Simple Sequence Repeat Markers Research Articles

Identification and Molecular Mapping of the Gene YrFL in Wheat Cultivar Flanders with Durable Resistance to Stripe Rust.

Stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most severe diseases of wheat (Triticum aestivum L.) worldwide. Identification and characterization of resistance genes is advantageous to cultivating wheat varieties with durable resistance, which is the most economic and effective strategy to control stripe rust. Flanders, a common wheat cultivar released in France in 1986, confers effective resistance to stripe rust both at the seedling and adult plant stages. To elucidate the genetic basis of resistance in Flanders, F1, F2, and F2:3 generations derived from the cross Mingxian169 × Flanders were evaluated with the most prevalent Chinese Pst race CYR33 at the seedling stage. Inheritance analysis showed that the stripe rust resistance of Flanders was controlled by a single dominant gene, temporarily designated as YrFL. Bulked segregant analysis (BSA) combined with a wheat 660K single-nucleotide polymorphism (SNP) array indicated that polymorphic SNP markers were mainly located in the 0 to 150 Mb on wheat chromosome 5A. One hundred and eleven kompetitive allele-specific PCR (KASP) and 39 simple sequence repeat (SSR) markers on chromosome 5A were used to locate the YrFL. Linkage analysis mapped YrFL with 19 KASP and three SSR markers on wheat chromosome 5AS, and the genetic distances of the closest flanking markers AX108925494 and Xbarc56 to YrFL were 0.6 and 2.0 cM, respectively. Chromosome location, resistance characterization, and molecular marker positions indicated that YrFL is likely a novel stripe rust resistance gene on wheat chromosome 5AS and could be pyramided with other resistance genes to improve resistance in wheat breeding programs.

Volatile profiling as a potential biochemical marker for validation of gamma irradiation derived putative mutants in polyembryonic genotypes of mango (Mangifera indica L.).

Putative mutants were generated through gamma irradiation in the polyembryonic mango genotype Nekkare. The putative mutant progenies along with control seedlings and mother plants were evaluated by comparing the compositions and relative proportions of their major volatile compounds. Volatile profiling was done using headspace-solid phase micro-extraction (HS SPME) method coupled with gas chromatography-mass spectrometry (GC-MS MS). Furthermore, characterisation of putative mutants and control seedlings was carried out using simple sequence repeat (SSR) markers to ascertain the genetic diversity present in the samples under study. Monoterpenes were the most abundant volatile compound in all the studied samples (ranging from 34.76% to 91.41%) out of which I-Phellandrene and cis-Ocimene formed the major fraction in mother plants (20.45%-21.86% and 16.17%-21.27%, respectively) and control seedlings (23.32%-24.95% and 18.95%-20.81%, respectively), while beta-Phellandrene was dominant in the selected putative mutant samples (2.34%-29.53%). Among sesquiterpenes, trans-Caryophyllene was detected only in the putative mutant samples (0.10%-30.18%). Grouping together of mother plants and control seedlings was seen in the cluster analysis, while the putative mutants grouped apart from them suggesting genetic diversity. Genetic distance between the mother plants and control seedlings ranged from 0.97 to 2.73, while between putative mutants, control seedlings, and mother plants, it ranged from 6.54 to 9.82. SSR-based characterisation of putative mutant seedlings showed that mutation caused variability in the treated population. This was evident from the high allelic richness ranging from 4 to 12 with a mean of 7 and a higher mean Shannon's Information Index (1.50) of the putative mutant population. The study demonstrates that volatile profiling and molecular characterisation using SSR markers could be used as a tool to detect variation in a mutated population. In addition, volatile profiling can be used to validate putative mutants in polyembryonic mango genotypes where the seedlings of nucellar origin are similar to mother plants.

