Genetic differentiation among natural populations of the lizard complex <Emphasis Type="Italic">Darevskia raddei</Emphasis> as inferred from genome microsatellite marking

The article presents the genetic parameters of the populations of lizards of the Darevskia raddei complex (D. raddei nairensis and D. raddei raddei) and the populations of D. valentini calculated on the basis of the analysis of variability of 50 allelic variants of the three nuclear genome microsatellite-containing loci of 83 individuals. It was demonstrated that the F_st genetic distances between the populations of D. raddei nairensis and D. raddei raddei were not statistically significantly different from the F_st genetic distances between the populations of different species, D. raddei and D. valentini. At the same time, these distances were statistically significantly higher than the F_st distances between the populations belonging to one species within the genus Darevskia. These data suggest deep divergence between the populations of D. raddei raddei and D. raddei nairensis of the D. raddei complex and there arises the question on considering them as separate species.     

Investigating the genetic diversity and differentiation patterns in the <Emphasis Type="Italic">Penstemon scariosus</Emphasis> species complex under different sample sizes using AFLPs and SSRs

Habitat fragmentation due to anthropogenic activities is the major cause of biodiversity loss. Endemic and narrowly distributed species are the most susceptible to habitat degradation. Penstemon scariosus is one of many species whose natural habitat is vulnerable to industrialization. All varieties of P. scariosus (P. scariosus var. albifluvis, P. scariosus var. cyanomontanus, P. scariosus var. garrettii, P. scariosus var. scariosus) have small distribution ranges, but only P. scariosus var. albifluvis is being considered for listing under the Endangered Species Act. We used eight microsatellites or simple sequence repeats (SSRs) loci and two amplified fragment length polymorphism (AFLP) primer combinations to investigate the population genetic structure and diversity of P. scariosus varieties. Moreover, we compared the utility of the two marker systems in conservation genetics and estimated an appropriate sample size in population genetic studies. Genetic differentiation among populations based on F_st ranged from low to moderate (F_st?=?0.056–0.157) and from moderate to high when estimated with D_es (D_es?=?0.15–0.32). Also, AMOVA analysis shows that most of the genetic variation is within populations. Inbreeding coefficients (F_is) were high in all varieties (0.20–0.56). The Bayesian analysis, STRUCTURE, identified three clusters from SSR data and four clusters from AFLPs. Clusters were not consistent between marker systems and did not represent the current taxonomy. MEMGENE revealed that a high proportion of the genetic variation is due to geographic distance (R²?=?0.38, P?=?0.001). Comparing the genetic measurements from AFLPs and SSRs, we found that AFLP results were more accurate than SSR results across sample size when populations were larger than 25 individuals. As sample size decreases, the estimates become less stable in both AFLP and SSR datasets. Finally, this study provides insight into the population genetic structure of these varieties, which could be used in conservation efforts.     

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.     

Mendelian Transmission Ratio Distortion (TRD) and Factors Determining the Low Frequency of the <Emphasis Type="Italic">t</Emphasis>-Haplotypes in Wild Populations of the House Mouse <Emphasis Type="Italic">Mus musculus</Emphasis> of Russia and the Neighboring Countries of Eurasia

The results of analysis of the frequencies of t-alleles and heterozygous +/t individuals of house mice of different subspecies (musculus, bactrianus, tataricus, wagneri, and gansuensis) are presented for the natural populations inhabiting eight cities and five regions of Russia and adjacent countries of Eastern Europe and Asia. It is shown that the frequencies of t-alleles are 0.18 ± 0.03 in small samples (1–30 individuals) and 0.09 ± 0.06 in medium-sized samples (31–60 individuals). The factors that reduce the frequencies of t-alleles in natural populations and the mechanisms that prevent invasion and fixation of t-mutant alleles in the Mus musculus genome are discussed.     

