Assessment of the genetic diversity and genetic relationships of Lilium in China using ISSR markers

China is a center of natural distribution and diversity of genus Lilium around the world. In the study, the genetic diversity and genetic relationships of Lilium in China were analyzed by inter-simple sequence Repeat (ISSR) markers. The 6 highly polymorphic ISSR primers were selected to amplify the 20 Lilium species. The results showed that a total of 114 DNA bands were amplified, all of which were polymorphic loci (P = 100%), the effective number of alleles (Ne) was 1.2753, and the difference value between observed number of alleles (Na) and effective number of alleles (Ne) was 0.7247, and the Nei's genetic diversity (H) was 0.2048, and the Shannon's information index (I) was 0.3503. These results indicated that there is significant genetic difference among Lilium species in China. Taking the average genetic similarity coefficient (Gs) 0.5313 as the threshold, the 20 tested Lilium species were clustered into 5 groups, which was not entirely consistent with traditional clustering by morphological traits. The results obtained from this study can provide a reference for the molecular study of Lilium germplasm resources.     

Analysis of Diversity in Chinese Cultivated Barley with Simple Sequence Repeats: Differences Between Eco-Geographic Populations

The genetic diversity of 116 barley accessions, representing five Chinese eco-geographic populations, was studied using simple sequence repeat (SSR) markers. The 21 SSR loci revealed 128 alleles with an average of 6.1 alleles per locus. The highest values of proportion of polymorphic loci (P) and gene diversity index (He) were obtained in the Northern (P = 1.00; He = 0.60) and the Yangtze River reaches and Southern populations (P = 1.00; He = 0.59). The lowest values were in the populations of the Yellow River reaches (P = 0.86; He = 0.44). The highest average number of alleles per locus (4.52) and number of unique alleles (7) were found in the Qinghai–Tibet plateau population. Cluster analysis revealed that together with the row type, strong eco-geographic variables influenced the classification. Associations of SSR and eco-geographic values were established for 11 SSR loci. Four to six markers were found to discriminate among geographic groups, which may serve as tools for diagnosis of the eco-geographic populations and provide evidence for the adaptive nature of SSR markers.     

Genetic diversity of a dominant species Stipa bungeana and its conservation strategy in the Loess Plateau of China

In order to investigate the genetic diversity and population structure of Stipa bungeana under the background of grassland utilization and grazing exclusion, ten S. bungeana populations were selected from different steppe type in the Loess Plateau of China. Sequence-related amplified polymorphism (SRAP) marker was used to assess the genetic diversity. Fifteen SRAP primer combinations generated a total of 482 amplification bands, 418 (86.72%) were polymorphic bands. A relatively high level of genetic diversity (PPB = 89.80%, h = 0.1972, H = 0.3154) was detected at the species level, but the genetic diversity was low at the population level (PPB = 17.01–33.33%, h = 0.0438–0.0967, H = 0.0361–0.1447). AMOVA analysis revealed a high level of genetic differentiation among populations (Φ_ST = 0.6757), and a limited among-population gene flow (N_m = 0.1200). There was no significant correlation between genetic distance and geographic distance by Mantel test (r = 0.1126, P = 0.204). Conservation implications were proposed for S. bungeana.     

Low genetic diversity and significant structuring in the endangered Mentha cervina populations and its implications for conservation

Eighteen populations of the endangered aromatic and medicinal plant Mentha cervina (Lamiaceae) were sampled across its natural range, in the western half of the Iberian Peninsula, and inter-simple sequence repeats (ISSRs) markers were used to assess genetic diversity and population structure. M. cervina populations exhibited a relatively low genetic diversity (percentage of polymorphic loci PPB = 14.2–58.3%, Nei's genetic diversity H_e = 0.135–0.205, Shannon's information index I = 0.08 − 0.33). However, the genetic diversity at species level was relatively high (PPB = 98.3%; H_e = 0.325; I = 0.23). The results of the analysis of molecular variance indicated very structured populations, with 50% of the variance within populations, 44% among populations and 6% between regions defined by hydrographic basins, in line with the gene differentiation coefficient (G_ST = 0.532). A Mantel test did not find significant correlation between genetic and geographic distance matrices (r = 0.064), indicating that isolation by distance is not shaping the present genetic structure. The levels and patterns of genetic diversity in M. cervina populations were assumed to result largely from a combination of evolutionary history and its unique biological traits, such as breeding system, low capacity of dispersion, small effective size and habitat fragmentation. The high genetic differentiation among populations indicates the necessity of conserving the maximum possible number of populations. The results also provide information to select sites for ex situ conservation. Optimal harvesting strategies, cultivation and tissue culture should also be developed as soon as possible to guarantee sustainable use of the species under study.     

