PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Germplasm resources”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Genomic prediction-aided incorporation of genetic resources into elite breeding: lessons from a collaborative multiparental design in flint maize.

A public private cooperative mating design between elite maize inbred lines and diversity donors shows that genomic prediction holds great promise to improve the use of genetic resources. Genetic diversity is essential for plant breeding, enabling long-term gains and adaptation to climate change and new agronomical practices. Breeders can access diverse genetic resources to enhance elite germplasm and introduce new favorable variations. The limited performance of genetic resources may hamper their use. To overcome this, a bridging population can be implemented to evaluate and select progenies from crosses between diversity donors and elite lines before their introduction in breeding programs. The choice of such crosses can be dealt with the usefulness criterion (UC), which determines its ability to produce transgressive individuals. This paper investigates the use of genome-wide marker effects to predict (i) the performance of individuals derived from crosses between donors and elite lines and (ii) the UC of crosses not observed yet. It also compares donor introduction strategies based on the UC or the H criterion, which considers the genome-wide donor-elite complementarity. We used a flint maize collaborative multi-parental BC1-S2 population, consisting in materials from six breeding companies and one public institute crossed to different donors. The 20 crosses had contrasted means and genetic variances, and most of them presented transgressive individuals above the elite parent. Results emphasize the importance of half-siblings derived from the elite line parent of the predicted cross to efficiently predict progeny performances or the UC. They also showed that using the H criterion appears promising to select iteratively donors that best complement initial elite materials. The paper concludes with guidelines for implementing a bridging population using genome-wide marker-based predictions.

Zea mays↗

Integrated Genomics and Transcriptomics Reveal Stable Resistance Loci and Candidate Genes for Powdery Mildew in Wheat.

Powdery mildew, caused by Blumeria graminis f. sp. tritici (Bgt), poses a substantial threat to global wheat production. Enhancing resistance through molecular breeding necessitates a comprehensive understanding of its genetic and molecular underpinnings. This study leveraged a 2-year phenotypic evaluation of 283 diverse wheat accessions combined with genome-wide association studies (GWAS) to pinpoint stable quantitative trait loci for powdery mildew resistance. We identified 52 robust resistance loci across the wheat genome, including seven novel loci consistently detected across four environments. Comparative transcriptome profiling of resistant and susceptible wheat lines revealed 95 differentially expressed genes, predominantly enriched in defense response, signal transduction, and transcription regulation pathways. By integrating the GWAS and transcriptomic data, we precisely identified three compelling candidate genes (TaPIP5K, TaPKG, and TaORR6) on chromosome 2A, which are implicated in cell wall reinforcement, jasmonic acid signaling, and reactive oxygen species scavenging, respectively. Further validation using expression analysis corroborated their pivotal roles in resistance. Our findings provide a rich repository of validated genetic markers, promising candidate genes, and superior resistant germplasms, offering critical resources to accelerate targeted molecular breeding efforts for durable powdery mildew resistance in wheat.

Blumeria graminis f. sp. tritici↗

Development and characterization of polymorphic microsatellite markers in taro (Colocasia esculenta).

Microsatellite-containing sequences were isolated from enriched genomic libraries of taro (Colocasia esculenta (L.) Schott). The sequencing of 269 clones yielded 77 inserts containing repeat motifs. The majority of these (81.7%) were dinucleotide or trinucleotide repeats. The GT/CA repeat motif was the most common, accounting for 42% of all repeat types. From a total of 43 primer pairs designed, 41 produced markers within the expected size range. Sixteen (39%) were polymorphic when screened against a restricted set of taro genotypes from Southeast Asia and Oceania, with an average of 3.2 alleles detected on each locus. These markers represent a useful resource for taro germplasm management, genome mapping, and marker-assisted selection.

Alleles↗

Stress-induced expression in wheat of the Arabidopsis thaliana DREB1A gene delays water stress symptoms under greenhouse conditions.

