Diversity and differentiation of <Emphasis Type="Italic">Oryza sativa</Emphasis> and <Emphasis Type="Italic">O. rufipogon</Emphasis> in Indonesia

Analysis of the genetic structure of Indonesian Oryza sativa and O. rufipogon using neighbour-joining trees based on single nucleotide polymorphism (SNP) and simple sequence repeat (SSR) markers revealed that O. sativa in Indonesia is separated from O. rufipogon. Accessions of O. sativa in this study were differentiated into two major groups, indica and tropical japonica, excluding some varieties. SSR and SNP markers revealed the high value of differentiation (F _ST) and genetic distance (D) between indica and tropical japonica and we discovered four loci by SNP markers and one locus by SSR markers that play a role in differentiation between indica and tropical japonica. Interestingly, genetic diversity (H) in O. rufipogon was lower than that in O. sativa, however H in O. rufipogon was the highest and H in tropical japonica was the lowest when O. sativa was divided into two groups. Inbreeding coefficient (Fst) showed evidences that gene flow (Nm) between species and within species might be one of the mechanisms related to the diversification and differentiation of Indonesian rice germplasm by asymmetric pattern between species and within O. sativa as revealed by SSR and SNP markers. In addition, we found evidences on stabilizing selection in Indonesian rice germplasm and they might be the reasons why Indonesian rice germplasm did not differentiate due to source location of landrace. However, we found a weak relation between SSR and SNP markers probably due to highly polymorphic in SSR and the different properties of both markers.     

Genetic diversity of Bolivian wild potato germplasm: changes during ex situ conservation management and comparisons with resampled in situ populations

Potato wild relatives are important sources of novel variation for the genetic improvement of the cultivated potato. Consequently, many natural populations have been sampled and were deposited as accessions in gene banks around the world. Here we investigate to what extent the genetic variation of Bolivian wild potato species is maintained under gene bank conditions and how this diversity relates to that of current in situ populations. For this purpose, materials from seven potato species were screened for microsatellite variation. Genetic changes between different generations of ex situ germplasm were not observed for Solanum leptophyes and S. megistacrolobum, but were detected for S. neocardenasii and S. okadae, while each of the species S. acaule, S. avilesii and S. berthaultii showed stability in some cases and genetic change in others. The observed changes were ascribed to genetic drift and contamination resulting from human error during regeneration. Re-collected populations of six of the studied species showed highly significant genetic differences with the ex situ accessions that, apart from changes during ex situ maintenance, are most likely to be attributed to sampling effects during collecting and in situ genetic changes over time. The implications of the results for ex situ and in situ conservation strategies of wild potato species are discussed.     

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.     

Characterization of wild Beta populations in and adjacent to sugar beet fields in the Imperial Valley,California

Populations of wild Beta L. species exist as weeds in commercial sugar beet (Beta vulgaris L. subspecies vulgaris) fields in the Imperial Valley, California. Significant losses to sugar yield and quality result if these wild plants are not removed. In cases of extreme infestation, fields are abandoned without harvest. No selective chemicals are available to differentiate conventional sugar beet from wild relatives and hand removal is labor intensive and expensive. Planting sugar beet varieties with tolerance to glyphosate is a potential solution for infested fields, but risk of gene flow to adjacent wild relatives must be determined. Previous research identified these populations as either Beta vulgaris L. subspecies maritima (L.) Arcang. or Beta macrocarpa Guss. This distinction is critical because B. v. subsp. maritima will readily cross hybridize with cultivated sugar beet while B. macrocarpa rarely will. In April 2011, we collected herbarium samples, mature seed, and leaf tissue from wild Beta populations in 25 infested sugar beet fields throughout the Imperial Valley. Bolting cultivated beets were identified at two locations. Taxonomy of whole plant herbarium samples was unclear due to wild beet stem elongation when under competition with sugar beet plants for canopy light. Morphology of plants from collected seed grown in non-competitive conditions assigned taxonomy of these populations to B. macrocarpa. We used molecular tools to determine the genetic structure of wild Beta populations throughout the Imperial Valley. Extracted DNA was genotyped with 22 simple sequence repeat molecular markers and evaluated for population structure. The bolting beet samples were clearly separated from the majority of B. macrocarpa samples, except for two. The remaining wild populations were further divided into two subgroups suggesting exchange of genetic information or a common ancestor.     

