Genetic diversity and taxonomic studies of date plum (Diospyros lotus L.) using morphological traits and SCoT markers

Date plum persimmon (Diospyros lotus L.) is an important fruit crop in China due to its better compatibility as a major root stock for Diospyros kaki Thunb. The objective of this study was to reveal the diversity and taxonomic status based on morphological and molecular markers for 26 date plum persimmon accessions from different ecogeographical areas. Significant variability was observed in the 26 date plum persimmon accessions using the analysis of 5 quantitative and 16 qualitative morphological characters of branches, fruits and seeds. Molecular diversity was analyzed using start codon targeted (SCoT) markers. A total of 118 bands were produced with 11 SCoT primers; genetic similarity was ranged from 0.42 to 0.83, which indicating higher genetic variation among accessions. Based on the cluster results of morphological and molecular data, the results showed that date plum persimmon may be divided into five taxonomic types which including male date plum persimmon, rounded seedless date plum persimmon, rounded seedy date plum persimmon, obround seedless date plum persimmon, and oblate seedy date plum persimmon.     

Genetic diversity and population structure detection in sponge gourd ( Luffa cylindrica ) using ISSR,SCoT and morphological markers

Investigation of genetic diversity is essential for the selection of parents for crop breeding and conservation of genetic resources. To estimate the genetic variability and population structure in the midst of 45 accessions of sponge gourd brought together from different geographical areas of India, morphological traits and two molecular markers, ISSR and SCoT markers were compared. Principal components analysis of 20 morphological traits showed 72.70% variability and significant positive correlations between fruit traits. All three marker techniques clustered all accessions into two groups with few outgroups. High level of polymorphism was observed among ISSR (74.6%) and SCoT (71.5%) primers. The Bayesian model revealed the hidden grouping and showed admixture type of population. The diversity pattern is influenced by genetic marker used, as different molecular markers have different polymorphism evaluation efficiency. This study can be helpful in amplifying the genetic base and selection of specific traits for breeding. Thus, ISSR and SCoT markers are potential marker for identification in sponge gourd and provide valuable data on its genetic correlation and structure.     

Genetic diversity of Southeastern Nigerien date palms reveals a secondary structure within Western populations

Date palm (Phoenix dactylifera L.) is mainly cultivated for its edible fruit and is of great socio-economic importance for the populations of arid zones. Analysis of the date palm genetic diversity in the Old World had revealed a strong genetic structure with the existence of two gene pools, one Eastern comprising Asia and Djibouti, and one Western, consisting of North African accessions. So far, mainly date palm populations from countries within the Maghreb and the Middle East were characterized, but no information from the Sahel was included. Here, we present the genetic diversity of date palms from Southeastern Niger. The DNA of 113 date palm accessions were analyzed and compared with a database containing the genetic information of 248 accessions from the Old World. The diversity generated from microsatellite markers was compared to that of the same loci of both the Eastern and Western genetic pools. Our results show that date palms from Southeastern Niger constitute a unique group with a high level of genetic diversity. Moreover, even though this group is included in the Western genetic pool, it shows a specific originality which differentiates it from other Western populations. It also shows one of the lowest admixture levels of the Western pool. Global analysis showed a secondary genetic structure within the Western pool highlighting a new genetic group located in Southeastern Niger that distinguishes itself from the North African group.     

Molecular insights into genetic diversity and population dynamics of five medicinal <Emphasis Type="Italic">Eulophia</Emphasis> species: a threatened orchid taxa of Africa

Genetic diversity existing amongst five Eulophia orchid species were assessed using start codon targeted polymorphism (SCoT) and inter-retrotransposon amplified polymorphism (IRAP) markers. A total of 12 SCoT and 5 IRAP markers revealed an average of 63% genetic variability [SCoT?=?63.87; IRAP?=?64.95%] amongst the five Eulophia species investigated. The genetic similarities were assessed using both UPGMA and Bayesian approaches which indicated identical clustering patterns at a genetic similarity level of 50%. Analysis of molecular variance (AMOVA) revealed the presence of a significant degree of genetic variability, mostly compartmentalized within the species level. Amongst the five assessed Eulophia species, E. parviflora was the most genetically diverse representative whereas E. welwitschii was found to be least diverse based on a comparative assessment of various population genetic parameters like Nei’s gene diversity (h) and Shannon’s information index (I) with an overall gene flow value greater than 1. In order to evaluate the comparative marker efficiency, SCoT and IRAP marker data were subjected to various benchmark analyses like marker index, resolving power, polymorphic index content, multiplex ratio and effective multiplex ratio which revealed the robustness of both the marker techniques in assessment of genetic diversity. The present report provides the first molecular insights into the aspects of inter and intra specific genetic variability in medicinally as well as horticulturally important Eulophia species along with addressing their conservation concerns. In a nutshell, the present approach is simple, rapid and cost effective and can be extended for analysis of genetic diversity of other related plant species.     

