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Understanding the adaptive mechanism of trees to climate change and effective management of genetic resources necessitate a comprehensive knowledge of the relationship between environmental factors and their adaptive power. This study focuses on the endangered Moroccan endemic tree, Argania spinosa L., known for its remarkable adaptive power in the Mediterranean climate and heavily impacted by climate change. Through genomic scans along a latitudinal gradient, we aimed to identify genomic regions associated with convergent or divergent selection by searching the genome for outlier loci demonstrating high population differentiation. Variation of dominant markers (Amplified Fragment Length Polymorphism) was correlated with variation of environmental factors to discern signals of natural selection in 13 natural populations of Argania spinosa L. along a latitudinal transect.Genotyping of 130 individuals with 477 AFLP markers revealed six outlier loci exhibiting elevated population differentiation values within argan forests. The BayeScan v2.1 software was used to detect outlier loci, and the (MLM) method strongly associated these loci with at least five environmental factors, particularly bioclimatic variables. Notably, all outlier loci exhibited significant correlations with Soil Moisture, with additional associations with Temperature, Precipitation, Landforms, and Soil Type, influencing the local adaptation of Argania spinosa L.The outlier AFLP loci may not be the direct targets of natural selection, but locate closely to genes that are potential involved in local adaptation. Consequently, further investigations are imperative to validate these candidate loci. This research underscores the significance of considering bioclimatic variables, especially Soil Moisture, in understanding the local adaptation of Argania spinosa L. amid climate change in Morocco.

Tomato Solanum lycopersicum L. is one of the main vegetable crops, accessions and cultivars of which are characterized by a low level of genomic polymorphism. Introgressive tomato breeding uses related wild Solanum species to improve cultivars for stress tolerance and fruit quality traits. The aim of this work was to evaluate the genome variability of 59 cultivars and perspective breeding lines of S. lycopersicum and 11 wild tomato species using the AFLP method. According to the AFLP analysis, four combinations of primers E32/M59, E32/M57, E38/M57, and E41/M59, which had the highest PIC (polymorphism information content) values, were selected. In the process of genotyping a collection of 59 cultivars/lines of S. lycopersicum and 11 wild tomato accessions, the selected primers revealed 391 fragments ranging in size from 80 to 450 bp, of which 114 fragments turned out to be polymorphic and 25 were unique. Analysis of the amplification spectra placed wild tomato accessions into separate clades. Sister clades included cultivars of FSCV breeding resistant to drought and/or cold and, in part, to late blight, Alternaria, Septoria, tobacco mosaic virus and blossom end rot, as well as tomato accessions not characterized according to these traits, which suggests that they have resistance to stress factors. In accessions of distant clades, there was clustering on the basis of resistance to Verticillium, cladosporiosis, Fusarium, tobacco mosaic virus, gray rot, and blossom end rot. The combination of accessions according to their origin from the originating organization was shown. The primer combinations E32/M59, E32/M57, E38/M57 and E41/M59 were shown to be perspective for genotyping tomato cultivars to select donors of resistance to various stress factors. The clade-specific fragments identified in this work can become the basis for the development of AFLP markers for traits of resistance to stress factors.

It is necessary to regard the biodiversity of carrot as a genetic source of useful and indispensable components for the human diet. Amplified fragment length polymorphism (AFLP) markers were used to discriminate eight carrot genotypes with different root colors. With the combination of enzymes Tru9I, PstI, and three sets of primer pairs corresponding to adapters joint to the restricted sites, 92 loci were produced, including 60 polymorphic ones. Each of the three primer sets showed high efficiency, according to estimations of PIC (0.34, 0.34, and 0.41), D (0.36, 0.67, and 0.67), Rp (5.5, 11.3, and 15), and HE (0.32, 0.49, and 0.49). The genetic distances were calculated using values of Nei's coefficient. The most genetically similar were Chantenay Coeur Rouge and Colmar a Coeur Rouge at a distance of 0.12, whereas the most distant were Saint Valery and Purple Dragon at the highest distance of 0.34. Confirming its genetic identity, Purple Dragon and Gelber Goliath with purple and yellow roots were the most detached varieties from others at distances of 0.23–0.34 and 0.23–0.28, respectively. Male sterile Berlicum breeding accessions were well distinct from other orange-colored varieties at the highest distance of 0.30 from Deep Purple F1. Slight modifications including the facilitation of gel staining enables the wide use of the AFLP method for genetic diversity assessment in carrot breeding accessions. [ABSTRACT FROM AUTHOR]

The present study aimed to characterize the genetic structure of Artemisia eriantha Ten. and the diversity of the rhizosphere microbiota. Plant leaves and rhizosphere soils were sampled from three areas of Central Italy, namely Monte Corvo, Monte Portella (both from the Gran Sasso massif), and Monte Focalone (Majella massif). The plant samples were subjected to genetic structure analysis by amplified fragment length polymorphism (AFLP) markers. The microbiota from the rhizosphere soils was investigated by 16S rRNA gene metabarcoding. The within and among population variability was typical of outbreeding species. The AFLP polymorphisms revealed a marked closeness among plant populations collected in Monte Focalone and Monte Corvo, despite the geographical proximity of the latter with Monte Portella, a result confirmed by cluster, STRUCTURE, and discriminant analyses. 16S rRNA gene metabarcoding showed higher values of diversity for Monte Corvo (H, 5.7; Chao1, 445) and Monte Focalone (H′, 5.57; Chao1, 446) than Monte Portella (H′, 5.3; Chao1, 275). At the phylum level, the communities were mainly represented by Proteobacteria, Actinobacteria, and Acidobacteria (>10%). At the genus level, the Monte Focalone and Monte Corvo microbiotas were closer than Monte Portella, thus confirming the results from the plant communities. The findings provided evidence for the first time of an association between the Artemisia eriantha plant and microbiota communities. The relevance of the results in terms of biodiversity and the conservation strategies of plant and microbiota communities in the Central Apennines are discussed. [ABSTRACT FROM AUTHOR]

It is necessary to regard the biodiversity of carrot as a genetic source of useful and indispensable components for the human diet. Amplified fragment length polymorphism (AFLP) markers were used to discriminate eight carrot genotypes with different root colors. With the combination of enzymes Tru9I, PstI, and three sets of primer pairs corresponding to adapters joint to the restricted sites, 92 loci were produced, including 60 polymorphic ones. Each of the three primer sets showed high efficiency, according to estimations of PIC (0.34, 0.34, and 0.41), D (0.36, 0.67, and 0.67), Rp (5.5, 11.3, and 15), and HE (0.32, 0.49, and 0.49). The genetic distances were calculated using values of Nei’s coefficient. The most genetically similar were Chantenay Coeur Rouge and Colmar a Coeur Rouge at a distance of 0.12, whereas the most distant were Saint Valery and Purple Dragon at the highest distance of 0.34. Confirming its genetic identity, Purple Dragon and Gelber Goliath with purple and yellow roots were the most detached varieties from others at distances of 0.23–0.34 and 0.23–0.28, respectively. Male sterile Berlicum breeding accessions were well distinct from other orange-colored varieties at the highest distance of 0.30 from Deep Purple F1. Slight modifications including the facilitation of gel staining enables the wide use of the AFLP method for genetic diversity assessment in carrot breeding accessions.