Genetic diversity analysis of Bitti (Vitex cofasssus), native species Indonesia based on Inter Simple Sequence Repeat (ISSR) marker

Bitti (Vitex cofassus) is a native species in Indonesia and is a superior wood in South Sulawesi. This type is a hardwood that is sought after and exported in large enough quantities. A narrow genetic base requires joint efforts to develop plant varieties, so it is necessary to carry out selection activities to obtain a superior diversity of traits. The most advanced method in assessing genetic diversity is a molecularly based approach using the Inter Simple Sequence Repeat (ISSR) marker. Germplasm exploration was carried out in Pattiroang Village, Kajang District, Bulukumba Regency, South Sulawesi Province. A total of 30 samples were extracted using the Genomic DNA Mini Kit (plant) method with modifications. Ten primers tested obtained six primers that produced bright polymorphic bands, namely UBC 820, UBC 822, UBC 823, UBC 824, UBC 827, and UBC 830. The highest He value is in the UBC 824 primary with a PIC of 0.48, while the lowest He values is in the UBC 827 primer with a PIC value of 0.15. The visualization of the dendrogram shows two large clusters, each consisting of a diverse number of individuals. It indicates a relatively moderate kinship between the types of V. cofassus.

Characterization of gill transcriptome, SSR/SNP markers and expression analysis of lysozyme LysC gene from Carassius auratus upon Aeromonas hydrophila infection

The gills are large mucosal surfaces and play primary roles in respiration and immune defences. However, the molecular mechanism for gills of fish needs still to be explored. In the present study, transcriptomic analysis and identification of SSR and SNP markers were performed in the gills of crucian carp Carassius auratus. The results showed a total of 84,259 unigenes were annotated to NCBI NR, KEGG and GO databases for 55,283, 39,303, 33,388, respectively. Enriched KEGG pathway analyses for the identified genes showed the mainly functional modules such as metabolism, cellular processes, environmental adaptation, genetic processing, organismal and immune systems. Moreover, 22,102 SSRs (simple sequence repeats) were potentially identified and 9776 (44.2%) were accounted for the most dinucleotides. Transition and transversion sites of SNPs (single nucleotide polymorphisms) were also observed. Tissue distribution showed that the expression level of lysozyme LysC gene was relatively high in intestine, liver, spleen and kidney tissues and up-regulated in gills, skin and brain after the A. hydrophila infection. We discovered the immune-related pathways through the transcriptome analysis in the gills of crucian carp, some potential SSR/SNP markers were identified, and lysozyme gene predominantly expressed in mucosal immune organs (eg., gills, skin, intestine) responded to A. hydrophila infection. To the best of our knowledge, this was the detailed report on the molecular characteristics in crucian carp gills with transcriptome analysis, which will not only provide a scientific reference for further understanding the local defense mechanism, but also lay a foundation for molecular marker-assisted breeding in fish.

Genetic Diversity of New Almond Accessions from Central Asian and Cold-adapted North American Germplasm

We evaluated the genetic diversity of a newly available collection of 94 almond [Prunus dulcis (Mill.) D.A. Webb] accessions from the former Improving Perennial Plants for Food and Bioenergy (IPPFBE) Foundation. Most of the collection (87 accessions) were collected as seeds from trees growing in the central Asian nations of Kyrgyzstan, Tajikistan, and Uzbekistan, and included several examples of Prunus bucharica (Korsh.) Hand.-Mazz, and related wild species. Of the remaining accessions, six were sourced from a nursery in northern Utah in the United States, and one was a seedling of ‘Nonpareil’, a major commercial cultivar. DNA fingerprints were generated from 10 simple sequence repeat markers. To evaluate the comparative diversity of these new accessions, 66 accessions from the US Department of Agriculture, National Plant Germplasm System (NPGS) almond germplasm collection near Davis, CA, USA, were also included. These NPGS accessions were chosen to represent those collected in similar regions of Central Asia and the Caucasus. The fingerprints were analyzed via hierarchical clustering, principal components analysis (PCA), and discriminant analysis of principal components (DAPC). Hierarchical clustering suggested that half of the Utah-sourced accessions are closely related to each other and to the ‘Nonpareil’ seedling. Additional close relationships were detected (including at least one duplication or mislabeling), and two P. bucharica accessions from the IPPFBE collection were separated from the rest of the collection. A plot of the first two principal components clearly separated wild almond relatives (P. bucharica and Prunus fenzliana Fritsch) from the remaining accessions. PCA after removal of the wild species separated the ‘Nonpareil’ seedling, the Utah-sourced accessions, and many of the IPPFBE accessions (mostly from Uzbekistan) from nearly all other individuals. The third principal component identified an additional population structure that separated groups of predominantly IPPFBE or NPGS accessions. DAPC showed a considerable admixture of accessions from Azerbaijan, and a little to no admixture of accessions from Georgia and Tajikistan. These results suggest that central Asian/Caucasian almond germplasm is generally distinct from ‘Nonpareil’ and its relatives, and that although there is overlap between the NPGS and IPPFBE collections from this region, the IPPFBE collection does enhance the diversity of available almond germplasm.

