Cophenetic Correlation Values Research Articles

Genetic Diversity of Common Bean (Phaseolus vulgaris L.) Landraces Based on Morphological Traits and Molecular Markers.

The objective of this study was to evaluate the genetic diversity among traditional common bean accessions through morphological descriptors and molecular markers. Sixty-seven common bean accessions from the Germplasm bank of the Instituto Federal of Espírito Santo-Campus de Alegre were evaluated. For this, 25 specific morphological descriptors were used, namely 12 quantitative and 13 qualitative ones. A diversity analysis based on morphological descriptors was carried out using the Gower algorithm. For molecular characterization, 23 ISSR primers were used to estimate dissimilarity using the Jaccard Index. Based on the dendrograms obtained by the UPGMA method, for morphological and molecular characterization, high genetic variability was observed between the common bean genotypes studied, evidenced by cophenetic correlation values in the order of 0.99, indicating an accurate representation of the dissimilarity matrix by the UPGMA clustering. In the morphological characterization, high phenotypic diversity was observed between the accessions, with grains of different shapes, colors, and sizes, and the accessions were grouped into nine distinct groups. Molecular characterization was efficient in separating the genotypes in the Andean and Mesoamerican groups, with the 23 ISSR primers studied generating an average of 6.35 polymorphic bands. The work identified divergent accessions that can serve different market niches, which can be indicated as parents to form breeding programs in order to obtain progenies with high genetic variability.

Sequence-related Amplified Polymorphism and Target Region Amplification Polymorphism Markers-based Profiling of Sodium Azide and Ethyl Methanesulfonate-derived Black Rot-resistant Dendrobium sp. ‘Earsakul’ Mutants from In Vitro Mutagenesis and Selection

To reveal the applicability of sequence-related amplified polymorphism (SRAP) and target region amplification polymorphism (TRAP) markers to mutant genotyping and marker identification for resistance to black rot (Phytophthora palmivora) in orchids (Dendrobium sp. ‘Earsakul’), we fingerprinted four nonmutagenized controls and 12 black rot-resistant mutants obtained with in vitro sodium azide (NaN3) and ethyl methanesulfonate (EMS) mutagenesis and in vitro selection using culture filtrate of P. palmivora. Each of the 20 SRAP and TRAP primer combinations yielded 375 and 384 scorable DNA bands, respectively, of which 94 (24.42%) and 88 (22.91%) were polymorphic, respectively. Mantel’s test cophenetic correlation coefficients of SRAP, TRAP, and SRAP/TRAP were 0.750, 0.921, and 0.861, respectively, indicating the efficiency of these markers, especially TRAP and SRAP/TRAP, for Dendrobium sp. ‘Earsakul’ mutant characterization. Moreover, the correlations between the matrices of cophenetic correlation values for the dendrograms of SRAP with TRAP, SRAP with SRAP/TRAP, and TRAP with SRAP/TRAP were 0.399, 0.566, and 0.793, respectively, and the dendrograms based on SRAP vs. TRAP and SRAP vs. SRAP/TRAP, with lower correlations, had more variations, i.e., the number of clusters, the members of clusters, and the placement of the materials, than the ones based on TRAP vs. SRAP/TRAP. Among the three dendrograms, all nonmutagenized controls were clustered together, whereas all the highly resistant and the most resistant mutants were distributed separately as individuals. Interestingly, the four SRAP and TRAP markers were significantly associated with black rot resistance. Overall, our results will be useful for facilitating future Dendrobium sp. ‘Earsakul’ breeding programs.

