Isolation of Polymorphic RAPD-SSR Markers from Xinjiang Arctic Grayling (<Emphasis Type="Italic">Thymallus arcticus grubei</Emphasis>) and a Test of Cross-Species Amplification

A total of 18 polymorphic microsatellite loci were isolated and characterized from RAPD products in the Xinjiang Arctic Grayling (Thymallus arcticus grubei). The number of alleles (N_a) per locus varied from 2 to 10. Observed (H_o) and expected (H_e) heterozygosities ranged from 0.64 to 0.92, and from 0.63 to 0.88, respectively. Considerable differences were found among HBH, FH and FY populations in the number of alleles, effective number of alleles, number of genotypes at all of these loci. These new RAPD-SSR markers have provided a helpful tool for genetic analyses and resources conservation of T. arcticus grubei. Five additional fish species, Amur grayling (Thymallus grubii), Taimen (Hucho taimen), Sea perch (Lateolabrax japonicus), Lenok (Brachymystax lenok) and Red seam bream (Pagrosomus major) were assessed for cross-species amplification. Three of the five species showed at least one polymorphic locus. In addition, seven loci were found to be polymorphic in at least one species.     

A novel set of 223 EST-SSR markers in <Emphasis Type="Italic">Casuarina</Emphasis> L. ex Adans.: polymorphisms,cross-species transferability,and utility for commercial clone genotyping

Simple sequence repeat (SSR) markers are very useful for genetic applications in plants, but SSR resource for the important tree genus Casuarina L. ex Adans. is still limited. In this study, we report a novel set of 223 SSR markers in Casuarina developed from expressed sequence tag (EST) resource of GenBank. The 223 EST-SSR markers were polymorphic among 10 unrelated individuals of C. equisetifolia L. Johnson, with the number of alleles per locus (N_a), observed heterozygosity (H_o), expected heterozygosity (H_e), and polymorphic information content (PIC) averaging at 5.5, 0.72, 0.86, and 0.63, respectively. The rates of cross-species transferability ranged from 96.9% (C. glauca Sieber ex Sprengel) through 97.8% (C. cunninghamiana Miquel) to 99.1% (C. junghuhniana Miquel). Fifty-five C. equisetifolia clones widely planted in China were successfully genotyped with a subset of 20 EST-SSRs. These newly developed markers will have a great potential for genetic and breeding applications in Casuarina species and related taxa.     

Identification and marker-assisted transfer of a new powdery mildew resistance gene at the <Emphasis Type="Italic">Pm4</Emphasis> locus in common wheat

Powdery mildew, a wheat (Triticum aestivum L.) foliar disease caused by Blumeria graminis (DC.) E.O. Speer f. sp. tritici, imposes a constant challenge on wheat production in areas with cool or maritime climates. This study was conducted to identify and transfer the resistance gene in the newly identified common wheat accession ‘D29’. Genetic analysis of the F₂ population derived from a cross of D29 with the susceptible elite cultivar Y158 suggested a single dominant gene is responsible for the powdery mildew resistance in this germplasm. This gene was mapped to chromosome 2AL in a region flanked by microsatellite markers Xgdm93 and Xhbg327, and co-segregated with sequence-tagged site (STS) markers Xsts_bcd1231 and TaAetPR5. An allelic test indicated that the D29 gene was allelic to the Pm4 locus. To further evaluate the resistance conferred by this gene and develop new germplasms for breeding, this gene, as well as Pm4a and Pm4b, was transferred to Y158 through backcross and marker-assisted selection. In the resistance spectrum analysis, the D29 gene displayed a resistance spectrum distinguishable from the other Pm4 alleles, including Pm4a, Pm4b, and Pm4c, and thus was designated as Pm4e. The identification of new allelic variation at the Pm4 locus is important for understanding the resistance gene evolution and for breeding wheat cultivars with powdery mildew resistance.     