QTL Mining and Validation of Grain Nutritional Quality Characters in Rice (Oryza sativa L.) Using Two Introgression Line Populations

Nutritional grain quality is mainly influenced by the protein fraction content and grain protein content. Quantitative trait loci (QTL) mining for five traits, about 245 and 284 BC3F3 individual families of two introgression line (IL) populations were derived from Kongyu 131/Cypress (population-I) and Kongyu 131/Vary Tarva Osla (population-II), respectively. A genetic linkage map was developed using 127 simple sequence repeat (SSR) markers in population-I and 119 SSR markers in population-II. In total, 20 and 5 QTLs were detected in population-I and population-II, respectively. About twenty QTLs were mapped in population-I: five QTLs for albumin, seven QTLs for globulin, six QTLs for prolamin, one QTL for glutelin, and one QTL for grain protein content. In total, five QTLs were mapped in population-II: one QTL for albumin and four QTLs for grain protein content. Out of 25 QTLs, 19 QTLs exhibit co-localization with the previously reported QTLs. QTL-like qGPC7.3 was delineated for total protein content. This QTL was derived from population-I and was successfully validated in NILs (near-isogenic lines). The grain protein phenotype showed a significant variation between two NILs. This investigation serves as groundwork for additional cloning of nutritional quality-related genes in rice grains.

Genetic diversity and population structure of Polygonatum cyrtonema Hua in China using SSR markers.

Polygonatum cyrtonema Hua is a perennial herbaceous plant of the Polygonatum genus, belonging to the Liliaceae family, with significant medicinal and nutritional value. In China, this species is a traditional medicinal and edible herb with a long history of application and is widely appreciated by the people. However, as the demand for medicinal herbs continues to grow, excessive harvesting has led to the depletion of wild resources and the risk of genetic erosion. In addition, the chaotic cultivation of varieties and the lack of high quality germplasm resources have led to inconsistent quality of medical materials. Therefore, it is urgent to conduct genetic diversity evaluation of this species and establish a sound conservation plan. This study assessed the genetic diversity and population structure of 96 samples collected from seven regions in China using the simple sequence repeat (SSR) molecular marker technology. In this study, a total of 60 alleles (Na) were detected across the 10 polymorphic SSR markers used, with an average of 6.0 alleles generated per locus. The values of polymorphic information content (PIC) values ranged from 0.3396 to 0.8794, with an average value of 0.6430. The average value of the effective number of alleles (Ne) was 2.761, and the average value of the Shannon's information index (I) was 1.196. The population structure analysis indicates that the Polygonatum cyrtonema Hua germplasm can be classified into three subpopulations (JZ, QY, JD) at the molecular level, which corresponds to the previous subgroups identified based on individual plant phenotypic traits. Analysis of Molecular Variance (AMOVA) showed that 74% of the genetic variation was between individuals within populations in different regions. The phylogenetic analysis of the 96 germplasm samples divided them into three main populations. The QY and JD subpopulations are largely clustered together, which could be attributed to their mountainous distribution and the local climate environment. The genetic differentiation coefficient (Fst) value was low at 0.065, indicating relatively low population differentiation. The ratio of the genetic differentiation coefficient (Fst) between the JZ population and the other two populations (QY and JD) is much higher than the ratio between the QY and JD populations. Based on the clustering results and the ratio of the genetic differentiation coefficient (Fst), it can be inferred that the genetic relationship between the QY and JD subpopulations is closer, with a certain degree of genetic differentiation from the JZ subpopulation. This study supports the conservation of germplasm resources of Polygonatum cyrtonema Hua in China and provides new parental material for germplasm genetic improvement and breeding programs.

