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 55 records · Page 3Linked to original sources

PubMed2026

Genome-Wide Characterization of the ZIP Transporter Family in Sea Island Cotton (Gossypium barbadense L.) and Expression Profiling Under Heavy Metal and Pathogen Stresses.

G. barbadense represents an indispensable germplasm resource for high-quality textile fiber and disease resistance; nevertheless, systematic information regarding its ZRT/IRT-like protein (ZIP) gene family remains limited. Here, a total of 46 GbZIP genes were identified across the G. barbadense genome. Comprehensive bioinformatic investigations revealed uneven chromosomal distribution and confirmed that segmental/whole-genome duplications, supplemented by localized tandem duplications, drove family expansion. Members clustered within the same phylogenetic clades shared conserved motif organization and gene architecture, while promoter regions harbored abundant cis-acting elements associated with phytohormone and stress signaling. Transcriptome profiling indicated distinct expression patterns across vegetative/reproductive tissues, fiber and ovule developmental stages, and diverse abiotic stress conditions (cold, hot, drought, and salt). Quantitative Real-Time PCR (qRT-PCR) further validated that several GbZIP candidates exhibited temporal expression variations upon exposure to cadmium toxicity, V. dahliae infection, and combined Cd-V. dahliae stress. Specifically, GbZIP13, GbZIP18, GbZIP27, and GbZIP36 displayed prominent broad-spectrum responses to all three stress conditions, whereas GbZIP16, GbZIP29, and GbZIP30 showed stress-specific regulatory divergence. Overall, this study aims to systematically analyze the evolutionary characteristics and expression patterns of the GbZIP family, and to specifically evaluate the response differences under Cd stress, V. dahliae stress, and combined stress, in order to identify potential key candidate genes.

Gossypium barbadense↗

PubMed2026

Genetic Analysis of Genomic and Methylomic Variation and Identification of Multi-Trait Mutants in Rice Carried on Chang'e-5.

Global food security is facing challenges from population growth to diminishing arable land. Space mutation breeding holds promise for overcoming the variation limitations in conventional breeding; however, the mutagenic effects of the deep-space environment on rice and the transgenerational inheritance patterns of induced variations remain unclear. In this study, rice seeds carried by the Chang'e-5 spacecraft were used as materials. Whole-genome sequencing and whole-genome bisulfite sequencing were performed on the first (SP1) and second generations (SP2) of space-mutagenized plants after their return to Earth. The results showed that the number of genomic variants in the SP2 generation increased significantly compared with SP1, and SNPs, homozygous sites, and variants in coding regions were more heritable. The genome-wide methylation level was elevated in the SP2 generation, and among differentially methylated cytosines, those in the CG context exhibited the highest heritability. Furthermore, large-scale screening for nitrogen efficiency, tolerance to PEG-induced stress, and germination-stage cold resistant mutants was conducted in the SP2 generation, and phenotypic validation was performed in the third generation (SP3). By integrating multi-omics analyses of representative mutants to mine candidate genes, a number of heritable elite mutants were obtained, and seven candidate genes for key traits were identified. This study systematically elucidates the transgenerational inheritance patterns of deep-space-induced variation in rice. The multi-trait mutants obtained provide valuable germplasm resources for gene cloning and breeding applications in rice.

DNA methylation↗

PubMed2001

[Effect of environmental factors on gonadal maturation as well as its ovulation and spawning in teleosts].

This paper reviewed the environmental factors affecting gonadal maturation as well as its ovulation and spawning in teleosts which include water temperature, sun-light, rainfall, current, chemical composition of waters, aquatic organisms, water pollution and so on. The impact of environmental pollution on the reproduction of teleosts was emphasized, aimed to approach strategies protecting fish germplasm resource from the standpoint of ecology.

Animals↗

PubMed2001

Cryopreservation of pig embryos: adaptation of vitrification technology for embryo transfer.