Insight into genetic relation and diversity of cultivated and semi-domesticated under-utilized Crotalaria species gained using start codon targeted (SCoT) markers

To augment conventional crop improvement approaches in cultivated sunnhemp (Crotalaria juncea L.) and other under-utilized Crotalaria species, genetic diversity of 94 genotypes from seven Crotalaria species was studied using 20 Start Codon Targeted (SCoT) markers. High allele number (1.32), polymorphism information content (0.37) and resolving power (6.59) established SCoT as a reliable marker system for genetic analysis in Crotalaria. All the species except Crotalaria retusa L. exhibited high number of SCoT amplicons. Analysis of molecular variance revealed significant variability between (24.0%) the species as well as within species (76.0%). A cluster analysis identified distinct groups corresponding to the seven species and also identified sub-groups within the species. The sunnhemp cultivars were distant from the landraces, suggesting the need of population improvement using distantly related genotypes. Species relationship identified Crotalaria pallida Aiton to be a close relative of C. juncea. The results of principal coordinate analysis were comparable to that of cluster analysis, revealing high genetic variability in sunnhemp and other semi-domesticated Crotalaria species. The study further suggests some measure for conservation of genetic resources and genetic improvement of these species based on the results of diversity analysis.     

A comparative assessment of phenotypic and molecular diversity in Doum (Hyphaene thebaica L.)

Doum palm (Hyphaene thebaica L.) has been reported as one of the most beneficial species worldwide. Its fruits are a good source of fibers, antioxidants, B-complex vitamins, essential minerals, monosaccharides, essential oil and flavonoids. Fruit extract shows anti-inflammatory, antioxidant, antimicrobial, anticancer and pharmacological potential. However, there is a lack of investigations dealing with its genetic diversity. Therefore, a collection of twelve mature female palm landraces grown in the botanical garden of Aswan, “Egypt” were used for genetic diversity assessment based on phenotypic and molecular levels. 18 vegetal and chemical traits were evaluated. Fifteen of them showed highly significant variation among the tested landraces. Euclidian-based-dendrogram discriminated the tested landraces based on their phenotypic similarities to three main clusters showing a high level of variability. Molecular analysis using inter simple sequence repeats (ISSR) vis-à-vis start codon targeted (SCoT) polymorphism markers displayed the relationships among the tested landraces molecularly. Both markers showed a reasonable degree of polymorphism, however SCoT was more effective than the ISSR by showing a higher percentage of polymorphism, polymorphism information content, resolving power and diversity index. Cluster analysis based on molecular data showed a clear relationship among the doum landraces. However, ISSR- and SCoT-based dendrograms were slightly different, and completely unlike that based on phenotypic data. Nevertheless, phenotypic and molecular evaluations might complement each other, and by data of both an excellent overview was obtained from principle coordinate analysis. The information herein is valuable and considered as a keystone for further proximate studies on doum genetic diversity to help in improvement and breeding approaches.

     

Genetic diversity of Indian jujube cultivars using SCoT,ISSR, and rDNA markers

Genetic variation and relationships among 37 cultivars of Ziziphus mauritiana (Lamk.) native of India were analyzed using start codon targeted (SCoT), inter-simple sequence repeats (ISSR), and ribosomal DNA (rDNA) markers. High level of polymorphism among SCoT (61.6%) and ISSR (61%) primers with higher PIC values ranging from 63.1 to 90.4% of SCoT and 47.3 to 88.8% of ISSR primers was recorded. SCoT and ISSR dendrograms revealed similarity coefficients ranging from 0.80 to 0.92 and 0.79 to 0.96, respectively, and clearly delineated all the cultivars of Z. mauritiana into well-supported distinct clusters. Greater Gst signifies higher amount of differentiation observed over multiple loci among seven Z. mauritiana populations. On the other hand, higher gene flow demonstrating a very high migration rate between Z. mauritiana populations indicated higher rates of transfer of alleles or genes from one population to another. The genetic diversity of population 1 (Rajasthan) was the richest among all the seven populations. The largest genetic distance was measured between Maharashtra and West Bengal and the least between Rajasthan and Punjab cultivars. Most of the genetic diversity exists within population rather than among populations. Substantial variation in the ITS-1 region signifies its phylogenetic utility specifically in assessing genetic diversity in Z. mauritiana. The clustering patterns using three molecular marker systems vis-à-vis place of origin exhibited no consistency in grouping of Z. mauritiana cultivars as cultivars from the same place of origin were genetically cataloged into different SCoT, ISSR, and ITS phylogram clusters indicating wide genetic diversity and distribution across agro-climatic zones validating the robustness of marker systems tested.     

