جستجوی مقالات مرتبط با کلیدواژه « poaceae » در نشریات گروه « زیست شناسی »

Twelve plant species belonging to seven families were collected from the wetlands of Kermanshah Province. Chromosome numbers for Sinapis arvensis L. (2n = 18), Rumex cyprius Murb. (2n = 18), Calamagrostis pseudophragmites var. tartarica (Hook. f.) R.R. Stewart (2n = 42) and Scandix stellata Banks & Sol. (2n = 20) are reported for the Flora of Iran for the first time. The karyomorphological parameters and Stebbins class were determined for all species.

The late Embryogenesis Abundant (LEA) protein family obtains a group of stress-induced hyper-hydrophilic proteins that accumulate in response to cellular dehydration. They are generally unstructured polypeptides without a well-defined three-dimensional structure and have been identified in a wide range of organisms from bacteria to higher plants. Herein, we made a phylogenetic and evolutionary analysis for LEA proteins in Poaceae. The full-length LEA protein sequences were acquired by performing the sequence search of sequenced hva1 against Poaceae species in the non-redundant protein database by a BlastX search tool. The sequences were aligned with the Clustal Omega tool. The MEME suite searched for conserved blocks among each LEA protein sequence. Also, the evolutionary relationship among the LEA protein sequences evaluates using the MEGA tool. The results display close sequence similarity not only into the species but also between species. The results demonstrated that LEA proteins cluster into two large subgroups. The overall average evolutionary difference in LEA protein sequence pairs estimated as 0.4022 amino acid substitutions per site from averaging over all sequence pairs. The LEA protein sequences contain a significant percentage of glycine residues but lack cysteine and tryptophan residues. The results indicate the occurrence of homologs in the subgroup before the divergence of the species. However, the expansion of the gene number in the Poaceae was approved by the duplication events in the preexisting genes rather than by the appearance of the altered LEA gene. Our data will provide novel insights for further studies of the Late Embryogenesis Abundant protein family in Poaceae.

Somatic chromosome numbers of 14 species from 6 families were studied in this research. The chromosome numbers of Silene viscosa (2n=24), Leucanthemum vulgare (2n=18), Odontites vernus (2n=40), Pedicularis sibthorpii (2n=16)have been reported here for the first time for the flora of Iran. Ideograms were depicted for each species.

According to various taxonomic treatments, Bromus has been divided into 8 to 9 sections, subgenera or even separate genera. The relationship of Bromus pumilio (syn.: Boissiera squarrosa) with other species of Bromus has long been a matter of dispute. To clarify this problem, the nuclear ribosomal DNA ITS and chloroplast DNA trnL-F sequences for 31 and 28 species respectively were used to reconstruct the phylogenetic relationship and reveal the infrageneric boundaries. Molecular analysis performed by Maximum Parsimony analyses and Bayesian method. The results based on nrDNA ITS show that sects. Bromus, Ceratochloa, Genea, Mexibromus and Neobromus are monophyletic, while the plastid data doesn’t support the monophyly of any sections in the genus Bromus.Evidence based on the nrDNA ITS data doesn’t show any close relationships between B. pumilio (sect. Boissiera) and B. danthoniae or B. lanceolatus (sect. Bromus) and instead robustly supports B. pumilio as the sister group of B. gracillimus (sect. Nevskiella), while in the plastid data B. pumilio is the sister group of a clade comprising B. inermis (sect. Pnigma), B. gunckelii (sect. Neobromus)and species of sect. Ceratochloa.

Ethylene response factor proteins are important for regulating gene expression under different stresses. Different isoforms for ERF have previously isolated from bread wheat (Triticum aestivum L.) and related genera and called from TaERF1 to TaERF5. We isolated, cloned and molecular characterized a novel one based on TdERF1, an isoform in durum wheat (Triticum turgidum L.) and called TaERF6. Its cDNA was synthesized, sequenced and compared with genomic sequence to figure out intron and exon regions and determine coding sequence region. The length of TdERF1 gene was 1939 bp and cDNA was 1065 bp including two exons, the first one 259 bp and the second one 806 bp separated by a 874 bp intron with a 111 bp 5'-UTR (untranslated region) and 401 bp 3'-UTR. TaERF6 encodes a 353 amino acids protein with nearly 99% identity to TdERF1. Hydrophobic cluster analysis revealed an N-terminal hydrophobic domain contains a highly conserved motif with the consensus sequence of M [C/L/Y] [G/R] [G/R/P] [A/G/V/L/R] [I/L/R/S/P/Q] [L/I/R/H] and hydrophobic clusters in AP2/ERF domain of which tends to form b-sheet. Three monopartite nuclear localization signals also identified in TaERF6 that play important role in getting back into the nucleus. The results showed several putative phosphorylation sites in TaERF6 that a motif from residues 246 to 266, the CMVII-4 motif, was predicted to phosphorylate by different kinase proteins and play important roles in TaERF6 function. Phylogenetic analysis showed 7 clusters (I to VII) and 10 subclusters according to their relatedness in Poaceae family.