Molecular genetic characteristic of dinucleotide microsatellite loci in parthenogenetic lizards <Emphasis Type="Italic">Darevskia unisexualis</Emphasis>

In the present study, the first molecular genetic investigation of dinucleotide (GT) _n microsatellite loci in parthenogenetic lizards Darevskia unisexualis was performed. New polymorphic locus, Du214, (GenBank Ac. No. EU252542) was identified and characterized in detail. It was demonstrated that allele of this locus differed in the size and structure of microsatellite locus, as well as in point mutations, the combinations of which enabled the isolation of stabile fixed double nucleotide substitutions A-A (alleles 2 and 4) and G-T (alleles 1, 3, 5, and 6). Double nucleotide substitutions described were also identified in the orthlogous loci of the parental species genomes, D. raddei (G-T) and D. valentine (A-A). Based on the analysis of allele distribution pattern at this locus in all populations of parthenospecies D. unisexualis, mathematic model was elaborated and realized. Using this model, frequencies of allelic variants for all populations of the species of interest were calculated and population genetic structure of D. unisexualis was characterized. Genetic contribution of each population to the species gene pool was determined. The data obtained demonstrated that microsatellite variation was one of the factors of clonal and genetic diversity of a parthenospecies.     

Nucleotide polymorphisms of candidate genes of adaptive significance in the ural populations of <Emphasis Type="Italic">Larix sibirica</Emphasis> Ledeb.

The objectives of conservation and sustainable forest management require in depth study of genomes of woody plants and definition of their intraspecific genetic diversity. In recent years, an approach was developed based on the study of “candidate genes” that can potentially be involved in the formation of adaptive traits. In this study, we investigated nucleotide polymorphism of several adaptive candidate genes in the populations of Siberian larch (Larix sibirica Ledeb.) in the Urals. Representatives of this genus are among the most valuable and widely distributed forest tree species in Russia. From ten selected gene loci in the genome of L. sibirica, we isolated and investigated three loci, one of which (ABA-WDS) was sequenced in L. sibirica for the first time. The total length of the analyzed sequence in each individual amounted to 2865 bp. The length of locus alignment was from 360 bp to 1395 bp. In total, we identified 200 polymorphic positions. The most conservative is locus 4CL1-363, and the most polymorphic is locus sSPcDFD040B03103-274. The studied populations of L. sibirica are characterized by a high level of nucleotide polymorphism in comparison with other species and genuses (Picea, Pinus, Pseudotsuga, Abies) conifers plants (Hd = 0.896; π = 0.007; θ_W = 0.015). The most selectively neutral polymorphism (D _T =–0.997) was attributed to locus 4CL1-363, and polymorphism with high probability of adaptability (D _T =–1.807) was determined for the ABA-WDS locus. We identified 54 SNP markers, only five of which were nonsynonymous (9.26%) replacements. The average frequency of SNPs in the three studied loci of L. sibirica was one SNP in 53 bp. We detected unique SNP markers for eight populations, which could potentially be used to identify populations. Populations that are characterized by the highest number of unique SNP markers can be recommended for selection in order to preserve the gene pool of the species.     

Genetic structure of the populations of <Emphasis Type="Italic">Dactylorhiza ochroleuca</Emphasis> and <Emphasis Type="Italic">D. incarnata</Emphasis> (Orchidaceae) in the area of their joint growth in Russia and Belarus

We carried out an allozyme analysis to investigate polymorphism and genetic structure of the populations of D. incarnata and D. ochroleuca in regions of their joint growth in Russia and Belarus. We found that D. ochroleuca individuals in the populations of the Urals and Siberia, which are distant fragments from the main range of the species, do not differ significantly from individuals within the main part of the area (Belarus) on the basis of the allelic composition of eight gene loci. We revealed that D. ochroleuca and D. incarnata are differentiated by different alleles of the GDH locus. Thus, we established a genetic marker suitable to distinguish these closely related taxa. In addition to the GDH locus, D. ochroleuca and D. incarnata in the places of their joint growth, differ in the allelic structure of the PGI and NADHD loci. D. incarnata from the Urals and Siberia were polymorphic for both loci, and individuals from Belarus were polymorphic for one locus (PGI). In contrast, all D. ochroleuca individuals growing in sympatric populations with polymorphic D. incarnata were homozygous for the same alleles. Thus, comparison of the genetic structure of D. ochroleuca and D. incarnata points to the existence of a genetic isolation and a functioning isolation mechanism even under conditions of their joint growth. We found that the GDH locus in D. incarnata is polymorphic only in populations which grow together with D. ochroleuca, with exception a few examples. Thus, we conclude that variability of the GDH locus in D. incarnata is associated with hybridization with D. ochroleuca.     