PERBANDINGAN METODE ANALISIS CLUSTER HIRARKI PADA DATA MARGIN PERDAGANGAN DAN PENGANGKUTAN (MPP) KOMODITAS STRATEGIS DI INDONESIA

Trade and Transport Margins is the difference between the sales value and th e purchase value of the commodity as compensation for the trader who is the distributor of the commodity. The higher Trade and Transport Margins indicates the longer and less efficient distribution pattern, so that it can harm producers and consumers. Data is taken from the 2020 Poldis survey with strategic commodities of Rice, Eggs, Sugar, and Cooking Oil. The value of the National Trade and Transport Margins in 2020 for rice and sugar has decreased but is not followed by an increasing number of provincial Trade and Transport Margins which have decreased. It is necessary to conduct an analysis to determine the characteristics of commodities in each province, hierarchical cluster analysis by comparing the application of the average, complete, single, ward's, and centroid methods to obtain the best method. Based on the results of hierarchical cluster analysis for all methods, then compared the cophenetic correlation values ​​ and the highest correlation on the average method with a correlation of 0.8318939. Then cluster profiling was carried out using the average method, it was concluded that Cluster 1 was dominated by low Trade and Transport Margins for all commodities, so that the distribution pattern of all commodities was efficient in 28 provinces in Indonesia. Cluster 2 has the characteristics of high Trade and Transport Margins of Rice and Cooking Oil as well as eggs and moderate sugar, so the distribution pattern is still not efficient for rice and cooking oil commodities in 4 provinces in Indonesia. Cluster 3 has the characteristics of high Trade and Transport Margins of eggs and sugar as well as medium of rice and cooking oil, so the distribution pattern is still not efficient for eggs and sugar in 2 provinces in Indonesia. Based on the results of the cluster analysis, it is hoped that it can be used as a reference in formulating and establishing policies as an effort to reduce the Trade and Transport Margins value of strategic commodities in provinces in clusters 2 and 3 according to the conditions of commodity characteristics so that the distribution pattern of strategic commodities becomes more efficient.

Pengelompokan Kabupaten/Kota Berdasarkan Produksi Tanaman Pangan Sumatera Utara Tahun 2020 Menggunakan Pengelompokan Hirarki Aglomeratif

Food plants are one of the basic needs of humans as a source of energy because they contain carbohydrates and proteins that are important for the human body. North Sumatra is one of the provinces in Indonesia, known for high potential in the agricultural sector, such as food crops. However, each district/city has a very diverse amount of food crop production in North Sumatra, so it is necessary to grouping in districts/cities based on the high and low of food crop production commodities in North Sumatra with the aim of assisting government in improving and optimizing government programs that engaged in agriculture. The grouping used agglomerative hierarchical cluster analysis methods, namely single linkage, average linkage, complete linkage, ward's, and centroid methods. Based on the highest cophenetic correlation value (close to 1), it was found that average linkage was the best cluster method. The results of this study that North Sumatra Province is divided into 4 clusters, consisting of regencies/cities, which can be seen from each food crop production in the very high category, the production of food crops in the high category, the production of food crops in the low category, and the production of food crops in the very low category.

GENETIC DIVERSITY OF S3 MAIZE GENOTYPES RESISTANT TO DOWNY MILDEW BASED ON SSR MARKERS

The compulsory requirement for releasing new high yielding maize varieties is resistance to downy mildew. The study aimed to determine the level of homozygosity, genetic diversity, and genetic distance of 30 S3 genotypes of maize. Number of primers to be used were 30 polymorphic SSR loci which are distributed over the entire maize genomes. The S3 genotypes used were resistant to downy mildew with homozygosity level of >80%, genetic distance between the test and tester strains >0.7, and anthesis silking interval (ASI) between inbred lines and tester lines was maximum 3 days. The results showed that 30 SSR primers used were spread evenly across the maize genomes which were manifested in the representation of SSR loci on each chromosome of a total of 10 chromosomes. The levels of polymorphism ranged from 0.13 to 0.78, an average of 0.51, and the number of alleles ranged from 2 to 8 alleles per SSR locus, an average of 4 alleles per SSR locus. The size of nucleotides in each locus also varied from 70 to 553 bp. Cophenetic correlation value (r) at 0.67 indicated that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was less reliable for differentiating genotypes in five groups. Of the total of 30 genotypes analyzed, 17 genotypes had homozygosity level of >80% so it can be included in the hybrid assembly program.