Development and evaluation of microsatellite markers in Phoenix dactylifera L. and their transferability to other Phoenix species

Forty one simple sequence repeats were isolated from two microsatellite enriched libraries of date palm (Phoenix dactylifera L.). After screening, 17 selected microsatellite loci were characterized and evaluated on a set of 31 cultivars and clones from Algerian and Californian germplasm. All primer pairs produced an amplification product of the expected size and detected high polymorphism among the analysed samples. These nuclear simple sequence repeat (SSR) markers are expected to be a very effective tool for evaluating genetic diversity in date palm germplasm. Acrosstaxa amplification showed the usefulness of most SSR markers in 14 other species across the genus Phoenix.     

Molecular characterization of Syrian date palm cultivars using plasmid-like DNA markers

Date palm (Phoenix dactylifera L.) is one of the most important domesticated fruit trees in the Near East and North African countries. This tree has been, for several decades, in serious threat of being completely destroyed by the “Bayoud” disease caused by Fusarium oxysporum f. sp. albedinis. In this study, 18 Syrian date palm cultivars and four male trees were analyzed according to the identity of mitochondrial plasmid-like DNAs. A PCR strategy that employs plasmid-like DNAs-specific primer pair was used. These primers amplify a product of either 373-bp or 265-bp that corresponds to the S- (Bayoud-susceptible) or the R-plasmid (Bayoud-resistant), respectively. Generated data revealed that only six cultivars (“Medjool”, “Ashrasi”, “Gish Rabi”, “Khineze”, and yellow- and red-“Kabkab”) have the S-plasmid, suggesting their susceptibility to the fusariosis, while the remaining 12 cultivars and the four male trees contain the R-plasmid, suggesting their resistance to the fusariosis. The PCR process applied here has been proved efficient for the rapid screening for the presence of the S and R DNAs in Syrian date palm. PCR markers developed in this study could be useful for the screening of date palm lines growing in the field. The availability of such diagnostic tool for plasmid characterization in date palm would also be of great importance in establishing propagation and breeding programs of date palm in Syria.     

Genetic stability analysis of tissue culture derived date palm cv. Dedhi plants using IRAP markers

Phoenix dactylifera cv. Dedhi is an excellent soft date palm cultivar of district Khairpur, Sindh-Pakistan with large size fruit, brittle texture and very low tannins at the Khalal stage. The population of this palm cultivar is currently threatened by pest and disease issues, a limited availability of offshoots and by the prevailing monoculture of semi-dry cultivars together with import of exotic elite cultivars into the region. Hence, the current study aimed to determine genetic stability of large-scale in vitro multiplied materials after their transfer to the field. The palms were phenotyped and then genotyped using two Inter-retrotransposons Amplified Polymorphism (IRAP) markers. Thirteen IRAP primers with 24 combinations were screened, of which 14 combinations produced 301 clear and reproducible bands which were all monomorphic. The IRAP banding patterns showed no variation among the tissue culture derived plants tested. No significant variation in fruit characteristics of the tissue culture derived plants was found when compared to mother plant. Using an optimized micropropagation protocol, number of plants unable to form inflorescences was reduced from 36.7% in the year 2016 to 10% in 2018. The study confirms the current micropropagation protocol to be effective for production of true-to-type plants and the applied marker system to be efficient for validating genetic stability of in vitro produced palms.     

