Search

Setaria (Poaceae, Paniceae, Cenchrinae) comprises 136 species worldwide and 3 species in Iran. This weedy grass is distributed in various parts of the world. In this study, the characters of the lemma and palea of 9 populations of Setaria were studied micromorphologically using a scanning electron microscope (SEM) to identify diagnostic characters for the delimitation of the studied species. A total of 18 qualitative and quantitative characters of the lemma and palea surfaces were considered. Different shapes of microhairs, epicuticular wax, and the occurrence of cork cells and silica cells were evident in the studied taxa. The results of this study revealed the taxonomic value of floret micromorphological characters in Setaria species. [ABSTRACT FROM AUTHOR]

Fallopia (Polygonaceae) as a noxious weed contains 17 species in the world out of which three species occur in Iran with invasive distribution. F. convolvulus growing in wide range of soil types causes significant problems for native ecosystems of river banks. In this study, we have examined genetic variability in F. convolvulus for the first time in Iran. Ten Inter Simple Sequence Repeats (ISSR) markers were used to study the genetic variability on 11 populations of this species. Genetic diversity parameters, genetic distance and gene flow were determined. Genetic variation at inter- and intra-population level was evaluated by different methods. AMOVA and structure analyses revealed high genetic diversity within populations. Mantel test revealed a significant correlation between genetic and geographic distances. Between populations a limited gene flow was observed. It is concluded that local adaptation, low gene exchange and genetic drift can affect genetic diversity of F. convolvulus. Despite self-compatibility of this species, it is proposed that outcrossing may occur because of higher genetic variation among populations of this taxon. [ABSTRACT FROM AUTHOR]

Selecting of the specific type of rootstock is an appropriate and shortterm method for increasing drought tolerance by improving the antioxidant systems in plants. In this research, the responses of the antioxidant systems of fig scion 'Sabz' were investigated on various rootstocks at different irrigation levels. Graft combinations were 'Sabz' on 'Sabz' (Sa/Sa), 'Siah' (Sa/Si) and 'Torch' (Sa/T) rootstocks, plus 'Sabz', 'Siah' and 'Torch' cultivars with no grafting, for a total of six groups. The plants were irrigated with 4 levels of 25, 50, 75 and 100% of water requirement (WR) for a duration of 12 weeks. The experiment was performed in a randomized complete design with 5 replications per treatment. The results showed that the 'Torch' rootstock induced the greatest amount of anthocyanin, glutathione and ascorbic acid in 'Sabz' (Sa/T) at 25% WR. Superoxide dismutase and catalase activities of 'Sabz' grafted on 'Siah' were more evidence compared to 'Sabz' grafted on 'Torch' rootstock at 25% of WR. The cv. Sabz grafted on both 'Siah' and 'Torch' rootstocks indicated higher chlorophyll content, chlorophyll stability index and shoot growth than cv. Sabz with no grafting. As a result, both rootstocks (T and Si) with the activation of enzymatic and non-enzymatic antioxidant systems caused the scion protects its integrity and be able to tolerate more water stress. [ABSTRACT FROM AUTHOR]

Persicaria with 70-100 species in the world is distributed in temperate regions of both hemispheres. It has 11 species in Iran growing in moist areas and margins of rivers. Through hybridisation, plasticity and existence of overlapping habitats, species identification shows difficulty. In this study, we aimed to investigate karyotype characters and morphological features, evaluate genetic variability within and among species studied and examine species relationship using ISSR data. Nine annual taxa of Persicaria were gathered from different localities in Iran and used for studies. Our studies showed that combination of karyological, morphological and molecular data can delimit species studied. Based on karyological results, three chromosome counts (P. hydropiper (2n = 2x = 20), P. maculosa (2n = 2x = 22), P. orientalis (2n = 2x = 22)) were the first reports for the Flora of Iran. Analyses of morphological characters showed diagnostic features among taxa. STRUCTURE and AMOVA analyses showed high intraspecific genetic diversity. Our results suggested that phenotypic plasticity and hybridisation may cause genetic diversity within Persicaria species. [ABSTRACT FROM AUTHOR]