Genetic diversity of wild and cultured swamp eel (Monopterus albus) populations from central China revealed by ISSR markers

Asian swamp eel is a highly commercial fish, primarily for China and other Asian countries. The aim of this paper is to evaluate the genetic diversity of wild and cultured samples of Asian swamp eel Monopterus albus using ISSR markers. A total of 129 individuals belonging to three wild samples, Xiantao (XT), Huanggang (HG), Xinyang (XY) and three cultured samples, Wuhan (WH), Jingzhou (JZ) and Nanjing (NJ) were randomly selected for genetic analysis. Twelve ISSR primers were used for screening the six populations and 110 loci were obtained. The polymorphic loci were estimated to be 54%, 56.3%, 58.2%, 60.6%, 69.5% and 71% in NJ,WH, JZ, XT, HG and XY samples, respectively. Average heterozygosity value varied from 0.1956 to 0.2449. The three wild samples showed higher genetic diversity than the cultured samples (P < 0.05), including polymorphic bands (PPB), observed number of alleles per locus (_to), effective number of alleles per locus (Ne), Nei’s gene diversity index (H) and Shannon’s information index (I).     

Novel Y‐chromosome short tandem repeats in Sus scrofa and their variation in European wild boar and domestic pig populations

Y‐chromosome markers are important tools for studying male‐specific gene flow within and between populations, hybridization patterns and kinship. However, their use in non‐human mammals is often hampered by the lack of Y‐specific polymorphic markers. We identified new male‐specific short tandem repeats (STRs) in Sus scrofa using the available genome sequence. We selected four polymorphic loci (5–10 alleles per locus), falling in one duplicated and two single‐copy regions. A total of 32 haplotypes were found by screening 211 individuals from eight wild boar populations across Europe and five domestic pig populations. European wild boar were characterized by significantly higher levels of haplotype diversity compared to European domestic pigs (H_D = 0.904 ± 0.011 and H_D = 0.491 ± 0.077 respectively). Relationships among STR haplotypes were investigated by combining them with single nucleotide polymorphisms at two linked genes (AMELY and UTY) in a network analysis. A differentiation between wild and domestic populations was observed (F_ST = 0.229), with commercial breeds sharing no Y haplotype with the sampled wild boar. Similarly, a certain degree of geographic differentiation was observed across Europe, with a number of local private haplotypes and high diversity in northern populations. The described Y‐chromosome markers can be useful to track male inheritance and gene flow in wild and domestic populations, promising to provide insights into evolutionary and population genetics in Sus scrofa.     

Exploring genetic variations in threatened medicinal orchids using start codon targeted (SCoT) polymorphism and marker-association with seed morphometric traits

We aimed to study the genetic diversity and population structure of eight Iranian terrestrial orchid species, including Anacamptis coriophora (L.) R. M. Bateman, Pridgeon and M. W. Chase, Dactylorhiza umbrosa (Kar. & Kir.) Nevski, Himantoglossum affine (Boiss.) Schltr., Orchis collina Banks and Solander, Orchis mascula (L.) L., Orchis simia Lam., Ophrys schulzei Bornm. and Fleischm., and Ophrys straussii H. Fleischm. and Bornm. using start target codon markers (SCoT) and finding markers associated with seed morphometric traits. A total of 254 reproducible SCoT fragments were generated, of which 248 fragments were polymorphic (average polymorphism of 96.18%). The SCoT markers showed a narrow range of polymorphism information content (PIC) varied from 0.397 for S9 primer to 0.499 for S11 and S20 primers. Based on the population analysis results, the Orchis simia accessions collected from Paveh region (Os.P) represented the lowest observed number of alleles (Na) (1.13) and effective number of alleles (Ne) (1.09). At the same time, the highest Na (1.29) and Ne (1.18) values were obtained in O. schulzei collected from Javanrood (Oyst.JA). Shannon’s information index (I) was ranged from 0.03 for D. umbrosa accessions collected from Marivan (Du.M population) to 0.263 for Ha.Ja population (H. affine accessions collected from Javanrood). The UPGMA dendrogram obtained with the Jaccard similarity coefficient (r = 0.97295) divided 97 studied terrestrial orchid accessions into eight groups mainly based on species type and geographical origin. Based on the Bayesian statistical index, the highest probability of the data was achieved when accessions were divided into eight groups (K = 8). Multiple association analysis (MRA) revealed significant associations between some of SCoT bands with seed morphometric traits. Our findings can be useful for germplasm characterization, conservation, and improvement of Iranian terrestrial orchid species.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12298-021-00978-4.     