Crystallicutis gen. nov. (Irpicaceae,Basidiomycota), including C. damiettensis sp. nov., found on Phoenix dactylifera (date palm) trunks in the Nile Delta of Egypt

The taxonomy of Polyporales is complicated by the variability in key morphological characters across families and genera, now being gradually resolved through molecular phylogenetic analyses. Here a new resupinate species, Crystallicutis damiettensis sp. nov. found on the decayed trunks of date palm (Phoenix dactylifera) trees in the fruit orchards of the Nile Delta region of Egypt is reported. Multigene phylogenetic analyses based on ITS, LSU, EF1α, RPB1 and RPB2 loci place this species in Irpicaceae, and forming a distinct clade with Ceraceomyces serpens and several other hitherto unnamed taxa, which we also incorporate into a new genus Crystallicutis. We name two of these species, Crystallicutis huangshanensis sp. nov. and Crystallicutis rajchenbergii sp. nov. The distinctive feature of Crystallicutis gen. nov. is the presence of crystal-encrusted hyphae in the hymenium and subiculum. Basidiomes are usually honey-yellow with white margins but there is variability in the presence of clamp connections and cystidia, as noted for other genera within Irpicacae. C. damiettensis is hitherto consistently associated with date palms killed by the red palm weevil Rhynchophorus ferrugineus, a highly damaging and invasive pest, recently spread to the Mediterranean region. C. damiettensis causes rapid wood decay by a potentially unusual white-rot mechanism and may play a role in the damage caused by R. ferrugineus.     

Impact of Mapped SSR Markers on the Genetic Diversity of Apricot (<Emphasis Type="Italic">Prunus armeniaca</Emphasis> L.) in Tunisia

The impact of mapped microsatellites on the study of genetic diversity of Tunisian apricot accessions was assessed. The genetic variability of 47 traditional apricot cultivars originating from several areas in Tunisia was investigated with 32 polymorphic microsatellite loci selected for their location throughout the eight linkage groups of Prunus genome. The higher polymorphism and greater transportability of these markers among Prunus species were proved by the expected heterozygosity (He = 0.56) and Shannon’s index of diversity (I = 1.05), indicating that Tunisian apricot germplasm maintained a substantial level of genetic diversity. According to their geographical origin, the genetic differentiation among groups (north, center, and south; Fst = 0.04) was lower, while the gene flow among groups was consequent (Nm = 4.79), attesting a narrow genetic background of apricot in the country. Both unweighted pair-group method with arithmetic mean dendrogram, based on Nei’s genetic distances and factorial correspondence analysis, separated northern cultivars from central and southern cultivars, revealing the same molecular basis of apricot material in the Center and the South of Tunisia. These results revealed the efficiency of mapped markers for genetic variability measurements compared to randomly ones, however, no advantage was observed considering the genetic relationships among studied accessions.     

Start Codon Targeted (SCoT) markers provide new insights into the genetic diversity analysis and characterization of Tunisian Citrus species

Start Codon Targeted markers were used to establish phylogenetic relationship among seven species from Citrus L. genus. Twelve SCoT primers were used for their ability to reveal polymorphism of the targeted codon of initiation. A total of 132 amplicons were generated and 93.9% of them were polymorphic. The polymorphism information content of 0.884 and the resolving power of 75.22 illustrate the efficiency of the tested SCoT primers in highlighting polymorphism. The average Nei's (1973) gene diversity (0.376), the Schannon's index (0.548) and the Gst parameter (0.346) describe an important polymorphism at the interspecies level in Citrus genus. Analysis of molecular variance suggested significant genetic differences within species. In fact, 84% of variance occurs within the species, whereas 16% of the variation was recorded among the species of Citrus. The limited gene flow (Nm = 0.941) was recognized as a major factor to explain the partition of the observed diversity. The principal coordinates analyses, Neighbor Joining and the Bayesian clustering approach based on the SCoT markers also confirm the discrimination of the species of Citrus. Our results confirm the relevance and suggest the effectiveness of the SCoT markers for assessing genetic diversity, characterization and identification of the species of Citrus.     

利用SCoT分析柳枝稷遗传资源的多样性

本研究利用SCoT标记对96份柳枝稷种质的亲缘关系和遗传变异进行了研究。筛选出20条引物对96份供试材料进行PCR扩增,共获得445条带,其中多态性条带402条,平均多态性条带比率(PPB)达90.31%,多态性信息含量(PIC)为0.166~0.410,平均值为0.332,标记指数(MI)为10.20。遗传相似系数(GS)为0.498~0.912,平均值为0.688。表明SCoT标记能够揭示柳枝稷种质间的遗传变异。通过UPGMA分析表明,96份种质资源聚为高地型和低地型两大类。经POPGENE1.32软件分析结果显示:96份柳枝稷基因多样性指数(H)为0.285,Shannon指数(I)为0.431,表明供试的种质间遗传多样性丰富,遗传多样性水平高。经AMOVA 1.55方差分析揭示:96份柳枝稷生态型内的遗传变异占总变异的72.85%,生态型间遗传变异占总变异的27.15%,结果表明ScoT可用于柳枝稷遗传多样性研究,该研究结果可为柳枝稷种质资源的进一步开发利用提供重要信息。     

