<Emphasis Type="Italic">In situ</Emphasis> conservation and genetic diversity of three populations of <Emphasis Type="Italic">Gossypium mustelinum</Emphasis> Miers ex Watt

Gossypium mustelinum Miers ex Watt is a native from Northeastern Brazil and belongs to the primary gene pool of the cultivated cotton. The unique places where the species was known to occur were visited to plan ex situ and in situ preservation. Two populations at Caicó became extinct, and only eleven individuals were found. At Jaguarari, although one population became extinct, a new one was localized with approximately 500 adult plants, where a fence avoided cattle feeding. The population from Macururé consisted of 28 plants protected from animals by thorns of Bromelia laciniosa Mart. ex Schult. f. Thirteen SSR primer pairs amplified 40 alleles, among which 30% were exclusive of one of the populations. The genetic differences between populations represented 58.3% of the total genetic variation observed. The high genetic distances are likely to be caused by geographical isolation as well as by the small number of individuals which contribute to new generations, and consequential genetic drift.     

Comparative Study of Common Bean (<Emphasis Type="Italic"> Phaseolus vulgaris</Emphasis>L.) Landraces Conserved <Emphasis Type="Italic">ex situ</Emphasis> in Genebanks and <Emphasis Type="Italic">in situ</Emphasis> by Farmers

Genetic diversity of populations stored ex situ or in situ can be altered due to the management practices they are subjected to. In this paper, we compare populations of two common bean (Phaseolus vulgaris L.) landraces grown on farms with material collected from the same farms and now kept in two ex situ collections (CIAT and REGEN) with the purpose to monitor any changes that have occurred due to ex situ conservation. The diversity was measured using seven bean microsatellite markers. Further phenotypic and developmental traits were registered in a field experiment. Compared with the in situ populations, the ex situ ones had a lower level of gene diversity and we suggest that this is due to the regeneration process. Most of the phenotypic traits did not differ significantly between ex situ and in situ populations, although for yield and 100-seed weight, the CIAT material showed significant lower values. We assume that these populations have gone through an adaptational change. Overall, the conservation ex situ has been successful in maintaining the majority of the adaptations found in the landraces studied, however, the probable loss of genetic diversity that we have observed, suggest that protocols for the regeneration process must be carefully worked out if the majority of alleles are to be preserved for the future. This study also highlights the complementarity of ex situ and in situ conservation methods in order to preserve landrace adaptations and to capture new, useful diversity generated in in situ populations.     

Perennial forage legumes endemic to the Canary Islands: collection and <Emphasis Type="Italic">ex situ</Emphasis> conservation

Several perennial legumes endemic to the Canary Islands have been recognized as forage resources for semi-arid zones. In the period 2008–2010, seed collecting missions focused on the genera Adenocarpus DC., Bituminaria Heist. ex Fabr., Chamaecytisus Link, Cicer L., Genista L., Teline Medik. and Vicia L. were carried out in the archipelago. Sixty-nine samples were gathered from 31 endemic taxa, eight of which are threatened. These accessions are conserved at the gene bank of the Instituto Canario de Investigaciones Agrarias for further characterization and evaluation. Collection and ex situ conservation contribute to preserve endemic legumes genetic resources for utilization in the Canary Islands and in other semi-arid regions of the world.     

Mountain oases in northern Oman: An environment for evolution and<Emphasis Type="Italic"> in situ</Emphasis> conservation of plant genetic resources

Several botanical studies have been conducted in different parts of Oman, but knowledge about agro-biodiversity in the rapidly decaying ancient mountain oases of this country remains scarce. To fill this gap we assessed the genetic resources of three mountain oases in the al-Hajar range using a GIS-based field survey and farmer interviews. While arid conditions prevail throughout the mountain range, the different elevations of Balad Seet (950–1020 m a.s.l.), Maqta (930–1180 m a.s.l.) and Al Jabal al Akhdar (1750–1930 m a.s.l.) provide markedly differing agro-climatic conditions. Overall, 107 different crop species were identified belonging to 39 families. Species number was highest among fruits (33 spp.), followed by vegetables (24 spp.). Intensive irrigation allows cultivation of a broad range of species at all oases. However, the number of species varied significantly between sites. Fruit species diversity and homogeneity of distribution of individual fruit species was highest at Balad Seet and lowest at Maqta as indicated by respective Shannon indices of 1.00 and 0.39 and evenness values of 32% and 16%. Century plant (Agave americana L.), faba bean (Vicia faba L. var. minor Peterm. em. Harz) and lentil (Lens culinaris Medik.) were identified as relict crops, supporting oral reports of past cultivation and providing evidence of genetic erosion. Some species, such as the temperate fruits of Al Jabal al Akhdar, were exclusively found at the coolest site, while others only occurred at the hotter locations. Overall greatest species similarity was found between Balad Seet and Al Jabal al Akhdar as indicated by a Sørensen coefficient of similarity of 67%. At all oases a multilayered vegetation structure dominated with a canopy, an understory and a ground layer. Greatest species richness was recorded in the lowest stratum. Overall the study shows a location-specific but surprisingly diverse mosaic of crops in Omani mountain oases which merits further studies and conservation efforts.     