Genetic diversity,genetic structure and migration routes of wild <Emphasis Type="Italic">Brassica juncea</Emphasis> in China assessed by SSR markers

The wild Brassica juncea (L.) Czern. et Coss., systematically belonging to the genus Brassica L. in the Cruciferae family, has become a noxious weed for cropping systems nowadays. Here, simple sequence repeat (SSR) markers were applied to investigate the genetic diversity, genetic structure and migration routes of the wild B. juncea populations in China. The results showed that a total of 90 alleles, with extensive allelic diversity, were observed at the 11 SSR loci of the wild B. juncea. The STRUCTURE analysis indicated that all the 25 wild populations were best described as belonging to two lineages. High Fst value (0.568), together with the partitioning, provided significant evidence for lineage differentiation in wild B. juncea. The high differentiation between the two lineages was, perhaps, due to limited gene flow (Nm?=?0.301) of this species. The analysis of molecular variance with distances among individuals corrected for the dominant nature of SSRs showed that most of the variation (59%) occurred within populations, and the remaining 41% variance was attributed to differences among populations. The distribution of diversity across China was significantly geographically dependent. NJ cluster analysis, based on genetic distance, grouped populations geographically, which further corroborated spatial pattern of two lineages. Based on these results, two routes were proposed for the migration of wild B. juncea in China after its origin from northwest China, heading east along the Yellow River or Yangtze River, respectively. We concluded that China, especially the northwest, is one of the primary origins of B. juncea.     

Species delimitation,genetic diversity and structure of the European indigenous wild pear (<Emphasis Type="Italic">Pyrus pyraster</Emphasis>) in Saxony,Germany

The present study investigated genetic diversity, structure and hybridization in a collection of the endangered wild pear species Pyrus pyraster (L.) Burgd. A total of 278 putative ‘true type’ P. pyraster trees originating from seven populations in the federal state of Saxony in Germany were analyzed along with 35 pear cultivars commonly cultivated in Saxony. The genetic analysis was performed using nine nuclear microsatellite markers (ncSSR) and two paternally inherited chloroplast marker (cpDNA) amplifying in the intergenic spacer region trnQ–rps16 and the intron region rps16. On basis of the ncSSR dataset after STRUCTURE analysis 80 % of the wild pear individuals were assigned as ‘true type’ P. pyraster genotypes. The cpDNA analysis showed shared haplotypes in P. pyraster and P. communis but with an unequal frequency in both species. The analysis of molecular variance resulted in a moderate (ncSSR) and great (cpDNA) variation among ‘true type’ P. pyraster and the pear cultivars. The genetic diversity in the ‘true type’ P. pyraster populations was still high and the genetic structure between the populations low (ncSSR and cpDNA) indicating a genetic exchange between the populations by pollen and seeds. The clear discrimination between the P. pyraster and P. communis confirms our expectation of the existence of ‘true type’ P. pyraster individuals in the study area. The existing genetic integrity and the high genetic diversity argue for the implementation of preservation measures in P. pyraster.     

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.     

Genetic diversity in tolerance of wild <Emphasis Type="Italic">Avena</Emphasis> species to aluminium (Al)

An evaluation of diversity of aluminium (Al) tolerance of 180 genebank accessions of diploid, tetraploid and hexaploid of wild Avena species from the world collection of the N.I. Vavilov Institute of Plant Genetic Resources (VIR) showed that the accessions with a high degree of aluminium tolerance belonged to the diploids A. canariensis, A. longiglumis and A. wiestii, the tetraploids A. barbata, A. vaviloviana, and hexaploids A. ludoviciana and A. sterilis. A comparison of the data on Al tolerance with the soil conditions demonstrated that most highly tolerance accessions tend to be collected on different type of soils. According to the results of the principal component analysis, preliminary screening for Al tolerance can be carried out among hexaploid species with higher degree of plant resistance to pathogens.     

