Mishna and Tosefta, compilations of rabbinic law derived from the same time period together with cucurbit images dating from antiquity including paintings, mosaics and sculpture. The goal was to identify taxonomically the Mediterranean cucurbits at the time of the Roman Empire. FINDINGS: By ancient times, long-fruited forms of Cucumis melo (melon) and Lagenaria siceraria (bottle gourd) were selected, cultivated and used as vegetables around the Mediterranean and, in addition, bottle-shaped fruits of L. siceraria were employed as vessels. Citrullus lanatus (watermelons) and round-fruited forms of Cucumis melo (melons) were also consumed, but less commonly. A number of cucurbit species, including Bryonia alba, B. dioica, Citrullus colocynthis and Ecballium elaterium, were employed for medicinal purposes. No unequivocal evidence was found to suggest the presence of Cucumis sativus (cucumber) in the Mediterranean area during this era. The cucumis of Columella and Pliny was not cucumber, as commonly translated, but Cucumis melo subsp. melo Flexuosus Group (snake melon or vegetable melon).

[Morphological and histological studies of Herpetospermum pedunculosum seeds and other substitutes].

OBJECTIVE: To provide new evidences for the identification of Herpetospermum pedunculosum seeds and other substitutes. METHOD: Microscopic examination of the cross sections and powers of the seeds of H. pedunculosum, Momordica charantia, Thladiantha setispina and M. cohinchinensis were made to characterize the drug materials. RESULT AND CONCLUSION: The external and internal structure of T. setispina and M. charantia were studied for the first time. Two types of different branched starry sclereids was found in M. cohinchinensis. Comparative studies on external and internal structure were carried out on seeds of the 4 species. As a result, they could be distinguished by external characteristics such as shape, size and color of their seeds, and by internal structure such as size and type of sclereid, epidermis and sub-epidermis cell of seed coat.

[Literature data investigation in semem of Herpetospermum pedunculosum].

Based on literature data, related specimens, commercial samples and field investigation, botanical origin of "bolingguazi" was clarified. Boling guazi was found to be used as a Tibetan medicine in China from 8th century, it was derived from Herpetospermum pedunculosum of cucurbitaceae, and main species of bolingguazi used in most areas of China were H. pednculosura, while seeds of Momordica charantia, Thladiantha setispina and M. cohinchinensis were also available in some areas of China.

On the possible function of Telfairia occidentalis agglutinin in the plant.

The fate of Telfairia occidentalis seed Agglutinin, TOA, has been monitored during germination. While the level of the Agglutinin in the cotyledons decreased sharply in the first three days to about half of the initial level, it stabilises at this level for the following twelve days. In this interval, Agglutinin activity becomes manifest in the radicle on the fourth day, peaking on the fifth and decreasing rapidly thereafter. In the plumule, the lectin activity becomes manifest on the sixth day, peaks on the seventh and decreases rapidly thereafter. No lectin activity is detectable in any plant tissue including the rump of the cotyledons twenty-seven days after germination. The implications of these observations on the possible role of lectins in plants are discussed.

[Study on the pharmacognosy of traditional Chinese medicine tubeimu].

In this article, we have studied the traditional Chinese medicine Tubeimu on the pharmacognosy. This paper reports the thickening condition on the epidermis cell walls of the bulbuls of Tubeimu [Bolbostemma paniculatum (Maxim) Franquet] for the first time and corrects the wrong record in before literature.

Some morphological structural studies of cucurbitaceous tendrils under arid conditions.

This study was carried out at Khulis, Khulis Governorate, Makkah region, on the first of April during the growing season of 2007, to study the morphology and anatomy of tendrils in different eight of cucurbit genera. The results showed a great variation among the most tested cucurbit genera concerning the twisting, branching, number of tendrils per node and presence of tendril trunk. Also, shape of transverse sections were ovate, sinuate-rhombic, sinuate-emarginate oblong, emarginate-ovate, spherical, notched-ovate and reniform. Furthermore, presence of collenchymatous, sclerenchymatous tissues, number of vascular bundles in Transverse Section (TV) and arrangement of vascular bundles varied according to the studied species. It could be conclude from this research that there are a numerous of qualitative traits of tendrils which plays an important role in identification of cucrbitaceous plants for examples; the twisting, branching, transverse section shape, collenchymatous tissue, scleranchymatous tissue, tylosis and arrangement of vascular bundles.

Detection of Cucumber mosaic virus and typing using serological and molecular methods in Razavi Khorasan Province.

Investigation was conducted during 2006 and 2007 to detect and determine typing of Cucumber mosaic virus (CMV) in field-collected samples from Razavi Khorasan Province. Leaves showing chlorosis, mosaic, distortion and shoestring symptoms were collected from the Mashhad Regions (Astan-e-ghods and Khaje-rabie), Neishabour, Torbat-e-heidarye, Ghochan, Chenaran, Fariman, Shirvan, Kalat and Kashmar. Samples were transferred to laboratory in order to detect the virus in the collected samples, Samples were tested by DAS-ELISA. Typing was done for those serologically positive-reacted samples by RT-PCR-RFLP. Specific primers have amplified 650 bp fragments of RNA2, in RT-PCR assay. Digestion was performed by restriction enzyme MluI. Present research showed that all of collected samples were in subgroup IA.