GENETIC DIVERSITY OF S3 MAIZE GENOTYPES RESISTANT TO DOWNY MILDEW BASED ON SSR MARKERS

The compulsory requirement for releasing new high yielding maize varieties is resistance to downy mildew. The study aimed to determine the level of homozygosity, genetic diversity, and genetic distance of 30 S3 genotypes of maize. Number of primers to be used were 30 polymorphic SSR loci which are distributed over the entire maize genomes. The S3 genotypes used were resistant to downy mildew with homozygosity level of >80%, genetic distance between the test and tester strains >0.7, and anthesis silking interval (ASI) between inbred lines and tester lines was maximum 3 days. The results showed that 30 SSR primers used were spread evenly across the maize genomes which were manifested in the representation of SSR loci on each chromosome of a total of 10 chromosomes. The levels of polymorphism ranged from 0.13 to 0.78, an average of 0.51, and the number of alleles ranged from 2 to 8 alleles per SSR locus, an average of 4 alleles per SSR locus. The size of nucleotides in each locus also varied from 70 to 553 bp. Cophenetic correlation value (r) at 0.67 indicated that the Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) was less reliable for differentiating genotypes in five groups. Of the total of 30 genotypes analyzed, 17 genotypes had homozygosity level of >80% so it can be included in the hybrid assembly program.

Genetic diversity and population structure analyses of Morinda tomentosa Heyne, with neutral and gene based markers

Morinda tomentosa Heyne (Rubiaceae) an evergreen small tree also known as Aal or Indian Mulberry or Nunaa has broad range of therapeutic and nutritional value and is broadly used for making morindone dye for the dyeing of silk, cotton and wool. This is the first report wherein twenty genotypes of M. tomentosa, an underutilized fruit plant collected from Madhya Pradesh, India were studied for genetic diversity analyses using 131 Start Codon Targeted Markers (SCoT) (gene based) and 97 Random Amplified Polymorphic DNA (RAPD) and 70 Inter Simple Sequence Repeat (ISSR) (neutral) markers. SCoT markers showed the highest level of polymorphism, Shannon’s Information Index and Polymorphism Information Content (70.23 %; 0.31 ± 0.27; 0.189 ± 0.103), while the total number of bands per primer (7.0) was highest for ISSR markers. Nei’s gene diversity (0.20) was found similar for both ISSR and SCoT markers. And geographical clustering was most pronounced with ISSR followed by SCoT and RAPD markers. Cumulative marker data revealed best clustering of genotypes based on their areas of the collection. And individually, our results showed the efficacy of both SCoT and ISSR (co-phenetic correlation values of 0.79 and 0.76 respectively) over RAPD (co-phenetic correlation value of 0.69) markers for genetic diversity and geographical patterning studies of M. tomentosa. Additionally, structure analysis grouped the twenty M. tomentosa genotypes into two sub-populations, this structuring and the identified markers can be utilized for making further strategies for collection and conservation of M. tomentosa from Madhya Pradesh and other states of India as well as for global collections.

Comparative analysis of DNA polymorphisms and phylogenetic relationships among Syzygium cumini Skeels based on phenotypic characters and RAPD technique.

The Indian black berry (Syzygium cumini Skeels) has a great nutraceutical and medicinal properties. As in other fruit crops, the fruit characteristics are important attributes for differentiation were also determined for different accessions of S. cumini. The fruit weight, length, breadth, length: breadth ratio, pulp weight, pulp content, seed weight and pulp: seed ratio significantly varied in different accessions. Molecular characterization was carried out using PCR based RAPD technique. Out of 80 RAPD primers, only 18 primers produced stable polymorphisms that were used to examine the phylogenetic relationship. A sum of 207 loci were generated out of which 201 loci found polymorphic. The average genetic dissimilarity was 97 per cent among jamun accessions. The phylogenetic relationship was also determined by principal coordinates analysis (PCoA) that explained 46.95 per cent cumulative variance. The two-dimensional PCoA analysis showed grouping of the different accessions that were plotted into four sub-plots, representing clustering of accessions. The UPGMA (r = 0.967) and NJ (r = 0.987) dendrogram constructed based on the dissimilarity matrix revealed a good degree of fit with the cophenetic correlation value. The dendrogram grouped the accessions into three main clusters according to their eco-geographical regions which given useful insight into their phylogenetic relationships.