<Emphasis Type="Italic">Panax</Emphasis> species identification with the assistance of DNA data

Panax species have been used as medicinal plants in China and adjacent areas, but the difficulty in wild species identification based on morphological characters prevents the exploration and utilization of these resources. To assist in identifying the species, three plastid intergenic spacers and four nuclear genes of 129 samples from 20 different localities were sequenced to conduct the clustering analyses. P. stipuleanatus and P. notoginseng were relatively easy to be distinguished from other species based on morphological characters and clustering results. Three samples collected from Laos grouped together with those collected from Jinping (China), and they were all identified as P. vietnamensis. However, the fourth one LW4 had closer genetic relationship to P. notoginseng than to P. vietnamensis. Although they were morphologically different in petiolule length, the samples preliminarily identified as P. zingiberensis grouped together in the clustering analyses, and the results of STRUCTURE analysis suggested that samples collected from Zhenyuan shared some genetic component with P. vietnamensis. As for the samples identified as P. japonicus and P. wangianus, there were so many variations in leaves, rhizomes and rootstocks that it was difficult to differentiate them from each other. Molecular data also showed that these taxa were genetically admixed and the samples identified as P. wangianus could be classified into P. japonicus. The nucleotide diversity results indicated that the wild relatives had more substantial genetic diversity compared to P. notoginseng.     

Genetic diversity of cultivated rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) and wild rice (<Emphasis Type="Italic">Oryza rufipogon</Emphasis> Griff.) in Asia,especially in Myanmar,as revealed by organelle markers

Asian rice (Oryza sativa L.) is widely cultivated in Asia, where it has been classified into Indica and Japonica Group, the latter is further classified into Tropical and Temperate Japonica Subgroup. O. rufipogon is believed to be the closest ancestor to O. sativa, but it remains unclear whether the two groups arose from a single ancestor or different ancestors. Therefore, here, we investigated the matrilineal ancestors of O. sativa using markers for organelle (chloroplast and mitochondrial) genomes, and 119 O. sativa landraces, 10 O. glaberrima Steud., 115 O. rufipogon Griff. from Asia, and 39 accessions from other wild rice species with AA genomes. We screened 18 organelle markers developed based on polymorphic loci in the organelle genomes. In addition, we used the open reading frame 100 of a chloroplast marker. The results indicated that O. rufipogon first differentiated into two lineages and then further differentiated into Indica and Japonica Group, respectively. Accessions of O. rufipogon (R-1f and R-2d types) from Myanmar appear to be the closest ancestors of Tropical Japonica Subgroup and Indica Group, respectively. Therefore, these wild strains may have made a strong contribution to the domestication of rice landraces in Myanmar.     

Assessing genetic diversity of wild southeastern North American <Emphasis Type="Italic">Vaccinium</Emphasis> species using microsatellite markers

Wild species representatives from Northwestern, Central and Southern Florida, and neighboring U.S. states were collected in multiple United States Department of Agriculture (USDA) exploration expeditions and are being preserved at the USDA, Agricultural Research Service, National Clonal Germplasm Repository in Corvallis, Oregon. Germplasm from these southeastern regions of North America is particularly vulnerable to loss in the wild due to encroachment of human development in key habitats and biotic and abiotic stresses from climate change. Fourteen simple sequence repeats (SSRs), previously developed from the highbush blueberry (Vaccinium corymbosum) cultivar ‘Bluecrop’, were used to estimate genetic diversity and genetic differentiation of 67 diploid individuals from three species, including 19 V. elliottii, 12 V. fuscatum, and 35 V. darrowii accessions collected throughout the species’ ranges. Results from our analyses indicated that the samples from each species could be reliably resolved using genetic distance measures with ordination and neighbor joining approaches. In addition, we estimated admixture among these species by using Bayesian assignment tests, and were able to identify a mis-labeled accession of V. darrowii ‘Johnblue’, two mis-classified accessions (CVAC 735.001 and CVAC 1223.001), and four accessions of previously undescribed hybrid origin (CVAC 734.001, CVAC 1721.001, CVAC 1741.001, and Florida 4B CVAC 1790). Allele composition at the 14 SSRs confirmed that Florida 4B CVAC 1790, the donor of low chilling for the southern highbush blueberry, was the critical parent of US 74. Genetic diversity assessment and identification of these wild accessions are crucial for optimal germplasm management and expand opportunities to utilize natural variation in breeding programs.     

