Identification of 27 <Emphasis Type="Italic">Porphyra</Emphasis> lines (Rhodophyta) by DNA fingerprinting and molecular markers

Twenty-seven Porphyra lines, including lines widely used in China, wild lines and lines introduced to China from abroad in recent years, were screened by random amplified polymorphic DNA (RAPD) technique with 120 operon primers. From the generated RAPD products, 11 bands that showed stable and repeatable RAPD patterns amplified by OPC-04, OPJ-18 and OPX-06, respectively were scored and used to develop the DNA fingerprints of the 27 Porphyra lines. Moreover, the DNA fingerprinting patterns were converted into computer language expressed with two digitals, 1 and 0, which represented the presence (numbered as 1) or absence (numbered as 0) of the corresponding band, respectively. Based on the above results, computerized DNA fingerprints were constructed in which each of the 27 Porphyra lines has its unique fingerprinting pattern and can be easily distinguished from others. Software named PGI (Porphyra germplasm identification) was designed for identification of the 27 Porphyra lines. In addition, seven specific RAPD markers from seven Porphyra lines were identified and two of them were successfully converted into SCAR (sequence characterized amplification region) markers. The developed DNA fingerprinting and specific molecular markers provide useful ways for the identification, classification and resource protection of the Porphyra lines.     

Prospects of molecular markers in <Emphasis Type="Italic">Fusarium</Emphasis> species diversity

Recent developments in genomics have opened up for newer opportunities to study the diversity and classification of fungi. The genus Fusarium contains many plant pathogens that attack diverse agricultural crops. Fusarium spp. are not only pathogenic to plants but are also known as toxin producers that negatively affect animal and human health. The identification of Fusarium species still remains one of the most critical issues in fungal taxonomy, given that the number of species recognized in the genus has been constantly changing in the last century due to the different taxonomic systems. This review focuses of various molecular-based techniques employed to study the diversity of Fusarium species causing diseases in major food crops. An introduction of fusarial diseases and their mycotoxins and molecular-marker-based methods for detection introduce the concept of marker application. Various well-known molecular techniques such as random amplified polymorphic DNA, amplification fragment length polymorphism, etc. to more modern ones such as DNA microarrays, DNA barcoding, and pyrosequencing and their application form the core of the review. Target regions in the genome which can be potential candidates for generation of probes and their use in phylogeny of Fusarium spp. are also presented. The concluding part emphasizes the value of molecular markers for assessing genetic variability and reveals that molecular tools are indispensable for providing information not only of one Fusarium species but on whole fungal community. This will be of extreme value for diagnosticians and researchers concerned with fungal biology, ecology, and genetics.     

Genetic diversity analysis and development of SCAR marker for detection of Indian populations of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f. sp. <Emphasis Type="Italic">ciceris</Emphasis> causing chickpea wilt

Genetic diversity of the isolates of Fusarium oxysporum f. sp. ciceris causing chickpea wilt collected from 12 states representing different agro-ecological regions of India was determined through randomly amplified polymorphic DNA (RAPD) markers. The UPGMA cluster analysis grouped the isolates into eight categories showing high magnitude of genetic diversity. Each group had the isolates from different states present in various agro-ecological regions of India. Therefore, the groups generated through the RAPD analysis were not corresponding to area of the origin of the isolates. The RAPD primers, namely, OPA 7 and OPA 11 produced Foc specific fragment of ≈1.3 kb and ≈1.4 kb, respectively in all the isolates. These fragments were eluted, purified, cloned in pGEM-T Easy vector and sequenced. Primers were designed with sequence information of these two fragments using primer.3 software. Two sets of sequence characterized amplified region markers (SC-FOC 1 and SC-FOC 2) developed from the sequences of these fragments were found to be specific to Foc and produced an amplicon of 1.3 and 1.4 kb, respectively. These set of markers were validated against the isolates of the pathogen collected from different locations of India representing various races of the pathogen. They are non-specific to the other Fusarium species, Rhizoctonia solani and R. bataticola.     