Cladistic analysis of Egyptian horse flies (Diptera: Tabanidae) based on morphological data

The family Tabanidae is one of the important families of superfamily Tabanoidea, having medical and veterinary importance. In Egypt, there is no strict cladistic approach on tabanid flies phylogeny yet. The 20 available Egyptian tabanids under 2 subfamilies are analyzed cladistically. Cladistic analysis is based on 91 morphological characters depending on Single linkage, UPGMA, Complete linkage clustering methods (Cophenetic correlation value). This produces a well-resolved and firmly supported phylogenetic hypothesis on the generic relationships. Based on our phylogenetic results, the revised classification of examined taxa is consistent with the conventional classification.

Comparative evaluation of genetic diversity using RAPD, SSR and cytochrome P450 gene based markers with respect to calcium content in finger millet (Eleusine coracana L. Gaertn.)

Genetic relationships among 52 Eleusine coracana (finger millet) genotypes collected from different districts of Uttarakhand were investigated by using randomly amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and cytochrome P450 gene based markers. A total of 18 RAPD primers, 10 SSR primers, and 10 pairs of cytochrome P450 gene based markers, respectively, revealed 49.4%, 50.2% and 58.7% polymorphism in 52 genotypes of E. coracana. Mean polymorphic information content (PIC) for each of these marker systems (0.351 for RAPD, 0.505 for SSR and 0.406 for cyt P450 gene based markers) suggested that all the marker systems were effective in determining polymorphisms. Pair-wise similarity index values ranged from 0.011 to 0.999 (RAPD), 0.010 to 0.999 (SSR) and 0.001 to 0.998 (cyt P450 gene based markers) and mean similarity index value of 0.505, 0.504 and 0.499, respectively. The dendrogram developed by RAPD, SSR and cytochrome P450 gene based primers analyses revealed that the genotypes are grouped in different clusters according to high calcium (300-450 mg/100 g), medium calcium (200-300 mg/100 g) and low calcium (100-200 mg/100 g). Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.95 for all the three marker systems. The dendrograms and principal coordinate analysis (PCA) plots derived from the binary data matrices of the three marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. Comparison of RAPD, SSR and cytochrome P450 gene based markers, in terms of the quality of data output, indicated that SSRs and cyt P450 gene based markers are particularly promising for the analysis of plant genome diversity. The genotypes of finger millet collected from different districts of Uttarakhand constitute a wide genetic base and clustered according to calcium contents. The identified genotypes could be used in breeding programmes and amajor input into conservation biology of cereal crops.

Efficiency of RAPD, SSR and Cytochrome P450 gene based markers in accessing genetic variability amongst finger millet (Eleusine coracana) accessions

Finger millet (Eleusine coracana L.) is an important crop used for food, forage, and industrial products. Three DNA marker techniques, random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and cytochrome P(450) gene based markers were used for the detection of genetic polymorphism in 83 accessions of finger millet collected from various geographical regions of India and Africa. A total of 18 RAPD, 10 SSR and 10 pairs of cytochrome P(450) gene based markers were generated 56.17, 70.19 and 54.29% polymorphism, respectively. Mean polymorphism information content (PIC) for each of these marker systems (0.280 for RAPD, 0.89 for SSR and 0.327 for cytochrome P(450) gene based markers) suggested that SSR marker were highly effective in determining polymorphism. The phenograms based on the three markers data indicate that genotypes from different geographical regions are clearly distinguishable as separate clusters. Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.90 for all the three marker systems. The dendrograms and PCA plots derived from the binary data matrices of the three marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. Based on the results of present study, SSR and cytochrome P(450) gene based markers appear to be particularly useful for the estimation of genetic diversity. This study reveals the potential of RAPD, SSR and gene based markers for characterizing germplasm of Eleusine coracana and narrow down the vast germplasm into distinct core groups.

Assessment of genetic diversity in cassumunar ginger (Zingiber cassumunar Roxb.) in Thailand using AFLP markers

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.

