Genetic diversity and gene-pool subdivisions of diploid D-genome <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Coss. (Poaceae) in Iran as revealed by AFLP

The diploid goatgrass Aegilops tauschii is considered the D-genome donor of bread wheat and has probably a centre of diversity in north of Iran. In order to measure the genetic diversity of and the relationships among different populations, varieties and subspecies belonging to Ae. tauschii in Iran, DNA was extracted from 48 accessions of Ae. tauschii collected across the geographic range of the species in the Country and the genetic diversity was assessed using AFLPs based on eight PstI/MseI +3 primer pairs resulted in 277 bands, 198 of which were polymorphic. High level polymorphism was detected, with an average of polymorphism rate of 0.715; relatively low genetic similarity (0.455) between accessions and significant difference between the lowest (0.179) and the highest genetic similarity (0.817). The Iranian Ae. tauschii populations showed high level of genetic diversity. The populations studied were divided into two groups: one group was mainly representing Northern populations collected from Southern Caspian Sea shore and the other group was mainly representing Northeast and Northwest populations. Based on the results of this study, it can be suggested that Ae. tauschii possesses two separate gene-pools in Iran: Northern and Northeastern–Northwestern. Considering the needs for introducing new characteristics and alleles for wheat improvement purposes, Ae. tauschii Iranian gene-pool is assumed to be of high importance for more investigation in the future.     

Microsatellite analysis of genetic diversity and population genetic structure of <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Coss. in Northern Iran

Genetic diversity and population genetic structure of Aegilops tauschii in Northern Iran were studied based on nine microsatellite loci. A high level of genetic diversity was observed from the accessions collected from six regions (provinces). These accessions include 79 samples of the two subspecies (tauschii and strangulata), the intermediate form (among morphologically distinguished subspecies) and ten accessions of Triticum aestivum. The nine microsatellites revealed a total of 141 alleles, with an average of 15.7 alleles per locus. A comparison of the parameters showing genetic diversity, including the observed heterozygosity (Ho), gene diversity (He) and Shannon’s information index (I) of Ae. tauschii accessions from different provinces in Northern Iran, indicated that subsp. tauschii possesses the highest genetic diversity, followed by intermediate form. Genetic distance between subsp. strangulata and subsp. tauschii was low, confirming high gene flow between these two subspecies. However, intermediate form was more distinct from both of them. It was also found that the genetic diversity of T. aestivum is obviously lower than that of Ae. tauschii accessions. Moreover, the level of genetic diversity for Gilan, Golestan and Mazanderan provinces was higher than for Ardebil, Ghazvin and Semnan provinces, suggesting that these regions may provide a readily available source of potentially useful variation for wheat improvement.     

Stripe rust resistance in <Emphasis Type="Italic">Aegilops tauschii</Emphasis> and its genetic analysis

Aegilops tauschii Coss., the D-genome progenitor of common wheat (Triticum aestivum L.) includes two subspecies, tauschii and strangulata (Eig) Tzvel. Subspecies tauschii has a wide geographic distribution spreading westwards to Turkey and eastwards to Afghanistan and China, while ssp. strangulata has a narrower distribution occurring only in two disjoined regions, southeastern Caspian Iran and Transcaucasia. A collection of 56 Ae. tauschii accessions was screened at adult stage against a mixture of pathotypes of stripe rust prevalent in the current wheat production in China. The results for three crop seasons indicated that among the 38 ssp. tauschii accessions, 37 were susceptible and only one was resistant, while all the 18 ssp. strangulata accessions were resistant. These results indicated that stripe rust resistance was related to taxonomic origin. Further genetic analysis revealed the resistance of stripe rust in ssp. strangulata accession AS2388 was conferred by a single dominant gene.     