Species delimitation is essential since species is regarded as the basic unit of analysis in nearly all biological disciplines, such as ecology, biogeography, conservation biology, and macroevolution. The genus Geranium (Geraniaceae) comprises about 350 species distributed throughout most parts of the world. The subg. Robertium comprises 30 species which are arranged in 8 sections. This subgenus is represented in Iran by 10 species. These species are grouped into 5 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 molecular (ISSR markers) and morphological studies of 147 accessions from 10 species of Geranium (subg. Robertium), that were collected from different habitats in Iran were performed. The aims of the present study are: 1) to find the diagnostic value of ISSR markers in delimitation of Geranium species, 2) to find 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 delimit the species. AMOVA and STRUCTURE analysis revealed that the species of subg. Robertium are genetically differentiated but have some degree of shared common alleles. [ABSTRACT FROM AUTHOR]

Geranium subg. Robertium (Geraniaceae) comprises eight sections, of which sect. Batrachioidea contains four species centred in Eurasia, Mediterranean region and the Himalaya Mountains. Three species of Geranium pusillum, G. molle and G. pyrenaicum occur in Iran show some degree of morphological overlaps that make the species delimitation difficult. Moreover, hybrids are known to be formed between these species elsewhere. Till present time, there has been no detailed information available on molecular phylogeny and genetic structure of these species in the country. Therefore, the present study was conducted with the aim to investigate species delimitation by both morphological and molecular data and to reveal genetic diversity and population structure in these three Geranium species. For this study, 216 randomly collected plants from 30 geographical populations in three Geranium species were used. We encountered extensive within species genetic and morphological diversity. ISSR molecular markers could not delimit the studied species. STRUCTURE analysis revealed the occurrence gene flow between these species. The Mantel test showed no correlation between genetic distance and geographical distance of the populations studied. Statistical analysis showed no significant difference between ITS and rbcL sequences and phylogenetic tree was constructed based on combined data set which separated outgroups from the studied species. Genetic affinity of the studied species has been discussed. [ABSTRACT FROM AUTHOR]

Geranium (Geraniaceae) comprises more than 23 annual or perennial species in Iran. There is no study in Iran with pollen morphology emphasize. The main aim of this study is to find diagnostic pollen characters in studied species. Totally 40 accessions of five species (G. albanum, G. molle, G. purpureum, G. mascatense and G. pusillum) were collected. Pollen grains were studied by use of light and Scanning electron microscopy. To reveal the species relationships different multivariate statistical methods were used. The pollen grains were monad, isopolar, radially symmetric and of spheroid, prolate-spheroid or oblate-spheroid classes. The main ornamentation type was clavate, however reticulate but striate was also observed. All sections are clearly separated by their pollen features except of Batrachioidea which show confusion with Ruberta. Species relationship is discussed. [ABSTRACT FROM AUTHOR]

Relative resistance of 43 Iranian as well as introduced apple cultivars to blue mold (Penicillium expansum) was studied within years 2010-2011. The fruit physicochemical traits were also evaluated as measures of potential resistance to decay. Local P. expansum strains were isolated from decayed apple fruits and the most aggressive isolate (5,000 spores ml-1) used as inoculum. Fruits were wound-inoculated, and after four months stored in cold storage, decay lesion diameter was recorded. Force to break epidermis, cortex firmness, Total Soluble Solids (TSS) and Titratable Acidity (TA) were determined and their correlation with decay severity detected. Based on the obtained, results significant differences were observed in decay diameters in cultivars and for both years of the study priod. Mash had was rated as the most susceptible cultivar while Granny Smith as the most resistant one. Relatively, 11.3% of cultivars were rated as susceptible, 54.5% as moderately susceptible, 31.8% as moderately resistant, and finally 2.2% resistant. The cultivars were significantly different in all the physicochemical traits studied. Correlation studies indicated weak negative correlations between decay diameter and TSS, TA, cortex firmness as well as epidermal toughness. Cortex firmness was directly correlated with epidermal toughness and is probable to influence blue mold severity. [ABSTRACT FROM AUTHOR]