Conservation genetics of endangered Trillium govanianum Wall. ex D. Don – A pharmaceutically prized medicinal plant from the Himalaya and implications for species recovery

Understanding the genetic diversity and population structure of pharmaceutically important endangered plant species is crucial for their conservation and sustainable use. Despite the continuous population decline in Trillium govanianum Wall. ex D. Don, a highly prized medicinal plant endemic to the Himalaya, information regarding its conservation genetics has been lacking. Here, we employed a conservation genetics approach to investigate how drastically declining populations in natural habitats impact population genetic diversity and structure of this endangered species across the Kashmir Himalaya. We used Start codon targeted (SCoT) and Simple sequence repeat (SSR) markers to assess the intra- and inter-population genetic variation in seven sites across the study region. Based on these markers, we found a very low genetic diversity in T. govanianum populations. Very low levels of observed heterozygosity (Ho = 0.000) and that expected (He = 0.064) in the populations indicate high heterozygote deficiency and high levels of inbreeding depression (FIS = 1.000). A high genetic differentiation was observed among the populations for both SCoT (Gst = 0.719) and SSR (Fst = 0.707) markers. Both the markers showed low gene flow, SCoT (Nm = 0.195) and SSR (Nm = 0.119), depicting high among-population variation than within-population variation. Analysis of molecular variance also indicated a higher genetic variation between the populations than within populations. We also observed a significant positive correlation between genetic divergence and geographical distance, indicating that genetic differentiation in T. govanianum follows a pattern of isolation by distance. Bayesian structure and cluster analysis grouped the populations according to their geographical proximity. Further, redundancy analysis (RDA) revealed the presence of one polymorphic locus for each marker with high discriminatory power. Overall, our findings reveal a very low genetic diversity, high levels of inbreeding, and high genetic differentiation among the populations; likely resulting from habitat fragmentation, population isolation, bottleneck effect, low gene flow, and predominantly asexual reproduction currently operative in the species. Finally, based on the insights gained, we discuss the potential implications of our findings in guiding species recovery and habitat rehabilitation of T. govanianum in the Himalaya with conservation lessons for elsewhere in the world.

Genetic diversity of ex-situ conserved Arabica cofee (Coffea arabica L.) accessions in Ethiopia as revealed by simple sequence repeats markers

So far, there has been limited use of molecular markers in arabica coffee breeding program in Ethiopia. The objectives of this study were to explore the effectiveness of simple sequence repeats markers (SSRs) in detecting polymor- phism and to assess the extent of genetic diversity and relationships among ex-situconserved Arabica coffee accessions. Sixty-two forest coffee accessions planted in the experimental plot of the Ethiopian coffee breeding program were evaluated using 14 SSR markers. These markers amplified a total of 100 alleles, varying from four to ten alleles per locus, with an average of 7.2 across all loci. The rate of polymorphism ranged from 75 to 100, with a mean value of 96.4 across the accessions. The polymorphic information content (PIC) varied from 0.26 to 0.92, with a mean value of 0.70. The genetic similarity coefficient values between 72% possible pair-wise combinations ranged from 0.18 to 0.50, with overall mean value of 0.44.The unweighted pair group method with arithmetic mean (UPGMA) dendrogram based on Jaccard’s genetic similarity grouped the accessions into five main clusters and two singletons at <0.47 similarity coefficient value. These results indicate the effectiveness of the SSR markers in detecting polymorphism and the presence of a high level of genetic diversity and distant relatedness among the studied coffee accessions. The observed diversity could be exploited in the future coffee breeding program to develop heterotic hybrid coffee varieties through crossing of divergent parental lines. The highly informative SSRs markers can be also used in genetic analysis of Arabica coffee germplasm conserved in the field gene bank at Jimma Agricultural Research Center (JARC) to establish core collections for effective conservation, management and utilization purposes