Genetic diversity of the house mouse <Emphasis Type="Italic">Mus musculus</Emphasis> and geographic distribution of its subspecies-specific RAPD markers on the territory of Russia

Genetic diversity and geographic distribution of taxon-specific RAPD markers was examined in ten local populations of the house mouse Mus musculus (n = 42). The house mice were generally characterized by moderate genetic variation: polymorphism P ₉₉ = 60%, P ₉₅ = 32.57%; heterozygosity H = 0.12; the observed allele number n _a = 1.6; the effective allele number n _e = 1.18; the within-population differentiation ?_s = 0.388; and Shannon index I = 0.19. The degree of genetic isolation of individual local populations was greatly variable. The genetic subdivision index G _st varied from 0.162 to 0.770 at the gene flow of Nm = 2.58?0.149, while the among-population distances D _N varied from 0.026 to 0.178. The largest part of the genetic diversity was found among the populations (H _T = 0.125), while the within-population diversity was twice lower (H _S = 0.06). The samples examined were well discriminated relative to the sets of RAPD markers. The character distribution pattern provided conditional subdivision of the mice into the “western” and the “eastern” groups with the putative boarder along the Baikal Lake. The first group was characterized by the prevalence of the markers typical of M. m. musculus and M. m. domesticus. The second group was characterized by the prevalence of the markers typical of M. m. musculus, M. m. gansuensis, M. m. castaneus, M. m. domesticus, and M. m. wagneri. The genotype of the nominative subspecies M. m. musculus was background for all populations. In the populations examined some of earlier described subspecies-specific molecular markers were found at different frequencies, pointing to the involvement of several subspecies of M. musculus in the process of hybridization.     

Root-derived bicarbonate assimilation in response to variable water deficit in <Emphasis Type="Italic">Camptotheca acuminate</Emphasis> seedlings

Water deficit is one of the key factors that limits the carbon (C) assimilation and productivity of plants. The effect of variable water deficit on recently root-derived bicarbonate assimilation in Camptotheca acuminate seedlings was investigated. Three-month-old seedlings were subjected to three water regimes, well-watered (WW), moderate stress (MS), and severe stress (SS) induced by polyethyleneglycol, in conjunction with relatively high (H) and low (L) natural ¹³C-abundance of NaHCO₃-labeled treatments in hydroponics for 14 days. The δ¹³C of the newly expanded leaves in H were generally more enriched in heavy isotopes than were those in L, indicative of the involvement of bicarbonate in aboveground tissues. The C isotope fractionation of newly expanded leaves relative to air (?¹³C_air-leaves) ranged from 17.78 to 21.78‰ among the treatments. The ?¹³C_air-leaves under the MS and SS treatments in H were both more negative than was that in L. A linear regression between Ci/Ca and ?¹³C_air-leaves in both L and H were different from the theoretical regression. On the basis of the two end-member mixing model, the proportion of fixed CO₂ supplied from bicarbonate contributing to the total photosynthetically inorganic C assimilation were 10.34, 20.05 and 16.60% under the WW, MS, and SS treatments, respectively. These results indicated that the increase in water deficit decreased the atmospheric CO₂ gain but triggered a compensatory use of bicarbonate in C. acuminate seedlings.     

Interactions of human serum albumin with bioactive 3<Emphasis Type="Italic">H</Emphasis>-imidazo[4,5-<Emphasis Type="Italic">a</Emphasis>]acridines: Insights from fluorescence spectroscopic studies

Several 3H-imidazo[4,5-a]acridine derivatives were conveniently synthesized by the reaction of imidazo[4,5-a]acridones in boiling POCl3. The imidazoacridones were obtained by rearrangement of 3H-imidazo[4',5':3,4]benzo[c]isoxazoles in concentrated sulfuric acid containing nitrous acid at room temperature. The structures of all newly synthesized compounds were confirmed by IR, ¹H NMR, and mass spectral data. The interactions of 3H-imidazo[4,5-a]acridines with human serum albumin (HSA) were studied by fluorescence spectroscopy. The binding of 3H-imidazo[4,5-a]acridines quenches the HSA fluorescence, revealing a 1: 1 interaction with a binding constant of about 2.34 × 10⁵–3.16 × 10⁶ M^–1. A decrease in fluorescence intensity at 339 nm, when excited at 280 nm, is attributed to changes in the environment of the protein fluorophores caused by the presence of the ligand. The differences in interactions of 3H-imidazo[4,5-a]acridines with HSA were observed using spectrofluorimetry technique.     