Molecular characterization of the black Aspergillus isolates responsible for ochratoxin A contamination in grapes and wine in relation to taxonomy of Aspergillus section Nigri

This work examines ochratoxigenic mycobiota in grapes by ap-PCR analysis sequence analysis of the ITS and IGS regions and ability to produce OTA. A comparison was also made with many reference strains of Aspergillus section Nigri. Based on ap-PCR profiles, derived from two microsatelite primers, three main groups were obtained by UPGMA cluster analysis corresponding to A. carbonarius, A. niger and A. tubingensis. The cophenetic correlation values corresponding to ap-PCR UPGMA analysis revealed a higher genetic variability in A. niger and A. tubingensis than in A. carbonarius. In addition, no genotypical differences could be established between OTA producers and nonproducers in all species analysed. Phylogenetic relationships inferred from ITS and IGS sequences are, mostly, congruent with earlier works. A. niger and A. tubingensis strains were closely related, but not identical, and they clustered into two distinct groups within the A. niger aggregate. Sequence analysis also showed genetic divergences between strains of A. foetidus and the rest of the Aspergillus section Nigri. Additionally, the phylogenetic analysis was consistent in separating a new group of ochratoxigenic strains, frequently isolated from grapes, named A. tubingensis-like. All strains of A. carbonarius analysed by sequence analysis had identical ITS and IGS sequences confirming the lack of significant genetic variability within this important ochratoxigenic species.

Genetic Diversity of Wilt and Root Rot Pathogens of Chickpea, as Assessed by RAPD and ISSR

Intra- and interspecific polymorphisms among fungal pathogens that cause wilt and root rot on chickpea were investigated by using 30 RAPD (random amplified polymorphic DNA) and 20 ISSR (inter-simple sequence repeats) primers. UPGMA (unweighted pair group method with arithmetic average) cluster analysis of RAPD and ISSR datasets using Dice's coefficient differentiated all fungal isolates from each other and revealed considerable genetic variability between the isolates. The isolates that were not easily separable using morphological characteristics were classified again according to their branching in dendrograms. A partial correlation was observed between cluster analysis and geographic origin of Fusarium solani isolates. Additionally, high cophenetic correlation values for RAPD and ISSR data, using the MXCOPH algorithm, were observed (0.983 and 0.987, respectively). The results show that both analyses were suitable for the evaluation of genetic polymorphisms among fungal populations.

Analysis of genetic diversity in Portuguese Ceratonia siliqua L. cultivars using RAPD and AFLP markers

Although carob ( Ceratonia siliqua L.) is of great economic importance little is still known about the pattern of genetic variation within this species. Morphological characteristics based on 31 fruit and seeds of continuous characters determinant for agro-industrial uses, were compared with RAPD and AFLP markers for assessing genetic distances in 68 accessions of carob trees, from different cultivars, varieties and eco-geographic regions of Algarve. Eighteen selected RAPD primers applied to the 68 accessions produced a total of 235 fragments ranging from 200 to 2000 bp, of which 93 (40%) were polymorphic. Four AFLP selective primer combinations generated a total of 346 amplification fragments of which 110 were polymorphic. The average level of polymorphism based on four primer combinations was 31.8%. The phenetic trees based on RAPD and AFLP analyses gave high co-phenetic correlation values, and were found to be consistent in general with the analysis of morphological data, carried out on the same accessions. A number of RAPD and AFLP markers were found to be diagnostic for ‘Canela’ cultivar and 13 wild ungrafted trees.

AFLP assessment of genetic variability in old vs. new London plane trees (Platanus × acerfolia)

SummaryLondon plane tree (Platanus acerfolia) is a popular street tree and is a hybrid between the American sycamore and the Oriental plane tree. Using AFLP markers, genetic diversity and phenetic relationships were estimated in 38 London plane tree samples from Schenley Park, Pittsburgh, PA, USA, and from several nurseries. This investigation was intiated in order to manage, more effectively, the replanting of London plane trees in an existing (approx. 100 yearold) stand of approx. 100 trees. Four selective primer combinations generated a total of 492 amplification products, and 381 polymorphic markers were detected. Polymorphism ranged from 60 – 82%, with an average of 77%. A phenetic tree was constructed using Nei and Li’s coefficient of similarity with UPGMA. Other clustering algorithms were examined and all gave similar co-phenetic correlation values. The phenetic tree separated the nursery trees from the Schenley Park samples. Bootstrap analyses were completed, and the values gave strong support for this clade. We investigated the different propagating techniques applied between these samples. The Schenley Park plants had been grown from seed or seedlings, while the nursery plants were clonally propagated, which correlated with the observed differences in similarity coefficients. The level of genetic variability detected by AFLP analysis within these London plane tree samples suggested that this is a reliable, efficient, and effective marker system that can be used for better management of rural tree plantings.