First insight into genetic diversity and population structure of the Caucasian wild apple (<Emphasis Type="Italic">Malus orientalis</Emphasis> Uglitzk.) in the Hyrcanian forest (Iran) and its resistance to apple scab and powdery mildew

Investigating population genetic structure and diversity, and resistance to pathogens in crop wild relatives are key steps to assess appropriate conservation and breeding programs. The Caucasian wild apple (Malus orientalis Uglitzk.) is an emblematic fruit tree of the Hyrcanian forest and is supposed to be a contributor to the cultivated apple genome (Malus domestica Borkh. Yet, no study has investigated its population structure, diversity and susceptibility to the two main pathogens of apples, the apple scab (Venturia inaqualis) and the powdery mildew (Podosphaera leucotricha). Here, we investigated population genetic structure and diversity of M. orientalis in the Hyrcanian forest as a mean to identifying future targeted populations for apple conservation and breeding programs. We genotyped using multilocus microsatellite 100 M. orientalis trees sampled in 14 sites. These trees were also screened for presence/absence of six (Rvi6, Vr, Rvi4, Rvi15, Rvi5 and Rvi11) and three (Pl-1, Pl-w, Pl-d) resistance genes to the apple scab and the powdery mildew respectively. Our results showed significant but weak between-site genetic differentiation and isolation by distance pattern suggesting substantial historical gene flow for M. orientalis in this area. We also detected a West-Eastern genetic structure across the Hyrcanian forest with five main populations showing admixture. We also showed a high diversity of resistance genes to apple scab across sites; in contrast, we only found one resistance gene to powdery mildew. These results are a first glimpse to settle wild apple conservation programs in Iran and pinpoint Iranian wild apple populations as an untapped source for apple breeding.     

Exploration of genetic diversity within Cichoriumendivia and Cichorium intybus with focus on the gene pool of industrial chicory

The present study used 15 simple sequence repeat loci to characterize the genetic diversity of the germplasm that originated the current industrial chicory and to establish the relationships between and inside Cichoriumintybus L. and Cichorium endivia L. Initially we analyzed 19 cultivated C. endivia accessions, 27 wild and 155 cultivated C. intybus accessions distributed among three groups: 83 root chicories, 42 Witloof and 30 leaf chicories. The leaf chicories comprised cultivars corresponding to the Radicchio, Sugarloaf and Catalogne subgroups. The latter has not been previously included in any genetic diversity study. Subsequently, 1297 individuals from the 15 modern root chicory cultivars at the origin of the breeding of the current industrial root chicory cultivars were analyzed. Although the accessions of C. endivia and C. intybus were clearly separated from each other, seven wild C. intybus individuals were genetically closer to C. endivia than to C. intybus, revealing complex genetic interrelationships between these species. The differentiation of C. intybus into three cultivar groups (Witloof, root chicory and leaf chicory) was confirmed. The leaf chicory individuals were divided into three genetic subgroups, corresponding to the Radicchio, Sugarloaf and Catalogne cultivars, thus attesting to the validity of the classification based on morphological factors. Clear differentiation was observed among the Belgian, Polish and Austrian modern industrial root cultivars, but not among the French industrial modern root cultivars. The high phenotypic and genetic variability of the modern industrial root cultivars indicates that this germplasm constitutes a useful gene pool for cultivar improvement and selection.     