Abstract Background In the present investigation, two genera of family Labiatae (genus Origanum and genus Thymus including their available species in Egypt) were analyzed genetically on DNA level using amplified fragment length polymorphism (AFLP) markers. Four selective primer combinations ( E-AGC/M-CAA, E-AGC/M-CAC, E-AGG/M-CTC, and E-ACC/M-CAT ) were used to detect genetic variations (polymorphisms) within and between the studied plant species of each genus and with their cultivated relatives. Results A total of 193 amplified fragments were obtained overall primer combinations with a disparity in the number of bands for each primer combination. The primer combination E-AGG/M-CTC exhibited a large number of amplicons (67) compared to the other primers with polymorphism percentage 69%. The polymorphism information content (PIC) was calculated for the four primer combinations showing a very high values ranging between 0.98 and 0.99. On the other hand, Thymus species (Thymus vulgaris, Thymus capitatus L., and Thymus decassatus Benth.) exhibited a total number of 171 amplicons for all primer combinations with an average of 42 bands. The primer combination E-AGG/M-CTC produced the largest number of bands (62 bands) with polymorphism percentage 35%, even though the primer combination AGC/M-CAA was more efficient to give high polymorphisms within Thymus species where it resulted in a total of 35 bands with polymorphism percentage 63%. The PIC values were calculated ranging from 0.96 to 0.99. Conclusion One can conclude that AFLP technique was informative and efficient technique to give a good coverage of Origanum and Thymus genomes. Furthermore, it was helpful to elucidate the genetic variations and phylogenetic relationships within the studied species as a basis for further studies on these genera and related species.

Abstract The genus Rubus, from the family ofRosaceae Juss, has about 750 species worldwide, of which 8 species and 5 hybrids have been reported from Iran. The present study was conducted to evaluate the genetic diversity of 21 populations of 6 species of Rubus from different parts of Golestan province using 9 AFLP primer combinations. Excel and Pop Gen software were used for data analysis. Similarity matrix and cluster analysis were used by PAST software. The dendrogram was plotted based on unweighted pair group method with arithmetic average (UPGMA), using Jaccard's similarity coefficient. The results showed that eight out of nine selected primer combinations had appropriate polymorphic primer combinations. M160-E110 with 0.203 had the highest genetic variation among all used markers. All selected primer combinations found 505 position and 277 loci locations. Based on the results of the dendrogram, the studied populations were divided into two groups. Based on the results of the dendrogram, the studied populations were divided into two groups and the Caspian-Irano-Turanian populations were partially separated from the Caspian populations. According to the results of correlation analysis, the highest number of markers were related to traits of petiole length, terminal leaflet length, lateral leaf length, inflorescence length, lateral leaf width, and peduncle length. Results showed that AFLP marker was highly efficient in the separation and isolation of populations of species of Rubus species in this study.

Persimmon (Diospyros kaki L.) belongs to the family Ebenaceae known as the Japanese persimmon kaki. This crop was introduced in the Highlands in Central and East Java-Indonesia. A genetic analysis of a small sample of accessions was conducted using the Amplified Fragment Length Polymorphism (AFLP) method with IRDye700 labelled Pst1 (P11-700) and Mse1 restriction enzymes and seven primers combinations (M48, M49, M50, M51, M53, M55, and M58). The analysis resulted in a set of 441 bands, of which 117 were monomorphic and 324 polymorphic. The average percentage of polymorphic bands was 73.4%. The four persimmon accessions were genetically distinguished into three groups, with a high genetic diversity among them, while accessions B (Batu) and D (Dampit) show little differences in their profiles. [ABSTRACT FROM AUTHOR]

Genetic marker studies can assist restoration practice through selection of seed sources that conserve historical levels of gene diversity and population genetic differentiation. We examined genetic variation and structure within and among mainland and island populations of Elymus glaucus, a perennial bunchgrass species native to western North American grasslands that is targeted for grassland restoration. Island populations of E. glaucus represent sensitive sites and potentially distinctive seed sources for reintroduction, and little is known of their genetic composition. Genetic diversity and structure were estimated using amplified fragment length polymorphism markers for 21 populations and 416 individuals distributed across two coastal California mainland locations and three California Channel Islands. Eight primer combinations resulted in 166 markers, of which 165 (99.4 %) were polymorphic. The number of polymorphic bands was significantly greater among mainland populations relative to island sites, and locally common alleles were present for each sampled island and mainland location. Population structure was high (62.9 %), with most variation (55.8 %) distributed among populations, 7.1 % between mainland and island locations, and the remainder (37.1 %) within populations. Isolation by distance was only apparent among islands. Using marker data to recommend appropriate seed sources for restoration, E. glaucus seeds are best derived within islands with collections representing a large number of individuals from matching environments. Given the limited gene flow and prior evidence of adaptive divergence among populations of this species, regional collections are recommended in all cases to maintain diversity and to avoid long-distance introductions of highly differentiated plant material.

Abstract Background The banana weevil Cosmopolites sordidus (Germar) is a major production constraint of bananas and plantains (Musa spp.) in the world. Differences in damage levels and pesticide response across regions led to the postulation that there might be considerable variation between banana weevil populations (biotypes) with varying levels of virulence. One of the most sustainable options for banana weevil control is the use of host plant resistance. While new resistant varieties are being developed through both conventional crossbreeding and biotechnology, there is a need to assess the genetic variation of banana weevil populations from eastern, central, southern, southwestern and midwest regions of Uganda to determine whether there are biotypes with different virulence levels. This would help guide new control strategies to target all the possible biotypes. The amplified fragment length polymorphism (AFLP) technique was used to analyze population genetic diversity using four primer combinations (EcoRI/MSeI). Results Analysis of molecular variance results presented no evidence to support significant genetic variability among the banana weevil populations from eastern, central, southern, southwestern and midwest regions. Practically, all the genetic variation was found to reside within populations (97% for sites and 98% for regions), with only approximately 3% and 2% residing among populations of sites and regions, respectively. Conclusions and recommendations AFLP markers clustered the banana weevils into two distinct populations consequently supporting the hypothesis of possible presence of banana weevil biotypes in Uganda. However, attempts should be made to make follow-up studies on the seemingly unique population of eastern Uganda using more robust molecular techniques to establish whether the eastern Uganda population constitutes a different biotype.