Molecular characterization of endophytic strains of Fusarium verticillioides (= Fusarium moniliforme) from maize (Zea mays. L)

The species Fusarium verticillioides (= F. moniliforme) is often found in maize seeds, constituting an important source of inoculum in the field. Fusarium spp., associated with symptomatic and asymptomatic plants, may be a primary causal agent of disease, a secondary invader or an endophyte. In the present work, endophytic fungi were isolated from two populations of Zea mays (BR-105 and BR-106) and their respective inbred lines. Within different inbred lines of maize, Fusarium was found at a frequency of 0 to 100% relative to the number of total isolated fungi. The frequency with which the genus occurred was practically the same in the two field sites (around 60%). Twenty-one F. verticillioides strains were analysed using the random amplified polymorphic DNA (RAPD) technique, employing 10 random primers. Variability analysis of endophytic isolates via RAPD showed genome polymorphism taxa of species around 60%. Endophytic isolates were clustered by their sites of origin. RAPD analysis clustered the endophytic isolates by their maize inbred lines hosts (Mil-01 to Mil-06), whereas at site A they clustered into two major groups related to the maize gene pool (BR-105 or BR-106 population). All strains isolated from seeds collected in Site A, except strains L9 and L10, were sub-grouped according to maize inbred lines. The analysis showed a discrete sub-grouping at site B. Results obtained here could be explained by a co-evolution process involving endophytic isolates of F. verticillioides and maize inbred lines.     

Characterization of gibberellin producing strains of Fusarium moniliforme based on DNA polymorphism

The gibberellins are one of the major groups of growth promoting hormones and are secondary metabolites of the fungus Fusarium moniliforme (Perfect stage: Gibberella fujikuroi). Sixteen strains of Fusarium from different geographical regions and different hosts were analysed for their ability to produce gibberellins (GA) and for genetic relatedness by random amplified polymorphic DNA (RAPD). Range of gibberellin production varied between 28.9 to 600.0 mg g^-1 dry weight of mycelium in different strains of Fusarium. RAPD analysis showed completely different pattern between high, moderate and low producing strains. High producers formed nearly identical RAPD patterns, whereas the low and moderate producers gave heterologous amplification patterns. Since Fusarium pallidoroseum was in another group, it was possible to distinguish between different species of the genus Fusarium by RAPD. These investigations may find an application in the diagnosis of unknown Fusarium species and in distinguishing isolates of Gibberella fujikuroi within the section of Liseola. This revised version was published online in June 2006 with corrections to the Cover Date.     

Fusarium Nail and Skin Infection: A Report of Eight Cases from Natal, Brazil

Fusarium spp. are non-dermatophytic hyaline moulds distributed worldwide and recovered from the nature as soil saprophytes and plant pathogens. Human infections are usually precipitated by local or systemic predisposing factors and disseminated infection is associated with impaired immune responses. We report eight cases of cutaneous lesions caused by Fusarium spp. All patients were immunocompetent. Seven cases with presented onychomycosis and one patient with interdigital intertrigo. It is important to alert the medical community about the relevance of the opportunistic fungi, such as Fusarium spp., which have emerged as human infectious agents, emphasizing the importance of correct etiological identification, allowing for appropriate treatment.     

Endophytic fungi from rhizomes of <Emphasis Type="Italic">Paris polyphylla</Emphasis> var. <Emphasis Type="Italic">yunnanensis</Emphasis>

About 63 fungal endophytic isolates were separated from rhizomes of Paris polyphylla var. yunnanensis, which is a traditional medicinal plant mainly distributed in China. The isolates were characterized and grouped based on the culture characteristics and the morphology of colony growth and conidia. Eleven representative ones were selected for further taxonomical identification. Five genera namely Fusarium, Gliocladiopsis, Gliomastix, Aspergillus and Cylindrocarpon were identified on the basis of their morphological characterizations. Of them, the most frequent genus was Fusarium (i.e. Ppf1, Ppf3 and Ppf14). Their ITS-rDNA sequences were compared with those available in the GeneBank databases to obtain the closest related species by BLAST analysis as well as to analyze their phylogenetic affiliation. The isolates were identified as Gliocladiopsis irregularis (Ppf2), Plectosphaerella cucumerina (Ppf4), Padospora sp. (Ppf6), Gliomastix murorum var. murorum (Ppf7), Aspergillus fumigatus (Ppf9), Pichia guilliermondii (Ppf10), Neonectria radicicola (anamorph: Cylindrocarpon) (Ppf12) and one uncultured mycorrhizal ascomycete (Ppf13) separately based on their morphological and molecular features. The molecular characters of the endophytic fungi were basically coincident with their morphology. The broad diversity and taxonomic spectrum were exhibited by the endophytic fungi from P. polyphylla var. yunnanensis.     