A novel set of EST-InDel markers in <Emphasis Type="Italic">Eucalyptus</Emphasis> L’Hérit.: polymorphisms,cross-species amplification,physical positions and genetic mapping

Insertion/deletion (InDel) markers are valuable for genetic applications in plant species, and the public databases of expressed sequence tags (ESTs) have facilitated the development of genic InDel markers. In this study, we developed a novel set of 144 InDel markers in an important tree genus Eucalyptus L’Hérit. using the ESTs of GenBank. Amplicon sequencing against two parents of a mapping population (Eucalyptus urophylla S. T. Blake × E. tereticornis Smith) revealed that the InDel size ranged from 2 to 44 bases, and the dinucleotide type was the most abundant (37.3 %). The cross-species/subgenus amplification rate ranged from 62.5 % in E. tessellaris F. Muell. (subgenus Blakella) to 99.3 % in E. grandis Hill ex Maiden (subgenus Symphyomyrtus) with an average of 85.4 %. There were 121 EST-InDels (84.0 %) polymorphic among 12 individuals of E. grandis, and the mean number of alleles per polymorphic locus (N _a), observed heterozygosity (H _o), expected heterozygosity (H _e) and polymorphic information content (PIC) were 4.0, 0.278, 0.538 and 0.465, respectively. Physical positions of 143 EST-InDels were predicted on the E. grandis genome sequence. A total of 81 EST-InDels were incorporated into prior dense genetic maps of E. urophylla and E. tereticonis, and extensive synteny and colinearity were observed between E. grandis genome sequence and the mapped EST-InDel markers. These EST-InDels will provide a valuable resource of functional markers for genetic diversity evaluation, genome comparison, QTL mapping and marker-assisted breeding in Eucalyptus.     

Rapid location of Glomerella leaf spot resistance gene locus in apple by whole genome re-sequencing

Glomerella leaf spot (GLS) is a new fungal disease of apple that damages apple leaves mainly during the summer in China. For efficient GLS-resistant apple breeding by marker-assisted selection (MAS) and a better understanding of the molecular mechanisms of the resistance, it is important to find molecular markers that are tightly linked to GLS resistance genes and construct fine mapping. However, the development and selection of DNA markers are time-consuming and labor-intensive processes. Next-generation sequencing technology provides a powerful tool to overcome this limitation and is faster and more efficient in establishing the association of GLS resistance with molecular markers or searching for candidate genes. In this study, we report a method for rapid location of a GLS resistance gene locus (R _gls ) in apple by whole genome re-sequencing technology coupled with bulked segregant analysis (BSA). A total of 3,399,950 single nucleotide polymorphisms (SNPs) were identified. Through the genome-wide comparison of SNP profiles between the resistant and the susceptible bulks constructed from F₁ individuals derived from a cross between “Golden Delicious” and “Fuji,” the R _gls locus was identified on apple chromosome 15 between 2 and 5 Mb. In this region, eight SNP markers were validated using high resolution melting (HRM), and the fine genetic mapping of the eight markers was constructed. The R _gls locus was sandwiched by two flanking markers SNP4208 and SNP4257, with the recombination frequency of 0.97% (2/207). The marker SNP4236 co-segregated with R _gls . The physical size of the R _gls locus was estimated to be 49 kb. In this genetic interval, nine genes were predicted. Our study provides an effective method for rapid identification of genomic regions and development of the diagnostic markers for MAS. This strategy is potentially useful for other agronomic traits or plant species.     