Genetic diversity of kale (Brassica oleracea L. var acephala) using agro-morphological and simple sequence repeat (SSR) markers

Kale (Brassica oleracea. var. acephala) is a nutrient-rich green leafy vegetable consumed as food and used in traditional medicine worldwide. An essential step in describing the available genetic resources and ensuring their effective use in breeding programs is to characterize the genetic diversity of available germplasm. In this study, the genetic diversity and structure of 26 kale accessions from South-East Europe were examined using 26 agro-morphological traits collected in the field and 12 simple sequence repeat (SSR) markers. Considerable agro-morphological variability was found in most quantitative (CV = 17.26–42.42%) and qualitative (H' = 0.61–1.79) traits. Multifactorial analysis (MFA) showed that country of origin (33.01%) and morphotype (32.30%) significantly influenced kale diversification. Leaf blade shape (20.62%), leaf incision (19.43%), anthocyanin distribution (16.43%), and leaf colour (15.55%) were the traits that most clearly differentiated accessions. The three common commercial kale cultivars were identified as independent outliers that differed from the other kale accessions in both MFA and UPGMA clustering analysis. The SSR markers were highly informative with 108 alleles and polymorphic information content ranging from 0.395 to 0.856. Strong genetic diversity was detected at the accession level (H' = 0.58) while genetic differentiation was low (Fst = 0.05). Similar to UPGMA clustering, Bayesian clustering suggests that the kale collection can be divided into four clusters with a high degree of admixture and no geographic grouping pattern is apparent. Overall, the study showed that the kale collection studied represents a valuable reservoir of genetic and agro-morphological variability that could be used for future breeding initiatives.

Genetic diversity evaluation of core collection gene bank using simple sequence repeat marker of Acorus calamus L.: An important aromatic species

Acorus calamus L. is an important medicinal and aromatic plant having economic and medicinal properties. In the present research, molecular diversity analysis was performed using 138 Acorus calamus accessions obtained from the varied regions of Northeast India. All the collected germplasm was maintained at the Council of Scientific and Industrial Research-North East Institute of Science and Technology (CSIR-NEIST) experimental farm, Jorhat, India. A molecular diversity study was conducted by employing 30 primers screened from 55 simple sequence repeat (SSR) primers based on their polymorphic nature. An average of 99.58% polymorphism was exhibited with a total of 186 polymorphic alleles shown by the selected SSR primers. To estimate the variations among A. calamus accessions, an analysis of molecular variance (AMOVA) was also performed. The genetic diversity among the population was found to be 28% and genetic variations of 72% were observed within the population. Genetic variations within and among populations were found significant with P value of 0.001. The analysis of population-based genetic diversity parameters revealed an average value of 1.84 for the observed number of alleles (Na), 1.48 for an effective number of alleles (Ne), 0.28 for Nei’s genetic diversity index (h), and 0.42 for Shannon's information index in four grouped populations. All the 138 accessions of A. calamus were subdivided into three clusters of dendrogram based on unweighted pair group method with arithmetic mean (UPGMA) analysis. Principal component analysis (PCoA) was further performed and a biplot was constructed for the validation and confirmation of the clusters. Moreover, three genetically diverse populations were also detected by the use of structure harvester software. Until now, there are no such reports on the analysis of the genetic diversity of this industrially important crop using SSR markers. So, it can be considered as the first report on the molecular diversity of A. calamus which will be helpful for the crop improvement, conservation, and identification of the elite genotypes.

Genome-wide survey and characterization of microsatellites in cashew and design of a web-based microsatellite database: CMDB.