Morphological Variation of Fruit in Mexican Populations of <Emphasis>Cocos nucifera</Emphasis> L. (Arecaceae) under <Emphasis Type="Italic">in situ</Emphasis> and <Emphasis Type="Italic">ex situ</Emphasis> Conditions

Morphological variation of the coconut fruit measured in situ has been used to estimate genetic diversity, and generate hypotheses about the evolutionary and geographical diffusion of coconut. Some authors have questioned the validity of this methodology due to the possibly high effect of the environment on the morphological characteristics of the fruit. The general aim of this study is to validate this methodology through: (1) characterizing the pattern of morphological variation of the fruit under homogeneous growing conditions ex situ; (2) comparing this pattern with those already reported in situ; (3) estimating the heritability values for the components of fruit in coconut. Results are also discussed in comparison with ex situ leaf variation and biochemical and molecular variation patterns previously studied. Principal components and discriminant analyses indicated that the characters that best differentiate groups are basically the same in situ and ex situ. Grouping patterns obtained with principal components and cluster analysis were similar for both growing conditions. They were also similar to the grouping pattern obtained with ex situ leaf characters. No significant differences were found in the variation coefficients of fruit characters between the same populations in situ and ex situ. Consistency was found between patterns of morphological variation of fruit ex situ and in situ, and those obtained using iso-enzymatic and molecular characteristics. The results are also consistent with hypotheses on the origin and diffusion of the germplasm introduced to Mexico. High values of heritability were found in nine characters. Weight and water percentage showed the highest values (0.88 and 0.883), with a strong correlation to the mass and the roundness of fruit and seed, suggesting that human selection of these characteristics led to the differentiation of domesticated populations. We conclude that morphological characterization of the coconut fruit in situ is useful to estimate its genetic variability because of its simplicity, speed and ease of application in the field and in remote areas.     

Population clonal diversity and fine-scale genetic structure in <Emphasis Type="Italic">Oryza officinalis</Emphasis> (Poaceae) from China,implications for <Emphasis Type="Italic">in situ</Emphasis> conservation

Population clonal diversity and fine-scale genetic structure of Oryza officinalis Wall. ex Watt, an endangered species in China recently experiencing habitat degradation, was estimated using inter simple sequence repeat markers. We analyzed the genetic variations of 440 samples exhaustively collected from nine O. officinalis populations. Relatively rich clonal diversity and poor genetic variation were found in the extant populations. We found that the number of genets, the percentage of polymorphic loci, and gene diversity decreased with population decline, suggesting that habitat degradation will lead to further genetic depletion of O. officinalis populations. A pronounced spatial genetic structure occurs at both the ramet and genet levels in several larger populations, which is the result of clonal growth and concomitant inbreeding. The in situ conserved population PS holds much more genotypes than other populations with the similar population size, which might have more seedling recruitments from the soil seed bank due to habitat disturbance, suggesting a moderate disturbance combined with habitat degradation-avoiding measures are effective for in situ conservation of this species.     