Great advancements in cryopreservation of pig embryos have been made since the last International Conference on Pig Reproduction (ICPR). In 1997, there were standard methods to cryopreserve germplasm and embryos of most livestock species, except for the pig, and development of this technology for use in the international pig industry was slow and in the early stages. Since 1997, there have been advancements in cryopreservation of pig embryos, with reports of production of live offspring after transfer of frozen-thawed and vitrified-warmed pig embryos. This review summarizes the progress in cryopreservation of pig embryos since 1997. Cellular and molecular biology have been used to understand the hypothermic sensitivity of pig embryos. Development of delipation technology has provided the first evidence that intracellular lipids are linked to hypothermic sensitivity. Cytoskeletal stabilization and vitrification have led to the production of live offspring from vitrified-warmed and transferred embryos. Recently, technology has been developed for cryopreservation of pig morulae. Development of open pulled straws has provided more rapid rates of cooling during vitrification and has been effective for cryopreservation of pig embryos. Although improvements and refinements of the technologies will continue, it is now time for the pig industry to consider cryopreservation of pig embryos as a tool for pig production and for propagation of select herd genetics, while maintaining germplasm resources for the future.

Animals↗

PubMed2002

[A study on genetic variation between wild and cultivated populations of Paeonia lactiflora Pall].

AIM: To discuss the genetic differentiation between wild and cultivated populations of Paeonia lactiflora Pall., and to find the reason for forming the genuineness of Radix Paeoniae rubra (Chishao) and Radix Paeoniae alba (Baishao). METHODS: Forty three representative samples of P. lactiflora from 11 localities were analyzed by RAPD method with 21 random primers. According to RAPD results, the genetic diversity and genetic differentiation of P. lactiflora were detected by the percentage of polymorphic sites (PPB), the coefficient of gene differentiation (GST) and analysis of molecular variance (AMOVA). RESULTS: (1) At species level, the PPB of P. lactiflora was 85.26%, the Nei's gene diversity (Ht) was 0.166. The PPB in wild population (WP) was 77.61%, which was more than that (54.96%) in cultivated population for medicine (MP), and that (61.76%) in cultivated population for ornament (OP). (2) AMOVA showed that 29.50% of the genetic diversity resulted from differentiation among populations. Pairwise Phist distance (0.3632) between WP and MP was furthest, while that (0.0973) between MP and OP was closest, indicating population differentiation was significant (P < 0.001). (3) In general, cluster analysis revealed that the samples of P. lactiflora were divided in wild and cultivated groups (except for 39). In WP, individuals of Duolun were separated from those of other localities. In MP, the clusters of samples corresponded well with their own habitats. CONCLUSION: In addition to environmental factor, genetic differentiation should be the main cause for the genuineness of "Chishao" and "Baishao". Because of over collection and worse habitat, P. lactiflora in Duolun, whose root is the famous Chinese Geo-herbal--"Duolun Chishao", is progresively rare. So, it should become the endangered germplasm resource to protect.

DNA, Plant↗

PubMed2002

[Genetic mapping of the intergenomic translocated "taigu" genic sterility gene (Ms2)].

The "Taigu" genic sterility gene Ms2 located on the short arm of the 4D chromosome of common wheat (AABBDD) originally incorporated into hexoploid triticale (AABBRR) and durum wheat (AABB) through intergenomic translocation in distant hybridization was introduced back into the genomes of common wheat. The dominant male sterility was expressed normally in the new "Taigu" genic sterile wheat carrying the intergenomically translocated Ms2, and the female fertility mechanism in its male sterile plants was normal as well. Observation of the chromosome configuration at meiosis of pollen mother cells (PMC) of the young ears of the sterile plants showed that they were euploid plants (2n = 42). No configurations different from those of the "Taigu" genic sterility gene located at the original locus were noticed of the Ms2 intergenomically translocated back into the common wheat. In systematic test crosses with marker genes the intergenomically translocated gene Ms2 was found to be linked with the dominant dwarf marker in common wheat Rht3 and, consequently, remapped and located on the short arm of the 4B chromosome of common wheat with a distance of 9.7 cM from Rht3. The new locus was designated as Ms2 (4BS). Discussions are given of the fate of Ms2 during translocation in the hexoploid triticale, the exchange of the names for 4A and 4B chromosomes in common wheat and the possible exploitation of the new locus Ms2 (4BS), and the following speculations are made: (a) In genic genes of allopolyploid organisms the donor chromosomes tend to be intergenomically translocated to their physiologically and evolutionarily close chromosomes with the same order number and the same arm; (b) it is confirmed that the 7th International Conference of Wheat Genetics was right to exchange the names between chromosomes 4A and 4B of common wheat in 1988; and (c) as a new genetic marker and a breeding tool for all the chromosome B-carrying species in the tribe of Triticeae, Ms2(4BS) may have wide application in building and expanding the gene pool of germplasm resources of various species of wheat.