Genetic Analysis of the <Emphasis Type="Italic">Indri</Emphasis> Reveals No Evidence of Distinct Subspecies

Subspecies were traditionally defined by identifying gaps between phenotypes across the geographic range of a species, and may represent important units in the development of conservation strategies focused on preserving genetic diversity. Previous taxonomic research proposed that phenotypic variation between scattered Indri indri populations warranted the naming of two distinct subspecies, I. i. indri and I. i. variegatus. We tested these subspecific designations using mitochondrial sequence data generated from the control region or D-loop (569 bp) and a large section (2362 bp) of multiple genes and tRNAs known as Pastorini’s fragment and nuclear microsatellite markers. This study used 114 samples of I. indri from 12 rainforest sites in eastern Madagascar, encompassing the entire range of the species. These genetic samples represent multiple populations from low- and high-elevation forests from both putative subspecies. Molecular analyses of the mitochondrial sequence data did not support the two proposed subspecies. Furthermore, the microsatellite analyses showed no significant differences across the range beyond population level differentiation. This study demonstrates the utility of incorporating multiple lines of evidence in addition to phenotypic traits to define species or subspecies.     

Bacterial metabolites from intra- and inter-species influencing thermotolerance: the case of <Emphasis Type="Italic">Bacillus cereus</Emphasis> and <Emphasis Type="Italic">Geobacillus stearothermophilus</Emphasis>

Bacterial metabolites with communicative functions could provide protection against stress conditions to members of the same species. Yet, information remains limited about protection provided by metabolites in Bacillus cereus and inter-species. This study investigated the effect of extracellular compounds derived from heat shocked (HS) and non-HS cultures of B. cereus and Geobacillus stearothermophilus on the thermotolerance of non-HS vegetative and sporulating B. cereus. Cultures of B. cereus and G. stearothermophilus were subjected to HS (42 or 65 °C respectively for 30 min) or non-HS treatments. Cells and supernatants were separated, mixed in a combined array, and then exposed to 50 °C for 60 min and viable cells determined. For spores, D values (85 and 95 °C) were evaluated after 120 h. In most cases, supernatants from HS B. cereus cultures added to non-HS B. cereus cells caused their thermotolerance to increase (D ₅₀ 12.2–51.9) when compared to supernatants from non-HS cultures (D ₅₀ 7.4–21.7). While the addition of supernatants from HS and non-HS G. stearothermophilus cultures caused the thermotolerance of non-HS cells from B. cereus to decrease initially (D ₅₀ 3.7–7.1), a subsequent increase was detected in most cases (D ₅₀ 18–97.7). In most cases, supernatants from sporulating G. stearothermophilus added to sporulating cells of B. cereus caused the thermotolerance of B. cereus 4810 spores to decline, whereas that of B. cereus 14579 increased. This study clearly shows that metabolites in supernatants from either the same or different species (such as G. stearothermophilus) influence the thermotolerance of B. cereus.     

Preliminary data on the variability of three microsatellite loci in Pacific <Emphasis Type="Italic">Gadus macrocephalus</Emphasis> and Atlantic <Emphasis Type="Italic">G. morhua</Emphasis> cod (Gadidae)

Variability of microsatellite DNA loci Gmo3, Gmo34, and Gmo35 is studied in samples of Pacific cod Gadus macrocephalus and Atlantic cod G. morhua. The results show high values of identity of the samples within the North Pacific basin (0.9766–0.9924) and within the Northeast Atlantic basin (0.9580). Based on the pairwise assessment of genetic differentiation, the F _ST values are significantly different in all variants between the samples of Pacific and Atlantic cod (F _ST = 0.5235–0.6719, p < 0.001). Within the basins, the significant differences in the frequencies of main alleles are revealed in the loci Gmo3 and Gmo34 for the samples from the Pacific and Atlantic oceans, respectively.     