A consensus map for <Emphasis Type="Italic">Cucurbita pepo</Emphasis>

Using random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), simple sequence repeats (SSR), and morphological traits, the first genetic maps for Cucurbita pepo (2n=2x=40) were constructed and compared. The two mapping populations consisted of 92 F₂ individuals each. One map was developed from a cross between an oil-seed pumpkin breeding line and a zucchini accession, into which genes for resistance to Zucchini Yellow Mosaic Virus (ZYMV) from a related species, C. moschata, had been introgressed. The other map was developed from a cross between an oil-seed pumpkin and a crookneck variety. A total of 332 and 323 markers were mapped in the two populations. Markers were distributed in each map over 21 linkage groups and covered an average of 2,200 cM of the C. pepo genome. The two maps had 62 loci in common, which enabled identification of 14 homologous linkage groups. Polyacrylamide gel analyses allowed detection of a high number of markers suitable for mapping, 10% of which were co-dominant RAPD loci. In the Pumpkin-Zucchini population, bulked segregant analysis (BSA) identified seven markers less than 7 cM distant from the locus n, affecting lignification of the seed coat. One of these markers, linked to the recessive hull-less allele (AW11-420), was also found in the Pumpkin-Crookneck population, 4 cM from n. In the Pumpkin-Zucchini population, 24 RAPD markers, previously introduced into C. pepo from C. moschata, were mapped in two linkage groups (13 and 11 markers in LGpz1 and LGpz2, respectively), together with two sequence characterized amplified region (SCAR) markers linked to genes for resistance to ZYMV.     

Identification and mapping on chromosome 9 of RAPD markers linked to Sw-5 in tomato by bulked segregant analysis

Bulked segregant analysis was used to identify random amplified polymorphic DNA (RAPD) markers linked to the Sw-5 gene for resistance to tomato spotted wilt virus (TSWV) in tomato. Using two pools of phenotyped individuals from one segregating population, we identified four RAPD markers linked to the gene of interest. Two of these appeared tightly linked to Sw-5, whereas another, linked in repulsion phase, enabled the identification of heterozygous and susceptible plants. After linkage analysis of an F₂ population, the RAPD markers were shown to be linked to Sw-5 within a distance of 10.5 cM. One of the RAPD markers close to Sw-5 was used to develop a SCAR (sequence characterized amplified region) marker. Another RAPD marker was stabilized into a pseudo-SCAR marker by enhancing the specificity of its primer sequence without cloning and sequencing. RAPD markers were mapped to chromosome 9 on the RFLP tomato map developed by Tanksley et al. (1992). The analysis of 13 F₃ families and eight BC₂ populations segregating for resistance to TSWV confirmed the linkage of the RAPD markers found. These markers are presently being used in marker-assisted plant breeding.     

Rhizospheric streptomycetes as potential biocontrol agents of <Emphasis Type="Italic">Fusarium</Emphasis> and <Emphasis Type="Italic">Armillaria</Emphasis> pine rot and as PGPR for <Emphasis Type="Italic">Pinus taeda</Emphasis>

Pinus taeda is one of the main timber trees in Brazil, occupying 1.8 million ha with an annual productivity of 25–30 m³ ha⁻¹. Another important species is Araucaria angustifolia, belonging to the fragile Rainforest biome, which for decades has been a major source of timber in Brazil. Some diseases that affect the roots and/or the stem of these trees and cause “damping-off” of the seedlings, with economic and environmental losses for the forest sector, are caused by the plant pathogenic fungi Fusarium sp. or Armillaria sp. This research project intended to isolate actinobacteria from the Araucaria rhizosphere, which present an antagonistic effect against these fungi. After the selection of the best pathogen inhibitors, morphologic characteristics, enzyme production, and their effect on the growth of Pinus taeda were studied. The actinobacteria were tested for their antagonistic capacity against Fusarium sp. in Petri plates with PDA as substrate. The inhibition zone was measured after 3, 5, 7, and 10 days. Of all the isolates tested, only two of them maintained inhibition zones up to 4 mm for 10 days. The inhibition of Armillaria sp. was tested in liquid medium and also in Petri dishes through the evaluation of the number of the fungal rhizomorphs in dual culture with the actinobacteria. It was found that all five isolates were able to inhibit the rhizomorph production, with the best performance of the isolate A43, which was capable of inhibiting both fungi, Fusarium and Armillaria. In a greenhouse experiment, the effect of five isolates on the growth of Pinus taeda seedlings was tested. Plant height, stem diameter, root and shoot dry matter were determined. The Streptomyces isolate A43 doubled plant growth. These results may lead to the development of new technologies in the identification of still unknown bacterial metabolites and new management techniques to control forest plant diseases.     

