The present study considers genetic diversity of 38 populations in 4 Cirsium species of the genus Cirsium Mill. (Asteraceae), occurring in different ecological regions and tries to compare degree of genetic variability among the species with wide geographical distribution versus endemic C. pyramidale showing confined geographical distribution. The results showed that the endemic species has similar value of genetic diversity parameters as the species with wider distribution. We also studied the possible admixture nature of these populations and tried to understand the relation between genetic changes, geographical distribution and polyploidy level and chromosome pairing in these species. ISSR analysis showed population difference in allele composition and frequency. Clustering and PcoA ordination produced different groupings in each species, while STRUCTURE and reticulation analyses revealed high degree of genetic admixture and gene exchange among populations as well as allelic rearrangement. No significant correlation was observed between geographical distance and genetic distance of the populations and AMOVA test revealed no significant difference among populations in each species studied. However, high amount of within population variation occurred in all 4 species indicating their cross-pollination nature and high genetic admixture. The populations also varied in chiasma frequency and chromosome pairing as well as the occurrence of heterozygote translocations all creating more variability to be used by plants for local adaptation.

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Meiotic studies were performed on 11 populations of 8 Stipa species concerning polyploidy level, chiasma frequency and distribution, chromosomes association and segregation. All the species and populations studied possessed nϭ22 (2nϭ4xϭ44) chromosome number. The chromosome numbers of 3 species are reported for the first time. The populations and species studied differed significantly in their meiotic characteristics. Meiotic abnormalities observed included laggard chromosome formation, stickiness and cytomixis. Cytomixis led to the formation of aneuploid meiocytes. Unreduced pollen grains were observed in 2 species, which differed significantly in their size compared to the normal (reduced) pollen grains.

Abstract:The genus Linum L. (Lineacea) has over 15 species, subspecies or ecotypes in Iran. These species show extensive geographical distribution and form many local populations throughout the country. Linum album is herbaceous medicinal plant containing important lignans such as podophyllotoxin (PTOX) and 6-methoxy podophyllotoxin (MPTOX), which have antiviral and anticancer properties. Studying the genetic and morphological diversity of different geographical populations produces detailed knowledge about population divergence and identification of the infra-species taxa if at all they are present. Moreover, the populations that differ in their genetic content and structure may also differ in their chemical and medicinal properties. The present study considers morphological and genetic diversity analyses of 20 L. album geographical populations by using nuclear ISSR markers, genome size, and cytogenetic characteristics. These populations differed significantly in many of their quantitative morphological characters and in some of their qualitative features. They also differed significantly in their molecular characteristics and genome size. Details of morphological and molecular variations are reported and discussed.

Meiotic study was performed in 22 Brassica napus cultivars considering chiasma frequency and distribution as well as chromosome pairing. All cultivars possessed n = 19 chromosome number (4x) and showed a deviant course of prophase-I meiosis with synezetic knot and post pachytene diffuse stage. Chromosome stickiness occurred in most of the cultivars from early prophase to late telophase-II leading to the formation of laggard chromosomes and micronuclei. The cultivars studied differed significantly in chiasma frequency and distribution as well as bivalent formation indicating their genomic differences. Cluster analysis and ordination based on principal components analysis grouped those cultivars showing meiotic similarities. Some of the cultivars showed the occurrence of unreduced meiocytes and pollen grains.

Successful management and preservation of natural populations depend on accurate assessment of genetic diversity. Knowing the genetic diversity within a population is important for choosing the conservation strategies for the species. Geranium pusillum L. is an annual or biennial herb mainly native to Europe, northern Africa, and western Asia, and G. pyrenaicum Burm is a frost hardy perennial native to areas of France and Spain to the Caucasus. In general, taxonomic and biosystematic studies of Geranium are not known in Iran; moreover, in a few cases, inter-specific hybrids and intermediate forms are recognized. A detailed morphological, micro-morphological and molecular (ISSR) study of Geranium is done here with the following objectives: (1) to delimitate the species; (2) to carry out a population genetic study and produce information on genetic structure and genetic variability within each population in G. pyrenaicum and G. pusillum. The present study revealed that a combination of morphological and micro-morphological (seed and pollen) data can separate the species. In the present study, 84 randomly collected plants from 12 geographical populations of two Geranium species were considered. A consensus tree based on morphological and genetic data separated some of these populations from the others, suggesting the existence of ecotypes in the studied taxa.

The genus Geranium (Geraniaceae); with about 320 species throughout the temperate regions, is chemically characterised by the presence of tannins, flavonoids, anthocyanins and essential oils which interfere with the extraction of pure genomic DNA. It is necessary to optimise the extraction protocols to reduce the effects of the presence of these compounds to the lowest level. The present study compares the plant genomic DNA extraction Kit (DNP TM Kit), CTAB DNA extraction method by Murray and Thompson and Sahu et al., from the extracting DNA point of view Geranium species. The results showed significant differences in DNA contents between the three methods. Quantity and quality of extracted genomic DNAs were compared by employing the spectrophotometer, Nano-Drop, agarose gel electrophoresis, and polymerase chain reaction (PCR) methods and molecular marker such as (ITS and trnL-F) and ISSR. The method of Sahu et al., provided the best results (200 ng/µL) in terms of quantity and quality of DNA, therefore, this method was taken and optimised for DNA extraction. Our results proposed that this method could be effective for plants with same polysaccharides, proteins and polyphenols components. The advantage of this method is that it omits the use of liquid nitrogen and toxic phenols which are expensive. The success of this method in obtaining high-quality genomic DNA has been demonstrated in the Geranium species group and the reliability of this method has been discussed.

Species identification is fundamentally important within the fields of biology, biogeography, ecology and conservation. The genus Geranium L. (Geraniaceae) comprises about 430 species distributed throughout most parts of the world. According to the most recent treatments, subg. Geranium is the largest subgenus with over 370 species classified in ten sections. The subg. Geranium is represented in Iran by 13 species. These species are grouped 3 sections. In spite vast distribution of many Geranium species that grow in Iran, there are not any available report on their genetic diversity, mode of divergence and patterns of dispersal. Therefore, we performed molecular (ISSR markers) and morphological studies of 102 accessions from 13 species of Geranium (subg. Geranium) that were collected from different habitats in Iran. The aims of present study are: 1) can ISSR markers identify Geranium species, 2) what is the genetic structure of these taxa in Iran, and 3) to investigate the species inter-relationship? The present study revealed that combination of morphological and ISSR data can identify the species.