Genetic characterization of <Emphasis Type="Italic">Brycon hilarii</Emphasis> (Characiformes) populations within the Pantanal: Aspects of their conservation within a globally important neotropical wetland

Brycon hilarii, a characid species endemic to the Upper Paraguay hydrographic basin, is important to regional artisanal and sports fisheries. To develop effective strategies for conservation of this species in the face of potential environmental changes in the Pantanal region, we characterized genetic structuring within and among six B. hilarii collections based on variation at five microsatellite DNA markers. Within-population genetic variability was high, with 75 different alleles; mean average allelic richness per locus per sample location ranged from 6.06 to 7.99. Nei’s gene diversity (hs) varied among drainages from 0.66 (±0.2) to 0.69 (±0.2), with an average across the four genetically identified populations of 0.68 (±0.02). Analyses of Jost’s D _EST and F _ST-like indices, AMOVA, and Structure-based clustering analyses indicated that B. hilarii populations exhibit a low level of genetic structure, with some indications that the Taquari River population is somewhat distinct from others. Results of K-means analysis suggested little or no structuring, with weakly differentiated populations above and below the confluence of the Paraguay and Taquari rivers. Because B. hilarii populations in the Pantanal are linked by high levels of gene flow, habitat alterations that would interfere with gene flow may jeopardize the long-term persistance of the species.     

Genetic diversity and population structure assessment of Chinese <Emphasis Type="Italic">Senna obtusifolia</Emphasis> L. by molecular markers and morphological traits of seed

Senna obtusifolia L. is an important medicinal plant in Asia. This study was the first report on the genetic diversity and population structure of S. obtusifolia which were collected from 47 geographic populations widespread in China. Inter-Simple Sequence Repeat (ISSR) and Start Codon Target Polymorphism (SCoT) combined with seeds morphological traits were used to investigate the relationship of 47 populations. 11 ISSR primers yielded 98 polymorphic bands with 81.67% polymorphism. 24 SCoT primers yielded 267 polymorphic bands with 89.59% polymorphism. The number of allele (Na), the number of effective allele (Ne), Nei’s diversity index (H), and Shannon’s information index (I) reflected a high level of genetic diversity of S. obtusifolia species. The greatest genetic distance (G _D) existed between Southwest and Northwest (0.4022_ISSR/0.5019_SCoT), while the Eastern and Northern showed the least genetic distance (0.1751_ISSR/0.2186_SCoT). The genetic differentiation (Gst) was 0.4875_ISSR/0.4434_SCoT, and the gene flow (Nm) was 0.5256_ISSR/0.6275_SCoT, which indicated that gene exchange among four regions was limited. 47 samples were divided into four clusters mainly according to their geographic distribution through clustering and structure analysis. The analysis on the combined data of ISSR and SCoT showed more reliable and superior results than single analysis of ISSR and SCoT. This study explored the effectiveness of ISSR and SCoT markers to evaluate the genetic diversity and population structure of S. obtusifolia and provided useful information for S. obtusifolia germplasm research and breeding program.     