Antimicrobial Activity and Biodiversity of Endophytic Fungi in <Emphasis Type="Italic">Dendrobium</Emphasis><Emphasis Type="Italic">devonianum</Emphasis> and <Emphasis Type="Italic">Dendrobium thyrsiflorum</Emphasis> from Vietman

Endophytic fungi are rich in orchids and have great impacts on their host plants. 53 endophytes (30 isolates from Dendrobium devonianum and 23 endophytic fungi from D. thyrsiflorum) were isolated, respectively, from roots and stems of Dendrobium species. All the fungi were identified by way of morphological and/or molecular biological methods. 30 endophytic fungi in D. devonianum were categorized into 11 taxa and 23 fungal endophytes in D. thyrsiflorum were grouped into 11 genera, respectively. Fusarium was the dominant species of the two Dendrobium species in common. Antimicrobial activity of ethanol extract of fermentation broth of these fungi was explored using agar diffusion test. 10 endophytic fungi in D. devonianum and 11 in D. thyrsiflorum exhibited antimicrobial activity against at least one pathogenic bacterium or fungus among 6 pathogenic microbes (Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Candida albicans, Cryptococcus neoformans, and Aspergillus fumigatus). Out of the fungal endophytes isolated from D. devonianum and D. thyrsiflorum, Phoma displayed strong inhibitory activity (inhibition zones in diameter >20 mm) against pathogens. Epicoccum nigrum from D. thyrsiflorum exhibited antibacterial activity even stronger than ampicillin sodium. Fusarium isolated from the two Dendrobium species was effective against the pathogenic bacterial as well as fungal pathogens. The study reinforced the assumption that endophytic fungi isolated from different Dendrobium species could be of potential antibacterial or antifungal resource.     

Identification and assessment of genetic relationships in three <Emphasis Type="Italic">Chlorophytum</Emphasis> species and two high yielding genotypes of <Emphasis Type="Italic">C. borivilianum</Emphasis> through RAPD markers

Conservation of identified germplasm is an important component for efficient and effective management of plant genetic resources. Since Chlorophytum species are important medicinal plants, studies were carried out for identification and establish genetic relationships in three species of Chlorophytum and two high yielding genotypes of Chlorophtum borivilianum using RAPD markers. Out of one hundred primers tested, 47 decamers amplified a total of 454 distinct bands ranging from 0.25–3.0 kbp to identify and to evaluate genetic relationships between and among three species of Chlorophytum and two genotypes of Chlorophtum borivilianum. The cluster analysis indicated that three species of Chlorophytum and two genotypes (NRCCB-1 and NRCCB-2) of C. borivilianum formed two major clusters. The first major cluster constituted C. arundinaceum and C. tuberosum, and the second major cluster composed of two subclusters; the first subcluster represented NRCB-1 and NRCB-2 where as the second subcluster represented C. borivilianum. Thus, the RAPD markers have the potential for identification and characterization of genetic relatedness among the species and genotypes. C. borivilianum along with two genotypes also showed similar banding patterns which could be chosen as candidate markers for differentiating the other two species such as C. arundinaceum and C. tuberosum. This would helpful for breeding programmes and provides an important input in conservation biology.     

Application of random amplified polymorphic DNA (RAPD) analysis coupled with microchip electrophoresis for high-resolution identification of <Emphasis Type="Italic">Monascus</Emphasis> strains

Monascus fungi are commonly used for a variety of food products in Asia, and are also known to produce some biologically active compounds. Since the use of Monascus is expected to increase in food industries, strain-level identification and management of Monascus will be needed in the near future. In the present study, random amplified polymorphic DNA (RAPD) analysis coupled with microchip electrophoresis was applied for this purpose. Evaluations of the analysis stability revealed that reproducible results could be obtained, although template DNA fragmentation could influence the resulting RAPD pattern. RAPD analysis using 15 Monascus strains consisting of four species, M. ruber, M. pilosus, M. purpureus, and M. kaoliang showed that each strain generated a unique RAPD pattern, which allows strain-level identification of Monascus. In addition, the phylogenetic tree constructed from RAPD patterns reflected M. ruber–M. pilosus and M. purpureus–M. kaoliang clusters inferred from both ITS and β-tubulin gene sequences, which indicated that the RAPD pattern could reflect their phylogenetic traits to a certain extent. On the other hand, RAPD analysis did not support the monophyletic clustering of the four Monascus species used in this study, which suggests the necessity of reexamination of species boundaries in Monascus.     

