Developing First Microsatellites and Analysing Genetic Diversity in Six Chia Cultivars

Chia (Salvia hispanica L.), originated in central and southern Mexico and Guatemala, is an emerging industry crop due to its high content of omega‐3 fatty acids and dietary fiber in its seeds. The seeds also have a high concentration of proteins and essential amino acids, and are becoming a promising source of bioactive peptides. Polymorphic DNA markers are essential tools to analyse genetic diversity and to accelerate genetic improvement. However, in Chia, polymorphic and codominant DNA markers are still lacking. In this study, fourteen polymorphic microsatellites were identified from DNA sequences and were characterized. The average allele number was 4.8 while the expected and observed heterozygosity was 0.24 and 0.34, respectively. The average PI was 0.50 while the combined PI was 9 ×10-6. These first 14 microsatellites in Chia are useful in genetic analysis and traceability. These 14 polymorphic microsatellites were used in analysing genetic diversity and population relationships in six cultivars originating in Mexico, Australia and Bolivia. Results showed that allelic diversity and gene diversity were low and ranged from 2.79 to 3.64 and 0.27 to 0.38, respectively. The Mexico black cultivar showed the highest allelic (3.64) and gene diversity (0.38). The six cultivars were closely related with high identity (> 0.893). Taken together, these Chia cultivars contain low genetic variation. Therefore, to initiate a breeding program for improving traits, it is essential to use seeds from multiple cultivars to enlarge genetic variation in the founder population.

Genetic Diversity Study of African Rice (Oryza glaberrima) and its Wild Relatives using Microsatellites Markers

The Africa Rice Center Gene Bank hold about 2,500 accessions of Oryza glaberrima. To understand well the genetic diversity in O. glaberrima and its wild species, the use of molecular tools is prominent. The sample consisted of 217 accessions of O. glaberrima, 46 of O. barthii and 7 of O. sativa (checks) was genotyped with 21 polymorphic microsatellites markers. A total of 245 alleles were detected with average 11.67 alleles per locus. Number of alleles was ranged from 2 (RM124) to 20 (RM536). The polymorphic information content value was 0.49 while the heterozygosity was 0.091. The result showed that the sample can be clustered into four genotypic groups. Two groups among them were homogeneous. The first one consisted of O. barthii accessions with 82 alleles in total with average 3.90 alleles per locus. However, the second one consisted of only O. glaberrima accessions with 122 alleles with average 5.80 alleles per locus. O. glaberrima accessions were analyzed using model-based population structure. Results revealed two groups among O. glaberrima accessions. At the end, the identified core collection has 26 accessions consisted of 16 O. glaberrima and 10 O. barthii based on 21 microsatellites markers.

Twelve new microsatellite loci of Eurasian perch Perca fluviatilis Linnaeus, 1758

The Eurasian perch (Perca fluviatilis Linnaeus, 1758) is native to almost entire Eurasia. For over the last two decades, this species became an important candidate for intensive freshwater aquaculture due to its high consumer’s acceptance and overall market value. Hence, the intensive production of Eurasian perch has increased considerably allowing effective domestication; there is still a need for the development of effective selective breeding programmes allowing its further expansion. This process, in turn, can be significantly facilitated by molecular genetics. The genetic information of Eurasian perch and its populations is limited. Up to date information of regarding genetic diversity of many populations is still missing, including microsatellites for Eurasian perch, which could be useful during the selective breeding programmes allowing parental assignment and/or to follow heritability of desired traits. In this study, we have developed and characterized new polymorphic microsatellites. Subsequently, those 12 markers have been used further to compare two Hungarian and one Polish Eurasian perch populations. The Hungarian stocks had high genetic similarity (with low diversity), as we assumed, while the Polish population differed significantly. All populations deviated significantly from the Hardy–Weinberg equilibrium, and heterozygote deficiency was detected in all, showing the presence of an anthropogenic effect.