Chromosome Mapping↗

PubMed2005

[Isolation and biological characteristics of rhizobia strains from Abrus cantoniensis].

OBJECTIVE: The research aimed at studying the biological characteristics of rhizobia isolated from Abrus cantoniensis. METHOD: The rhizobia strains, isolated from different environments in Guangxi, were studied for their growing characters and the generation time. They were also compared for survival capabilities under stresses caused by NaCl, pH, temperature, and different kinds and concentration of antibiotics. RESULT: The strains obtained from A. cantoniensis in subtropical zone produced alkali in YMA medium, the average generation time was 14.8 hours, and thus they belong to slow-growing rhizobia. Rhizobia strains differed greatly in respect to tolerance of high temperature, adaptability of acidic environment and sensitivity to four antibiotics, but they had the same abilities of using different carbon and nitrogen sources. After 70 days from inoculated strains, the seedling formed nodules on the root (85.0%), and the dry matter of vine was increased by 51.1%. CONCLUSION: The rhizobia strains isolated from different ecological environments are good germplasm resources of tolerances to high temperature and acidic environment. The research will greatly help utilize the rhizobia resources and enhance the quality of crude drugs of medicinal leguminosae.

Abrus↗

PubMed2005

[Genetic diversity of yam (Dioscorea opposita Thunb) detected by ISSR markers].

Genetic diversity of 28 cultivars of yam (Dioscorea opposita Thunb) was assessed by means of Inter-simple sequence repeat (ISSR) markers. The results showed that seven proper primers, with rich polymorphism, could be selected from a total of forty four ISSR ones; distinct differences appeared among 28 cultivars amplified bands, and the rate of polymorphic bands was 83.01%; Shannon's Information index was 0.3191; a Jaccard's genetic similarity matrix and a dendrogram for these cultivars were formed, in which they could be divided into four groups: Group 1 was composed of D. opposita. cv. Ribenbai, D. opposita. cv. Huashanyao and D. opposita. cv. Ribenyuan; Group2 contained D. opposita. cv. Xiaoye; Group 3 contained D. opposita. cv. No.1 Songye; other 23 cultivars were put into Group4. PCA(Principal component analysis) was employed to evaluate the resolving power of the markers to differentiate among them. This laid the foundation of the identification of yam cultivars and the efficient use of its germplasm resources.

DNA, Plant↗

PubMed2006

[RAPD analysis for genetic diversity of Chrysanthemum morifolium].

OBJECTIVE: To investigate the genetic diversity of Chrysanthemum morifolium at the level of molecular biology. METHOD: The total genomic DNA was extracted from medicinal chrysanthemums by 2% CTAB method. And the genetic diversity of 22 C. morifolium accessions was tested by RAPD marks. The NTSYS software was used to analyze the marks. RESULT: 26 10-mer arbitrary primers were found to acquire polymophic results. A total of 233 bands were amplified, of which 89.7% bands were found to be polymophic. 8.04 polymophic bands were amplified by each primer on the average. The results of cluster analysis by using UPGMA method showed that all the tested accessions could be differentiated by RAPD marks. CONCLUSION: There actually existed much genetic diversity at the molecular level among the germplasm resources of C. morifolium. RAPD marks could be effective tools to construct DNA fingerprintings of C. morifolium. The differences between the tested chrysanthemums are related to the environments. However, it was affected by genetic facters more significantly.

China↗

PubMed2006

[Growth comparison among Psammosilene tunicoides populations in tissue culture].

The comparison between the growth of eight populations from Psammosilene tunicoides at Yunnan Province was made by the tissue culture. The initial results showed out two populations from Yunshanping (Lijiang) and Xiaomoyu (Kunming) was dominant than orthers. It would be regard as one of fine germplasm resources for the culture of Psammosilence tunicoides.

Caryophyllaceae↗

PubMed2006

Analysis of intraspecific variation of Chinese Carthamus tinctorius L. using AFLP markers.