Genetic diversity,effective population size,and structure among black bear populations in the Lower Mississippi Alluvial Valley,USA

Multiple small populations of American black bears Ursus americanus, including the recently delisted Louisiana black bear subspecies U. a. luteolus, occupy a fragmented landscape in the Lower Mississippi Alluvial Valley, USA (LMAV). Populations include bears native to the LMAV, bears translocated from Minnesota during the 1960s, and recently reintroduced and colonizing populations sourced from within the LMAV. We estimated population structure, gene flow, and genetic parameters important to conservation of small populations using genotypes at 23 microsatellite markers for 265 bears from seven populations. We inferred five genetic clusters corresponding to the following populations: White River and western Mississippi, Tensas River and Three Rivers, Upper Atchafalaya, Lower Atchafalaya, and Minnesota. Upper Atchafalaya was suggested as the product of Minnesota-sourced translocations, but those populations have since diverged, likely because of a founder effect followed by genetic drift and isolation. An admixture zone recently developed in northeastern Louisiana and western Mississippi between migrants from White River and Tensas River, resulting in a Wahlund effect. However, gene flow among most populations has been limited and considerable genetic differentiation accumulated (global F_ST?=?0.22), particularly among the three Louisiana black bear populations that existed when federal listing occurred. Consistent with previous bottlenecks, founder effects, and persisting isolation, all LMAV bear populations had low genetic diversity (A_R?=?2.08–4.81; H_E?=?0.36–0.63) or small effective population size (N_E?=?3–49). Translocating bears among populations as part of a regional genetic restoration program may help improve genetic diversity and increase effective population sizes.     

Review of Indo-Pacific dwarf lionfishes (Scorpaenidae: Pteroinae) in the <Emphasis Type="Italic">Dendrochirus brachypterus</Emphasis> complex,with description of a new species from the western Indian Ocean

A taxonomic review of the Dendrochirus brachypterus complex resulted in the recognition of five species, including Dendrochirus barberi (Steindachner 1900), Dendrochirus bellus (Jordan and Hubbs 1925), Dendrochirus brachypterus (Cuvier in Cuvier and Valenciennes 1829), Dendrochirus hemprichi sp. nov. and Dendrochirus tuamotuensis Matsunuma and Motomura 2013. The complex is defined as having usually 9 dorsal-fin soft rays, usually 5 anal-fin soft rays, 17–20 (rarely 20) pectoral-fin rays, no ocellated spots on the soft-rayed portion of the dorsal fin and usually 2 (sometimes none) barbels on the snout tip. Dendrochirus barberi, known from the Hawaiian Islands and Johnston Atoll, is characterized by usually 18 pectoral-fin rays, a relatively high number of scale rows in the longitudinal series (modally 51 vs. 39–49 in other species) and mottled markings on the pectoral fin in large specimens. Dendrochirus bellus, restricted to the northwestern Pacific Ocean from the South China Sea north to southern Japan, is characterized by usually 17 pectoral-fin rays, a relatively low number of scale rows in the longitudinal series (modally 38 vs. 44–51 in other species), and the absence of skin flaps on the orbit surface and uppermost preopercular spine base. Dendrochirus tuamotuensis, recorded only from the Tuamotu Archipelago, is characterized by 19 pectoral-fin rays, the posterior margin of the pectoral fin strongly notched, and a relatively shallow and narrow head and body. Dendrochirus hemprichi sp. nov. is distributed in the western Indian Ocean, including the Red Sea. Although previously confused with a closely related congener (D. brachypterus, known from the northern and eastern Indian Ocean and western Pacific), D. hemprichi can be distinguished from the former by having fewer scale rows between the last dorsal-fin spine base and lateral line, and between the sixth dorsal-fin spine base and lateral line [4–7 (5) in D. hemprichi vs. 5–7 (6) in D. brachypterus, in both cases], a slightly greater interorbital width at the mid-orbit [5.5–10.7 (mean 7.8) % SL vs. 4.5–8.9 (6.8) % of SL] and at preocular spine base [4.4–9.1 (6.6) % SL vs. 3.5–7.8 (5.7) % of SL], and slightly shorter posteriormost (usually 13th) dorsal-fin spine length [11.8–19.9 (15.3) % SL vs. 13.3–21.3 (17.2) % of SL]. Moreover, D. hemprichi tends to have relatively more spinous points on the head spines and ridges, compared with D. brachypterus. Notwithstanding the morphological similarity between the two species, an obvious genetic difference was observed between D. hemprichi and D. brachypterus. Dendrochirus chloreus Jenkins 1903 and Dendrochirus hudsoni Jordan and Evermann 1903 were synonymized under Pterois barberi, as in some previous studies. Scorpaena koenigii Bloch 1789 was regarded as conspecific with D. brachypterus, which it predated. However, the former name should be suppressed under Reversal of Precedence.     