Natively oxidized amino acid residues in the spinach cytochrome <Emphasis Type="Italic">b</Emphasis><Subscript><Emphasis Type="Italic">6</Emphasis></Subscript><Emphasis Type="Italic">f</Emphasis> complex

The cytochrome b ₆ f complex of oxygenic photosynthesis produces substantial levels of reactive oxygen species (ROS). It has been observed that the ROS production rate by b ₆ f is 10–20 fold higher than that observed for the analogous respiratory cytochrome bc₁ complex. The types of ROS produced (O₂^{??, 1}O₂, and, possibly, H₂O₂) and the site(s) of ROS production within the b ₆ f complex have been the subject of some debate. Proposed sources of ROS have included the heme b _p , PQ _p ^?? (possible sources for O₂^??), the Rieske iron–sulfur cluster (possible source of O₂^?? and/or ¹O₂), Chl a (possible source of ¹O₂), and heme c _n (possible source of O₂^?? and/or H₂O₂). Our working hypothesis is that amino acid residues proximal to the ROS production sites will be more susceptible to oxidative modification than distant residues. In the current study, we have identified natively oxidized amino acid residues in the subunits of the spinach cytochrome b ₆ f complex. The oxidized residues were identified by tandem mass spectrometry using the MassMatrix Program. Our results indicate that numerous residues, principally localized near p-side cofactors and Chl a, were oxidatively modified. We hypothesize that these sites are sources for ROS generation in the spinach cytochrome b ₆ f complex.     

Phylogeographic structure of <Emphasis Type="Italic">Spondias tuberosa</Emphasis> Arruda Câmara (Anacardiaceae): seasonally dry tropical forest as a large and continuous refuge

Spondias tuberosa occurs in the Caatinga domain (seasonally dry tropical forest biome) of north-eastern Brazil, a large biome with ecogeographic regions that may have modelled the population structure of the species. Here we studied the phylogeographic pattern of S. tuberosa using sequences of the accD-psaI plastid region and six SSR markers in individuals distributed across 20 localities. The results for accD-psaI demonstrated nine haplotypes: some of which were exclusive to Caatinga ecoregions, whereas others were found in all localities. Spatial analysis of molecular variance revealed two groups (F_ct?=?0.34, P?<?0.0039) with 33.91% variation between them. The SSR analyses displayed 2–5 alleles at each locus, some of which were unique to certain localities. As in the accD-psaI region, the population structure obtained using SSR markers fell into two groups: (1) a large group containing the majority of the geographic region of Caatinga and (2) a small group near the Atlantic forest. We demonstrate the population structure of S. tuberosa, identifying the Caatinga as large, continuous refuge and the region near the interface between the Caatinga and the Atlantic forest as second refuge.     

Polymorphism of the genes for antioxidant defense enzymes and their association with the development of chronic obstructive pulmonary disease in the population of Bashkortostan

In this study, frequencies of the polymorphic variants of the genes encoding antioxidant enzymes, GSTM1, GSTT1, GSTP1, CAT, GPX1, NQO1, SOD1, and SOD3 were examined in three ethnic groups of healthy subjects from the Republic of Bashkortostan (Russians, Tatars, and Bashkirs). An association of these markers with the development of chronic obstructive pulmonary disease (COPD) was tested. Interethnic differences relative to the distribution of the polymorphic variants of the GSTP1 locus Ile105Val and the NQO1 locus 609C/T were revealed. Relative to the genotype distribution at the Ile105Val locus of the GSTP1 gene, ethnic group of Bashkirs was found to be statistically significantly different from Tatars (χ² = 8.819; d.f. = 2; P = 0.012). Relative to the genotype frequency distribution pattern at the NQO1 locus 609C/T, the group of Bashkirs differed from Russians (χ² = 8.913; d.f. = 2; P = 0.012). An association of genotype Val/Val of the GSTP1 Ile105Val locus with the risk of COPD in Russians (χ² = 5.25; P = 0.022; P _cor = 0.044; OR = 4.09), and of the GSTP1 haplotype *D in Tatars, was demonstrated (χ² = 11.575; P = 0.0014; P _cor = 0.0042; OR = 3.178). Genotype TT of the CAT ?262C/T locus marked resistance to the COPD development in Russians (χ² = 6.82; P = 0.0098; P _cor = 0.0196; OR = 0.31; 95%CI, 0.119 to 0.77). The risk for COPD in the ethnic group of Tatars was associated with the CAT haplotype (?262)C/(1167)T (χ² = 6.038; P = 0.0147; P _cor = 0.044; OR = 1.71). Analysis of the NQO1 haplotypes at the 465C/T and 609C/T loci showed that haplotype 465C/609T was associated with COPD in Russians (χ² = 4.571; P = 0.0328; P _cor = 0.01; OR = 1.799). It was demonstrated that Gly allele of the Arg213Gly polymorphic locus of the SOD3 gene marked the risk for COPD in the ethnic group of Tatars (OR = 2.23; 95%CI, 1.22 to 4.1). Thus, GSTP1, CAT, NQO1, and SOD3 polymorphisms play an important role in the development of COPD among the population of Bashkortostan.     