Detection of section-specific random amplified polymorphic DNA (RAPD) markers in Lilium

Random amplified polymorphic DNA (RAPD) markers were utilized for the identification of Lilium species and inter-specific hybrids. The optimum annealing temperature of the polymerase chain reaction (PCR) for the RAPD assay in Lilium was 54 °C, which is relatively higher than the temperature used for other genera reported by previous researchers. Among 76 primers used to amplify genomic DNA by PCR, 18 primers (24%) generated polymorphic DNA fragments in Lilium species and hybrids. Cultivars were also identified by RAPD markers. Some amplified fragments were unique to species of each section and to hybrids derived from these species; that is, they were the section-specific DNA markers. Sections, Sinomartagon, Leucolirion b, Leucolirion a and Archelirion could be identified by 6 section-specific markers amplified with five primers. Seven inter-section hybrids showed the section-specific bands of both parental sections, indicating that these markers would be useful for identifying the parental sections of inter-section hybrids.     

A genetic map of melon (Cucumis melo L.) based on amplified fragment length polymorphism (AFLP) markers

 Genetic maps facilitate the study of genome structure and evolution, and the identification of monogenic traits or Mendelian components of quantitative traits. We evaluated 228 RAPD, microsatellite and AFLP markers for linkage analysis in melon (Cucumis melo L.) varieties MR-1 (resistant to Fusarium wilt, powdery and downy mildews) and Ananas Yokneum (AY; susceptible to these diseases) and constructed a detailed genetic map. The mapping population consisted of 66 backcross progenies derived from AY×(MR-1×AY). Despite a relatively low level of polymorphism in the species, AFLP markers were found to be more efficient in mapping the melon genome than RAPD or microsatellite markers. The map contains 197 AFLPs, six RAPDs and one microsatellite marker assigned to 14 major and six minor linkage groups, and covers 1942 cM with the average distance between adjacent markers of approximately 10 cM. The maximum distance allowed between markers is 27.5 cM. About 11% of the intervals (20 out of 173) are over 20 cM (but less than 27.5 cM). The map has immediate utility for identifying markers linked to disease resistance genes that are suitable for marker-assisted breeding. The use of microsatellite markers for integration with other maps is also discussed. Received: 12 March 1997 / Accepted: 20 May 1997     

Molecular characterization and identification of markers for toxic and non-toxic varieties of <Emphasis Type="Italic">Jatropha curcas</Emphasis> L. using RAPD,AFLP and SSR markers

Jatropha curcas L., a multipurpose shrub has acquired significant economic importance for its seed oil which can be converted to biodiesel, is emerging as an alternative to petro-diesel. The deoiled seed cake remains after oil extraction is toxic and cannot be used as a feed despite having best nutritional contents. No quantitative and qualitative differences were observed between toxic and non-toxic varieties of J. curcas except for phorbol esters content. Development of molecular marker will enable to differentiate non-toxic from toxic variety in a mixed population and also help in improvement of the species through marker assisted breeding programs. The present investigation was undertaken to characterize the toxic and non-toxic varieties at molecular level and to develop PCR based molecular markers for distinguishing non-toxic from toxic or vice versa. The polymorphic markers were successfully identified specific to non-toxic and toxic variety using RAPD and AFLP techniques. Totally 371 RAPD, 1,442 AFLP markers were analyzed and 56 (15.09%) RAPD, 238 (16.49%) AFLP markers were found specific to either of the varieties. Genetic similarity between non-toxic and toxic verity was found to be 0.92 by RAPD and 0.90 by AFLP fingerprinting. In the present study out of 12 microsatellite markers analyzed, seven markers were found polymorphic. Among these seven, jcms21 showed homozygous allele in the toxic variety. The study demonstrated that both RAPD and AFLP techniques were equally competitive in identifying polymorphic markers and differentiating both the varieties of J. curcas. Polymorphism of SSR markers prevailed between the varieties of J. curcas. These RAPD and AFLP identified markers will help in selective cultivation of specific variety and along with SSRs these markers can be exploited for further improvement of the species through breeding and Marker Assisted Selection (MAS).     