One of the major environmental factors limiting plant productivity is lack of water. This is especially true for the major cereals maize, rice, and wheat, which demonstrate a range of susceptibility to moisture deficit. Although conventional breeding and marker-assisted selection are being used to develop varieties more tolerant to water stress, these methods are time and resource consuming and germplasm dependent. Genetic engineering is attractive because of its potential to improve abiotic stress tolerance more rapidly. Transcription factors have been shown to produce multiple phenotypic alterations, many of which are involved in stress responses. DREB1A, a transcription factor that recognizes dehydration response elements, has been shown in Arabidopsis thaliana to play a crucial role in promoting the expression of drought-tolerance genes. In our efforts to enhance drought tolerance in wheat, the A. thaliana DREB1A gene was placed under control of a stress-inducible promoter from the rd29A gene and transferred via biolistic transformation into bread wheat. Plants expressing the DREB1A gene demonstrated substantial resistance to water stress in comparison with checks under experimental greenhouse conditions, manifested by a 10-day delay in wilting when water was withheld.

Arabidopsis↗

Variations of main quality components of tea genetic resources [Camellia sinensis (L.) O. Kuntze] preserved in the China National Germplasm Tea Repository.

The variations of the main quality components of tea, tea polyphenols, catechins, amino acids, caffeine, and water extract of 596 accessions Chinese tea genetic resources, preserved in the China National Germplasm Tea Repository (CNGTR), were analyzed. Tea polyphenols content on a dry weight basis varied from 13.6 to 47.8%, averaging 28.4%. The tea polyphenols content increases gradually from northern and eastern provinces to southern provinces, the highest is in Yunnan tea resources. The content of catechins ranged from 81.9 g/kg to 262.7 g/kg, averaging 144.6 g/kg. The genetic resources from Hunan province had the highest catechins content, inconsistent with the tea polyphenols, which were highest in Yunnan tea resources. The amino acids content ranged from 1.1 to 6.5%, with an average of 3.3%. It was much lower in the southern provinces compared with northern and eastern provinces. The average caffeine content was 4.2%, varying from 1.2 to 5.9%. Yunnan province has plentiful high caffeine genetic resources, next is Fujian province. Caffeine content of Chinese and Japanese tea genetic resources were very similar. The average of water extract content was 44.7%, varying from 24.4 to 57.0%. The variation pattern was similar to that of tea polyphenols. Tea genetic resources of transnormal components are valuable and they could be used directly or indirectly for commercial functional components extract, breeding, and production.

Amino Acids↗

Molecular characterization of Buffalograss germplasm using sequence-related amplified polymorphism markers.

Buffalograss [ Buchloe dactyloides (Nutt.) Englem] germplasm has a broad resource of genetic diversity that can be used for turfgrass, forage and conservation. Buffalograss is the only native grass that is presently used as a turfgrass in the Great Plains region of North America. Its low growth habit, drought tolerance and reduced requirement for fertilizer and pesticides contribute to interest in its use. The objectives of this study were to use sequence-related amplified polymorphism (SRAP) markers in the evaluation of genetic diversity and phenetic relationships in a diverse collection of 53 buffalograss germplasms, and to identify buffalograss ploidy levels using flow cytometry. Based on their DNA contents, buffalograss genotypes were grouped into four sets, corresponding to their ploidy levels. Thirty-four SRAP primer combinations were used. This is the first report of the detection of differentiating diploid, tetraploid, pentaploid and hexaploid buffalograss genotypes, representing diverse locations of origin, using SRAP markers. Cluster analysis by the unweighted pair-group method with arithmetic averages based on genetic similarity matrices indicated that there were eight clusters. The coefficients of genetic distance among the genotypes ranged from 0.33 up to 0.99 and averaged D=0.66. The genetic diversity estimate, He, averaged 0.35. These results demonstrated that genotypes with potential traits for turfgrass improvement could readily be distinguished, based on SRAP. The use of PCR-based technologies such as SRAP is an effective tool for estimating genetic diversity, identifying unique genotypes as new sources of alleles for enhancing turf characteristics, and for analyzing the evolutionary and historical development of cultivars at the genomic level in a buffalograss breeding program.