Genetic diversity of Hemarthria altissima and its related species by EST-SSR and SCoT markers

There is a need for an appropriate evaluation of Hemarthria germplasm resources using genetic analysis. Understanding their genetic background will promote effective development and utilization of its germplasm resources in plant breeding. We examined the genetic diversity and relationships among 46 Hemarthria germplasm resources from four continents. Expressed Sequence Tags-Simple Sequence Repeat (EST-SSR) and Start Codon Targeted (SCoT) markers were used to investigate species Hemarthria altissima (36), Hemarthria compressa (8) and Hemarthria uncinata (2). We selected 19 EST-SSR primers and generated 550 polymorphic (94.7%). Twenty one SCoT primers were selected and amplified to produce 597 bands with 89.4% of polymorphic bands. The Mantel test between EST-SSR and SCoT matrices revealed significant correlations (r = 0.854) and the data from both markers were combined for cluster analysis. The 46 materials were clustered into two main groups by UPGMA clustering with a similarity coefficient ranging from 0.573 to 0.940 and the dendrogram was basically concordant with geographical origins and species. Among the three Hemarthria species, H. altissima was genetically closest to H. compressa while it was not close to H. uncinata. When the utility of the two markers were compared, we found EST-SSR to be more efficient than SCoT in determining the genetic diversity study of Hemarthria species.     

Genetic structure of the date palm (Phoenix dactylifera) in the Old World reveals a strong differentiation between eastern and western populations

Background and Aims Date palms (Phoenix dactylifera, Arecaceae) are of great economic and ecological value to the oasis agriculture of arid and semi-arid areas. However, despite the availability of a large date palm germplasm spreading from the Atlantic shores to Southern Asia, improvement of the species is being hampered by a lack of information on global genetic diversity and population structure. In order to contribute to the varietal improvement of date palms and to provide new insights on the influence of geographic origins and human activity on the genetic structure of the date palm, this study analysed the diversity of the species.Methods Genetic diversity levels and population genetic structure were investigated through the genotyping of a collection of 295 date palm accessions ranging from Mauritania to Pakistan using a set of 18 simple sequence repeat (SSR) markers and a plastid minisatellite.Key Results Using a Bayesian clustering approach, the date palm genotypes can be structured into two different gene pools: the first, termed the Eastern pool, consists of accessions from Asia and Djibouti, whilst the second, termed the Western pool, consists of accessions from Africa. These results confirm the existence of two ancient gene pools that have contributed to the current date palm diversity. The presence of admixed genotypes is also noted, which points at gene flows between eastern and western origins, mostly from east to west, following a human-mediated diffusion of the species.Conclusions This study assesses the distribution and level of genetic diversity of accessible date palm resources, provides new insights on the geographic origins and genetic history of the cultivated component of this species, and confirms the existence of at least two domestication origins. Furthermore, the strong genetic structure clearly established here is a prerequisite for any breeding programme exploiting the effective polymorphism related to each gene pool.     

Molecular diversity and relationships among <Emphasis Type="Italic">Cymbidium goeringii</Emphasis> cultivars based on inter-simple sequence repeat (ISSR) markers

Spring orchid (Cymbidium goeringii) is a popular flowering plant species. There have been few molecular studies of the genetic diversity and conservation genetics on this species. An assessment of the level of genetic diversity in cultivated spring orchid would facilitate development of the future germplasm conservation for cultivar improvement. In the present study, DNA markers of intersimple sequence repeats (ISSR) were identified and the ISSR fingerprinting technique was used to evaluate genetic diversity in C. goeringii cultivars. Twenty-five ISSR primers were selected to produce a total of 224 ISSR loci for evaluation of the genetic diversity. A wide genetic variation was found in the 50 tested cultivars with Nei’s gene diversity (H = 0.2241) and 93.75% of polymorphic loci. Fifty cultivars were unequivocally distinguished based on ISSR fingerprinting. Cultivar-specific ISSR markers were identified in seven of 50 tested cultivars. Unweighted pair-group mean analysis (UPGMA) and principal coordinates analysis (PCA) grouped them into two clusters: one composed the cultivars mainly from Japan, and the other contained three major subclusters mainly from China. Two Chinese subclusters were generally consistent with horticultural classification, and the third Chinese subcluster contained cultivars from various horticultural groups. Our results suggest that the ISSR technique provides a powerful tool for cultivar identification and establishment of genetic relationships of cultivars in C. goeringii.     