The cashew is an edible tree nut crop having a wide range of food and industrial applications. Despite great economic importance, the genome-wide characterization of microsatellites [simple sequence repeats (SSRs)] in cashew is lacking. In this study, we carried out the first comprehensive genome-wide microsatellites/SSRs characterization in cashew and developed polymorphic markers and a web-based microsatellite database. A total of 54526 SSRs were discovered in the cashew genome, with a mean frequency of 153 SSRs/Mb. Among the mined genome-wide SSRs (2-6 bp size motifs), the dinucleotide repeat motifs were dominant (68.98%) followed by the trinucleotides (24.56%). The Class I type of SSRs (≥20 bp) were 45.10%, while Class II repeat motifs (≥12-<20 bp) were 54.89% of the total genomic SSRs discovered here. Further, the AT-rich SSRs occurred more frequently in the cashew genome (84%) compared to the GC-rich SSRs. The validation of the in silico-mined genome-wide SSRs by PCR screening in cashew genotypes resulted in the development of 59 polymorphic SSR markers, and the polymorphism information content (PIC) of the polymorphic SSR markers ranged from 0.19 to 0.84. Further, a web-based database, "Cashew Microsatellite Database (CMDB)," was constructed to provide access to the genome-wide SSRs mined in this study as well as transcriptome-based SSRs from our previous study to the research community through a user-friendly searchable interface. Besides, CMDB provides information on experimentally validated SSRs. CMDB permits the retrieval of SSR markers information with the customized search options. Altogether, the genome-wide SSRs characterization, the polymorphic markers and CMDB database developed in this study would serve as valuable marker resources for DNA fingerprinting, germplasm characterization, genetic studies, and molecular breeding in cashew and related Anacardium species.

Screening and Evaluation of Excellent Blackberry Cultivars and Strains Based on Nutritional Quality, Antioxidant Properties, and Genetic Diversity.

To screen and evaluate excellent blackberry cultivars and strains, 17 indexes of plant growth and fruit horticultural and nutritional characteristics were measured, 20 simple sequence repeat (SSR) markers were analyzed, the fingerprints of 23 blackberry cultivars and strains were constructed, and the processing characteristics of 10 excellent cultivars and strains were evaluated. The results showed that 'Chester' and 'Shuofeng' had the highest plant yield (6.5 kg per plant), of which the 'Chester' fruit also had the highest hardness (2.78 kg/cm2). 'Kiowa' had the highest single fruit weight (10.43 g). '10-5n-2' had the highest total anthocyanin content (225.4 mg/100 g FW) and total polyphenol content (3.24 mg/g FW), but a low plant yield. These results suggest that 'Shuofeng' and 'Chester' are the top two blackberry cultivars planted in Nanjing, with the best growth and comprehensive quality. Moreover, a total of 119 alleles were detected with an average number of 6 alleles per locus. The polymorphism information content (PIC) was 0.374~0.844, with an average of 0.739, indicating a high genetic diversity among the 23 blackberry cultivars and strains. This study provides insight into the plant growth, fruit characteristics and genetic diversity of the 23 blackberry cultivars and strains, and is thus conducive to the protection and utilization of blackberry cultivars and strains.

Genetic Diversity and Population Structure of Juniperus seravschanica Kom. Collected in Central Asia.

Juniperus seravschanica Kom. is a species that grows widely in the mountain ranges from Central Asia to Oman. It is an important tree for the formation of shrub-forest massifs in mountainous areas and for draining and fixing soils from middle to high altitudes. A comprehensive study of the species' genetic diversity and population structure is a basic approach to understanding the current status of J. seravschanica resources for the development of future conservation strategies. Samples from 15 populations of J. seravschanica were collected from the mountain ranges of Uzbekistan, Kyrgyzstan, and Kazakhstan. The genetic diversity and population structure of 15 Central Asian populations of J. seravschanica were assessed using 11 polymorphic simple sequence repeat (SSR) markers. Genetic diversity parameters, including the number of alleles (na), the effective number of alleles (ne), Shannon's information index (I), the percentage of polymorphic loci (PPL), Nei's genetic diversity index (Nei), principal coordinate analysis (PCoA), etc., were evaluated. The analysis of 15 J. seravschanica populations based on 11 polymorphic SSRs detected 35 alleles. The average PIC value was 0.432, and the highest value (0.662) was found in the JT_40 marker. Nei's genetic diversity index for the J. seravschanica populations was 0.450, ranging from 0.407 (population 14) to 0.566 (population 4). The analysis of molecular variance (AMOVA) showed that 90.3% of total genetic variation is distributed within the population. Using the alleles of all the populations, the gene flow (Nm) was found to be 4.654. Population structure analysis revealed poor clustering in the studied populations and confirmed our AMOVA results. The output of this work can be efficiently used for the maintenance of the species across the Central Asian region.