RAPD-based Analysis of Genetic Diversity and Selection of Lingonberry (<Emphasis Type="Italic">Vaccinium vitis-idaea</Emphasis> L.) Material for <Emphasis Type="Italic">ex situ</Emphasis> Conservation

Random amplified polymorphic DNA markers were used to assess relatedness and genetic diversity for 15 lingonberry (Vaccinium vitis-idaea) populations. Seven primers yielding 59 polymorphic bands were used to analyse 13 populations, representing ssp. vitis-idaea from Sweden, Finland, Norway, Estonia and Russia, and two populations, representing ssp. minus from Japan and Canada. A cluster analysis and a multidimensional scaling analysis (MDS) showed similar phenetic patterns among populations, with a pronounced geographic grouping in most cases. Significant correlations were obtained between geographic and genetic distances for the entire set of populations as well as for the 13 ssp. vitis-idaea populations. Mean within-population diversity was 0.206 when estimated with Lynch and Milligan's index, and 0.431 when estimated with Shannon's index, which is in agreement with the mixed mating system reported for lingonberry. Within-population variability accounted for 68.6% of the total variance when all populations were included, and for 78.8% when only populations of ssp. vitis-idaea were analysed. Two different approaches were applied to the selection of plant material for a potential gene bank: (1) a hierarchical sampling strategy based on a cluster analysis and (2) the Maximum genetic diversity program, developed for the establishment of core collections. Random sampling was undertaken for comparisons with the selected data sets. The most diverse and representative set of lingonberry specimens was obtained when samples were selected with the Maximum diversity program.     

Exploration and conservation of <Emphasis Type="Italic">Stylosanthes</Emphasis> (Leguminosae) genetic resources in Venezuela

Stylosanthes Sw. is considered one of the economically most important tropical forage legumes. The genus is essentially Neotropical, and Brazil, Venezuela and Mesoamerica are the main centres of species diversification. In view of its importance, an extensive review of Venezuelan Stylosanthes genetic resources was carried out. Firstly, the known natural distributions of all 11 species based on herbarium specimens were georeferenced and mapped and, by comparing them with information of germplasm (=seed) collection site distributions, for each species regions were identified which in terms of collecting and safeguarding genetic resources of Stylosanthes had not been explored yet. Secondly, the actual status of the Stylosanthes collection in Venezuela in terms of collected seed samples and available germplasm is discussed, as is the need for further explorations, including targeting ecologically important locations. Finally, the different Stylosanthes species in Venezuela are grouped according to their perceived agronomic value and potential as forage for animal production systems, and recommendations are given regarding research, collection and preservation needs. Overall, this study compiled baseline information for future considerations of an important genetic resource in Venezuela. The endangerment of the three endemic species, Stylosanthes falconensis Calles et Schultze-Kr., Stylosanthes sericeiceps S.F. Blake and Stylosanthes venezuelensis Calles et Schultze-Kr. should be a major concern and warrants priority considerations for preservation.     

Production and cytogenetics of trigeneric hybrid involving <Emphasis Type="Italic">Triticum</Emphasis>, <Emphasis Type="Italic">Psathyrostachys</Emphasis> and <Emphasis Type="Italic">Secale</Emphasis>

Trigeneric hybrids may help establish evolutionary relationships among different genomes present in the same cellular-genetic background, and also offers the possibility to transfer different alien characters into cultivated wheat. In this study, a new trigeneric hybrid involving species from the Triticum, Psathyrostachys and Secale was synthesized by crossing wheat-P. huashanica amphiploid (PHW-SA) with wheat-S. cereale amphiploid (Zhongsi 828). The crossability of F₁ hybrid was high with 35.13%, and the fertility was 41.95%. The morphological characteristics of F₁ plants resembled the parent Zhongsi 828. The trigeneric hybrids pollen mother cells (PMCs) regularly revealed averagely 19.88 univalents, 9.63 ring bivalents, 3.97 rod bivalents, 0.60 trivalents and 0.03 tetravalents per cell. Multivalents consisted of trivalents and tetravalents can be observed in 52.7% of cells. A variation of abnormal lagging chromosome, micronuclei and chromosome bridge were formed at anaphase I and telophase II. The mean chromosomes number of F₂ progenies was 2n = 46.13, and the distribution range was 42–53. GISH results revealed that most F₂ plants had 6–12 S. cereale chromosomes, and only 0–2 P. huashanica chromosomes were detected. The results indicated that S. cereale chromosomes can be preferentially transmitted in the F₂ progenies of trigeneric hybrid than P. huashanica chromosomes. A survey of disease resistances revealed that the stripe rust resistance from the PHW-SA were completely expressed in the F₁ and some F₂ plants. The trigeneric hybrid could be a useful bridge for the transference of P. huashanica and S. cereale chromatins to common wheat.     