Genetic diversity of Shiraia bambusicola from East China assessed using ISSR markers

To understand the genetic differentiation of the medicinal fungus Shiraia bambusicola, the genetic diversity of 107 individuals from eight populations collected from Jiangsu, Anhui and Zhejiang provinces were studied using inter-simple sequence repeat (ISSR) analysis. The results revealed that the 11 employed primers produced a total of 241 ISSR loci, of which 240 loci (PPB = 99.6%) were polymorphic. Both Nei's gene diversity indexes and Shannon's gene diversity indexes showed that the genetic differentiation of S. bambusicola primarily occurred within the populations. AMOVA revealed that the variation among populations was 40.0%, and the variation within populations was 60.0%. The results of an unweighted pair group method arithmetic average (UPGMA) analysis and a principal coordinate analysis (PCA) revealed that the populations with minimal geographic separations frequently exhibited regional characteristics. These findings revealed that the relationship between sibship and geographical distribution was intensive.     

Genetic variability of the narrow endemic Rhamnus persicifolia Moris (Rhamnaceae) and its implications for conservation

Rhamnus persicifolia Moris is an endemic small tree belonging to the Rhamnus cathartica group, growing along mountainous streams of Central-Eastern Sardinia (Italy). ISSR markers were used to detect the genetic diversity within and among six populations representative of the species distribution range. In spite of the limited distribution of this endemic taxon, fairly high levels of genetic diversity were detected. Percentage of polymorphic bands (PPB), gene diversity (H_S and H_T) and Shannon information measure (Sh) were calculated both at population (PPB = 30.70%, H_S = 0.1105, Sh = 0.1646) and at species level (PPB = 68.42%, H_T = 0.2066, Sh = 0.3139).The existence of a spatial distribution of genetic diversity in R. persicifolia was revealed by a low gene flow, a fairly high level of genetic differentiation (G_ST = 0.4583) among populations and a positive correlation between genetic and geographic distances (Mantel test, r = 0.71, p = 0.016). The spatial genetic structure was also confirmed with BAPS analysis. Our results show that a certain level of isolation by distance and sex-ratio bias may explain the distribution of genetic diversity among populations.Conservation measures are suggested on the basis of the genetic diversity detected, by implementing an integrated in situ and ex situ conservation program for each population, in order to ensure effective protection for this endemic species.     

Development of sequence‐tagged microsatellites for the barley net blotch pathogen,Pyrenophora teres

A modified sequenced‐tagged microsatellite (STM) profiling procedure was used to develop 80 STMs for the barley net blotch pathogen, Pyrenophora teres. Of these, 60 STMs amplified 67 loci in one or both of the spot (P. teres f. maculata) and net (P. teres f. teres) forms of the pathogen. When screened on six field‐sampled isolates of each pathogen form, 25 STMs revealed 26 polymorphic loci, with an average of 3.2 ± 1.0 alleles and mean gene diversity of 0.59 ± 0.12.     

Population structure and genetic diversity analysis of Indian and exotic rice (Oryza sativa L.) accessions using SSR markers

In order to understand the population structure and genetic diversity among a set of 82 rice genotypes collected from different parts of the Asian countries including India were characterized using 39 microsatellite loci. The Population structure analysis suggested that the optimum number of subpopulations was four (K = 4) among the rice genotypes, whereas phylogenetic analysis grouped them into three populations. The results obtained from phylogenetic and STRUCTURE analysis proved to be very powerful for the differentiation of rice genotypes based on their place of origin. The genetic diversity analysis using 39 SSR loci yielded 183 scorable alleles, out of which 182 alleles were observed to be polymorphic with an average of 4.8 alleles per locus. The Polymorphism Information Content (PIC) values for all the polymorphic primers across 82 rice genotypes varied from 0.02 to 0.77, with an average of 0.50. Gene diversity (He) was found to be in the range of 0.02 (RM484) to 0.80 (OSR13) with an average value of 0.55, while heterozygosity (Ho) was observed with an average of 0.07, ranging from 0.01 (RM334) to 0.31 (RM316). The present study resulted in identification of seven highly polymorphic SSR loci viz., OSR13, RM152, RM144, RM536, RM489, RM259 and RM271 based on the parameters like PIC value (≥0.70), gene diversity (≥0.71), and polymorphic alleles (≥6). These seven polymorphic primers can effectively be used in further molecular breeding programs and QTL mapping studies of rice since they exhibited very high polymorphism over other loci. SSR analysis resulted in a more definitive separation of clustering of genotypes indicating a higher level of efficiency of SSR markers for the accurate determination of relationships between accessions.     