Pomegranate (Punica granatum L.) is native to Iran with several ecotypes which have been adapted to various climatic conditions and diseases. Although it is one of the important exported fruits, there is not a precise identification criteria to determine the authenticity of genetic inheritance and proprietary rights in the country. In the present study the genetic relationships of 47 pomegranate genotypes, including 9 cultivated genotypes (from the collection of Yazd) and 38 wild genotypes (from Mazandaran, Gilan and Golestan provinces), were investigated with AFLP markers. Using 10 primer combinations, 825 bands were obtained of which 697 showed polymorphism. Among the primers, primer combination of M-CTT and E-ACG showed the highest number of bands (148) and primer combination of E-ACC, M-CTG produced the lowest number of bands (40). The average value for PIC was 0.21, while Average Marker Index (MI) was 17.33 that the highest one belonged to primer combination of M-CAC and E-AAG. Maximum genetic similarity belonged to Bahnamir with Shirin Kan Tehran samples and the minimum genetic similarity observed between Berenjestanak and Khosh Darreh. Principal component analysis showed that 57% of the total variance was explained by first three components. The identified primer combinations in this study could be used as a powerful tool for determination of genetic relationships between Pomegranate genotypes

Xanthosoma sagittifolium (L.) Schott originated from the American tropics. Domestication may have occurred in various places as this Araceae species is an important food source. It has been cultivated for many decades. In this study, Amplified Fragments Length Polymorphism (AFLP) markers were used to analyze the genetic relationships among 78 Ethiopian X. sagittifolium accessions, for conservation purpose. Cormels were collected from Bench-Maji, Kefa, Dawuro and Wolaita zones, representing four populations. The accessions belonged to either green (G) or purple (P) colored leaf and petiole accessions. Three different AFLP primer combinations resulted in 478 scorable bands, of which 99.2% were polymorphic. The mean Nei’s gene diversity (He) within populations was 0.35 while the G accessions featured higher He (0.38) than the P ones (0.35). The Nei’s gene diversity (He) at entire collection level was 0.38. The detected high genetic diversity may indicate the X. sagittifolium plants growing in the country may derive from diverse parental genotype stock elsewhere and/or there may be multiple introductions to the country. Low levels of genetic differentiation were detected among populations (Gst = 0.07) and between the G and P accessions (Gst = 0.02). Insignificant genetic and geographic correlation was revealed by Mantel test. Clustering analysis grouped 91% of the accessions together. Conservation and management of X. sagittifolium in the country should concentrate on maintaining high level genetic diversity within each population as well as at entire collection level through both ex situ and in situ conservation actions. [ABSTRACT FROM AUTHOR]

Polygala tenuifolia Willd. is an important protected species used in traditional Chinese medicine. In the present study, amplified fragment length polymorphism (AFLP) markers were employed to characterize the genetic diversity in wild and cultivated P. tenuifolia populations. Twelve primer combinations of AFLP produced 310 unambiguous and repetitious bands. Among these bands, 261 (84.2%) were polymorphic. The genetic diversity was high at the species level: percentage of polymorphic loci (PPL) = 84.2%, Nei's gene diversity ( h ) = 0.3296 and Shannon's information index ( I ) = 0.4822. Between the two populations, the genetic differentiation of 0.1250 was low and the gene flow was relatively high, at 3.4989. The wild population (PPL = 81.9%, h = 0.3154, I = 0.4635) showed a higher genetic diversity level than the cultivated population (PPL = 63.9%, h = 0.2507, I = 0.3688). The results suggest that the major factors threatening the persistence of P. tenuifolia resources are ecological and human factors rather than genetic. These results will assist with the design of conservation and management programs, such as in natural habitat conservation, setting the excavation time interval for resource regeneration and the substitution of cultivated for wild plants. [ABSTRACT FROM AUTHOR]

Freshwater Pangasiid catfish species and hybrids are difficult to identify on the basis of morphological characteristics, especially for larvae and fingerlings. In this study, we identified genetic markers for Pangasiid catfish breeds, viz. Pagasianodon gigas, Pagasianodon hypophthalmus and their F1 and F 2 hybrids. Twenty primer comb inations were used to screen for specific amplified fragment length polymorphism (AFLP) markers. A total of 486 DNA bands were identified and 335 polymorphic bands were found to be segregated among these catfish types. The level of polymorphism detected using 20 different primer combinations ranged between 65.38-100%. Eleven distinct markers were found to be significantly associated with P. gigas (two markers), P. hypophthalmus (three markers), their F1 hybrid (three markers) and F2 hybrid (three markers). Using these markers, 100% of the individuals were accurately assigned to their correct species. These results demonstrate that AFLP markers can be used to genetically i dentify Pangasiid catfish species and hybrids.

According to the importance of studies of abiotic stress, present study was done in order to identify of molecular markers with significant association to flooding stress tolerance in barley. This study carried out using of AFLP markers and 40 barley genotypes. Generally 22 variables in both normal and flooded, eight characters including shoot dry weight, length, volume, wet weight, dry weight, leaf area, root diameter and density tolerance was assessed with six indicators (SSI, STI, GMP, TOL, YI and YSI). Seven primer combinations of EcoRI and MseI a total of 245 bands were produced, of which, 227 bands were polymorphic and had an average of 92.37 percent polymorphism. Three combinations E90-M160, E100-M160 and E90-M150 had higher values of genetic variation compared to other combinations and were more effective in distinguish of genotypes. Association analysis was performed using structure matrix and statistical models of GLM and MLM by using of TASSEL software for 22 variables. The MLM model in 5 percent probability level identified 87 markers related to evaluated traits. According to the results of association analysis in normal condition the highest of coefficient of determination was for E100M16027 with explanation of 32 percent of root diameter variation and for tolerance indices and stress condition the highest coefficient of determination were for E80M1501 and E100M15022 with 24 percent explanation of variation of GMP index and shoot dry weight respectively.

Background: Hypericum perforatum is one of the valuable medicinal plants in Iran that is used in treating human diseases likes mania, anxiety and depression. Objective : Iranian H. perforatum populations were gathered from deferent region of Iran and also their genetic diversity in company with the possible relationship between genetic diversity and geographical distribution were studied. Methodes: DNA was isolated by CTAB method from young leaves and double digested by EcoRI and Tru1I enzymes. Polymorphic DNA markers generated by DNA fingerprinting technique AFLP (Vos method) using 12 primers combinations. DNA fragments detected with silver nitrate staining according to Basam protocol. Results: Totally 235 bands were scored, that 97% of them were polymorphic. The PIC values ranged between 0.31 and 0.45 with mean of 0.38. The highest and the lowest levels of genetic similarity were 0.89 and 0.29, respectively. Cluster analysis using UPGMA method and DICE similarity coefficient indicated a high genetic diversity among H. perforatum populations. There was no relationship between genetic diversity and geographical distribution. Also for the all loci, the PC1 and PC2 explained 12.8% and 8.3% of the variation, respectively. Conclusion: Wide genetic diversity between Iranian H. perforatum pupulations provide applied information to performance of breeding programs and genetic resource management. Of course, investigation of amount of hypericin and hyperforin metabolites in these populations are requiring to selection paramount genotypes.