The present study reports somatic chromosome numbers of 7 species belong to 6 familiesfrom Iran.The chromosome numbersofEpilobium palustre (2n=36), Geranium pyrenaicum (2n=26), Sium sisarum (2n=20), Veronica beccabunga (2n=18)were reported for the first time for the flora of Iran. Ferula persica (2n=22)and Tragopogon jesdianus (2n=12)are reported for the first time. The report for Bromus scoparius (2n=28) is the second count for the species in Iran. Ideograms are depicted for each species.

The genus Elymus has been studied to prepare the draft of Elymus for the Flora of Iran. In this research, the plant specimens of Central Herbarium of Iran (TARI) were identified and a new key of the Iranian species of the genus Elymus is presented. Delimitation of the genus is discussed. Among the specimens, a new species from Zagros Mountain ranges was recognized which is described and illustrated as E. shirazicus. The new species is well characterized among the Iranian species of the genus by caespitose habit, having densely imbricate spikelets with none or short awns. Elymus shirazicus seems to be related to E. transhyrcanus but well distinguished by narrower spikes and much shorter rachis internodes. Elymus dorudicus based on E. nodosus subsp. dorudicus is introduced as a new combination. Elymus lazicus subsp. iranicus is described as a new subspecies.

During the study of the plants collected from South-East Iran (Baluchestan), a specimen was identified as Coelachyrum brevifolium which is reported as a new record to the flora of Iran. The genus was previously known with one species (C. piercei) in Iran. Unlike C. piercei, the species is an annual plant. Morphological characteristics, habitat, images, distribution map and identification key to the species of the genus in Iran are presented.

Piptatherum denaense is described as a new species from south west of Iran، Dena Mountain. It is close to P. laterale but differs from it by having glabrous lemma in lower half and toward the apex، narrower vegetative shoots and unbearded anthers. Piptatherum holciforme subsp. holciforme var. glabrum is not accepted as a distinct variety. Piptatherum sphacelatum formerly known as a synonym of P. molinioides is established as a separate species due to having distinct morphological characters as well as molecular differences based on literature. Thus، the number of taxa in the genus Piptatherum changes to 9 species، 2 subspecies and 4 varieties in Iran. An identification key to Piptatherum taxa occuring in Iran is provided. The distribution map of P. denaense with P. laterale subsp. laterale and the illustration of the new species are included.

Based on a taxonomic review of the Iranian materials of the genus Eremopoa and the relevant literatures, four species and three varieties were recognized for the genus in Iran. A variety (E. persica var. oxyglumis as a new combination) is added to the flora of Iran.

Festuca karatavica (Bunge) B. Fedtsch. (subgen. Xanthochloa) is reported as a new species and subgenus record for the flora of Iran from Binalood mountain range in Khorassan. This species is morphologically compared with its closely related species of Festuca subgen. Leucopoa in Iran. Illustration, distribution map and notes on biogeography, conservation status and habitats are provided

This article is a taxonomic review after Flora Iranica concerning some species of Bromus sect. Bromus. Comparing the holotype, isotype and paratype of B. pseudobrachystachys with the lectotype of B. brachystachys and also reexamination of three Iranian and Iraqi herbarium sheets putatively determined under the latter’s name showed all belong to the former. B. racemosus, B. arvensis and B. secalinus are confirmed to occur in Iran. Despite B. tigridis was identified from Turkey based on the sheet Sorger & Buchner 82-62-54, the Iranian specimen was identified as B. racemosus. Furthermore, a new record of this section i.e., B. macrocladus is reported here from mountains of Razi village (W Khoy, NW Iran).

As a result of a taxonomic review of the Iranian materials of the genus Vulpia and the relevant literature this genus was recognized as possessing five species and four subspecies occurring in Iran. The novelties of this study for the flora of Iran are: describing one new taxon: V. unilateralis subsp. tomentosa; reporting one new record for the flora of Iran: V. ciliata subsp. plumosa; and literature correction of V. ciliata Dumort. and accepting the correct Name “Vulpia unilateralis (L.) Stace” for “Nrdurus maritimus (L.) Murb.” for the floar of Iran.