An intersubspecific genetic map of<Emphasis Type="Italic"> Lens</Emphasis>

A Lens map was developed based on the segregational analysis of five kinds of molecular and morphological genetic markers in 113 F₂ plants obtained from a single hybrid of Lens culinaris ssp. culinaris × L. c. ssp. orientalis. A total of 200 markers were used on the F₂ population, including 71 RAPDs, 39 ISSRs, 83 AFLPs, two SSRs and five morphological loci. The AFLP technique generated more polymorphic markers than any of the others, although AFLP markers also showed the highest proportion (29.1%) of distorted segregation. At a LOD score of 3.0, 161 markers were grouped into ten linkage groups covering 2,172.4 cM, with an average distance between markers of 15.87 cM. There were six large groups with 12 or more markers each, and four small groups with two or three markers each. Thirty-nine markers were unlinked. A tendency for markers to cluster in the central regions of large linkage groups was observed. Likewise, clusters of AFLP, ISSR or RAPD markers were also observed in some linkage groups, although RAPD markers were more evenly spaced along the linkage groups. In addition, two SSR, three RAPD and one ISSR markers segregated as codominant. ISSR markers are valuable tools for Lens genetic mapping and they have a high potential in the generation of saturated Lens maps.Communicated by H.C. Becker     

Fungal species residing in the sclerotia of <Emphasis Type="Italic">Polyporus umbellatus</Emphasis>

Sclerotia of Polyporus umbellatus is a traditional Chinese herb. The sclerotia can survive in soils for long time and their growth depends upon a symbiotic association with Armillariella mellea. But it is unclear whether other fungi reside or play a role in the sclerotia. In this study, wild sclerotial samples were collected from seven provinces, which span southwest to northeast China. A total of 148 fungal isolates were recovered from the sclerotia of P. umbellatus and classified into 19 morphological taxa. Seventeen belonged to five genera: Fusarium, Eurotium, Penicillium, Geomyces and Mucor. The fungi found within the sclerotia varied depending on the province from which they were collected. The possible role of these fungi is discussed.     

Cloning and characterization of the ribosomal protein L3 (<Emphasis Type="Italic">RPL3</Emphasis>) gene family from <Emphasis Type="Italic">Triticum aestivum</Emphasis>

Plant pathogenic fungi of the genus Fusarium can cause severe diseases on small grain cereals and maize. The contamination of harvested grain with Fusarium mycotoxins is a threat to human and animal health. In wheat production of the toxin deoxynivalenol (DON), which inhibits eukaryotic protein biosynthesis, is a virulence factor of Fusarium, and resistance against DON is considered to be part of Fusarium resistance. Previously, single amino acid changes in RPL3 (ribosomal protein L3) conferring DON resistance have been described in yeast. The goal of this work was to characterize the RPL3 gene family from wheat and to investigate the potential role of naturally existing RPL3 alleles in DON resistance by comparing Fusarium-resistant and susceptible cultivars. The gene family consists of three homoeologous alleles of both RPL3A and RPL3B, which are located on chromosomes 4A (RPL3-B2), 4B (RPL3-B1), 4D (RPL3-B3), 5A (RPL3-A3), 5B (RPL3-A2) and 5D (RPL3-A1). Alternative splicing was detected in the TaRPL3-A2 gene. Sequence comparison revealed no amino acid differences between cultivars differing in Fusarium resistance. While using developed SNP markers we nevertheless found that one of the genes, namely, TaRPL3-A3 mapped close to a Fusarium resistance QTL (Qfhs.ifa-5A). The potential role of the RPL3 gene family in DON resistance of wheat is discussed.     

The genetic analysis and germplasm identification of the gametophytes of Undaria pinnatifida (Phaeophyceae) with RAPD method

Eleven pairs of Undaria pinnatifida (Harv.) Suringar gametophytes were identified with random amplified polymorphic DNA (RAPD) technique. After screening 100 primers, 20 ten-base primers were determined for the RAPD analysis. A total of 312 polymorphic loci were obtained, of which 97.7% were polymorphic. The primer S198 was found to distinguish all the selected Undaria pinnatifida gametophytes. The genetic distances between each two of the twenty-two U. pinnatifida gametophytes ranged from 0.080 to 0.428, while the distances to the Laminaria was 0.497 on average. After reexamination, two sequences characterized amplification region (SCAR) markers were successfully converted, which could be applied to U. pinnatifida germplasm identification. All these results demonstrated the feasibility of applying RAPD markers to germplasm characterization and identification of U. pinnatifida gametophytes, and to provide a molecular basis for Undaria breeding.