Traditionally, tetraploid Paspalum notatum was considered an obligate or a facultative apomict according to cytoembryological analyses. The degree of facultativeness was usually determined by the relative amount of mature ovules bearing aposporous or meiotic (sexual) embryo sacs, or both together. We established, through progeny tests conducted with the aid of AFLP markers, the degree of residual sexuality expressed in four selected biotypes. The results showed it to be substantially and significantly lower than predicted by previous embryological analyses for the same biotypes. Moreover, the lowest expression of residual sexuality was coincident with maximum flowering period. Seed development in facultative apomictic P. notatum shows a definite bias against meiotic embryo sacs.

An extremely endangered population of Viola uliginosa Besser at the classical locality of this taxon has been studied. The AFLP analysis was based on 18 specimens of V. uliginosa (about 10% of preserved individuals); additionally, two individuals of V. riviniana were included in the data set as the out group. A high genetical uniformity of the whole population (similarity indexes close to 1) was detected. It was not correlated significantly with the spatial distribution of the plants. The study serves as a basis for practical conservation measures and at the same time as a starting point for a more extensive research on the genetical variability of the species throughout its range.

The morphology of Calamagrostis canescens and C. stricta recorded in the Małopolska Upland (the vicinity of Zbijów Mały, ca. 10 km northeast of the town of Skarżysko-Kamienna, Central Poland) was examined due to intermediate individuals found in sympatric populations of these species. Both putative parents as well as individuals that appeared hybrid-like were found in an extensive, wet hay-meadow. Various vegetative and reproductive characteristics were studied to identify hybrids. Interestingly, Polish accessions of C. ×gracilescens exhibited some degree of morphological intermediacy but resembled C. stricta in spikelet morphology. Branching of the mid-culm, the number of nodes per culm, callus hair length and relative callus hair length are the best characters to distinguish the Polish C. ×gracilescens. AFLP analysis proved to be suitable for detecting recent hybridization events between C. canescens and C. stricta. Analysis of the Bayesian clustering analysis showed that C. ×gracilescens were subjected to gene flow from the C. canescens gene pool as well as from the C. stricta gene pool.

Viola uliginosa (bog violet) is a declining species throughout its range due to - mostly anthropogenic - drying out of the wet habitats it occupies. Using AFLP markers, we aimed to estimate the genetic diversity in Polish populations, that may give an insight into the situation of plant populations facing rapid loss of natural habitats. Bog violet from several dispersed Polish populations is generally characterized by very low genetic diversity ( HT = 0.048), even lower than several other endangered violets; therefore, we suggest that it should preserve at least EN rank in the red lists/red data books. The mean gene diversity within all populations ( HS) was much lower than gene diversity ( GST) between populations (0.020 versus 0.583, respectively) which supports the prevalence of clonal propagation of the species (mainly by stolons) but may also point to some significance of autogamy in cleisto- and chasmogamous flowers. A high FST value and the Mantel test for all populations revealed significant isolation by distance. Geographically neighboring pairs of populations formed genetic clusters supported by all (in the case of two closest populations) or most statistical analyses applied. Special attention should be paid to the locus classicus of the species in Rząska, consisting of a small number of individuals, forming a genetically distinct group, revealing very low gene diversity ( Hj = 0.009) and the longest genetic distance to the remaining populations. Our results can contribute to planning future protection measures for the species at this and other locations. Genetic structure of the studied populations suggests local affinities of populations but does not generally support hypothesized recent continuity of V. uliginosa range along the river valleys of southern Poland; this view may, however, be altered with widening of the scope of studied populations and chosen molecular markers. [ABSTRACT FROM AUTHOR]

The conservation of plants in germplasm banks ensures the characterization and availability of these resources for future generations. The present study used DNA markers to obtain genetic information about germplasm collections of Lippia sidoides and L. gracilis, which are maintained in an Active Germplasm Bank (AGB). Genetic variability of samples in the AGB was assessed using 12 combinations of ampliied fragment length polymorphism (AFLP) primers (EcoRI/MseI). Twenty simple sequence repeat primers designed for L. alba were tested to determine their transferability in L. sidoides and L. gracilis. The AFLP markers generated 789 markers. The assessed loci exhibited a moderate Shannon diversity index (I = 0.42) in both species, suggesting that the conserved accessions possess an intermediate level of genetic diversity. Twelve microsatellite loci ampliied satisfactorily, and nine loci were polymorphic in each species. A total of 23, 22, and 36 alleles, with an average of 2.5, 2.4, and 3.27 alleles per locus were identiied for L. sidoides and L. gracilis accessions in the AGB, and Lippia sp sampled plants, respectively. Analyses of genetic structure permitted the identiication of three different groups using both sets of markers, of which two were representative of L. sidoides. The information generated in this study may help to create, expand, and maintain collections of these species and may assist in genetic-breeding programs. [ABSTRACT FROM AUTHOR]

Genome size (or C-value) can present a wide range of values among eukaryotes. This variation has been attributed to differences in the amplification and deletion of different noncoding repetitive sequences, particularly transposable elements (TEs). TEs can be activated under different stress conditions such as interspecific hybridization events, as described for several species of animals and plants. These massive transposition episodes can lead to considerable genome expansions that could ultimately be involved in hybrid speciation processes. Here, we describe the effects of hybridization and introgression on genome size of Drosophila hybrids. We measured the genome size of two close Drosophila species, Drosophila buzzatii and Drosophila koepferae, their F1 offspring and the offspring from three generations of backcrossed hybrids; where mobilization of up to 28 different TEs was previously detected. We show that hybrid females indeed present a genome expansion, especially in the first backcross, which could likely be explained by transposition events. Hybrid males, which exhibit more variable C-values among individuals of the same generation, do not present an increased genome size. Thus, we demonstrate that the impact of hybridization on genome size can be detected through flow cytometry and is sex-dependent. [ABSTRACT FROM AUTHOR]