DNA, Plant↗

The RrWRKY75-mediated activation of ascorbate synthesis in Rosa roxburghii Tratt contributes to salt stress tolerance.

L-Ascorbic acid (AsA) is a key antioxidant that alleviates oxidative stress in plants. Previous yeast one-hybrid (Y1H) screening identified RrWRKY75 as a transcription factor capable of binding to the promoter of RrGGP2 (GDP-L-galactose pyrophosphatase 2), a key structural gene responsible for massive AsA accumulation in Rosa roxburghii fruit. The function of RrWRKY75 in plant stress responses remains unclear. Here, RrWRKY75 is verified to specifically bind to the RrGGP2 promoter and activate its transcription. This positive regulatory effect on RrGGP2 transcript levels and AsA accumulation is further confirmed through overexpression or silencing of RrWRKY75 in R. roxburghii fruit or callus. Among various abiotic stress conditions, RrWRKY75 expression is significantly induced by salt stress. Upon its overexpression in callus or Arabidopsis thaliana, elevated AsA levels and antioxidant capacity are observed, thereby enhancing salt tolerance. Interestingly, RrWRKY75 also binds to the promoter of RrUNE12, a salt-responsive factor in R. roxburghii, and activates its expression. Moreover, yeast two-hybrid and bimolecular fluorescence complementation (BiFC) assays confirm the physical interaction between RrWRKY75 and RrUNE12, which jointly upregulates RrGGP2 expression and AsA production. Collectively, RrWRKY75 boosts AsA biosynthesis and salt tolerance both by directly trans-activating RrGGP2 and by synergizing with RrUNE12 through transcriptional activation and protein complex formation. These findings provide insights into the regulatory role of RrWRKY75 in abiotic stress tolerance and offer valuable genetic resources for R. roxburghii germplasm improvement.

Rosa↗

Comparative chemical attributes of native North American hop, Humulus lupulus var. lupuloides E. Small.

The genetic diversity of 159 representative genotypes of native hop (Humulus lupulus var. lupuloides E. Small, Cannabaceae) from 34 selected populations was assessed by relative magnitudes and ranges of alpha acids (AA), beta acids (BA), and the cohumulone (CoH) component of alpha acids, with reference to temporal changes between 1989-1990 and 2001, and to the same attributes in American and European hop cultivars, principally H. lupulus var. lupulus L. Chemical profiles of these genotypes were generated by high pressure liquid chromatography (HPLC) of methanol extracts from their processed samples (cones). The alpha ratio (AR, alpha acids / alpha+beta acids) measured the degree to which alpha acids predominated in cone extracts. Synchronous ranges of AR and CoH were also selected for graphic portrayals of native hop genotypic diversity. Cones sampled and analyzed from eight populations that were accessible in both 1989 and 2001 were distinct in chemical attributes, indicating a succession of genotypes, and suggesting temporal cycling of H. lupulus var.lupuloides germplasm. The principal distinctions between the two sub-species were a markedly higher proportion of CoH (38-88% vs. 19-41%) in alpha acids of H. l. var. lupuloides, and generally higher concentrations of AA in cultivars of both American and European commercial hop cultivars, predominantly H. lupulus var. lupulus. All of the 159 native hop genotypes also contained detectable levels of xanthohumol and xanthogalenol, prenylflavonoids recently reported to have mammalian anti-cancer activity. Some native genotypes had previously exhibited natural repellence of insect and mite pests; thus H. lupulus var. lupuloides germplasm offers a diverse resource of underutilized and yet undefined biochemicals.

Carboxylic Acids↗

Transgenic crops, biotechnology and ownership rights: what scientists need to know.