Diversity Assessment of Winged Bean [Psophocarpus tetragonolobus (L.) DC.] Accessions from IITA Genebank

The capability of winged bean to support food and nutrition security in sub-Saharan Africa is recurrently being affected by several constraints, which include a lack of genetic improvement. The dearth of adequate information on the level of available genetic diversity in winged bean germplasm has been a major setback in planning appropriate improvement programs. Fifteen winged bean accessions were assessed for genetic diversity using 10 quantitative traits and 10 simple sequence repeat (SSR) markers. The accessions were laid out in RCBD with three replicates for two growing seasons. Leaf samples were obtained from 10 plants representing each accession for SSR marker genotyping. The accessions exhibited significant (p &lt; 0.05) differences for measured traits. Broad-sense heritability estimates varied from 10.31% for days to first plant maturity to 72.67% for pod weight. Pod weight had a positive and significant correlations with pod length (0.53, p &lt; 0.05), pod width (0.70, p &lt; 0.01), and number of seeds per pod (0.64, p &lt; 0.01). However, the number of seeds per pod was negatively correlated with days to maturity (−0.71, p &lt; 0.01). Number of seeds per pod was positively predicted by pod weight, seed thickness, and days to maturity. Cluster analysis delineated the accessions into two distinct groups. Average number of alleles of 4.2, gene diversity of 0.25, and polymorphic information content of 0.22 were recorded. Analysis of molecular variance revealed intra-accession variation of 95% as compared to inter-accession variation of 5%. Two primary genetic groups were identified and only three accessions, namely TPt-6, TPt-126, and TPt-48, showed genetic purity. The results of this study provide the basis for exploiting the existing diversity for winged bean improvement.

Development and application of simple sequence repeat markers based on whole-genome sequencing in Codonopsis lanceolata

Development and application of simple sequence repeat markers based on whole-genome sequencing in Codonopsis lanceolata

Genetic Diversity of Coffee Genotypes Using Simple Sequence Repeat (SSR) Markers

Coffee plays an important role in the global economy, human health and society. It is one of the major cash crops constituting the backbone of the Nigerian economy before the emergence and re-emergence of petroleum oil. Molecular markers are reliable and valuable tool for analyzing polymorphism, screening and selection of desirable genotypes in breeding programs. The study aimed at determining the genetic diversity among coffee genotypes. Fifty genotypes of coffee (Coffea spp) collected from Cocoa Research Institute of Nigeria (CRIN) germplasm were assessed using 12 simple sequence repeat (SSR) markers. The findings revealed that polymorphic information content (PIC) ranged between 0.311 and 0.882 with an average of 0.545. The gene diversity (0.602) was high and the Unweighted Pair Group Method of Analysis using arithmetic averages (UPGMA) dendrogram grouped the genotypes into four major clusters with subclusters. The results revealed high levels of polymorphism indicating genetic diversity and confirm uniqueness among the coffee genotypes.

Multiple-Genome-Based Simple Sequence Repeat Is an Efficient and Successful Method in Genotyping and Classifying Different Jujube Germplasm Resources.