Com objetivo de estudar diversidade genética e identificar marcadores associados à resistência ao míldio (Plasmopara viticola) e ao oídio (Uncinula necator), foram analisadas as cultivares de videira A 1976, CG 87746, CNPUV 154-27, Crimson Seedless, Gota de Ouro, Itália, Seyve Villard 12327 e Seyve Villard 12375. As análises de polimorfismo de comprimento de fragmento amplificado (AFLP) seguiram as etapas de digestão, ligação, pré-amplificação e amplificação. Efetuou-se a separação dos fragmentos amplificados em gel de 7% de poliacrilamida desnaturante (uréia 7M) e coloração com nitrato de prata. A similaridade foi estimada com base no coeficiente de Jaccard, e a agregação, por UPGMA. Foi gerada uma matriz de similaridade com bom ajustamento da agregação (r = 0,84). Os agrupamentos obtidos corresponderam à origem e classificação botânica das cultivares. Foram identificadas 15 marcas dissimilares associadas à resistência, sendo oito para míldio e sete para oídio.The grapevine cultivars A 1976, CG 87746, CNPUV 154-27, Crimson Seedless, Gota de Ouro, Itália, Seyve Villard 12327 and Seyve Villard 12375 were analyzed to establish the genetic relationship and to identify markers associated with resistance to downy mildew (Plasmopara viticola) and powdery mildew (Uncinula necator). The amplified fragment lenght polymorphism (AFLP) analysis comprise the steps of digestion, ligation, preamplification and amplification. The amplified fragments were separeted on a 7% denaturing polyacrylamide gel (7M urea) and silver stained. The similarity was estimated using Jaccard's coefficient and the clustering was estimated by UPGMA. A similarity matrix was generated with a good fit for aggregation (r = 0,84). The clusters corresponded to origin and botany classification of the cultivars. Fifteen markers were associated with resistance, eight for downy mildew and seven for powdery mildew.

Background: Bhutan is a small Himalayan country lying within the region considered to be the origin of citrus. Diverse citrus wild types grow naturally in different climates, elevations and edaphic conditions, but only mandarin is cultivated commercially. The first report of Huanglongbing (also known as greening disease) in Bhutan in 2003, and the threat it posed to the country's citrus orchards prompted the collection of mandarin germplasm from across the country. This paper describes the genetic diversity of mandarin accessions in Bhutan using amplified fragment length polymorphic (AFLP) markers. Results: Twenty three accessions of Bhutanese mandarin were analyzed using AFLP markers to assess the genetic variability that is believed to exist only in Bhutan and some parts of North East India and South China. Five primer pairs (E-ACA/M-CAG, E-ACG/M-CAT, E-ACC/M-CTT, E-AAG/M-CAA and E-ACA/M-CTC) were identified (based on the number and quality of polymorphic bands produced) and used for the analyses. A total of 244 bands were scored visually of which 126 (52%) were polymorphic with an average polymorphism information content of 0.95 per marker. A cluster dendrogram based on multiscale bootstrap sampling categorized twenty three accessions into two broad groups containing eight and 14 accessions, respectively. Group A consisted accessions (Tsirang1, Tsirang3, Sarpang1, Dagana4, Samtse4, Dagana1, and Trongsa2) from five districts (Tsirang, Sarpang, Samtse, Dagana and Trongsa) and their grouping was strongly supported by bootstrap analysis (B p-value = 96%, AU p-value = 86%). Cluster B consisted of 14 accessions divided into three sub-groups (1, 2 and 3). However, bootstrap value supported significantly for subgroup1 (containing accessions: Tsirang4, Sarpang5, and Tsirang2) and subgroup3 (with accessions - Zhemgang2, Zhemgang3 and Zhemgang4). Conclusion: This study indicates that Bhutanese mandarin germplasm collected from across the country are genetically diverse although the level of variability differed among the accessions assessed. The variation in genetic variability was observed irrespective of where the accessions were collected suggesting that phenotype and geographical location can serve a basis for future germplasm collection in Bhutan. Further, five primer pair combinations could separate 23 mandarins accessions considered in this study, suggesting that AFLP markers can be a useful tool for future identification. [ABSTRACT FROM AUTHOR]

Background: Interspecific hybridization is a useful tool in ornamental breeding to increase genetic variability and introduce new valuable traits into existing cultivars. The successful formation of interspecific hybrids is frequently limited by the presence of pre- and post-fertilization barriers. In the present study, we investigated the nature of hybridization barriers occurring in crosses between Kalanchoë species and evaluated possibilities of obtaining interspecific hybrids. Results: The qualitative and quantitative analyses of pollen tube growth in situ were performed following intra- and interspecific pollinations. They revealed occurrence of pre-fertilization barriers associated with inhibition of pollen germination on the stigma and abnormal growth of pollen tubes. Unilateral incongruity related to differences in pistil length was also observed. The pollen quality was identified as a strong factor influencing the number of pollen tubes germinating in the stigma. In relation to post-fertilization barriers, endosperm degeneration was a probable barrier hampering production of interspecific hybrids. Moreover, our results demonstrate the relation of genetic distance estimated by AFLP marker analysis of hybridization partners with cross-compatibility of Kalanchoë species. At the same time, differences in ploidy did not influence the success of interspecific crosses. Conclusions: Our study presents the first comprehensive analysis of hybridization barriers occurring within Kalanchoë genus. Reproductive barriers were detected on both, pre- and post-fertilization levels. This new knowledge will contribute to further understanding of reproductive isolation of Kalanchoë species and facilitate breeding of new cultivars. For the first time, interspecific hybrids between K. nyikae as maternal plant and K. blossfeldiana as well as K. blossfeldiana and K. marnieriana were generated. [ABSTRACT FROM AUTHOR]

Out of the total accessions of cultivated barley, held at ICARDA, a subset core collection consisting of 153 accessions originating from different countries was established. Genetic diversity of the core collection was studied using AFLP markers. The accessions were grouped into different geographic sub-regions and the total genetic variation was estimated using Popgene software. Genetic distance matrix was computed and hierarchical unrooted tree was performed using Phylip software package. Our results demonstrate that the AFLP markers were highly informative and were useful in generating a meaningful classification of the cultivated barley that we determined as a subset of core collection.

Freshwater Pangasiid catfish species and hybrids are difficult to identify on the basis of morphological characteristics, especially for larvae and fingerlings. In this study, we identified genetic markers for Pangasiid catfish breeds, viz. Pagasianodon gigas, Pagasianodon hypophthalmus and their F1 and F2 hybrids. Twenty primer combinations were used to screen for specific amplified fragment length polymorphism (AFLP) markers. A total of 486 DNA bands were identified and 335 polymorphic bands were found to be segregated among these catfish types. The level of polymorphism detected using 20 different primer combinations ranged between 65.38-100%. Eleven distinct markers were found to be significantly associated with P. gigas (two markers), P. hypophthalmus (three markers), their F1 hybrid (three markers) and F2 hybrid (three markers). Using these markers, 100% of the individuals were accurately assigned to their correct species. These results demonstrate that AFLP markers can be used to genetically identify Pangasiid catfish species and hybrids. [ABSTRACT FROM AUTHOR]