Natural hybridization among subspecies of <Emphasis Type="Italic">Turnera sidoides</Emphasis> L. (Passifloraceae) revealed by morphological and genetic evidence

Turnera sidoides is a complex of outcrossing, perennial, rhizomatous herbs that is widely distributed in southern South America. Five subspecies are recognized taxonomically based on morphological features and geographical distribution. In certain regions, the areas of distribution of the subspecies overlap partially. In such contact zones, the extent of reproductive barriers among subspecies is still largely unknown, but morphologically intermediate individuals have been found in the field, indicating that hybridization may actually occur between subspecies. Crossability among subspecies of T. sidoides has been shown by experimental studies with cultivated plants, but the mechanisms involved in natural populations are still unknown. To investigate the mechanisms that underlie gene flow within the T. sidoides complex, in this paper we analyze the morphological and genetic variation, as well as the crossability among taxa in a contact zone between subspecies pinnatifida and sidoides, in southeastern Uruguay. Our results constitute the first evidences of ongoing natural hybridization between subspecies of T. sidoides and suggest that, although hybridization may not have been of significance in the early phase of the species differentiation, reticulate evolution is ongoing enhancing the current morphological and genetic variability of the complex.     

Experimental hybridization and an evaluation of the fertility of some forms of the house mouse supraspecies complex <Emphasis Type="Italic">Mus musculus</Emphasis> (Rodentia,Muridae)

The degree of development of the mechanisms of postcopulatory isolation was evaluated on the basis of experimental hybridization of representatives of three subspecies of M. musculus (M. m. musculus, M. m. wagneri, and M. m. gansuensis) and remote populations of the subspecies M. m. musculus. Experimental crosses between the different subspecies and populations indicated the presence of initial stages of postcopulatory reproductive isolation between some forms of house mice. In a number of crosses conducted between different populations and subspecies of M. musculus, asymmetry was observed. In one variant of mating, M. m. musculus (male) × M. m. wagneri (female), a reduced intensity of breeding and nonviability of pups were observed. A decrease in the intensity of reproduction was found in all variants of crosses that used male M. m. musculus from the city of Ishim. These data are assumed to confirm the previous assumption about the hybrid origin of mice inhabiting that city. The results confirm a significant level of divergence of the subspecies M. m. musculus and M. m. wagneri. Thus, initial stages both of post- and precopulatory isolation mechanisms between M. m. wagneri and M. m. musculus were shown.     

Modern State of Populations of Endemic <Emphasis Type="Italic">Oxytropis</Emphasis> Species from Baikal Siberia and Their Phylogenetic Relationships Based on Chloroplast DNA Markers

The genetic diversity and population structure of the endemic species of Baikal Siberia Oxytropis triphylla, O. bargusinensis, and O. interposita were studied for the first time on the basis of the nucleotide polymorphism of intergenic spacers psbA–trnH, trnL–trnF, and trnS–trnG of chloroplast DNA. All populations of these species were characterized by a high haplotype (0.762–0.924) and relatively low nucleotide (0.0011–0.0022) diversity. Analysis of the distribution of variability in O. triphylla and O. bargusinensis showed that there was no significant genetic differentiation between populations of each species; the gene flow was 4.43 and 8.91, respectively. The high level of genetic diversity in the studied populations indicates a relatively stable state of these populations. A study of the phylogenetic relationships of closely related species confirms the concept of the origin of O. bargusinensis and O. tompudae as a result of intersectional hybridization of the species of the sections Orobia and Verticillares.     