Analysis of genetic diversity through AFLP, SAMPL, ISSR and RAPD markers in Tribulus terrestris, a medicinal herb

Tribulus terrestris is well known for its medicinal importance in curing urino-genital disorders. Amplified fragment length polymorphism (AFLP), selective amplification of microsatellite polymorphic loci (SAMPL), inter-simple sequence repeat (ISSR) and randomly amplified polymorphic DNA (RAPD) markers were used for the first time for the detection of genetic polymorphism in this medicinal herb from samples collected from various geographical regions of India. Six assays each of AFLP and SAMPL markers and 21 each of ISSR and RAPD markers were utilized. AFLP yielded 500 scorable amplified products, of which 82.9% were polymorphic. SAMPL primers amplified 488 bands, 462 being polymorphic (94.7%). The range of amplified bands was 66 [(TC)(8)G + M-CAG] to 98 [(CA)(6)AG + M-CAC] and the percentage polymorphism, 89.9 [from (CT)(4)C (AC)(4)A + M-CTG] to 100 [from (GACA)(4) + M-CTA]. The ISSR primers amplified 239 bands of 0.4-2.5 kb, 73.6% showed polymorphism. The amplified products ranged from 5 to 16 and the percentage polymorphism 40-100. RAPD assays produced 276 bands, of which 163 were polymorphic (59%). Mantel test employed for detection of goodness of fit established cophenetic correlation values above 0.9 for all the four marker systems. The dendrograms and PCA plots derived from the binary data matrices of the four marker systems are highly concordant. High bootstrap values were obtained at major nodes of phenograms through WINBOOT software. The relative efficiency of the four molecular marker systems calculated on the basis of multiplex ratio, marker index and average heterozygosity revealed SAMPL to be the best. Distinct DNA fingerprinting profile, unique to every geographical region could be obtained with all the four molecular marker systems. Clustering can be a good indicator for clear separation of genotypes from different regions in well-defined groups that are supported by high bootstrap values.

AFLP analysis of genetic relationships among the cultivated eggplant, Solanummelongena L., and wild relatives (Solanaceae)

The AFLP technique of DNA analysis was evaluated as a tool for assessing genetic relationships among the cultivated eggplant, S. melongena, and related species [Solanum L. subgenus Leptostemonum (Dunal) Bitter, section Melongena (Mill.) Dunal, series Incaniformia Bitter]. Genetic distances based on the AFLP data were estimated for 49 samples of 36 distinct accessions. Phenetic trees were constructed using Jaccard's coefficient and UPGMA, and other clustering methods: they all had very high co-phenetic correlation values, and were found to be consistent with previous trees based on other data types, in particular ITS-1 sequences, isozymes and morphology, carried out on the same accessions. These results indicated that the AFLP technique is both an efficient and effective tool for determining genetic relationships among species of Solanum. A new classification is proposed for series Incaniformia.

AFLP analysis of genetic relationships in the tribe Datureae (Solanaceae)

The AFLP technique was evaluated as a tool for assessing species relationships within the tribe Datureae and genetic distances were estimated for 47 accessions of over 12 species. The phenetic trees from various analyses of the AFLP data gave very high co-phenetic correlation values, and were found to be consistent with previous trees based on the analysis of different data types, in particular ITS-1 sequences, isozymes and morphology, carried out on the same accessions. These results indicated that the AFLP technique is both an efficient and effective tool for determining genetic relationships among taxa in the Solanaceae. A new classification is proposed for the tribe Datureae, which maintains the arborescent species as a separate genus, Brugmansia, and recognises three sections within the genus Datura; Stramonium, Dutra and Ceratocaulis. D. discolor, previously placed in section Dutra, was found to be intermediate between sections Dutra and Stramonium.