Domestication and saponins contents in a gradient of management intensity of agaves: <Emphasis Type="Italic">Agave cupreata</Emphasis>, <Emphasis Type="Italic">A. inaequidens</Emphasis> and <Emphasis Type="Italic">A. hookeri</Emphasis> in central Mexico

Saponins occur in numerous plants, including agaves, determining benefic and harmful properties to humans; their presence may favor using plants as soap and other products, but also they may cause caustic effects producing contact dermatitis. In domestication, favorable and unfavorable properties of saponins may cause an increase or decrease of their content, respectively. This study quantified and identified saponins among wild and managed populations of three agave species: A. cupreata Trel. et Berger, A. inaequidens Koch with wild and cultivated populations used for mescal production, and A. hookeri Jacobi, existing exclusively cultivated, used for production of the fermented beverage pulque. We studied 272 plants from 19 populations, quantifying contents of crude saponins through spectrometry. In 12 populations, the saponins types were identified by High Performance Liquid Chromatography–Mass-Spectrography-Time-of-Flight HPLC-MS-TOF. The highest crude saponins content was recorded in A. hookeri (26.09 mg/g), followed by A. cupreata (19.85 and 15.17 mg/g in wild and cultivated populations, respectively). For A. inaequidens, we recorded 14.21, 12.95, and 10.48 mg/g in wild, silvicultural managed and cultivated populations, respectively. We identified 18 saponins types, A. inaequidens showing all of them. A hecogenin glycoside (HG1) is found in high amounts in A. hookeri but in low quantities in A. inaequidens and A. cupreata. A. inaequidens had the greatest diversity of saponins. The contents of crude saponins in A. inaequidens and A. cupreata decrease with management intensity, but contrarily to what we expected, it was the highest in A. hookeri. We hypothesize that such high amount could be due to some saponins, probably HG1, may be precursors of sugars.     

Genetic diversity and origin of North American green foxtail [<Emphasis Type="Italic">Setaria viridis</Emphasis> (L.) Beauv.] accessions

Setaria viridis (L.) P. Beauv. and its domesticated form, S. italica (L.) P. Beauv., have been developed over the past few years as model systems for C₄ photosynthesis and for the analysis of bioenergy traits. S. viridis is native to Eurasia, but is now a ubiquitous weed. An analysis of the population structure of a set of 232 S. viridis lines, mostly from North America but also comprising some accessions from around the world, using 11 SSR markers, showed that S. viridis populations in the US largely separate by latitude and/or climatic zone. S. viridis populations from the Northern US and Canada (north of 44°N) group with accessions from Western Europe, while populations in the Mid and Southern US predominantly group with accessions from Turkey and Iran. We hypothesize that S. viridis in the US was most likely introduced from Europe, and that introductions were competitive only in regions that had climatic conditions that were similar to those in the regions of origins. This hypothesis is supported by the fact that Canadian S. viridis lines were fast cycling and undersized when grown in the Mid-Western and Southern US compared to their morphology in their native environment. A comparison of the population structure obtained with 11 SSR markers and ~40,000 single nucleotide polymorphisms (SNPs) in a common set of S. viridis germplasm showed that both methods essentially yielded the same groupings, although admixture was identified at a higher frequency in the SNP analysis. Small numbers of SSR markers can thus be used effectively to discern the population structure in this inbreeding species.     

Evidence for two domestication events of hyacinth bean (<Emphasis Type="Italic">Lablab purpureus</Emphasis> (L.) Sweet): a comparative analysis of population genetic data

Studying molecular genetic relationships can substantially contribute to the understanding of the pathways of domestication of a species. Although an increasing number of molecular genetic studies have been performed on Lablab purpureus (hyacinth bean), many covered germplasm of restricted geographic origin or limited intra-specific systematic position. Integrating the molecular diversity found with phenotypic or morpho-agronomic diversity is also deficient. This investigation combines findings of eight molecular genetic studies that include about 400 accessions of both wild and cultivated germplasm, thus providing the largest assessment of diversity in Lablab purpureus to date. In particular, results from a recent molecular investigation (Robotham and Chapman 2015) are revisited and reinterpreted by integrating them with known phenotypic diversity. Wild accessions clearly fall into two types, with characteristic pods—2-seeded and 4-seeded. The large majority of cultivated types are more closely related to 4-seeded pod-types. Certain cultivated 2-seeded pod-type accessions from Ethiopia are genetically closer to wild 2-seeded pod-types. These two major phenotypes are reflected in two chloroplast DNA haplotypes A and B. Hence, two domestication events appear to exist in L. purpureus based on this combined data. No other geographic patterns of diversity, which might assist to trace the dispersal of L. purpureus, were found as cultivated accessions predominantly fell into 2-3 major groups. In all studies, the greatest genetic diversity was found in Africa, making Ethiopia one of the probable centers of domestication.     