Dendrobium is one of the largest genera in the Orchidaceae family. Information on the genetic diversity and relationships among species and hybrids is important for breeding purposes and species conservation. The objectives of this study were to assess genetic relatedness and to determine whether morphological, molecular, or combined analysis can discriminate among Dendrobium species, commercial hybrids, and interspecific hybrids. A total of 81 Dendrobium accessions were characterized with 12 amplified fragment length polymorphism (AFLP) primer pairs and 21 morphological characters. Mean genetic relatedness for morphological characters, AFLP analysis, and combined analysis were 0.61, 0.37, and 0.43, respectively. Dendrograms were generated using an unweighted pair group method with arithmetic averages (UPGMA); the analysis was performed on a Jaccard similarity coefficient matrix. The data from morphological characters revealed that the Jaccard similarity coefficient ranged from 0.20 to 1.0, where the tested 81 Dendrobium accessions could be grouped into four clusters. For the AFLP analysis, the number of polymorphic fragments for each primer varied from 80 to 284 with 78% average percentage of polymorphic loci and the similarity coefficient ranging from 0.125 to 1.0 with Dendrobium accessions grouped into three clusters. The similarity coefficients estimated through a combined analysis of morphological and AFLP data ranged from 0.21 to 1.0 and the Dendrobium accessions appeared clustered into two groups. The results revealed some similarities among the three data sets. The combined data set was the most useful in discriminating Dendrobium accessions based on species sections and relationship among species and their hybrids. The correlation between the AFLP data and the combined data was highly significant (r = 0.98, P > 0.001), indicating the usefulness of AFLP data for species discrimination and hybrid identity in the absence of floral morphological characters. [ABSTRACT FROM AUTHOR]

To date, different studies about the genetic basis of hybrid male sterility (HMS), a postzygotic reproductive barrier thoroughly investigated using Drosophila species, have demonstrated that no single major gene can produce hybrid sterility without the cooperation of several genetic factors. Early work using hybrids between Drosophila koepferae (Dk) and Drosophila buzzatii (Db) was consistent with the idea that HMS requires the cooperation of several genetic factors, supporting a polygenic threshold (PT) model. Here we present a genome-wide mapping strategy to test the PT model, analyzing serially backcrossed fertile and sterile males in which the Dk genome was introgressed into the Db background. We identified 32 Dk-specific markers significantly associated with hybrid sterility. Our results demonstrate 1) a strong correlation between the number of segregated sterility markers and males’ degree of sterility, 2) the exchangeability among markers, 3) their tendency to cluster into low-recombining chromosomal regions, and 4) the requirement for a minimum number (threshold) of markers to elicit sterility. Although our findings do not contradict a role for occasional major hybrid-sterility genes, they conform more to the view that HMS primarily evolves by the cumulative action of many interacting genes of minor effect in a complex PT architecture. [ABSTRACT FROM AUTHOR]

The understanding of the genetic diversity and structure of populations of Jatropha curcas in their postulated centre of origin will permit to identify genetic material useful for future improvement of the species. Although it is estimated that Mexico is the likely centre of origin and domestication of J. curcas, so far the “true” centre of origin still has to be found. A representative set of 175 accessions of J. curcas from nine central and southeastern Mexican states (Chiapas, Veracruz, Oaxaca, Michoacán, Morelos, Yucatán, Guerrero, Hidalgo and Puebla), including toxic, non-toxic, and contrasting protein and oil content genotypes was used for diversity analysis by AFLP markers. The results indicate that Mexico has a high genetic diversity of J. curcas; molecular analysis suggests population structuring in the different states where this species is spread. The germplasm from Chiapas, where contrasting protein and oil content genotypes were detected, showed the highest genetic diversity and clearly varies from the accessions from the other states. This is probably the most comprehensive study of diversity of germplasm of J. curcas from Mexico, and together with previous reports on the genetic diversity, biochemistry, morphology and germplasm agronomics of J. curcas from Chiapas, suggest the likelihood that this area is the centre of origin for this species and that domestication took place in the states bordering the Gulf of Mexico, such as Veracruz, Hidalgo, Puebla and Yucatán, where genotypes with low or no phorbol ester content exist. [ABSTRACT FROM AUTHOR]

Backgound and Aims Extending the cultivation of forage legume species into regions where they are close to the margin of their natural distribution requires knowledge of population responses to environmental stresses. This study was conducted at three north European sites (Iceland, Sweden and the UK) using AFLP markers to analyse changes in genetic structure over time in two population types of red and white clover (Trifolium pratense and T. repens, respectively): (1) standard commercial varieties; (2) wide genetic base (WGB) composite populations constructed from many commercial varieties plus unselected material obtained from germplasm collections. Methods At each site populations were grown in field plots, then randomly sampled after 3–5 years to obtain survivor populations. AFLP markers were used to calculate genetic differentiation within and between original and survivor populations. Key Results No consistent changes in average genetic diversity were observed between original and survivor populations. In both species the original varieties were always genetically distinct from each other. Significant genetic shift was observed in the white clover ‘Ramona’ grown in Sweden. The WGB original populations were more genetically similar. However, genetic differentiation occurred between original and survivor WGB germplasm in both species, particularly in Sweden. Regression of climatic data with genetic differentiation showed that low autumn temperature was the best predictor. Within the set of cold sites the highest level of genetic shift in populations was observed in Sweden. Conclusions The results suggest that changes in population structure can occur within a short time span in forage legumes, resulting in the rapid formation of distinct survivor populations in environmentally challenging sites. [ABSTRACT FROM AUTHOR]

A collection of 168 Cochliobolus miyabeanus isolates was made from cultivated wildrice ( Zizania palustris) paddies in Minnesota, USA, during 2007 and 2008. Analysis of 26 polymorphic amplified fragment length polymorphism (AFLP) markers generated with three primer-pair combinations indicated a moderate average gene diversity () of 0·283. Genotypic diversity was high in all collection areas with the exception of a paddy in Itasca County. Significant population subdivision by collection site was found with amova tests using both the entire fungal population data ( FST = 0·29, P < 0·001) and the clone-corrected data ( FST = 0·08, P < 0·001), and with a Markov chain Monte Carlo approach. Abundant immigrants, shared haplotypes and admixed genotypes were found in paddies in central-eastern areas. Although indirect tests did not support the hypothesis of random mating at the subpopulation level, sexual recombination nevertheless may be possible in areas where both mating type idiomorphs, MAT1-1 and MAT1-2, were found. These results may have implications in breeding for resistance and disease management. [ABSTRACT FROM AUTHOR]