Genetic differentiation in endangered Gynostemma pentaphyllum (Thunb.) Makino based on ISSR polymorphism and its implications for conservation

Studies were performed to investigate the genetic variation of 14 natural populations of Gynostemma pentaphyllum (Thunb.) Makino, an outcrossing clonal plant species in China, using inter-simple sequence repeat (ISSR) markers. Fourteen selected primers were used to amplify DNA samples from 140 individuals, and totally 194 loci were detected. The percentage of polymorphic bands (PPBs) showed that the genetic diversity was pretty high at the species level (PPB = 96.39%) but quite low at the population level (PPB = 1.03–25.26%). Shannon's information index (I) and Nei's gene diversity (h) displayed a similar trend to PPB. According to the hierarchical analysis of molecular variance (AMOVA) and Nei's analysis of gene diversity, the percentages of genetic variation among populations were 88.66 and 88.94%, respectively, indicating a high level of inter-population genetic differentiation. The low levels of genetic diversity within populations and high genetic differentiation among populations were assumed to result from the limited gene flow, the clonal nature and genetic drift. Based on the genetic data, effective conservation strategies were proposed for conserving this traditional Chinese medicinal herb. Concerning the management of G. pentaphyllum, we suggested that in situ conservation be an important and practical measure for maintaining the genetic diversity and that a possibly maximum number of populations be conserved. Populations EMS and HLT, in which particularly low levels of genetic variation were characterized, should be given the priority for ex situ conservation.     

Analysis of genetic structure of Jamunapari goats by microsatellite markers

Genetic variation at 23 microsatellite loci, population structure, and genetic bottleneck hypothesis were examined for Jamunapari goat population found in Etawah, Uttar Pradesh, India. Estimates of genetic variability such as effective number of alleles and gene diversities revealed substantial genetic variation frequently displayed by microsatellite markers. Number of alleles observed across the microsatellite loci varied from 2 to 10 with an overall mean of 4.913 ± 1.905. Average polymorphism across the studied loci and expected gene diversity in the population were 1.066 ± 0.510 and 0.528 ± 0.237, respectively. Population was observed to be significantly differentiated into different groups, and showed fairly high level of inbreeding (f = 0.189 ± 0.049) and global heterozygote deficit. Bottleneck analysis indicated the introduction of unique/rare alleles by immigrants.     

Microsatellite loci in the house fly,Musca domestica L. (Diptera: Muscidae)

Genomic libraries from house flies enriched for (CA)₁₅ and (CAG)₁₀ repeats were constructed by using biotinylated probes. Twenty‐five loci were isolated and evaluated for polymorphisms in wild flies representing two geographically diverse populations. Fourteen of 19 dinucleotide loci, and one of six trinucleotide loci were polymorphic. One hundred and twenty‐seven alleles were detected, 39 of which were private. Average number of alleles per polymorphic locus was 8.4 ± 2.5 and average heterozygosity was 72 ± 4%. F_ST by the private allele method was 0.73. Three of 15 loci showed significant heterozygote deficiencies, attributed to null alleles. Five of 15 loci were amplified in the face fly, Musca autumnalis.     

Genetic variation and clonal diversity in populations of Nelumbo nucifera (Nelumbonaceae) in central China detected by ISSR markers

To obtain accurate estimates of population structure for purposes of conservation planning for wild lotus (Nelumbo nucifera Gaertn.) in central China, genetic diversity among and within six populations, and clonal diversity within another two populations of the species were analyzed. The genetic diversity was high (percentage of polymorphic bands, PPB = 90.0%; Shannon's information index, I = 0.383 ± 0.234) at the species level, but low within individual study populations (PPB = 35.8%; Shannon's information index I = 0.165 ± 0.241). The mean coefficient of gene differentiation (G_st) was 0.570, indicating that 43.0% of the genetic diversity resided within the population. Analysis of molecular variance (AMOVA) indicated that 50.47% of the genetic diversity among the study populations was attributed to geographical location while 12.3% was attributed to differences in their habitats. An overall value of mean estimated number of gene flow (N_m = 0.377) indicated that there was limited gene flow among the sampled populations. The level of clonal diversity found within the populations was considerably high (Simpson's diversity index, D = 0.985) indicating that clonal diversity contributes to a major extent to the overall genetic variation in the genetic structure of N. nucifera. On the basis of the high G_st and D values detected in this study we recommend that any future conservation plans for this species should be specifically designed to include those representative populations with the highest genetic variation for both in situ conservation and germplasm collection expeditions.     