Genetic structure of populations of Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis> (L.) Karst. from Ukrainian Carpathians

The genetic diversity, subdivision, and differentiation of nine populations of Norway spruce (Picea abies (L.) Karst.) in Ukrainian Carpathians were studied using electrophoretic analysis of variability of enzyme systems in 346 trees aged from 80 to 150 years. Based on electrophoretic fractionation of enzymes extracted from seed endosperms in vertical slabs of 7.5% polyacrylamide gel, 20 loci of nine enzyme systems (ADH, ACP, DIA, GDH, GOT, MDH, LAP, FDH, SOD) were identified, and 71 allele variant were revealed. Each tree was heterozygous on average in 15.8% of its genes. The populations were characterized by low subdivision (F _ST = 0.017) and differentiation (D _N = 0.005). The main contribution to heterogeneity of population genetic structure was made by loci Dia-3, Lap-1, and Sod-3. Clustering and multivariate analysis revealed no observed trends in geographical or altitudinal position of the populations.     

High genetic diversity in an endangered medicinal plant, <Emphasis Type="Italic">Saussurea involucrata</Emphasis> (<Emphasis Type="Italic">Saussurea</Emphasis>, Asteraceae), in western Tianshan Mountains,China

Saussurea involucrata (Asteraceae) is a medicinal and second-degree national priority endangered plant that is mainly distributed in the high latitude region of the western Tianshan Mountains. The population is fragmented and isolated, and extensive human impact merits a suitable and specific conservation strategy, which can be compiled based on the genetic diversity, population structure, and demographic history. Phylogeographic studies were conducted on a total of five natural populations and 150 individuals were sampled. Data from three cpDNA intergenic spacer regions (trnL-F, matK, and ndhF-rpl32) and nrDNA ITS sequences showed that twelve haplotypes in cpDNA and five haplotypes in nrDNA indicated high genetic diversity among populations sampled (H _T?=?0.820 and 0.756) and within populations sampled (H _S?=?0.792 and 0.721). Additionally, the high genetic diversity did not mirror genetic structure in either cpDNA (F _ST?=?0.03153, G _ST?>?N _ST, p?<?0.05) or nrDNA (F _ST?=?0.03666, meaningless G _ST and N _ST). Two groups (north and south) were determined for a SAMOVA analysis. Based on this analysis, the demographic history was conducted with a Bayesian Skyline Plot and Isolation with Migration analysis, which showed sustainable and stable extension without a marked bottleneck. Divergence time was indicated at c. 6.25 Mya (90%HPD: 15.30–0.22 Mya) in the Miocene, which is consistent with the formation of the Kelasu section of Tianshan. The southern populations in the Bayanbulak and Gonglu regions require additional attention and transplanting would be an effective way to restore rare cpDNA haplotypes, increase effective population size, and migration rate. Our results suggested that in situ conservation of S. involucrata in western Tianshan should be the main strategy for protection and recovery of the species.     

Revealing physiological and genetic properties of a dominant maize dwarf <Emphasis Type="Italic">Dwarf11</Emphasis> (<Emphasis Type="Italic">D11</Emphasis>) by integrative analysis

Plant height is an important agronomic trait involved in lodging resistance and harvest index. The identification and characterization of mutants that are defective in plant height have implications for trait improvement in breeding programs. Two dominant maize dwarf mutants D8 and D9 have been well-characterized. Here, we report the characterization of a dominant maize dwarf mutant Dwarf11 (D11). Dwarf stature of D11 was mainly attributed to the inhibition of longitudinal cell elongation. The levels of bioactive GA₃ were significantly lower in D11. Contrarily, D8 mutant accumulates markedly higher levels of GA₃. The expression of GA biosynthetic and catabolic genes was dramatically decreased in D11. Expression variations of d8 and d9 genes were not observed in D11 mutant. Moreover, genetic suppressors of D11 were identified in inbred line Chang 7-2. Integrated omics data indicated that D11 is a novel dominant maize dwarf. The ultimate D11 gene cloning and its regulatory network elucidation may strengthen our understanding of the genetic basis of plant architecture and provide cues for breeding of crops with plant height ideotypes.