AIM: To investigate the intraspecific variation of Carthamus tinctorius L. (safflower) and establish foundation for further breeding of safflower germplasm resource and screening the quality correlation genes. METHODS: Amplified fragment length polymorphism (AFLP) was carried out to analyze genetic variation of 28 safflower populations collected in China. Unweighed pair-group method of with arithmetical averages (UPGMA) cluster analysis was used to construct a dendrogram and to estimate the genetic distances among the populations. RESULTS: All populations could be uniquely distinguished using 12 selected primer combinations. Similarity coefficients ranged from 0.48 to 0.96 among the populations. Dendrogram revealed distinct segregation of all the cultivars into three main groups and one midst group. CONCLUSION: Limited genetic diversity exists within the tested 28 collections at intra specific level and AFLP-based phyiogeny was not absolutely consistent with that based on morphological characters may be due to the interaction effect between genotype and environment.

Carthamus tinctorius↗

PubMed2006

[Transgenic wheat (Triticum aestivum L.) with increased resistance to the storage pest obtained by Agrobacterium tumefaciens--mediated].

The transgenic wheat of improved resistance to the storage pest was production. We have introduced the cowpea trypsin inhibitor gene (CpTI) into cultured embryonic callus cells of immature embryos of wheat elite line by Agrobacterium-mediated method. Independent plantlets were obtained from the kanamycin-resistant calli after screening. PCR and real time PCR analysis, PCR-Southern and Southern blot hybridization indicated that there were 3 transgenic plants viz. transformed- I, II and III (T- I, T-II and T-III). The transformation frequencies were obviously affected by Agrobacterium concentration, the infection duration and transformation treatment. The segregations of CpTI in the transgenic wheat progenies were not easily to be elucidated, and some transgenic wheat lines (T- I and T-III) showed Mendelian segregations. The determinations of insect resistance to the stored grain insect of wheat viz. the grain moth (Sitotroga cerealella Olivier) indicated that the 3 transgenic wheat progeny seeds moth-resistance was improved significantly. The seed moth-eaten ratio of T- I, T-II, T-III and nontransformed control was 19.8%, 21.9%, 32.9% and 58.3% respectively. 3 transgenic wheat T1 PCR-positive plants revealed that the 3 transgenic lines had excellent agronomic traits. They supplied good germplasm resource of insect-resistance for wheat genetic improvement.

Agrobacterium tumefaciens↗

PubMed2006

[Studies on cytogeography of Pinellia ternata poliploid complex].

OBJECTIVE: In order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically. METHOD: Cytological and cytogeographical methods were used in the study. RESULT: P. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found. CONCLUSION: The genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.

Aneuploidy↗

PubMed2026

Pan-genome-based resequencing of 2,320 accessions reveals structural variations and accelerates breeding advances in cultivated peanut.

The cultivated peanut is a crucial global legume crop that is essential for food security and nutrition, particularly in developing regions. However, its limited genetic variation hampers breeding progress and yield improvement. Here we constructed a graph-based pan-genome for peanut, incorporating 14 genomes that represent all 6 peanut varieties. Using this pan-genome, we genotyped 2,320 accessions, covering 88.03% of ICRISAT and 59.21% of USDA core germplasm, enriching valuable resources for genomic studies and breeding. We cataloged genomic structural variations and investigated the role of homoeologous exchanges in population divergence. Through our pan-genome approach, we overcame the challenges of genotyping posed by homoeologous exchanges and identified key genes associated with flowering and dwarfism in peanut. By integrating superior haplotypes and germplasm resources guided by the pan-genome, we further developed high-yield dwarf lines. This work provides essential genomic resources to accelerate functional gene discovery and modern peanut breeding.

Journal Article↗

PubMed1999

Role of reproductive technologies and genetic resource banks in animal conservation.

In combination with modem reproductive technologies, there is potential to use frozen and stored germplasm (genetic resource banks) to support conservation measures for the maintenance of genetic diversity in threatened species. However, turning this idea into reality is a complex process, requiring interdisciplinary collaboration and clearly defined goals. As the number of species deserving the attention of conservation scientists is overwhelmingly large, yet detailed knowledge of reproductive physiology is restricted to relatively few of them, choosing which species to conserve is one of the most difficult issues to be tackled. Besides the direct application of technologically advanced reproductive procedures, modern approaches to non-invasive endocrine monitoring play an important role in optimizing the success of natural breeding programmes. Through the analysis of urine and faecal samples, this type of technology provides invaluable management information about the reproductive status of diverse species. For example, it is possible to diagnose pregnancy and monitor oestrous cycles in elephants and rhinos without causing stress through restraint for sample collection. In this review, we identify the potential contribution of reproductive biology and genetic resource banks to animal conservation, but also highlight the complexity of issues determining the extent to which this potential can be achieved.