Background and Aims The Mediterranean Basin is one of the most important regions for the Earth's plant biodiversity; however, the scarcity of studies on fine scale patterns of genetic variation in this region is striking. Here, an assessment is made of the spatial genetic structure of all known locations of the three Sardinian endemic species of Aquilegia in order to determine the relative roles of gene flow and genetic drift as underlying evolutionary forces canalizing the divergence of Sardinian Aquilegia taxa, and to see if the spatial genetic structure found fits the current taxonomic differentiation of these taxa. Methods DNA from 89 individuals from all known locations of Aquilegia across Sardinia was analysed by means of amplified fragment length polymorphism (AFLP) markers. Both principal co-ordinates analysis (PCoA) and Bayesian clustering analyses were used to determine the spatial genetic structure irrespective of any taxonomic affiliation. Historical effects of gene flow and genetic drift were assessed by checking for the existence of isolation-by-distance patterns. Key Results STRUCTURE and PCoA analyses revealed a pattern of genetic variation geographically structured into four spatial genetic groups. No migration–drift equilibrium was detected for Aquilegia in Sardinia, when analysed either as a whole or in individual groups. The scenario approached a Case III pattern sensu Hutchinson and Templeton, which is associated with extreme isolation conditions where genetic drift has historically played a dominant role over gene flow. Conclusions The pattern of genetic variation of Sardinian taxa of Aquilegia indicates that genetic drift has been historically more influential than gene flow on population structure of Sardinian species of Aquilegia. Limited seed dispersal and divergent selection imposed by habitat conditions have been probably the main causes reinforcing post-Pleistocene geographical isolation of Aquilegia populations. The spatial genetic structure found here is not fully compatible with current taxonomic affiliations of Sardinian Aquilegia taxa. This is probably a consequence of the uncoupling between morphological and genetic patterns of differentiation frequently found in recently radiated taxa. [ABSTRACT FROM PUBLISHER]

Adaptive processes in invasive plant populations may explain exotic range expansions and ecotypic shifts between native and invasive populations of the same species. Sufficient genetic variation in invasive populations occurring within the new range is a precondition for selection. While genetic diversity can be considerably reduced during invasions following founder effects and genetic drift, it can also be maintained via mechanisms of effective gene flow. Rhododendron ponticum L., an aggressive invader in the British Isles, is an appropriate test species for investigating changes in genetic diversity and differentiation. Six native populations in Georgia and Spain each and six invasive populations in Ireland were analyzed with amplified fragment length polymorphism markers to calculate genetic distances, genetic diversity, and differentiation within and among populations. While the highest level of genetic diversity was found within native Georgian populations, thus indicating a refugium, native Spanish and invasive Irish populations showed reduced levels of genetic diversity but displayed no further reduction in the invasive range. Genetic differentiation within countries was weak. Spanish and Irish populations showed close relationships supporting a probable Spanish provenance for the invasive Rhododendron. We suggest that the preservation of sufficient genetic variation in invasive R. ponticum populations in Ireland has been vital to the species' adaptation to new environmental conditions. [ABSTRACT FROM AUTHOR]

Drought stress is one of the most important environmental factors that limit plant growth and development, thus reducing yield. The objective of the present research was to correlate the genetic structure of different Fragaria genotypes, as assessed by Expressed Sequence Tag (EST) and Amplified Fragment Length Polymorphism (AFLP) markers, and plant responses to drought stress. Firstly, physiological parameters related to the plant response to drought stress such as leaf relative water content (RWC) and water losing rate (WLR) were measured. WLR and RWC were compared for 20 cultivars of the octaploid Fragaria × ananassa, two ecotypes of the diploid species F. vesca and one octaploid species F. chiloensis. These parameters could discriminate genotypes showing a contrasting response to water stress. Secondly, AFLP and ESTs were compared in terms of their information content and efficiency in the study of genetic diversity and relationships among these 23 Fragaria genotypes. To evaluate the genetic basis for the observed variation in the measured physiological parameter, the effect of specific AFLP/EST loci on WLR and RWC for the different Fragaria genotypes was quantified by Kruskal-Wallis analysis. By Mantel testing, the hierarchical clustering of the Fragaria genotypes based on associated EST or AFLP markers was compared to the observed eco-physiological relevant grouping. A better discriminating capacity for associated markers was noted, enabling a functional marker selection approach to screen the strawberry gene pool for drought tolerance. Correlation of EST markers to leaf RWC and WLR enforces them as potential candidate genes in control of plant responses to drought stress in Fragaria sp. [ABSTRACT FROM AUTHOR]

Traditionally, tetraploid Paspalum notatum was considered an obligate or a facultative apomict according to cytoembryological analyses. The degree of facultativeness was usually determined by the relative amount of mature ovules bearing aposporous or meiotic (sexual) embryo sacs, or both together. We established, through progeny tests conducted with the aid of AFLP markers, the degree of residual sexuality expressed in four selected biotypes. The results showed it to be substantially and significantly lower than predicted by previous embryological analyses for the same biotypes. Moreover, the lowest expression of residual sexuality was coincident with maximum flowering period. Seed development in facultative apomictic P. notatum shows a definite bias against meiotic embryo sacs. [ABSTRACT FROM AUTHOR]

Sunflower is one of the major annual world crops grown for edible oil and its meal is a potential source of protein for human consumption. It contains tocopherol that decreases potential risk of chronic diseases in human. The objectives of the current research are to assess the genetic variability and to identify AFLP markers and candidate genes associated with seed-quality traits under well-irrigated and water-stressed conditions in gamma-induced mutants of sunflower. Two mutant lines, M8-826-2-1 and M8-39-2-1, with significant increased level of oleic acid were identified that can be used in breeding programs for quality increase high oxidative stability and heart-healthy properties. The significant increased level of tocopherol in mutant lines, M8-862-1N1 and M8-641-2-1, is justified by observed polymorphism for tocopherol pathway-related gene; MCT. The most important marker for total tocopherol content is E33M50_16 which explains 33.9% of phenotypic variance. One of the most important candidate genes involving fatty acid biosynthesis, FAD2 ( FAD2- 1), is linked to oleic and linoleic acids content and explained more than 53% of phenotypic variance. Common markers associated with different seed-quality traits in well-irrigated and water-stressed conditions could be used for marker-assisted selection (MAS) in both conditions. Other markers, which are specific for one condition whereas linked to different traits or specific for a trait, could be useful for a given water treatment. [ABSTRACT FROM AUTHOR]

Clonal herbs are an important feature of the understorey of Amazonian forests. However, little is known about the environmental drivers determining the population genetics of these herbs and about the spatial scale of gene flow. With amplified fragment length polymorphism markers, we analysed the clonal diversity and genetic structure of a clonal Amazonian herb ( Heliconia metallica) in south-eastern Peru at two spatial scales. First, we sampled leaves in 24 patches differing in flooding frequency and canopy openness in 2 km of a floodplain forest, and second in 21 riverine populations from the Andean foothills to the Amazon lowlands along a 550-km stretch of river. At the small spatial scale in the floodplain forest, the clonal diversity of H. metallica was higher at flooded than at non-flooded sites, but clonal diversity did not increase with canopy openness. At the large spatial scale, clonal diversity was very low in riverine populations at up- and downriver sites, suggesting that seedling recruitment was higher at mid-altitudes where the flooding intensity is intermediate. Genetic diversity of riverine populations monotonously increased downriver, indicating unidirectional gene flow mediated by hydrochory. Genetic differentiation among riverine populations was very low ( F = 0.06) and followed an isolation-by-distance pattern, indicating a stepping-stone type of gene flow by seeds. Despite the much smaller spatial scale, genetic differentiation among patches in the floodplain forest was higher ( F = 0.16), due to spatially restricted gene flow in the forest understorey. Synthesis. The genetic structure of H. metallica is the result of seedling recruitment being largely limited to flooded sites and of hydrochoric seed dispersal between populations growing on riverbanks. We conclude that river dynamics are the major determinant of the genetic structure of Amazonian plants and that largely undisturbed river systems, such as the Amazon, provide a crucial vector for gene flow, even at large spatial scales. [ABSTRACT FROM AUTHOR]