Red List assessment of nine <Emphasis Type="Italic">Aegilops</Emphasis> species in Armenia

The aims of this study are to determine the geographical and ecological distribution of nine Aegilops species in Republic of Armenia and to make an assessment of their IUCN Red List status, using the IUCN Red list categories and criteria, in order to develop an in situ conservation strategy for wild relatives of wheat in Armenia. Ecogeographic surveys of nine Aegilops species were undertaken over 2 years in Armenia. They included a herbarium survey followed by extensive ground-truthing field surveys where targeted Aegilops species occur. The study showed that of the nine Aegilops species studied, four are threatened and of these, Ae. mutica and Ae. crassa are critically endangered. The latter species may even be extinct in Armenia. Ae. neglecta and A. biuncialis are endangered. Additional studies are required to assess the threat status of Ae. umbellulata. Ae. columnaris was assessed as near threatened, while the remaining species (Ae. triuncialis, Ae. cylindrica and Ae. tauschii) are of least concern. There has been a dramatic decline in the genetic resources of Aegilops species during recent years in Armenia as a result of adverse human impacts such as expansion of agriculture, urbanization and uncontrolled grazing. Several species, especially Ae. mutica and Ae. crassa, should be prioritized in conservation activities in Armenia. Efforts should be made to conserve genetic diversity of crop wild relative species both in situ and ex situ, bearing in mind that their germplasm carries potentially valuable information (traits) that can improve adaptability and productivity of cultivated wheat varieties.     

Diversity analysis of Central Asia and Caucasian lentil (<Emphasis Type="Italic">Lens</Emphasis><Emphasis Type="Italic">culinaris</Emphasis> Medik.) germplasm using SSR fingerprinting

Diversity analysis was performed among 39 cultivated lentil (Lens culinaris Medik.) accessions of Central Asia and Caucasian origin using five highly polymorphic microsatellite markers. A total of 33 alleles determined ranging from 3 to 8 per locus. Estimated gene diversity value for 33 loci was 0.66. Genetic similarity indices among 39 accessions ranged from 0.24 to 1.0. Cluster analysis using the unweighted pair group method with arithmetic mean method classified accessions into six major groups at 0.5 similarity coefficient. More than half accessions from Tajikistan formed large cluster. On the other hand, a few accessions from each country showed unique genotypes. Overall, most of the accessions, except ones with closely related origin, were distinguished by the present high quality DNA fingerprinting. This molecular diversity information gives important basis for conservation strategy in gene bank and exotic germplasm introduction in breeding programs in Central Asia and Caucasian countries.     

Polymorphism of <Emphasis Type="Italic">Got2</Emphasis> DNA sequences sheds light on <Emphasis Type="Italic">Aegilops tauschii</Emphasis> Coss. intraspecies divergence and origin of <Emphasis Type="Italic">Triticum aestivum</Emphasis> L.

DNA sequences of nuclear gene Got2 was studied in 60 accessions of Aegilops tauschii, 29 of subsp. tauschii and 31 of subsp. strangulata. It was found that Got2 allozyme polymorphism in Ae. tauschii is due to a single, unique, mutation which led to replacement of glutamic acid by isoleucine in residue 256 of the enzyme molecule, encoded by Got2. As revealed by Got2 DNA sequences variation, initially in its history Ae. tauschii was presented by subsp. strangulata, and among phylogenetic lineages of subsp. strangulata, the lineage “t-9¹s” (TauL3) is the most ancient, a relict one. Subspecies tauschii is relatively “young”. Initially it was presented by the lineage marked by combination of allozyme alleles Got2 ¹⁰⁵ and Acph1 ¹⁰⁰. In the past it inhabited the Continental area from Caucasia to Pakistan, but later on it was forced out by newly originated, now—a major lineage of subsp. tauschii, marked by Got2 ¹⁰⁰. This lineage extended the Continental area of the species up to Kirgizstan, but actually failed to penetrate into pre-Caspian area, occupied by subsp. strangulata. These results essentially differ from those obtained previously, using chloroplast DNA (cpDNA) sequences polymorphism. As revealed by cpDNA, the major, “usual”, subsp. strangulata (TauL2) is “younger” than subsp. tauschii, which resided on phylogenetic tree between relict lineage “t-9¹s”of subsp. strangulata—and major subsp. strangulata. But both cpDNA and Got2 DNA sequences indicate that the level of genetic variation in subsp. tauschii is much lower than in subsp. strangulata. According to Got2 DNA sequences variation, it was Ae. tauschii subsp. strangulata lineage “k-109″ which donated genome D to Triticum aestivum L. This lineage includes accessions: k-109 from South-Eastern Precaspian Azerbaijan; KU-2105, KU-2159 from Western Precaspian Iran; KU-2080 from Eastern Precaspian Iran.     