Ownership of intellectual and tangible property (IP/TP) rights in agricultural biotechnology (ag-biotech) and transgenic plants has become critically important. For scientists in all institutions, whether industrialized or developing country, public or private sector, an understanding of IP/TP rights is fundamental in both research and development. Transgenic plants and ag-biotech products embody numerous components and processes, each of which may have IP/TP rights attached. To identify these rights, a transgenic plant or ag-biotech product must be dissected into its essential components and processes, with each 'piece' analysed under the IP/TP 'microscope'. This product deconstruction is an integral step in product clearance (PC) analysis leading to freedom to operate (FTO). To facilitate a PC analysis, the following points are important: (1) knowing what one has and where it's from, (2) organizing material transfer agreements and licences, (3) researching scientific and patent databases and relevant literature, (4) instituting a laboratory notebook policy, (5) keeping track of ownership of germplasm and plant genetic resources, and (6) promoting ongoing IP/TP management, awareness and training. However, a FTO opinion does not solve the IP/TP issues of releasing a transgenic plant or ag-biotech product; rather, it is a management tool for assessing the risks of litigation. When transferring transgenic plants or ag-biotech to developing nations, scientists from industrialized countries have the heightened responsibility of verifying that IP/TP issues are fully addressed and documented. Successful technology transfer goes beyond research, development and licensing; it is an holistic package leading to long-term partnerships in international development. Managing IP/TP requires capacity-building in scientists and technology transfer offices, in both industrialized and developing countries.

Biotechnology↗

Genetic diversity, phylogenetic relationships, and marker development between Hydrangea serrata and H. macrophylla based on plastome and 45S nrDNA.

Ornamental hydrangeas (genus Hydrangea) are cultivated worldwide for their diverse flower colors and attractive morphology. Here, we assembled the complete plastid genome (plastome) and 45S nuclear ribosomal DNA (45S nrDNA) sequences of 22 individuals representing H. serrata, H. macrophylla, and related species (H. arborescens, H. paniculata, H. petiolaris, and H. hydrangeoides). The plastomes contained up to 2,344 single-nucleotide polymorphisms (SNPs) and 367 insertions/deletions (InDels) within the genus, whereas the assembled 45S nrDNA sequences showed 119 SNPs and 10 InDels. Phylogenetic analyses based on plastome and 45S nrDNA sequences clearly separated H. serrata and H. macrophylla from the other Hydrangea species. In the plastome-based tree, H. petiolaris was placed in the same clade as H. arborescens, whereas in the 45S nrDNA-based tree it showed a close relationship to H. hydrangeoides. The H. serrata and H. macrophylla samples were not always separated according to their species boundaries, as observed in samples Hse8-Hse12. Notably, one H. serrata sample (Hse8), collected from a wild mountainous region of Japan, exhibited a closer genetic relationship to H. macrophylla samples, indicating that cultivated hydrangeas may have originated from a specific wild lineage of H. serrata adapted to mountainous habitats. Using plastome-derived molecular markers, 66 Hydrangea samples were further classified into five groups, with Group II comprising both cultivated H. macrophylla and a subset of wild H. serrata samples, suggesting a close genetic affinity between this group and the ancestral gene pool of cultivated H. macrophylla. Based on these genomic resources, eight plastome-derived molecular markers were developed to differentiate cultivated hydrangeas from wild genotypes and to assess genetic diversity within H. serrata and H. macrophylla, providing practical tools for germplasm identification, breeding, and genetic resource management of Hydrangea species.

hydrangea↗

Genetic diversity of oil palm (Elaeis guineensis Jacq.) germplasm collections from Africa: implications for improvement and conservation of genetic resources.