Animals↗

PubMed2003

Linking genotype to phenotype: the International Rice Information System (IRIS).

The International Rice Information System (IRIS, http://www.iris.irri.org) is the rice implementation of the International Crop Information System (ICIS, http://www.icis.cgiar.org), a database system for the management and integration of global information on genetic resources and germplasm improvement for any crop. Building upon the germplasm genealogy and field data components of ICIS, IRIS is being extended to handle diverse rice genomics data including: genetic mapping, genome annotation, genotype, mutant, transcripteome, proteome and metabolomic data. Users can access information in the database through stand-alone programs and WWW interfaces offering specialist views to researchers with different interests.

Database Management Systems↗

PubMed2025

Cytotype classification and genetic diversity of Platostoma palustre revealed by rDNA localization and chloroplast genome.

BACKGROUND: Platostoma palustre A. J. Paton is an edible medicinal plant that plays a significant role in traditional food production and medicinal applications. However, the genetic basis of P. palustre remains unclear, thereby hampering research on its genome and polyploid evolution. RESULTS: To characterize the karyotype and ploidy of P. palustre, we performed fluorescence in situ hybridization (FISH) by using 35 S and 5 S rDNA probes in P. palustre. FISH results indicated that 35 S rDNA mapped to the end of the chromosome (chromosome satellite, heterochromatic region) and that 5 S rDNA was located close to the centromere of the chromosomes. Based on the rDNA sites, we identified three distinct cytotypes of P. palustre: diploid (2n = 2x = 30, x = 15), triploid (2n = 3x = 45, x = 15), and tetraploid (2n = 4x = 60, x = 15). To further explore the genetic evolutionary relationship among these P. palustre cytotypes, we conducted Illumina sequencing and assembled the chloroplast (CP) genome. The CP genomes of P. palustre accessions maintained a conserved single circular molecule with a length of 152,534 - 152,788 bp, comprising a large single-copy region (LSC) and small single-copy region (SSC) separated by two inverted repeat regions (IRs). Phylogenetic trees were also created based on CP and nuclear molecular markers, showing that most P. palustre accessions clustered together corresponding to their collection regions. Of these, GDZC2 (2n = 2x = 30) clustered with several triploid accessions, suggesting that it may share a common ancestor with these triploid accessions. CONCLUSIONS: This is the first study to characterize the karyotype, identify three cytotypes of P. palustre using FISH, and provide molecular evidence for an evolutionary relationship among different P. palustre accessions. These findings will be useful for further genomic studies and polyploid evolution of P. palustre.

Genome, Chloroplast↗

PubMed2006

The National Animal Germplasm Program: challenges and opportunities for poultry genetic resources.

In the United States, poultry genetic resources have consolidated because of economic pressures. Such consolidations can potentially jeopardize the poultry industry and the ability of research communities to respond to future challenges. To address the loss of genetic resources for all livestock and aquatic species, USDA established the National Animal Germplasm Program (NAGP) in 1999. Since the initiation of NAGP, population surveys have been conducted on nonindustrial chicken and turkey breeds. These surveys not only provide insight into breed status, but also serve as a benchmark for future comparisons. The survey results revealed that 20 chicken breeds and 9 turkey breeds were in various stages of being lost. The NAGP has initiated an ex situ repository for cryopreserved germplasm and tissue that already contains 59 chicken lines and 2,915 tissue samples. As the NAGP, along with its industry and university partners, continues developing the ex situ collection, there are research opportunities in cryopreserved tissue utilization and studies of genetic diversity. For cryopreserved tissues, several key research areas include improving the cryopreservation protocols for rooster and tom semen by using cryoprotectants other than glycerol and utilizing embryonic cells. Although surveys have been conducted on public research lines and rare breeds, there is a void in understanding the level of genetic diversity present in U.S. poultry populations. Therefore, an opportunity exists to perform a series of genetic diversity studies using molecular- based approaches. Such an evaluation can help clarify population differences between research lines and rare breeds and, thereby, facilitate conservation strategies. There appears to be growing consumer interest in poultry products derived from heritage breeds and/or poultry raised in nonindustrial production systems. Although the depth of such market trends is unknown, such an interest may provide an important niche for rare poultry breeds and, thereby, strengthen the genetic base.

Agriculture↗