Jujube (Ziziphus jujuba Mill.) is a commercially important tree native to China, known for its high nutritional value and widespread distribution, as well as its diverse germplasm resources. Being resilient to harsh climatic conditions, the cultivation of jujube could provide a solution to food insecurity and income for people of arid and semi-arid regions in and outside of China. The evaluation of germplasm resources and genetic diversity in jujube necessitates the use of Simple Sequence Repeat (SSR) markers. SSR markers are highly polymorphic and can be used to evaluate the genetic diversity within and between cultivars of Chinese jujube, and are important for conservation biology, breeding programs, and the discovery of important traits for Chinese jujube improvement in China and abroad. However, traditional methods of SSR development are time-consuming and inadequate to meet the growing research demands. To address this issue, we developed a novel approach called Multiple-Genome-Based SSR identification (MGB-SSR), which utilizes the genomes of three jujube cultivars to rapidly screen for polymorphic SSRs in the jujube genome. Through the screening process, we identified 12 pairs of SSR primers, which were then used to successfully classify 249 jujube genotypes. Based on the genotyping results, a digital ID card was established, enabling the complete identification of all 249 jujube plants. The MGB-SSR approach proved efficient in rapidly detecting polymorphic SSRs within the jujube genome. Notably, this study represents the first successful differentiation of jujube germplasm resources using 12 SSR markers, with 4 markers successfully identifying triploid jujube genotypes. These findings offer valuable information for the classification of Chinese jujube germplasm, thereby providing significant assistance to jujube researchers and breeders in identifying unknown jujube germplasm.

Genetic variation, correlation, and association mapping of seed yield and its component traits in sesame

AbstractSesame is an important and specific oilseed crop with high quality. Here, we systematically investigated the relationships between plant seed yield (PSY) and nine related traits in 369 sesame core accessions under five environments. The PSY and related traits had general heritability ranging from 14% for PSY to 72% for height to the first capsule (FCH) and final flowering stage (FFS). Correlation analysis suggested that seven yield-related traits, including capsule number per plant (CNP, r = 0.67), capsule stem length (CSL, 0.56), thousand-seed weight (TSW, 0.26), plant height (PH, 0.24), FFS (0.17), initial flowering stage (IFS, − 0.16) and FCH (− 0.14) were the key factors associated with seed yield in sesame (P &lt; 0.01). For the uniculm and branching groups, CNP, CSL, and TSW were the common key factors. Path analysis showed similar direct effects of these key factors on PSY. Association mapping identified 13 simple sequence repeat (SSR) markers significantly associated with the nine seed yield-related traits (P &lt; 0.001). Among these, three SSR markers were repeatedly detected in two environments. Marker Hs635 was associated with the seed number per capsule (SNC). Hs345 was associated with the CNP. Hs618 was associated with the IFS in uniculm accessions. These results provide insights into the traits that influence PSY and their genetics in sesame.

Morpho-molecular exploration and selection of elite genotypes from indigenous Syzygium cumini L. Skeels (jamun) diversity of North-Western Indian Himalayas

AbstractEfficiently distinguishing various Syzygium cumini L. Skeels (jamun) accessions holds practical significance for selection purposes. This study concentrated on 15 superior genotypes of jamun from the North Western Indian Himalayas, selected for their pivotal horticultural traits. Drawn from a pool of 82 collected genotypes and assessed across two consecutive years (2019 and 2020), these genotypes underwent morphological evaluations utilizing a randomized block design replicated thrice. Concurrently, random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers were employed for molecular analysis. Substantial variations surfaced among genotypes, both in morphological traits and fruit biochemistry. Notably, tree 43 exhibited promise across multiple horticultural facets, encompassing fruit weight, length, pulp weight, pulp-to-seed ratio and pulp percentage. Conversely, tree 49 excelled in elevated levels of total soluble solids, total sugar and reducing sugar. While principal component analysis and cluster analysis unveiled modest genetic variability, RAPD and ISSR markers unveiled pronounced molecular-level polymorphism. Agglomerative hierarchical clustering delineated the genotypes into five distinct clusters. Cluster I encompassed two genotypes, cluster II embraced five while the largest group, cluster III, included six genotypes. Clusters IV and V highlighted individual genotypes, trees 43 and 54 respectively. In the molecular analysis, UPGMA clustering yielded two primary clusters, spotlighting the noteworthy similarity between genotypes trees 49 and 52 whereas, trees 40, 43, 44 and 48 stood distinct. The observed genetic diversity stands as a valuable resource with substantial potential to enrich diverse breeding initiatives. These salient genetic variations underscore the richness within the studied population, offering a valuable asset for focused future pursuits.