A total of 723 accessions of oil palm ( Elaeis guineensis Jacq.) from 26 populations representing ten countries in Africa and one Deli dura family were screened for allelic variation at seven enzyme loci from six enzyme systems using starch gel electrophoresis. On average, 54.5% of the loci were polymorphic (0.99 criterion). The average and effective number of alleles per locus was 1.80 and 1.35, respectively. Mean expected heterozygosity was 0.184, with values ranging from 0.109 (population 8, Senegal) to 0.261 (population 29, Cameroon). The genetic differentiation among populations was high (F(ST)=0.301), indicating high genetic divergence. The calculation of F(ST) by geographic zones revealed that the high F(ST) was largely due to F(ST) among populations in West Africa, suggesting diversifying selection in this region. The mean genetic distance across populations was 0.113. The lowest genetic distance (D) was observed between population 5 from Tanzania and population 7 from the Democratic Republic of the Congo (0.000) and the highest was found between population 4 from Madagascar and population 13 from Sierra Leone (0.568). The total gene flow across oil palm populations was low, with an Nm of 0.576, enhancing genetic structuring, as evident from the high F(ST) values. UPGMA cluster analysis revealed three main clusters; the western outlying populations from Senegal and Sierra Leone were in one cluster but separated into two distinct sub-clusters; the eastern outlying populations from Madagascar were in one cluster; the populations from Angola, Cameroon, The Democratic Republic of the Congo, Ghana, Tanzania, Nigeria and Guinea were in one cluster. The Deli dura family seems to be closely related to population 6 from Guinea. Oil palm populations with high genetic diversity-i.e. all of the populations from Nigeria, Cameroon and Sierra Leone, population 6 of Guinea, population 1 of Madagascar and population 2 of Senegal should be used in improvement programmes, whereas for conservation purposes, oil palm populations with high allelic diversity (A(e)), which include populations 22 and 29 from Cameroon, populations 39 and 45 from Nigeria, population 6 from Guinea, populations 5 and 13 from Sierra Leone and population 1 from Madagascar should be selected for capturing as much genetic variation as possible.

Africa↗

A biological and molecular characterization of some Egyptian barley genotypes which are resistant to net blotch disease.

A survey for resistance against net blotch disease (caused by Pyrenophora teres) was performed on some Egyptian barley landraces and some selected resistance and susceptible standard German barley genotypes. The results indicated that most of the Egyptian barley landraces are extremely resistant to the disease. Molecular analysis using RAPD and AFLP showed unique banding profiles for the different genotypes, and specific AFLP markers for the Egyptian genotypes were identified. The effectiveness of RAPD and AFLP for identifying different barley genotypes of different origins and with different reactions against P. teres was discussed. The results of the biological evaluation and molecular characterization done in this study can be seen as the starting point needed to identify the valuable net blotch resistant Egyptian barley germplasm at both the phenotype and genotype levels and draw the attention of breeders and banks of natural plant genetic resources towards this valuable yet neglected germplasm.

Ascomycota↗

Enhancement of Seedling Emergence in Sweet Corn by Marker-Assisted Backcrossing of Beneficial QTL.

Seedling emergence is an important trait that can limit commercialization of sweet corn hybrids. This study was designed to test what effect beneficial QTL alleles that enhance seedling emergence exert when introgressed, using marker-assisted backcrossing, into sweet corn commercial germplasm. Three RFLP marker alleles linked to QTL that enhanced seedling emergence were identified in an F(2:3) sweet corn mapping population. A recombinant inbred line (RIL, F(8)) derived from this population was used as a donor parent to backcross the marker-QTL alleles into three elite commercial sweet corn inbreds. Plants in the three segregating BC(2) populations were crossed to the non-recurrent commercial inbreds to produce three BC(2)F(1) populations with families either segregating or lacking the marker donor allele(s). These three populations were evaluated for seedling emergence under field conditions in two successive years. Across the three populations, BC(2)F(1) families segregating for the donor QTL allele linked to the marker umc139 (on chromosome 2), bnl9.08 (on chromosome 8), or php200689 (on chromosome 1) displayed 40.8, 30.2, and 28.2% increases in seedling emergence, respectively, over the unmodified F(1)s. The introgressed QTL alleles were observed to enhance seedling emergence in the BC(2)F(1) generation as was observed in the original F(2:3) mapping population. Marker-QTL associated effects were reproducible across generations and populations indicating that QTL identified in one population can exert similar effects in different genetic backgrounds. Results suggest that using DNA marker technology can help to identify and introgress beneficial QTL alleles, shortening the time and resources required to develop improved germplasm.