Putative Role of <Emphasis Type="Italic">Flavobacterium</Emphasis>, <Emphasis Type="Italic">Dokdonella</Emphasis> and <Emphasis Type="Italic">Methylophilus</Emphasis> Strains in Paracetamol Biodegradation

Paracetamol, the most widely and globally used analgesic and antipyretic, is easily accumulated in aquatic environments. In the present study, the biodegradation of paracetamol in different media (one for general growth, one specific for sulfate reducing bacteria, a mineral salts medium and municipal wastewater) inoculated with two types of sludge (from anaerobic lagoon and from oxidation ditch) under different oxygenic conditions (anoxic; moderate oxygenation in open flasks and high oxygenation by aeration) was investigated. In addition, bacteria with relative abundances increasing simultaneously with paracetamol degradation, when this drug was the only carbon source, thus with a putative role in its degradation, were identified using 16S rRNA gene sequences. The results show that aerobic microorganisms had a major role in the degradation of paracetamol, with 50 mg/L totally removed from municipal wastewater after 2 days incubation with aeration, and that the metabolites 4-aminophenol and hydroquinone plus one compound not identified in this work were produced in the process. The identification of bacteria with a role in the degradation of paracetamol revealed a strain from genus Pseudomonas with the highest final relative abundance of 21.2%, confirming previous works reporting strains of this genus as paracetamol decomposers. Besides, genera Flavobacterium, Dokdonella and Methylophilus were also in evidence, with initial relative abundances of 1.66%, 1.48 and 0.00% (not detected) in the inoculum and 6.91%, 3.80 and 3.83% after incubation, respectively. Therefore, a putative role of these genera in paracetamol biodegradation is suggested for the first time.

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Graphical Abstract ?

     

Exploitation of <Emphasis Type="Italic">Malus</Emphasis> EST-SSRs and the utility in evaluation of genetic diversity in <Emphasis Type="Italic">Malus</Emphasis> and <Emphasis Type="Italic">Pyrus</Emphasis>

A total of 8117 suitable SSR-contaning ESTs were acquired by screening from a Malus EST database, among which dinudeotide SSRs were the most abundant repeat motif, within which, CT/TC followed by AG/GA were predominant. Based on the suitable sequences, we developed 147 SSR primer pairs, of which 94 pairs gave amplifications within the expected size range while 65 pairs were found to be polymorphic after a preliminary test. Eighteen primer pairs selected randomly were further used to assess genetic relationship among 20 Malus species or cultivars. As a result, these primers displayed high level of polymorphism with a mean of 6.94 alleles per locus and UPGMA cluster analysis grouped twenty Malus accessions into five groups at the similarity level of 0.6800 that were largely congruent to the traditional taxonomy. Subsequently, all of the 94 primer pairs were tested on four accessions of Pyrus to evaluate the transferability of the markers, and 40 of 72 functional SSRs produced polymorphic amplicons from which 8 SSR loci selected randomly were employed to analyze genetic diversity and relationship among a collection of Pyrus. The 8 primer pairs produced expected bands with the similar size in apples with an average of 7.375 alleles per locus. The observed heterozygosity of different loci ranged from 0.29 (MES₉₆) to 0.83 (MES₁₃₈), with a mean of 0.55 which is lower than 0.63 reported in genome-derived SSR marker analysis in Pyrus. The UPGMA dendrogram was similar to the previous results obtained by using RAPD and AFLP markers. Our results showed that these EST-SSR markers displayed reliable amplification and considerable polymorphism in both Malus and Pyrus, and will contribute to the knowledge of genetic study of Malus and genetically closed genera.     

<Emphasis Type="Italic">Rhizobium</Emphasis>,<Emphasis Type="Italic"> Bradyrhizobium</Emphasis> and<Emphasis Type="Italic"> Agrobacterium</Emphasis> strains isolated from cultivated legumes