Evaluation and utilization of <Emphasis Type="Italic">Aegilops</Emphasis> and wild <Emphasis Type="Italic">Triticum</Emphasis> species for enhancing iron and zinc content in wheat

Grains of 80 accessions of nine species of wild Triticum and Aegilops along with 15 semi-dwarf cultivars of bread and durum wheat grown over 2 years at Indian Institute of Technology, Roorkee, were analyzed for grain iron and zinc content. The bread and durum cultivars had very low content and little variability for both of these micronutrients. The related non-progenitor wild species with S, U and M genomes showed up to 3–4 folds higher iron and zinc content in their grains as compared to bread and durum wheat. For confirmation, two Ae. kotschyi Boiss. accessions were analyzed after ashing and were found to have more than 30% higher grain ash content than the wheat cultivars containing more than 75% higher iron and 60% higher zinc than that of wheat. There were highly significant differences for iron and zinc contents among various cultivars and wild relatives over both the years with very high broad sense heritability. There was a significantly high positive correlation between flag leaf iron and grain iron (r = 0.82) and flag leaf zinc and grain zinc (r = 0.92) content of the selected donors suggesting that the leaf analysis could be used for early selection for high iron and zinc content. ‘Chinese Spring’ (Ph ^I ) was used for inducing homoeologous chromosome pairing between Aegilops and wheat genomes and transferring these useful traits from the wild species to the elite wheat cultivars. A majority of the interspecific hybrids had higher leaf iron and zinc content than their wheat parents and equivalent or higher content than their Aegilops parents suggesting that the parental Aegilops donors possess a more efficient system for uptake and translocation of the micronutrients which could ultimately be utilized for wheat grain biofortification. Partially fertile to sterile BC₁ derivatives with variable chromosomes of Aegilops species had also higher leaf iron and zinc content confirming the possibility of transfer of required variability. Some of the fertile BC₁F₃ and BC₂F₂ derivatives had as high grain ash and grain ash iron and zinc content as that of the donor Aegilops parent. Further work on backcrossing, selfing, selection of fertile derivatives, leaf and grain analyses for iron and zinc for developing biofortified bread and durum wheat cultivars is in progress. Nidhi Rawat, Vijay K. Tiwari, and Neelam Singh have contributed equally to the work.     

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.     

Genetic Characterization of Brazilian Annual <Emphasis Type="Italic">Arachis</Emphasis> Species from Sections <Emphasis Type="Italic">Arachis</Emphasis> and <Emphasis Type="Italic">Heteranthae</Emphasis> using RAPD Markers

The genus Arachis is divided into nine taxonomic sections. Section Arachis is composed of annual and perennial species, while section Heteranthae has only annual species. The objective of this study was to investigate the genetic relationships among 15 Brazilian annual accessions from Arachis and Heteranthae using RAPD markers. Twenty-seven primers were tested, of which nine produced unique fingerprintings for all the accessions studied. A total of 88 polymorphic fragments were scored and the number of fragments per primer varied from 6 to 17 with a mean of 9.8. Two specific markers were identified for species with 2n = 18 chromosomes. The phenogram derived from the RAPD data corroborated the morphological classification. The bootstrap analysis divided the genotypes into two significant clusters. The first cluster contained all the section Arachis species, and the accessions within it were grouped based upon the presence or absence of the ‘A’ pair and the number of chromosomes. The second cluster grouped all accessions belonging to section Heteranthae.     

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.     