Journal Article↗

[Conservation of endangered species resources of Tibetan medicine in China].

OBJECTIVE: To further investigate and discuss the cause of species endangerment, the status and present problem of conservation of traditional Tibetan medicine in China. METHOD: Previous relevant investigations and literatures were summed up in the field. The present situation of conservation of traditional Tibetan medicine was analyzed. RESULT: The status of endangered resources, cause of species endangerment, the conserving status and conserving measures etc were elaborated. The classification was made and suggestion of species conservation of traditional Tibetan medicine were put forward. CONCLUSION: The endangered species conservation of traditional Tibetan medicine was carried out by building protective area of endangered species resources and plant garden, setting up germplasm bank, developing the domestication and cultivation of Tibetan medicinal herbs most in use, strengthening the investigation and study of endangered species, launching exchange and cooperation of conservation techniques on endangered species, enhancing the protective awareness of endangered species traditional Tibetan medicine etc. By so doing we can facilitate the sustainable development of traditional Tibetan medicine in China.

Conservation of Natural Resources↗

Avian genetic resource banking: can fish embryos yield any clues for bird embryos?

Cryopreservation of avian germplasm is becoming better understood and more commonly practiced. However, one area that would be of great benefit for genome resource banking is the preservation of avian embryos. Little is know about the cryobiology of avian embryos, and they have never been successfully cryopreserved. However, it is likely that they share many of the challenges of other yolk-filled multicompartmental embryos. For example, the fish embryo has 1) a large overall size, resulting in a low surface-to-volume ratio, which retards water and cryoprotectant efflux/influx; 2) large-sized cells, such as the yolk, which could increase the likelihood of membrane disruption by intracellular ice formation; 3) compartments, such as the blastoderm and yolk, with differing permeability properties; and 4) susceptibility to chilling injury. Both the avian and fish systems share many physical and anatomical properties, and it is predicted that some of the same permeability barriers would exist in both as well. Although the systems are similar, some of the goals, and thus the practices, to protect the genome may be quite different. One of these major goals in avian developmental biology is to produce chicken:chicken transgenic animals, especially those with germ line transmission. Producing efficient germ line transmissions and being able to cryopreserve these transmissions would be extremely beneficial to both basic and agricultural science. This could be accomplished through the cryopreservation of embryonic gonadal tissue followed by grafting into a host. The gonadal/tail-graft system would provide an advantage for cryopreservation because it is small (in comparison with the whole embryo), has fairly uniform tissue, and contains the essential primordial germ line cells capable of recreating the genetic line of interest. Moreover, because the chicken is such a robust model for most other avian species, the cryopreservation of the gonadal/tail-graft may potentially open up similar treatments for other commercially important species.

Animals↗

Avian germplasm preservation: embryonic stem cells or primordial germ cells?

Presently, avian genetic resources are best maintained as living collections of birds. Unfortunately, these stocks have been under constant pressure to be destroyed because of the decline in the number of Poultry Science Departments and pressures to cut costs at land grant institutions. Cryopreservation of semen is often suggested as a means to bank avian germplasm. However, this is only applicable for single-gene traits and does not allow for full reconstitution of the genetics of the original line. Over the last 15 yr, advances in the manipulation of the early chick embryo, manipulation of primordial germ cells (PGC), and the culture of embryonic stem cells (ESC) suggests that cryopreservation of blastodermal cells, ESC, or PGC might offer a means to preserve the entire genome of highly selected, specialized stocks of poultry. Freezing each of these cell types is possible with varying degrees of efficiency. Similarly, the effectiveness of generating germ line chimeras using blastodermal cells, ESC, or PGC also varies greatly. Other factors that must be considered include the choice of the recipient lines to develop the germ line chimeras and the number of individuals needed to reconstitute the line. Finally, the low efficiency rate of reconstitution and the high cost associated with current technologies makes these approaches prohibitive. Significant challenges remain to be overcome before the entire genome of poultry stocks can be routinely cryoperserved and reconstituted.