The present study was conducted to isolate and characterize rhizobial strains from root nodules of cultivated legumes, i.e. chickpea, mungbean, pea and siratro. Preliminary characterization of these isolates was done on the basis of plant infectivity test, acetylene reduction assay, C-source utilization, phosphate solubilization, phytohormones and polysaccharide production. The plant infectivity test and acetylene reduction assay showed effective root nodule formation by all the isolates on their respective hosts, except for chickpea isolate Ca-18 that failed to infect its original host. All strains showed homology to a typical Rhizobium strain on the basis of growth pattern, C-source utilization and polysaccharide production. The strain Ca-18 was characterized by its phosphate solubilization and indole acetic acid (IAA) production. The genetic relationship of the six rhizobial strains was carried out by random amplified polymorphic DNA (RAPD) including a reference strain of Bradyrhizobium japonicum TAL-102. Analysis conducted with 60 primers discriminated between the strains of Rhizobium and Bradyrhizobium in two different clusters. One of the primers, OPB-5, yielded a unique RAPD pattern for the six strains and well discriminated the non-nodulating chickpea isolate Ca-18 from all the other nodulating rhizobial strains. Isolate Ca-18 showed the least homology of 15% and 18% with Rhizobium and Bradyrhizobium, respectively, and was probably not a (Brady)rhizobium strain. Partial 16S rRNA gene sequence analysis for MN-S, TAL-102 and Ca-18 strains showed 97% homology between MN-S and TAL-102 strains, supporting the view that they were strains of B. japonicum species. The non-infective isolate Ca-18 was 67% different from the other two strains and probably was an Agrobacterium strain.     

Realizing value of genetic resources of <Emphasis Type="Italic">Allium</Emphasis> in India

The genetic resources of Allium in India are potential source of genes for widening the crop genetic base. Despite their high economic value, limited number of germplasm accessions of wild species have been collected and conserved mainly due to difficult access to areas of occurrence. The present work mainly highlights information on species diversity distribution and utilization of wild Allium species to assess the value of Indian germplasm and prioritization for future collection and conservation programmes.     

<Emphasis Type="Italic">Trichoderma</Emphasis> improves the growth of <Emphasis Type="Italic">Leymus chinensis</Emphasis>

Bio-fertilizer application has been proposed as a strategy for enhancing soil fertility, regulating soil microflora composition, and improving crop yields, and it has been widely applied in the agricultural yields. However, the application of bio-fertilizer in grassland has been poorly studied. We conducted in situ and pot experiments to investigate the practical effects of different fertilization regimes on Leymus chinensis growth, with a focus on the potential microecological mechanisms underlying the responses of soil microbial composition. L. chinensis biomass was significantly (P?<?0.05) increased by treatment with 6000 kg ha^?1 of Trichoderma bio-fertilizer compared with other treatments. We found a positive (R² =?0.6274, P <?0.001) correlation between bacterial alpha diversity and L. chinensis biomass. Hierarchical cluster analysis and nonmetric multidimensional scaling (NMDS) revealed that soil bacterial and fungal community compositions were all separated according to the fertilization regime used. The relative abundance of the most beneficial genera in bio-fertilizer (BOF) (6000 kg ha^?1Trichoderma bio-fertilizer) was significantly higher than in organic fertilizer (OF) (6000 kg ha^?1 organic fertilizer) or in CK (non-amend fertilizer), there the potential pathogenic genera were reduced. There were significant negative (P?<?0.05) correlations between L. chinensis biomass and the relative abundance of several potential pathogenic genera. However, the relative abundance of most beneficial genera were significantly (P?<?0.05) positively correlated with L. chinensis biomass. Soil properties had different effects on these beneficial and on these pathogenic genera, further influencing L. chinensis biomass.     

PCR Marker-based Analysis of Wild and Cultivated Yams (<Emphasis Type="Italic">Dioscorea</Emphasis> spp.) in Nigeria: Genetic Relationships and Implications for <Emphasis Type="Italic">ex situ</Emphasis> Conservation

Reliable characterization of the variation among wild and cultivated yams in Nigeria is essential for improved management and efficient utilization of yam genetic resources. RAPD and double stringency PCR (DS-PCR) analyses were used to investigate genetic relationships and the extent of redundancy among 30 accessions of two cultivated, and 35 accessions of four wild yam species collected from Nigeria. Twenty-five selected random decamer and two microsatellite primers were used individually and in combination to generate DNA profiles for each accession of the six Dioscorea species. The number of amplified fragments varied from 7 to 18 fragments per primer/primer combination. Different levels of intraspecific genetic diversity were found, with Dioscorea rotundata Poir. being the most variable. Based on identical profiles for the RAPD and DS-PCR primers, 12 duplication groups consisting of a total number of 37 accessions were observed in the present study. An UPGMA analysis grouped the majority of plants according to the species. Cultivated yams belonging to the D. cayenensis–rotundata species complex, which were classified into seven morphotypes/varietal groups, could be clearly separated into two major groups corresponding to D. rotundata Poir. and D. cayenensis Lam. D. cayenensis cultivars exhibited a low level of intraspecific variation and were genetically close to the wild species Dioscorea burkilliana J. Miège. D. rotundata cultivars classified into six varietal groups showed a high degree of DNA polymorphism and were separated into two major groups that appeared most closely related to Dioscorea praehensilis Benth. and Dioscorea liebrechtsiana de Wild. We propose, based on these results, that cultivars classified into D. cayenensis should be considered as a taxon separate from D. rotundata. The implications of intraspecific variability for the ex situ conservation of wild and cultivated yam germplasm in Nigeria are discussed.     