Genotyping-by-sequencing to remap QTL for type II Fusarium head blight and leaf rust resistance in a wheat–tall wheatgrass introgression recombinant inbred population

Fusarium graminearum Schwabe (Fusarium head blight, FHB) and Puccinia triticina Eriks (leaf rust) are two major fungal pathogens posing a continuous threat to the wheat crop; consequently, identifying resistance genes from various sources is always of importance to wheat breeders. We identified tightly linked single nucleotide polymorphism (SNP) markers for the FHB resistance quantitative trait locus (QTL) Qfhs.pur-7EL and the leaf rust resistance locus Lr19 using genotyping-by-sequencing (GBS) in a wheat–tall wheatgrass introgression-derived recombinant inbred line (RIL) population. One thousand and seven hundred high-confidence SNPs were used to conduct the linkage and QTL analysis. Qfhs.pur-7EL was mapped to a 2.9 cM region containing four markers within a 43.6 cM segment of wheatgrass chromosome 7el₂ that was translocated onto wheat chromosome 7DL. Lr19 from 7el₁ was mapped to a 1.21 cM region containing two markers in the same area, in repulsion. Five lines were identified with the resistance-associated SNP alleles for Qfhs.pur-7EL and Lr19 in coupling. Two SNP markers in the Qfhs.pur-7EL region were converted into PCR-based KASP markers. Investigation of the genetic characteristics of the parental lines of this RIL population indicated that they are translocation lines in two different wheat cultivar genetic backgrounds instead of 7E–7D substitution lines in Thatcher wheat background, as previously reported in the literature.     

Characterization and genetics of multiple soybean aphid biotype resistance in five soybean plant introductions

Key message

Five soybean plant introductions expressed antibiosis resistance to multiple soybean aphid biotypes. Two introductions had resistance genes located in the Rag1, Rag2, and Rag3 regions; one introduction had resistance genes located in the Rag1, Rag2, and rag4 regions; one introduction had resistance genes located in the Rag1 and Rag2 regions; and one introduction had a resistance gene located in the Rag2 region.

Abstract

Soybean aphid (Aphis glycines Matsumura) is the most important soybean [Glycine max (L.) Merr.] insect pest in the USA. The objectives of this study were to characterize the resistance expressed in five plant introductions (PIs) to four soybean aphid biotypes, determine the mode of resistance inheritance, and identify markers associated with genes controlling resistance in these accessions. Five soybean PIs, from an initial set of 3000 PIs, were tested for resistance against soybean aphid biotypes 1, 2, 3, and 4 in choice and no-choice tests. Of these five PIs, PI 587663, PI 587677, and PI 587685 expressed antibiosis against all four biotypes, while PI 587972 and PI 594592 expressed antibiosis against biotypes 1, 2, and 3. F₂ populations derived from PI 587663 and PI 587972 were evaluated for resistance against soybean aphid biotype 1, and populations derived from PIs 587677, 587685, and 594592 were tested against biotype 3. In addition, F_2:3 plants were tested against biotypes 2 and 3. Genomic DNA from F₂ plants was screened with markers linked to Rag1, Rag2, Rag3, and rag4 soybean aphid-resistance genes. Results showed that PI 587663 and PI 594592 each had three genes with variable gene action located in the Rag1, Rag2, and Rag3 regions. PI 587677 had three genes with variable gene action located in the Rag1, Rag2 and rag4 regions. PI 587685 had one dominant gene located in the Rag1 region and an additive gene in the Rag2 region. PI 587972 had one dominant gene located in the Rag2 region controlling antixenosis- or antibiosis-type resistance to soybean aphid biotypes 1, 2, or 3. PIs 587663, 587677, and 587685 also showed antibiosis-type resistance against biotype 4. Information on multi-biotype aphid resistance and resistance gene markers will be useful for improving soybean aphid resistance in commercial soybean cultivars.