Genetic diversity of HMW glutenin subunits in diploid,tetraploid and hexaploid <Emphasis Type="Italic">Triticum</Emphasis> species

The genetic variations of high-molecular-weight (HMW) glutenin subunits in 1051 accessions of 13 Triticum subspecies were investigated using sodium dodecyl sulfate polyacrylamide-gel electrophoresis. A total of 37 alleles were detected, resulting in 117 different allele combinations, among which 20, 68 and 29 combinations were observed in diploid, tetraploid and hexaploid wheats, respectively. Abundance and frequency of allele and combinations in tetraploid wheats were higher than these in hexaploid wheats. Allele Glu-A1c was the most frequent subunit at Glu-A1 locus in tetraploid and hexaploid wheats. Consequently, the results also suggested that the higher variations occurred at Glu-B1 locus compared to Glu-A1 and Glu-D1. Therefore, carthlicum wheat possessing the allele 1Ay could be presumed a special evolutional approach distinguished from other tetraploid species. Furthermore, this provides a convenient approach of induction of the 1Ay to common wheat through direct cross with carthlicum wheat. Alleles Glu-B1c and Glu-B1i generally absent in tetraploid wheats were also found in tetraploid wheats. Our results implied that tetraploid and hexaploid wheats were distinguished in dendrogram, whereas carthlicum and spelta wheats and however displayed the unique performance. In addition, founder effect, no-randomness of diploidization, mutation and artificial selection could cause allele distribution of HMW-GS in Triticum. All alleles of HMW-GS in Triticum could be further utilized through hybrid in the quality improvement of common wheat.     

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.     

Transfer of leaf rust and stripe rust resistance from <Emphasis Type="Italic">Aegilops umbellulata</Emphasis> Zhuk. to bread wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Aegilops umbellulata acc. 3732, an excellent source of resistance to major wheat diseases, was used for transferring leaf rust and stripe rust resistance to cultivated wheat. An amphiploid between Ae. umbellulata acc. 3732 and Triticum durum cv. WH890 was crossed with cv. Chinese Spring Ph ^I to induce homoeologous pairing between Ae. umbellulata and wheat chromosomes. The F₁ was crossed to the susceptible Triticum aestivum cv. ‘WL711’ and leaf rust and stripe rust resistant plants were selected among the backcross progenies. Homozygous lines were selected and screened against six Puccinia triticina and four Puccinia striiformis f. sp. tritici pathotypes at the seedling stage and a mixture of prevalent pathotypes of both rust pathogens at the adult plant stage. Genomic in situ hybridization in some of the selected introgression lines detected two lines with complete Ae. umbellulata chromosomes. Depending on the rust reactions and allelism tests, the introgression lines could be classified into two groups, comprising of lines with seedling leaf rust resistance gene Lr9 and with new seedling leaf rust and stripe rust resistance genes. Inheritance studies detected an additional adult plant leaf rust resistance gene in one of the introgression lines. A minimum of three putatively new genes—two for leaf rust resistance (LrU1 and LrU2) and one for stripe rust resistance (YrU1) have been introgressed into wheat from Ae. umbellulata. Two lines with no apparent linkage drag have been identified. These lines could serve as sources of resistance to leaf rust and stripe rust in breeding programs.     

Genetic diversity of Swiss maize (<Emphasis Type="Italic">Zea mays</Emphasis> L. ssp. <Emphasis Type="Italic">mays</Emphasis>) assessed with individuals and bulks on agarose gels

