Species divergence in <Emphasis Type="Italic">Iris</Emphasis> series <Emphasis Type="Italic">Lacteae</Emphasis> (Iridaceae) in Russia and adjacent countries based on chloroplast DNA sequence data

In Russia, the species of the genus Iris L., series Lacteae Doronkin, the taxonomic structure of which still remains controversial, are found in the south of Siberia and the Russian Far East, as well as in other regions of Asia. Sequence analysis of three chloroplast DNA regions (rps4, trnL–trnF, and trnS–trnG) shows that, in Russia and adjacent countries, there are two genetically and geographically isolated Lacteae species. I. oxypetala Bunge grows in the south of the Russian Far East, and I. lactea Pall. grows in Siberia, Mongolia, and Kazakhstan. Genetic differentiation between the populations of I. lactea is extremely low and statistically insignificant (the fixation index Φ_ST = 0.057, P > 0.05), pointing to the unity of the gene pool and the absence of other Lacteae species in this area.     

Divergence of Oxytropis Species from the Section Verticillares (Fabaceae) of Steppe Flora of Baikal Siberia Based on Analysis of Chloroplast DNA

Russian Journal of Genetics - The analysis of nucleotide sequence polymorphism of chloroplast DNA psbA–trnH, trnL–trnF, and trnS–trnG intergenic spacers in the Oxytropis lanata,...     

Phylogenetic Relationships of the Far Eastern Araliaceae Inferred from ITS Sequences of Nuclear rDNA

In eight species of the family Araliaceae, inhabiting the territory of the Russian Far East, the sequences of ITS regions of nuclear rDNA were determined. A comparison of these sequences enabled establishment of phylogenetic relationships between the Far Eastern and other members of the family. It was demonstrated that Aralia elata populations from Primorye and Sakhalin were genetically different and, hereby, could be classified as intraspecific taxa. Aralia continentalis along with A. cordata were attributed to the section Aralia sensu Wen. Oplopanax elatus and O. horridus were found to be very close to each other, possibly being the subspecies of one species or relatively young species. Legitimacy of the discrimination between two sections within the genus Eleutherococcus was confirmed.__________Translated from Genetika, Vol. 41, No. 6, 2005, pp. 800–810.Original Russian Text Copyright © 2005 by Artyukova, Gontcharov, Kozyrenko, Reunova, Zhuravlev.     

Analysis of Genetic Variation in Rare Endemic Species Oxytropis chankaensis Jurtz. (Fabaceae) Using RAPD Markers

The method of polymerase chain reaction with random primers (RAPD) was used to assess genetic variation and population differentiation in the rare endemic plant Oxytropis chankaensis Jurtz. (Fabaceae). DNA samples from plants of two isolated populations were compared at 133 loci detected by use of ten primers. Both populations examined were characterized by high polymorphism levels (P ₉₅ = 72.9%; A = 1.92 and P ₉₅ = 74.4%; A = 1.88, respectively). They were also statistically significantly different in the frequencies of most of the amplicons. For each of the plants, unique multilocus RAPD phenotype was established using 17 to 20 RAPD markers. Diagnostic markers were not revealed. The populations were poorly differentiated. On average, the between-population component accounted for about 8% of the variation, while 92% of the variation was detected within populations. High variation along with the low degree of differentiation characteristic of two most geographically remote populations of O. chankaensis can have several explanations, among which a polyploid origin of the species seems to be most important.     

Genetic Relationships among Far Eastern Species of the Family Araliaceae Inferred by RAPD Analysis

A molecular genetic study of Far Eastern species of the family Araliaceae by means of RAPD analysis was conducted. Using 21 primers we assessed variability at 595 loci. Based on matrices of genetic distances D, dendrograms of genetic relationships among eleven species of this family were constructed. Our results suggest that Acanthopanax sessiliflorus and Eleutherococcus senticosus belong to different genera, Aralia cordata andA. continentalis are different species, and A. elata and A. mandshurica probably cannot be regarded as distinct species. Genetic similarity of Far Eastern A. cordata and American A. hispida is shown.     

Independent species status of <Emphasis Type="Italic">Iris vorobievii</Emphasis> N.S. Pavlova, <Emphasis Type="Italic">Iris mandshurica</Emphasis> Maxim., and <Emphasis Type="Italic">Iris humilis</Emphasis> Georgi (Iridaceae): Evidence from the nuclear and chloroplast genomes

-Nuclear (RAPD) and chloroplast (trnH-psbA, atpB-rbcL, rps4, trnL-trnF, and trnS-trnG) molecular DNA markers were used to study the populations of closely related species of the genus Iris L.: Iris vorobievii N.S. Pavlova, I. mandshurica Maxim., and I. humilis Georgi. An analysis of 243 RAPD fragments made it possible to calculate the main population parameters and to identify species-specific RAPD markers. Differences that discriminated the species were found in all but one (trnL-trnF) cpDNA region. The total length of the four variable cpDNA regions was 3640 bp, indels included. Their variation was low. A total of 22 variable sites (0.63%) were found; of these, 13 were parsimony informative and 9 were noninformative. Analysis of molecular variance (AMOVA) revealed significantly (P < 0.0001) high differentiation of both nuclear (F ST = 0.681) and chloroplast (F ST = 0.854) genomes for the species examined. Thus, a multigene approach confirmed the independent species status of I. vorobievii, I. mandshurica, and I. humilis and showed that I. vorobievii and I. mandshurica, but not I. humilis, are found in Primorye.     

High chloroplast haplotype diversity in the endemic legume <Emphasis Type="Italic">Oxytropis chankaensis</Emphasis> may result from independent polyploidization events

Oxytropis chankaensis Jurtz. (Fabaceae) is an endangered perennial tetraploid species endemic to the Khanka Lake coast. In Russia, O. chankaensis is distributed across a very restricted zone along the western shore of this lake. To characterise all known populations of this species, we assessed the genetic diversity of four noncoding regions of chloroplast DNA (cpDNA). Variable sites detected within the trnL–trnF, the petG–trnP, and the trnS–trnG regions allowed the identification of seven haplotypes. On the other hand, no variation was found in the trnH–psbA region. O. chankaensis exhibited an overall low level of nucleotide diversity (π = 0.00052) but a marked haplotype diversity (h = 0.718). A combination of three or four haplotypes was found in each population, and most of the cpDNA variation (above 90%) was distributed within populations. The level of genetic structure that we detected in O. chankaensis using maternal plastid DNA markers was much lower (G _ST = 0.037) than the average that is estimated for angiosperms. We found no evidence for isolation by distance or for phylogeographic structuring in O. chankaensis. Our data suggest that autopolyploidy has arisen more than once in the evolutionary history of this species. Repetitive expansion and contraction during past and ongoing demographic events both seem to be involved in shaping the current genetic structure of O. chankaensis. This study provides valuable information for developing the most appropriate strategy for conserving this endemic species with a narrow habitat range.