     

Development of microsatellite markers and their use in genetic diversity and population structure analysis in <Emphasis Type="Italic">Casuarina</Emphasis>

Casuarina is a widely cultivated plantation tree species in coastal India, primarily due to its fast growth, high productivity and suitable for pulp and paper production. However, genetic studies of Casuarina have been hindered by lack of genomic resources and genetic markers. Knowledge of the genetic diversity and population structure of Casuarina germplasms will provide the basis for utilizing and improving resource in the breeding program. Keeping this in view, in the present study, we have identified a total of 11,503 simple sequence repeat (SSR) makers from 86,415 expressed sequence tags (ESTs) of Casuarina equisetifolia and C. junghuhniana after redundancy elimination. Dinucleotide repeats were the most abundant accounting for 72.5 % of all microsatellites, followed by trimer (23.4 %), hexamer (1.7 %), tetramer (1.5 %), and very few pentamer (0.6 %) repeats. Of these, 50 markers were used to estimate genetic diversity and population structure among 96 accessions of C. cunninghamiana and C. junghuhniana. EST-SSR markers revealed high level of polymorphism, detecting a total of 829 alleles with an average of 17 alleles per locus. Polymorphic information content (PIC) values ranged from 0.32 to 0.93, with an average of 0.78 per locus. The average observed (H _o ) and expected heterozygosity (H _e ) obtained was high and fairly similar in C. cunninghamiana and C. junghuhniana, thereby suggesting highly heterogeneous nature of Casuarina. Population structure using a Bayesian model-based clustering approach identified clear delineation between C. cunninghamiana and C junghuhniana. Further, these markers were also evaluated in four species of Casuarina confirming high rate of cross-species transferability. The results of this study can provide valuable insights for genetic and genomic research in Casuarina.     

Check of Gene Number during the Process of rDNA Magnification

THE multiple sequences of rDNA (DNA complementary to ribosomal RNA) of the Drosophila genome are localized at the bobbed locus, located in the X chromosome, position 66 and in the short arm of the Y chromosome^1,2. Wild bobbed (bb⁺) is that locus which, without a partner, gives rise to a normal phenotype. That locus which in similar conditions is incapable of giving rise to a normal phenotype is called a bobbed mutation (bb) and contains fewer genes for rRNA. The number of genes for rRNA in different individuals can vary considerably. One mechanism for rDNA variation is unequal crossing over³. Another mechanism, described by Tartof⁴, becomes apparent when individual flies, carrying only one bobbed locus, are constructed and only if such a locus is on the X chromosome; that is, if one constructs Xbb⁺/O males (and also Xbb/O males) or Xbb⁺/X_NO- females. Such individuals show a higher rDNA content than expected from the analysis of the same locus in Xbb⁺/Xbb⁺ females or in Xbb⁺/Ybb⁺ males. The increase of rDNA in this case is not inheritable⁴.     