Impact of different numbers of microsatellite markers on population genetic results using SLAF-seq data for Rhododendron species

Microsatellites (simple sequence repeats, SSRs) are co-dominant nuclear markers that are widely used in population genetic studies. Population genetic parameters from different studies might be significantly influenced by differences in marker number. In our study, 265 sequences with polymorphic microsatellites were obtained from SLAF-seq data. Then, subpopulations containing different numbers (5, 6, 7,…, 15, 20, 25, 30, 35, 40) of markers were genotyped 10 times to investigate the impact of marker numbers on population genetic diversity results. Our results show that genotyping with less than 11 or 12 microsatellite markers lead to significant deviations in the population genetic diversity or genetic structure results. In order to provide markers for population genetic and conservation studies for Rhododendron, 26 SSR primers were designed and validated in three species.

Development of Genomic Resources From Crossostephium Chinense (Asteraceae) Based on Genome Skimming Data

Crossostephium chinense is a traditional Chinese medicinal herb and it is often cultivated as an ornamental plant. Previous studies on this species mainly focused on its chemical composition and it was represented rarely and marginally in genetic studies, which limited knowledge about its genetic background, and thus genomic resources remain scarce. To develop both chloroplast and nuclear polymorphic microsatellites for C. chinense, potential microsatellites were screened from genome skimming data of two individuals of C. chinense. Sixty-four and 63 cpSSR markers were identified from two chloroplast genomes of C. chinense. This study performed for the first-ever study on employment of genome skimming data and CandiSSR, consequently a total of 133 polymorphic nSSRs were developed. Ten nSSRs were randomly selected to test their transferability across 35 individuals from three populations of C. chinense, and 20 individuals each of Artemisia stolonifera and A. argyi. Cross-amplifications were successful done for C. chinense, and were partially successful amplified for both Artemisia species. The number of alleles varied from two to nine. The observed heterozygosity and expected heterozygosity per locus ranged from 0.000 to 0.286 and from 0.029 to 0.755, respectively. These genomic resources will be valuable for population genetics and conservation studies in C. chinense and Artemisia.

Development and characterization of microsatellite markers for two subspecies of Handroanthus chrysanthus

An understanding of the genetic diversity and structure of plant species is essential in order to comprehend the degree of biodiversity loss and to develop successful restoration programs. Handroanthus is an important genus that presents one of the most valuable timbers of South America. Handroanthus chrysanthus is an important species distributed in Central and South America. Microsatellite markers are not previously developed for this species. Ten microsatellites for Handroanthus chrysanthus developed using high-throughput sequencing are presented here. The usefulness of these microsatellite loci for the genetic analysis of subspecies H. chrysanthus subsp. chrysanthus (distributed in coastal dry forests) and subspecies H. chrysanthus subsp. meridionalis (distributed in premontane moist forests) is analyzed. At least eight polymorphic microsatellites are useful for each subspecies, seven of which can be used in both subspecies.

Genassemblage 2.0 software facilitates conservation of genetic variation of captively propagated species

In conservation of captively propagated species, conserving genetic diversity is important. Here, we present an example of the use of Genassemblage 2.0 software in conserving the genetic variation of the lake minnow (Eupallasella percnurus). This fish has low genetic variation and is at risk of extinction in the western edge of its range, which includes Poland. Fish from one Polish population were captured (23 males, 25 females). Fin clips were taken, and DNA was extracted. Polymorphic microsatellites (13) were used to prepare genetic profiles, assess genetic variation in the fish and estimate genetic diversity in their progeny. Alleles were scored using an automatic capillary sequencer. The four and eight best variants of spawning pairs, and the optimal sets for group volitional breeding (four males, four females; eight males, eight females) were identified using Genassemblage 2.0. In the sets of 8 and 16 fish for group breeding, the mean heterozygosity, the number of alleles, and the share of “weak” heterozygotes (0.493, 24, 0.239 and 0.479, 23, 0.257, respectively) were better than the mean values for the progeny of all potential breeding pairs. For group volitional breeding, one set of four males and four females, and numerous sets of eight males and eight females would enable transmission of all 33 alleles identified in the potential broodstock and an expected progeny heterozygosity of 0.441 and 0.414, respectively. These expected heterozygosity values are higher than those in the broodstock. For practical purposes, the larger sets would be preferable for avoiding a future inbreeding and genetic drift.