<Emphasis Type="Italic">Achromobacter insolitus</Emphasis> and <Emphasis Type="Italic">Zoogloea ramigera</Emphasis> associated with wheat plants (<Emphasis Type="Italic">Triticum aestivum</Emphasis>)

This study reports for the first time the presence of diazotrophic bacteria belonging to the genera Achromobacter and Zoogloea associated with wheat plants. These bacterial strains were identified by the analysis of 16S rDNA sequences. The bacterium IAC-AT-8 was identified as Azospirillum brasiliense, whereas isolates IAC-HT-11 and IAC-HT-12 were identified as Achromobacter insolitus and Zoogloea ramigera, respectively. A greenhouse experiment involving a non-sterilized soil was carried out with the aim to study the endophytic feature of these strains. After 40 days from inoculation, all the strains were in the inner of roots, but they were not detected in soil. In order to assess the location inside wheat plants, an experiment was conducted under axenic conditions. Fifteen days after inoculation, preparations of inoculated plants were observed by the scanning electron microscope, using the cryofracture technique, and by the transmission electron microscope. It was observed that all isolates were present on the external part of the roots and in the inner part at the elongation region, in cortex cells, but not in the endodermis or in the vascular bundle region. No colonizing bacterial cells were observed in wheat leaves.     

Evaluation of genetic resources in the genus <Emphasis Type="Italic">Asparagus</Emphasis> for resistance to <Emphasis Type="Italic">Asparagus virus 1</Emphasis> (AV-1)

Forty-four Asparagus officinalis cultivars, gene bank accessions and breeding lines as well as thirty-four accessions of wild relatives of Asparagus were evaluated for resistance to Asparagus virus 1. Three different test strategies were developed for the assessment of individual plants: (1) natural infection under field conditions, or two vector-mediated infection assays using the green peach aphid Myzus persicae (2) in an insect-proof gauze cage or (3) in a climate chamber. The AV-1 infections were verified by DAS-ELISA and RT-PCR approaches. All tested 660 individual plants of A. officinalis germplasm were susceptible to AV-1 infection. In contrast, in 276 plants of 29 Asparagus wild accessions no virus infection could be detected. These resistant accessions comprised of nineteen diploid, tetraploid and hexaploid species of both the Eurasian clade and the African clade of the asparagus germplasm. Data of the AV-1 resistance evaluation are discussed in relation to the genetic distance of the resistance carrier and potential application in breeding.     

Adult plant resistance to <Emphasis Type="Italic">Puccinia triticina</Emphasis> in a geographically diverse collection of <Emphasis Type="Italic">Aegilops tauschii</Emphasis>

Despite extensive genetics and breeding research, effective control of leaf rust caused by Puccinia triticina Eriks. and an important foliar disease of wheat, has not been achieved. This is mainly due to the widespread use of race-specific seedling resistance genes, which are rapidly overcome by new virulent races. There is increased emphasis now on the use of race-nonspecific adult plant resistance (APR) genes for durable control of leaf rust. The objective of this study was the evaluation of Aegilops tauschii Coss. (the D-genome donor of bread wheat) for APR, previously known to be a rich source of seedling resistance genes to leaf rust. A geographically diverse collection of A. tauschii maintained by the Wheat Genetics Resource Center was evaluated for APR in the field with a leaf rust composite culture of predominant races. Out of a total of 371 A. tauschii accessions, 50 with low to moderate levels of disease severity were subsequently tested at the seedling stage in the greenhouse with four races and one composite culture of leaf rust. Nine accessions displayed moderate resistance to one or more races of leaf rust at the seedling stage. The remaining 41 seedling-susceptible accessions are potential sources of new APR genes. Accessions from Afghanistan only displayed APR whereas both seedling resistance and APR were common in the Caspian Sea region (Iran and Azerbaijan). The APR in these newly identified A. tauschii accessions will be further characterized for novelty, effectiveness, and race-specificity.