Analysis of applicability of triplet-state emission of molecular hydrogen for spectral diagnostics of a DC discharge

The applicability of emission of the N ³Λ_σ triplet states of molecular hydrogen for spectral diagnostics of the positive column of a dc glow discharge in hydrogen at translational gas temperatures of 360–600 K, specific absorbed powers of 0.8–4.25 W/cm, gas pressures of p = 0.3–15.0 Torr, reduced fields of E/N = 30–130 Td, and electron densities of n _e = 4.0 × 10⁹–6.5 × 10¹⁰ cm^–3 is analyzed by using an advanced level-based semi-empirical collisional?radiative model. It is found that secondary processes make the main contribution to the population and decay of the N ³Λ_σ = a ³Σ⁺ _g , c ³Π _u , g ³Σ⁺ _g , h ³Σ⁺ _g , and i ³Π _g triplet states. The dipole-allowed transitions e ³Σ⁺ _g → a ³Σ⁺ _g , f ³Σ⁺ _g → a ³Σ⁺ _g , g ³Σ⁺ _g and k ³Π _u → a ³Σ⁺ _g can be used for spectral diagnostics of a dc discharge within a simplified coronal model.     

QTL mapping for haploid male fertility by a segregation distortion method and fine mapping of a key QTL <Emphasis Type="Italic">qhmf4</Emphasis> in maize

Key message

Four QTL related to haploid male fertility were detected by a segregation distortion method and the key QTL qhmf4 was fine mapped to an interval of ~800 kb.

Abstract

Doubled haploid (DH) technology enables rapid development of homozygous lines in maize breeding programs. However, haploid genome doubling is a bottleneck for the commercialization of DH technology and is limited by haploid male fertility (HMF). This is the first study reporting the quantitative trait locus (QTL) analysis of HMF in maize. Four QTL, qhmf1, qhmf2, qhmf3, and qhmf4, controlling HMF have been identified by segregation distortion (SD) loci detection in the selected haploid population derived from ‘Yu87-1/Zheng58’. Three loci, qhmf1, qhmf2, and qhmf4, were also detected in the selected haploid population derived from ‘4F1/Zheng58’. The QTL qhmf4 showed the strongest SD in both haploid populations. Based on the sequence information of ‘Yu87-1’ and ‘Zheng58’, thirteen markers being polymorphic between the two lines were developed to saturate the qhmf4 region. A total of 8168 H₁BC₂ (haploid backcross generation) plants produced from ‘Yu87-1’ and ‘Zheng58’ were screened for recombinants. All the 48 recombinants were backcrossed to ‘Zheng58’ to develop H₁BC₃ progeny. The heterozygous H₁BC₃ individuals were crossed with CAU5 to induce haploids. In each H₁BC₃ progeny, haploids were genotyped and evaluated for anther emergence score (AES). Significant (or no significant) difference (P?<?0.05) between haploids with or without ‘Yu87-1’ donor segment indicated presence or absence of qhmf4 in the donor segment. The analysis of the 48 recombinants narrowed the qhmf4 locus down to an ~800 kb interval flanked by markers IND166 and IND1668.

     

Hybrid peony (<Emphasis Type="Italic">Paeonia hybrida</Emphasis> Pall.), a rare endangered plant of Bashkir Trans-Uralian region: Autocorrelation analysis of the spatial genotype distribution under different environmental conditions

Hybrid peony (Paeonia hybrida Pall.) is listed as endangered in Russian Federation (since 1988) and in several regions of Russia. The structure of the isolated population from Bashkir Trans-Uralian region, separated by 1500 km from the main geographic range of this species, has been studied using isoenzyme markers from 11 loci. The population is split between two geographical locations, both characterized by a relatively high genetic diversity (mean allele number A = 1.9±0.3, percentage of polymorphic loci P = 0.54, observed heterozigosity H _O = 0.223±0.068, expected heterozigosity H _E = 0.229±0.067) and a quite low intergroup genetic differentiation (fixation index F _ST = 0.008, Nei’s genetic distance D = 0.011). In a subpopulation located near a swampy lake in dense cereal grass and steppe shrubby vegetation, autocorrelation analysis has revealed spatial structuring of genetic variability. In the other location, a stipa-forb steppe on a flat hill slope, a uniform spatial structure of the genotypes has been observed. The results are discussed with respect to the ecological characteristics of the species and the conservation of the genetic pool of the population in situ and ex situ.