Abstract: Grasspea is an interesting crop for rational crop rotations in inner areas of the Marche region. However, breeding efforts are needed to improve its agronomic performance and to lower as much as possible the neuro-active amino acid β-ODAP in the seeds. Since the year 2000, a germplasm collection and evaluation program has been carried out. Accessions were evaluated by field trials for morphological, physiological and agronomic traits and for seed β-ODAP content. Significant variability was detected. In particular, populations collected in local farms showed a higher seed production compared with unadapted accessions. β-ODAP content varied between 0.26% and 0.53%. Moreover, AFLP molecular markers were applied to investigate genetic variation characterizing the populations included in the collection. In the year 2008 a breeding plan was started using two household populations, one with the lowest average β-ODAP content and one with the highest agronomic performance. Based on these results, a within population analysis for this trait will be started using the accession with the lowest β-ODAP content. Interesting information was also gathered using AFLP molecular markers, since a wide range of genetic variation supported the possibility of starting a mapping project aimed at the identification of genes of the biochemical pathway for β-ODAP. [Copyright &y& Elsevier]

Realizing the inconsistencies that exist in the extent and nature of differentiation in the Withania somnifera genetic resources in India, the 21 cultivated and wild accessions, and the two hybrids (cultivated × wild accessions and vice versa) were investigated for morphological, cytogenetical, chemical profiling, and crossability features. Their nuclear and chloroplast genomes were also assayed at the nucleotide sequence level, and by use of DNA markers. Chloroplast DNA diversity and somatic chromosome number (2 n = 48) were not helpful in identifying the differences. Other approaches, on the other hand, especially restriction endonuclease digests, types and sequence length composition of ITS 1 and ITS 2 of nuclear ribosomal DNA, AFLP fingerprinting, and crossability barriers unambiguously provided startling discrete differences between the cultivated and wild accessions, indicating a clear division of W. somnifera into two distinct lineages. These data, therefore, are indicative of the fact that because of the unique characteristics of its nuclear genome, and strong crossability barriers vis-à-vis wild accessions of W. somnifera, the cultivated accessions should be relegated to the rank of the separate species, W. ashwagandha. [ABSTRACT FROM AUTHOR]

The article discusses a study that was conducted to identify quantitative trait loci (QTL) for economically important traits in the silkworm, Bombyx mori. It is stated that 159 amplified fragment length polymorphism (AFLP) markers were assigned to 24 linkage groups of 78 F[2] progenies of silkworm, of which 21 AFLP were identified. It further states that QTL is controlled by under, additive, partial and over dominance.

The genetic relationship among cassumunar gingers (Zingiber cassumunar) in Thailand was assessed by amplified fragment length polymorphism (AFLP). Twelve AFLP primer combinations generated a total of 309 fragments, of which, 242 bands were polymorphic with an average of 20.2 bands per primer pair. Genetic similarities were obtained using Jaccard similarity coefficients, and a phylogenetic tree was constructed using the UPGMA clustering method. Pairwise similarity estimated between cassumunar gingers ranged from 0.7644 to 1.00 with an average of 0.879. Cluster analysis divided the samples into five groups with a high co-phenetic correlation value (r = 0.99). Genetic variability within and among collection regions was estimated by analysis of molecular variance (AMOVA). High molecular variance (84%) was found within samples from the same region. The results implied dispersal of plant materials between collection regions. The genetic similarity assessed by AFLP showed that there are duplicate accessions in the germplasm collection. This genetic information is very useful for germplasm maintenance and a crop improvement program. [ABSTRACT FROM AUTHOR]

Iron deficiency chlorosis (IDC) is a major problem reducing yield of mungbean in many countries. In this study, we crossed “KPS1”, the most popular Thai mungbean cultivar susceptible to IDC with “NM10-12”, a mungbean line from Pakistan resistant to IDC. Segregation analysis of the F population revealed that the resistance is controlled by a major gene ( IR) with dominant effect. Two AFLP markers, E-ACT/M-CTA and E-ACC/M-CTG were identified closely linking with the IR gene. The frequencies of these markers were assessed in 241 mungbean accessions from several countries. The accessions could be divided, in relative to total chlorophyll content of the resistant check (NM10-12) and the susceptible check (KPS1), into the resistant group with 125 accessions and the susceptible group with 116 accessions. Among 125 resistant accessions, E-ACT/M-CTA and E-ACC/M-CTG were present in 119 (95%) and 109 (87%) accessions, respectively. Both markers can identify all resistant accessions from England, Indonesia and Pakistan, but only E-ACT/M-CTA linked to all resistant accessions from Australia, India, Iraq, Taiwan and Thailand. Understanding the inheritance and identifying molecular markers linking to the IR gene can help plant breeders to improve this crop for growing in iron-deficient soils. [ABSTRACT FROM AUTHOR]

A protocol for the induction of regeneration from leaves of Helichrysum italicum was established. Calli were found to form on the basal medium only when it was supplemented with thidiazuron (TDZ) alone or in combination with naphthalene acetic acid (NAA), with a percentage ranking of at least 80%. The hormone-free medium showed the highest percentage of shoot regeneration (62%) even though no callus formed. AFLP markers were employed to verify tissue culture-induced variation in the regenerated plantlets obtained by direct shoot regeneration or the indirect shoot regeneration process (callus formation). Seven out of the eleven AFLP primer pairs yielded polymorphic patterns. The average number of fragments per primer pair was 64.1. Singletons were represented by 12 (2.7%) fragments. Student’s T-test was performed both on the average number of shared fragments and on the nucleotide diversity, and no significant statistical difference was observed between the two regeneration treatments. [ABSTRACT FROM AUTHOR]

Background and Aims: In the sexually deceptive Ophrys genus, species isolation is generally considered ethological and occurs via different, specific pollinators, but there are cases in which Ophrys species can share a common pollinator and differ in pollen placement on the body of the insect. In that condition, species are expected to be reproductively isolated through a pre-mating mechanical barrier. Here, the relative contribution of pre- vs. post-mating barriers to gene flow among two Ophrys species that share a common pollinator and can occur in sympatry is studied. [ABSTRACT FROM PUBLISHER]