About 65 years ago, more than 150 Swiss maize landraces (Zea mays L. ssp. mays) of the flint type were collected and conserved ex situ. Due to the climatically and culturally diverse environment of the Alps, a considerable genetic diversity of this material was assumed. To prove this, an efficient method was required to carry out genetic profiling of all the accessions in the Swiss Gene Bank. Simple sequence repeat marker (SSR) profiling in combination with the visualization of the polymerase chain reaction (PCR) products on agarose gels was chosen. Here a set of 19 different landrace accessions was analyzed to: (i) investigate their genetic diversity, (ii) investigate and display the population structure and (iii) determine whether DNA bulks rather than single plants can be used for such analyses. Four repeated samples of one accession were found to be much closer to one another than to the rest of accessions. Furthermore, specific alleles were identified for several accessions. The PCR products of the bulked DNA samples represented only a small part of the variation revealed by the analysis of individuals. Loci with four base repeat motifs performed better in the analysis of bulks than loci with other repeat motifs. The correlation between genetic distance matrices, based on the analysis of individuals and bulks, respectively, was significant. Thus, the single plant approach allowed for sufficient differentiation of accessions, and DNA bulks visualized on agarose gels led to correlated genetic distances although a limited number of alleles were detected. Although the limited resolution of agarose gels likely causes some bias, profiling of larger sets with the individual plant approach appears feasible and more informative compared to the bulk analysis we conducted.     

Development and utilization of diagnostic DAMD-PCR markers for <Emphasis Type="Italic">Capsicum</Emphasis> accessions

A polymerase chain reaction (PCR) based approach involving the directed amplification of minisatellite DNA region (DAMD-PCR) was used to identify accession specific DNA markers and study genetic relationships between and within 15 accessions corresponding to 11 species in genus Capsicum. A touch down PCR profile and unique chemical concentration of ingredients resulted in reproducible and reliable DNA amplifications. The number of amplified products varied from 1 to 12 fragments depending on the template DNA and the primers. The DAMD-PCR technique provided a total of 38 accession specific DNA markers (diagnostic DAMD-PCR) which can be utilized in accession identification, preservation and genetic studies of Capsicum germplasm. Based on 1,292 polymorphic and monomorphic DNA markers directed with 22 minisatellite specific primers, accessions were divided into four major groups, three of which corresponded to the three distinct Capsicum complexes. Capsicum chacoense was found to be the most distinct species.     

Identification of <Emphasis Type="Italic">Aegilops</Emphasis> L. species and <Emphasis Type="Italic">Triticum aestivum</Emphasis> L. based on chloroplast DNA

The genus Aegilops L. is a very important genetic resource for the breeding of bread wheat Triticum aestivum. Therefore, an accurate and easy identification of Aegilops species is required. Traditionally, identification of Aegilops species has relied heavily on morphological characters. These characters, however, are either not variable enough among Aegilops species or too plastic to be used for identification at the species level. Molecular markers that are more stable within species, therefore, could be the alternative strategy towards an accurate identification. Since the chloroplast DNA has a lower level of evolution compared to the nuclear genome, an attempt was made in this study to investigate polymorphism in the chloroplast DNA among 21 Aegilops species (including Ae. mutica that is now known as Amblyopyrum muticum) and between the latter and T. aestivum to generate markers for the diagnosis of all targeted species. Cleaved amplified polymorphic sequence (CAPS) applied on 22 coding and non-coding chloroplast regions using 80 endonucleases and sequencing of two of those regions revealed little polymorphism between T. aestivum and the various Aegilops species examined and to a less extent was the variation among Aegilops species. Polymorphism observed among species analysed allowed the discrimination of T. aestivum and 12 Aegilops species.     

Microsatellite diversity and effective population size in a germplasm bank of <Emphasis Type="Italic">Hymenaea courbaril</Emphasis> var. <Emphasis Type="Italic">stilbocarpa</Emphasis> (Leguminosae), an endangered tropical tree: recommendations for conservation

Deforestation in southeast Brazil has led to the extinction of Hymenaea courbaril var. stilbocarpa and ex situ conservation has been established. In this study, the levels of genetic diversity and the effective population size of H. courbaril in a germplasm bank were investigated using six nuclear microsatellite loci. A total of 79 and 91 alleles were found in 65 seed-trees and their 176 offspring, respectively. Offspring have a higher average number of alleles per locus (A = 15.2) than seed-trees (A = 13.2), but lower observed heterozygosity (offspring: H _o = 0.566; seed-trees: H _o = 0.607). The estimate of outcrossing rate shows that the study population is perfectly outcrossed (t _m  = 0.978, P > 0.05). Significant deviations from random mating were detected through mating among relatives and correlated matings. The average variance in effective population size for each family was 2.63, with a total effective population size retained in the bank of 170.1. These results confirm that the preserved population of H. courbaril retains substantial genetic variability. Moacyr Antonio Mestriner and Ana Lilia Alzate-Marin—CEEFLORUSP Members.     

