Authors:S. Marghali, H. Chennaoui, H. Bourguiba, M. Marrakchi, and N. Trifi-Farah
Amplified fragment length polymorphism (AFLP) has been proposed as a valuable tool for finding molecular markers linked to QTL controlling architectural trait. Segregation of polymorphic AFLP fragments was followed in F2 offsprings Hedysarum coronarium derived from two native wild accesions crossing: Jebel Zit×El Haouaria, which had previously characterised by morphological and AFLP markers. A comparison of profiles from the morphologically contrasted parental individuals and F2 offspring has been assessed using five AFLP primer combinations. These generated 178 bands revealed by silver-stained denaturing polyacrylamide gels, of which 150 were polymorphic. Several AFLP markers appeared to be implied in the orthotropic form that can assist the selection and improve Hedysarum forage crop.
Authors:T. Sumíková, J. Remešová, L. Leišová, L. Kucera, J. Chrpová, and V. Šíp
Savelkoul, P.H.M., Aarts, H.J.M., De Haas, J., Dijkshoorn, L., Duim, B., Otsen, M., Rademaker, J.L.W., Schouls, L., Lenstra, J.A. 1999. Amplified-fragmentlengthpolymorphism analysis: The state of an art. J. Clin. Microbiol. 37 :3083
Authors:Khaled Masmoudi, Ahmed Rebai, and Radhouane Ellouz
Bread wheat (
L.) is an economically and nutritionally important cereal crop in the Mediterranean region. Characterization of wheat germplasm by means of DNA fingerprinting techniques provides a tool to assess genetic diversity and to identify varieties. In this study, six Tunisian bread wheat cultivars were characterized by AFLP and SSR markers. Five AFLP primer pairs showed clear different patterns and seems to be the most suitable for analysis of the bread wheat varieties. Three SSR primers were polymorphic with more than two alleles. The pairwise genetic similarities (GS) based on these molecular markers were calculated and used to construct a dendrogram that allowed the discrimination of the six cultivars. The GS among the six varieties ranged from 0.79 to 0.36. The six varieties used in this work clustered into four groups using either AFLP or SSR markers. A high GS was found between Tebecca and Vaga Varieties which have a similar pedigree.
In order to target factors involved in plant-pathogen interactions, gene expression differences were investigated on pepper (
L.) plants after artificial infection with the bacterial pathogen
. Amplified Fragment Length Polymorphism investigations on reverse transcribed DNA fragments (cDNA-AFLP) were used to compare the expression profiles of parental lines and of resistant and susceptible individuals from pepper populations segregating for the
gene, which confers a general defence system in pepper. In total, 73 transcript-derived fragments (TDFs) displaying differential expression patterns could be identified (presence-absence and/or different time courses in resistant and susceptible genotypes). Of these, 67 fragments were cloned and sequenced. In the case of several TDFs, sequence comparisons revealed close homologies to genes known to be responsible for abiotic stress or biotic elicitors, presenting potentially interesting targets for more detailed studies on gene expression and signal transduction.
The heterogeneity among ten most widely grown old, recently released varieties and landraces of Syrian durum wheat was studied using amplified fragment length polymorphism (AFLP) markers. The 11 primer combinations used in this study amplified 533 scorable AFLP loci of which 141 (26.5%) were polymorphic. The values of average polymorphic information content (PIC) for these markers were estimated to be 0.34. The dissimilarity
values ranged from 0.120 to 0.729 with an average 0.421. The PCA analysis with the entire AFLP data separated the landraces from the durum wheat cultivars. The low PIC and dissimilarity values among modern varieties might be attributed to the rigorous selection pressure aimed at cultivar purity and associated breeding practices. It is included that AFLP markers can be used for detecting polymorphism leading to genotype identification and for estimating genetic diversity.
Authors:G. Surányi, C. Máthé, Ágnes Mosolygó, G. Borbély, and G. Vasas
Crocus taxonomy has until now been based primarily on morphology, taking chromosome numbers into consideration. The genetics and genome structure of the genus, the relationships and diversity within the genus are not well known. Amplified fragment length polymorphism (AFLP) is a whole genome approach to study genetic variation that is gaining in popularity for lower-level systematics. The present study employed the AFLP technique for analyzing relationships among taxa of the Crocus genus (particularly the Crocus vernus aggregate) with Carpathian Basin origin. The molecular variance obtained was based on amplification, separation and detection of EcoRI and Tru1I double-digested Crocus spp. genomic DNAs. Our results confirm the relatedness of C. tommasinianus, C. vittatus and C. heuffelianus at the Verni series of the Crocus genus. C. banaticus is taxonomically isolated as the sole member of the subgenus Crociris based on unique morphological features, but the difference is not convincing from AFLP data. The second interesting AFLP analysis result is the position of C. scepusiensis which separated it from the Crocus vernus aggregate.