Molecular characterization and genetic variability studies associated with fruit quality of indigenous mango (Mangifera indica L.) cultivars

Start codon-targeted (SCoT) markers were used for characterization and genetic comparison analysis among 20 mango cultivars (15 indigenous and 5 popular) with respect to fruit quality. Out of 80 SCoT markers used, 19 were able to amplify. These primers produced total 117 loci across 20 cultivars, of which 96 (79.57 %) were polymorphic with an average of 5.05 polymorphic fragments per primer. Out of 19, 17 SCoT primers produced 34 cultivar-specific DNA finger prints. These were 25 unique fragments for identification of 15 indigenous cultivars and 9 fragments for the identification of five popular cultivars. The three SCoT primers—40, 45, and 51 are most informative in identifying mango cultivars as they possess the higher primer index values. The 20 mango cultivars were clustered into two major groups based on the SCoT data analysis with UPGMA. Three indigenous cultivars—Khodi, Amrutiyo, and Kaju and one popular—Dasheri out grouped from other 16 cultivars and shared only minimum similarity (11 %). In clustering pattern, indigenous cultivars—Kaju and Amrutiyo grouped together and shared 37 % similarity with higher boot strapping values (63 %). Clustering pattern is corresponding well with their physical and/or biochemical properties of fruits. The results of principal coordinates analysis (PCoA) analysis were comparable to the cluster analysis. The first three most informative PC components explained 56.61 % of the total variation. In PCoA, three indigenous cultivars—Jamrukhiyo, Chappaniyo, and Sopari appears to be distinct from other 12 indigenous, which be different in fruit size, sugars, ascorbic acids, and carotenoids content. Similarly, popular cultivars—Jamadar and Kesar were also discrete from Alphonso, Dasheri, and Neelum in PCoA. The results demonstrate that the SCoT marker system is useful for cultivar identification and genetic diversity analysis of mango cultivars based on their biological traits.     

Molecular insights of genetic variation in milk thistle (Silybum marianum [L.] Gaertn.) populations collected from southwest Iran

Milk thistle (Silybum marianum) is among the world’s popular medicinal plants. Start Codon Targeted (SCoT) marker system was utilized to investigate the genetic variability of 80 S. marianum genotypes from eight populations in Iran. SCoT marker produced 255 amplicons and 84.03% polymorphism was generated. The SCoT marker system’s polymorphism information content value was 0.43. The primers’ resolving power values were between 4.18 and 7.84. The percentage of polymorphic bands was between 33.3 and 100%. The Nei’s gene diversity (h) was 0.19–1.30 with an average 0.72. The Shannon’s index (I) ranged from 0.29 to 1.38 with an average value of 0.83. The average gene flow (0.37) demonstrated a high genetic variation among the studied populations. The variation of 42% was displayed by the molecular variance analysis among the populations while a recorded variation of 58% was made within the populations. Current investigation suggested that SCoT marker system could effectively evaluate milk thistle genotypes genetic diversity.

     

Assessment of genetic diversity and relationships among maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.) Italian landraces by morphological traits and AFLP profiling

In the present study we have analyzed the genetic diversity pattern in a sample of 54 Italian maize landraces, using morphological traits and molecular markers. Although the 54 landraces surveyed in this study were restricted to Lombardy, the core region of maize production in Italy, our data revealed a large genetic heterogeneity for both morphological and molecular traits in the accessions analyzed. Additionally, our data confirm that the AFLP markers produced a high frequency of polymorphic bands and were able to unequivocally fingerprint each of the landraces considered. Cluster analysis based on AFLP markers displayed a clearer separation of the accessions in comparison to morphological data. Different populations were divided into four major clusters reflecting the geographical origin and seasonal employment of the landraces analyzed. Molecular analysis of variance showed significant (P < 0.01) differences among groups, among populations within groups, and among individuals within populations. Approximately 74% of the total variance could be attributed to differences within populations. Conversely, a lower level of differentiation was detected among groups (~4%). Regarding population structures, the genetic distance between populations (F _ST = 0.25 ± 0.3) and the degree of inbreeding within groups (F _SC = 0.22 ± 0.2), did not diverge significantly, while both significantly differed from the degree of relatedness between markers within groups (F _CT = 0.04 ± 0.03). Results are discussed in relation to a suitable conservation method.