Powdery mildew resistance in Aegilops tauschii coss. and synthetic hexaploid wheats

Summary A collection of 400 Ae. tauschii (syn. Ae. squarrosa) Coss. accessions were screened for powdery mildew resistance based on the response patterns of 13 wheat cultivars/lines possessing major resistance genes to nine differential mildew isolates. 106 accessions showed complete resistance to all isolates, and 174 accessions revealed isolate-specific resistance, among which were 40 accessions exhibiting an identical response pattern as wheat cultivar Ulka/^*8Cc which is known to possess resistance gene Pm2. Expression of both complete and isolate-specific resistance from Ae. tauschii was observed in some synthetic hexaploid wheats derived from four mildew susceptible T. durum Desf. parents, each crossed with five to 38 resistant diploid Ae. tauschii accessions. Synthetic amphiploids involving different combinations of T. durum and Ae. tauschii generally showed a decrease in resistance compared with that expressed by the Ae. tauschii parental lines.     

Analysis of the geographic distribution and relationships among Peruvian wild species of <Emphasis Type="Italic">Arracacia</Emphasis>

Relationships between Arracacia species were studied according to 28 morphological discriminant characters, in 90 accessions: 83 Arracacia (Arracacia elata, A. incisa and A. xanthorrhiza), and seven accessions of Neonelsonia acuminata, which has been confused with A. elata. The geographic distribution of the Arracacia species was determined from the passport data of the 90 accessions. A. elata was clearly differentiated from N. acuminata according to morphological characteristics. The species A. incisa was more closely related to A. xanthorrhiza. Within A. xanthorrhiza two forms, monocarpic, and polycarpic, were identified. The distribution of wild Arracacia species in Peru is characterized by two main ecological zones: (1) a dry zone, like the western Yunga and western and inter-Andean valleys of the Quechua region (with seasonal rain from November to March), where the species A. incisa and A. xanthorrhiza are present, and (2) a humid zone, like the Eastern Quechua where A. elata is adapted. These informations could be useful to establish strategies for in situ and ex situ conservation and management of germplasm.     

Cross-transferability of SSR markers in <Emphasis Type="Italic">Osmanthus</Emphasis>

Developing a molecular tool kit for hybrid breeding of Osmanthus species and related genera is an important step in creating a systematic breeding program for this species. To date, molecular resources have been aimed solely at Osmanthus fragrans with little work to develop markers for other species and cultivars. The objectives of this study were to (1) determine cross-transferability of O. fragrans and Chionanthus retusus derived SSRs in diverse Osmanthus taxa, (2) quantify the influence of locus-specific factors on cross-transferability, and (3) determine the genetic relationships between accessions. We tested 70 SSR markers derived from O. fragrans and C. retusus in 24 accessions of Osmanthus. Sixty-seven markers showed transfer to at least one other Osmanthus species with an overall transfer rate of 84% of loci across taxa. Genotyping with 42 microsatellite markers yielded a total of 367 loci. Number of alleles per locus ranged from 2 to 17 with a mean of 8.7 ± 4.8. Mean observed and expected heterozygosities were 0.560 ± 0.225 and 0.688 ± 0.230, respectively. Percent of polymorphic loci ranged from 40% in Osmanthus delavayi to 100% in O. fragrans. Osmanthus fragrans had the highest mean number of alleles per locus (4.2) while O. delavayi had the lowest (1.1). A reduced suite of eight-markers can distinguish between accessions with non-exclusion probabilities of identity from 3.91E?⁰⁴ to 2.90E?⁰⁷. The SSR markers described herein will be immediately useful to characterize germplasm, identify hybrids, and aid in understanding the level of genetic diversity and relationships within the cultivated germplasm.