Authors:Anna Resetár, Zita Demeter, Emese Ficsor, Andrea Balázs, Ágnes Mosolygó, Éva Szőke, S. Gonda, L. Papp, G. Surányi, and C. Máthé
In this study, we report on the production of bulb scale-derived tissue cultures capable of efficient shoot and plant regeneration in three genotypes of snowdrop (Galanthus nivalis L., Amaryllidaceae), a protected ornamental plant. For culture line A, high auxin and low cytokinin concentration is required for callus production and plant regeneration. The type of auxin is of key importance: α-naphthaleneacetic acid (NAA) in combination with indole-3-acetic acid (IAA) at concentrations of 2 mg L−1 or 2–10 mg L−1 NAA with 1 mg L−1 N6-benzyladenine (BA), a cytokinin on full-strength media are required for regeneration. Cultures showing regeneration were embryogenic. When lines B and C were induced and maintained with 2 mg L−1 NAA and 1 mg L−1 BA, they produced mature bulblets with shoots, without roots. Line A produced immature bulblets with shoots under the above culture condition. Amplified Fragment Length Polymorphism (AFLP) analysis showed that (i) genetic differences between line A and its bulb explants were not significant, therefore these tissue cultures are suitable for germplasm preservation, and (ii) different morphogenetic responses of lines A, B and C originated from genetic differences. Culture line A is suitable for field-growing, cultivation and germplasm preservation of G. nivalis and for the production of Amaryllidaceae alkaloids.
Radiofrequency radiations (RFR) are electromagnetic frequencies (EMFs) that encompass frequencies below that of visible light and above that of extremely low frequency fields. Typical man-made sources of RFR include broadcast AM/FM/TV, mobile phones and base stations, microwave ovens and radar. In this investigation, the cytological and molecular effects of RF-EMFs at 2.45 GHz, the frequency commonly used in telecommunication and microwave ovens, have been investigated in dividing root cells of five wheat cultivars following grain exposure to very short times ranging from one second to one minute. Enhanced mitotic activity and increased proportion of chromosomal abnormalities were scored in root cells as the exposure time increased. Most abnormalities are comprised of cmetaphase configurations, unoriented chromosomes at metaphase, laggards and multipolar ana-telophases indicating an action on the mitotic apparatus as well as chromosomal bridges and the formation of micronuclei indicating true clastogenic effects by the used radiation. In addition, the amplified fragment length polymorphism (AFLP) fingerprinting indicated marked DNA polymorphism among wheat cultivars and also as a result of exposure to RF-EMFs at 2.45 GHz. The results indicate remarkable cytogenetic and molecular consequence of man-made sources of RFR in plants that may lead to genetic variation. However, further research on this aspect is required to get a concrete answer for its mutagenic/carcinogenic activity.
Authors:H. Xie, Z. Lin, Z. Zhang, L. Du, Z. Xin, Y. Ma, X. Ye, and X. Chen
The common wheat line, YW243, developed in our research group, was tested for the resistances of barley yellow dwarf virus (BYDV), powdery mildew (Pm) and stripe rust in field, and was analyzed by molecular markers for convenient trace of the resistant genes in breeding. Genomic in situ hybridization (GISH) analysis and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) assay further demonstrated that YW243 was a homozygous multiple translocation line of
Triticum aestivum, Thinopyrum intermedium
(T7DS·7DL-7XL & 1BL·1RS). The disease resistance test and marker analysis showed that YW243 carried seven resistance genes to the three diseases, including
to BYDV on 7DL-7XL,
to powdery mildew on 2AL,
Yr2, Yr9, Sr 31
and a new
to stripe rust on 7B, 1BL, 1RS and 2BL. Restriction fragment length polymorphism (RFLP) markers
, sequence tagged site (STS) marker STS
, simple sequence repeat (SSR) markers
, SSR markers
can be used as diagnostic tools to track
Bdv2, Pm4, Yr2, Yr9
, respectively; and two amplified fragment length polymorphism (AFLP) markers
can also be used to select
Bacopa monnieri (L.) Pennell, commonly known as Brahmi, is an important medicinal plant of the Ayurvedic System of Medicine and is categorized as Medhya Rasayana, used for boosting memory. Bacoside A and B (saponins) are major bioactive compounds of the plant responsible for memory enhancement. Consistent quality and quantity of the bioactive compounds are a must to produce highly efficacious herbal drugs. The phytochemical diversity due to ecogeographical variations affects the persistent therapeutic effect. In the present study, quantification of the major bioactive principle of B. monnieri, bacoside A, was performed in order to evaluate chemodiversity in the plants collected from different ecogeographical locations. The analysis of 75 accessions showed a wide range of significant variation in bacoside A content. Further, genetic diversity study was carried out between high- and low-yielding accessions to correlate the effect of the genetic composition on chemical diversity. The cluster analyses of amplified fragment length polymorphism (AFLP) data of high and low bacoside A producing plants using dendogram and principal coordinate analysis (PCoA) revealed no specific clustering. The genetic diversity parameters calculated also support less genetic differentiation between low- and high-yielding accessions. The results clearly indicate that there is a prevalence of agroclimatic conditions on differential bacoside A accumulation in B. monnieri. The study will help to produce quality plant material to be used as phytomedicine.