Isolation and characterization of microsatellite loci in Tripterygion delaisi

We isolated 49 microsatellite loci from a genomic library of Tripterygion delaisi×anthosoma enriched for CA and GA repeats. Ten loci were screened in 30 individuals with high numbers of alleles per locus (averaging 15.5 ± 2.86) and observed heterozygosity (averaging 0.765 ± 0.052). No deviations from Hardy–Weinberg expectations were detected. These highly polymorphic markers will be useful in determining the spatial patterns of genetic diversity between and within subspecies of Tripterygion delaisi.     

Across-species patterns of genetic variation in forest trees of Central Europe

The study focuses on geographical patterns of genetic variation at allozyme loci common for four main tree species of Central Europe (Norway spruce, silver fir, common beech and sessile oak). Moving-window averaging of four indicators of allelic richness and diversity (proportion of polymorphic loci, mean number of alleles per locus, effective number of alleles and expected heterozygosity) with window size of 50 × 50 km was used to identify the patterns. Moreover, local genetic divergence was assessed using the G _ST (Nei, Molecular population genetic and evolution, Amsterdam and Oxford, North-Holland, 1975) and D _j (Gregorius and Roberds, Theor Appl Genet 71:826–834, 1986) statistics for common beech and silver fir, where raw genotype data were available. Spatial patterns of diversity and allelic richness were quite similar. Romanian Carpathians were identified as the most important hotspot of genetic diversity and evolutionary divergence in Central Europe. Implications for genetic conservation are briefly discussed.     

Characterization of ten polymorphic microsatellite markers for the protected Spanish moon moth <Emphasis Type="Italic">Graellsia isabelae</Emphasis> (Lepidoptera: Saturniidae)

Ten polymorphic microsatellite loci were developed for Graellsia isabelae. Polymorphism was assessed for 20 individuals from a Spanish population (Els-Ports-de-Beseit, Catalonia) and 39 more individuals from one population in the French Alps and six other Spanish localities. Overall, the number of alleles per locus ranged from 5 to 24. Els-Ports-de-Beseit showed an average number of alleles per locus of 9.80 (SD = 4.32), observed heterozygosity was 0.71 (SD = 0.226), and expected heterozygosity was 0.788 (SD = 0.146). Genotypic frequencies conformed to Hardy–Weinberg equilibrium at the Catalonian population, and no evidence for linkage disequilibrium was observed. Multilocus genotypes resulting from this set of markers will be useful to determine genetic diversity and differentiation within and among populations of this highly protected moth. Several loci amplified and resulted polymorphic in two related species: two loci in Actias neidhoeferi, and three loci in A. luna.     

Characterization of eight polymorphic microsatellite markers in the tarnished plant bug,Lygus lineolaris (Palisot de Beauvois)

A partial genomic library of the tarnished plant bug, Lygus lineolaris, enriched for microsatellite sequences was screened to identify marker loci. Eight polymorphic loci suitable for population genetic studies were identified by screening 192 field‐collected insects. The observed number of alleles ranged from four to 21 with an average of 12.25 (SE ± 1.94) while the effective number of alleles ranged from 1.23 to 11.05 with an average of 4.49 (SE ± 1.15). No linkage disequilibria or significant deviations from Hardy–Weinberg expectations were detected at any of the loci. Seven of the eight L. lineolaris microsatellite loci were transferable to Lygus hesperus.     

Allozyme variations in Anatolian populations and cytotypes of the blind mole rats (Nannospalax)

Enzymatic proteins encoded by 28 putative loci in 326 samples of 12 mol rat cytotypes collected from 97 localities in Anatolia were investigated by standard horizontal starch-gel electrophoresis. A total of 61 alleles were determined for 28 isozyme loci and 23 of the 28 were polymorphic. Eight of the 23 polymorphic loci were agreeable to the Hardy–Weinberg equilibrium. It was determined that deviations from the Hardy–Weinberg equilibrium in the examined populations were due to a heterozygote deficiency. It was revealed by allozyme analyses that mole rat populations in Anatolia have formed 4 cytotypes groups, represented by 4 species (Nannospalax xanthodon, Nannospalax ehrenbergi, N. cilicicus, and N. nehringi). Cytotypes in western Anatolia (2n = 36, 2n = 38, 2n = 40, 2n = 52) showed private alleles in different enzyme systems; therefore, these cytotypes were genetically different, both from each other and other cytotypes. Although cytotypes in central Anatolia (2n = 52S, 2n = 56, 2n = 58, and 2n = 60) contained a different diploid chromosome number, they showed identical patterns in terms of their allele content in the 28 enzymatic loci.