Characteristics of the root system in the diploid genome donors of hexaploid wheat (<Emphasis Type="Italic">Triticum aestivum</Emphasis> L.)

Wild crop relatives are of considerable interest in plant breeding and significant efforts have been made to transfer their genetic variation into modern crops. Of the three diploid progenitors of bread wheat (Triticum aestivum L.), only Aegilops tauschii Coss. has been explored and exploited and only for some above ground characteristics. The three wild progenitors (Aegilops speltoides Tausch., Triticum urartu Tumanian ex Gandilyan, and Aegilops tauschii) have never been assayed for root traits. Here we report such a root study, and include Triticum monococcum L. subsp. boeoticum (Boiss.) Hayek and T. turgidum L. subsp. dicoccoides (Koern. ex Asch. et Graebn.) Thell. Fifteen accessions were selected from the above wild species and tested in the presence of one bread wheat cultivar Pavon F76. Significant variation was observed between and within the taxa. Of all accessions tested, cv. Pavon F76 had the smallest root system at maturity while A. speltoides had the largest root system. Moreover, Aegilops spp. had larger mean values for root biomass when compared with Triticum spp. These results suggest there is significant unexplored potential for the use of wheat wild relatives in wheat breeding to improve the root system, or to develop synthetic mapping populations to study root traits.     

Genotyping-by-sequencing reveals the origin of the Tunisian relatives of cultivated carrot (<Emphasis Type="Italic">Daucus carota</Emphasis>)

Tunisia, other countries in northwestern Africa, and the Iberian Peninsula, represent a center of diversity of Daucus. The genus traditionally has included about 20–25 species worldwide, but a recent molecular study redefined and expanded Daucus to include representatives from nine other genera. By this classification, Daucus now contains about 40 species, with some of them having winged fruits in addition to its traditionally recognized spiny fruits. The taxonomy of Daucus in Tunisia has recently been studied with morphological data, concluding that D. carota subsp. capillifolius is a subspecies that co-occurs and crosses with subsp. carota. The present study extends these findings with additional data from Genotyping-by-Sequencing (GBS) from 33 Tunisian accessions of D. carota (93 individuals with two to three replicates per accession), including the first collections of subsp. gummifer from Tunisia. Placed in the context of additional GBS data, D. carota subsp. gummifer has separate origins from other collections of subsp. carota in Tunisia and/or immediately adjacent areas to the north in Italy or its surrounding islands. Our results add support to the utility of large SNP datasets for species-level phylogenetic studies in Daucus.     

Collection and evaluation of wild tulip (<Emphasis Type="Italic">Tulipa</Emphasis> spp.) resources in China

China is known throughout the world as one of the most diverse centres of wild Tulipa L. resources. There are 17 wild Tulipa species distributed in China, and 12 species are only distributed in Xinjiang Province. In this paper, total 83 accessions were collected from Xinjiang, Liaoning and several other provinces. Their distribution, collection, classification and evaluation were described. According to morphological characteristics, they were classified into eight species, which included T. sinkiangensis Z. M. Mao, T. altaica Pall. ex Spreng., T. iliensis Regel, T. heterophylla Baker, T. buhseana Boiss., T. thianschanica Regel, T. schrenkii Regel and T. edulis (Miq.) Baker. Their phenotypic genetic relationships were analysed and showed that the eight Tulipa species were divided into two groups: Group I included one species T. edulis, and Group II included the other seven species. Bulb renewal was observed in eight wild Tulipa species; T. iliensis and T. edulis showed that one or more long fleshy stolons formed horizontally or vertically at the basal plate of the mother bulbs, new bulblets (dropper) appeared at the top of each fleshy stolon, and the mother bulbs eventually disappeared. The analytic hierarchy process was used to evaluate the ornamental value, utilization potential and ecological adaptability of the eight identified species. The results showed that T. iliensis, T. buhseana and T. thianschanica had better ornamental value and utilization potential than any other species. The distribution, collection, classification, and evaluation of wild Tulipa species could be helpful in creating novel tulip germplasms in China.