Animals↗

Development and validation of a high-density 'Amahysnp' genotyping array in grain amaranth (Amaranthus hypochondriacus).

BACKGROUND: Grain amaranth has recently gained global attention as a promising crop alternative to traditional cereals due to its nutritional value and adaptability to various growing conditions. Although gene banks conserve extensive collections of amaranth germplasm, the genomic and phenotypic characterization of these resources is limited, which hinders their full utilization in breeding programs. A major challenge is the lack of high-throughput genotyping assays essential for comprehensive genomic characterization and trait mapping. High-density SNP arrays have become standard tools for genome-wide analysis across multiple loci, enabling molecular breeding across a range of crop species. RESULTS: In this study, we developed a 64 K high-throughput SNP genotyping array named "AmahySNP", using Affymetrix® Axiom® technology. The array contains 64,069 high-density SNPs distributed across both genic (55.17%) and non-genic (44.83%) regions of the Amaranthus hypochondriacus genome. The genic region includes 8,879 genes, which consist of 4,830 single-copy genes and 4,049 multi-copy genes distributed across 16 scaffolds. These genes cover various functional regions, including exons (10.5%), introns (40.1%), 5'UTRs (1.6%), and 3'UTRs (2.9%), respectively. The AmahySNP array was effectively utilized for population structure analysis, genetic diversity studies, core development, and genome wide association studies (GWAS) in amaranth germplasm. A representative core set of 112 accessions was identified, which includes two released varieties (Annapurna and Suvarna) and 100 diverse accessions from 12 different regions, representing 12% of the total 917 accessions evaluated. Phylogenetic analysis revealed three major genetic clusters, independent of their geographical origins. GWAS conducted using 22,763 polymorphic SNPs from 540 genotypes identified 13 novel loci associated days to flowering (DTF) trait, seven of which were located within annotated genes. CONCLUSIONS: The AmahySNP 64 K SNP chip a valuable genomic tool for amaranth research and breeding with a strong potential to accelerate its genetic improvement. It enables high-throughput genotyping for a wide range of applications, including GWAS and other genomic studies, and will significantly advance the exploration of natural genetic variations. Ultimately, this resource will empower amaranth breeders to develop improved amaranth cultivars with enhanced crop yield, resilience, and nutritional quality, contributing to global food security and sustainable agriculture.

Amaranthus↗

Geographic information system method for assessing chemo-diversity in medicinal plants.

The spatial distribution of wild germplasm of Podophyllum peltatum L. (American mayapple) has been analyzed using the Geographic Information System (GIS) with the objective to develop a method and a database for evaluation of biotic and abiotic factors influencing drug yield, and to map elite genotypes for propagation and improvement. The field assessment followed a standard procedure including geographical coordinates of each accession, leaf biomass randomly harvested, identification of associate species, collection of herbarium specimen, soil sample and digital pictures of the site. By overlaying morphological and chemical data with geomorphic information, a thematic map was created locating the podophyllotoxin-rich accessions and the uniqueness of each site was recorded for post-collection analysis. This work has enabled the establishment of a database of P. peltatum germplasm in Mississippi with drug yield linked to spatial locations for rational utilization of our natural resources. While this method integrates information of well-characterized diverse in situ P. peltatum germplasm, it might become a strategy for curators to reduce cost for establishing and maintaining ex situ collections since the genetic material is geo-referenced.

Databases, Factual↗