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

Prunus subgenus Cerasus belongs to the Rosaceae family with about 100 species in the world, of which 19 taxa are distributed in Iran. Pollen micromorphological traits of the Iranian taxa belonging to three sections, (Microcerasus, Cerasus, and Mahaleb) were examined using light and scanning electron microscopes. The hierarchical clustering method and principal component analysis of the pollen traits were performed using InfoStat. The results showed that in the subgenus Cerasus pollen grains are monad, radially symmetrical, isopolar, tricolpate to tricolporate, and medium-sized. Pollen shape is rectangular to cylindrical in the equatorial view and triangular to circular in the polar view. The exine ornamentation is striate with or without perforations. The studied pollen can be divided into two types and six subtypes. The rugulate exine ornamentation was only found in P. pseudoprostrata. Ward’s hierarchical clustering method and principal component analysis results did not support the existing sectional delimitation of taxa. However, a high variation in pollen grain characteristics could be observed in taxa within the subgenus Cerasus, especially in dwarf cherries (sect. Microcerasus). These differences are remarkable among closely related species, such as P. microcarpa and its allies. Finally, an identification key to the species is provided.

Three new specie including Pimpinella gilanica (Apiaceae), Potentilla humilis (Rosaceae) and Verbascum gilanicum (Scrophulariaceae) are described. In addition, three new records including Aethusa cynapium L. (Apiaceae), Hypochaeris glabra L. (Asteraceae) and Turritis laxa (Sibth. & Sm.) Hayek (Brassicaceae) are reported as new records for the flora of Iran.

In the current survey, pollen, seed and fruit micro-morphological characters of the genus Geum L., comprising 5 species from two subgenera, Orthostylus Fisch & Mey. and Geum were examined using scanning electron microscope (SEM) and light microscope (LM). The pollen grains are monad, radially symmetrical, isopolar, tricolporate, medium in size, elliptical (from equatorial view) and triangular to circular (from polar view) in outline, subprolate to prolate in shape. The exine ornamentation is striate with micro perforation. Seeds coat micro -morphology revealed two types of sculpturing (including sulcat-ribbed and sulcat-foveolate) and fruits morphological analysis showed the importance of joint position and hairs on the style, beak length and hook in this genus. Principal component analysis (PCA) was carried out using a total of 20 characters. The result supports current classifications and emphasizes the importance of micro- macro-morphologocal traits for separating the two subgenera and species of the genus. Based on the important distinguishing characters a key is presented.

In this study we mapped the Rosaceae species richness with the point-to-grid richness analysis tool DIVA-GIS, using a 10×10 kilometer grid cell and the circular neighborhood option with the 50 km radius, to identify potential areas for conservation of Rosaceae. This analysis is accomplished by 5762 georeferenced observations. The main potential areas for conservation of this family in Iran belong to the Irano-Turanian Region with its two important parts including central Alborz and Zagros Mountains respectively. These areas cover the centre of endemism of the family in Iran. The Rosaceae has 91 rare and 70 endemic species. Mazandaran with the highest number of rare species (23) is one of the most important areas for conservation (in central Alborz).

Cerasus paradoxa is described and illustrated as a new species endemic to Lorestan province, in the west of Iran. It is similar, and most closely related to C. microcarpa and C. yazdiana. The diagnostic morphological characteristics, as well as a full description, taxonomic status and figure of the new species are presented.

Pollen grains of 13 species of the genus Rosa belonging to two subgenera, Rosa and Hulthemia, and one hybrid species were performed using light (LM) and scanning electron microscopy (SEM). The basic shape of pollen grains in 11 studied taxa is subprolate but prolate and rarely prolate- spheroidal pollen grains also can be found in nine species. The grains are usually trizonocolporate, aperture structure consists of 3 ectocolpi and 3 endopores. Endopores are located in the middle part of ectocolpi. Similar to the other genera of Rosaceae, striate sculpturing is the main ornamentation of pollen grains. According to surface sculpturing features such as slope, diameter and distance between ridges, number and size of perforations is classified into four major types and four subordinate types; however, other ornamentation types such as gemmate are observed. Characters of pollen grain provide useful criteria for separating taxa in sectional and specific levels.

Pyrus pashia is reported as a new record from NE Iran. This species is distinguished from its closest relative, P. boissieriana, by having more or less ovate, acuminate leaves and fruit size. An illustration of this species in fruit and flower and a geographical distribution map and also photographs of the two species are given.

In this study, anatomical features of blade and midrib region in 14 species of genus Cotoneaster belonging to two sections Cotoneaster and Chaenopetalum are presented. These species include Cotoneaster nummularioides, C. kotschyi, C. turcomanicus, C. multiflorus, C. nummularius, C. hissaricus, C. luristanicus, C. suavis, C. morulus, C. ovatus, C. discolor, C. assadii, C. melanocarpus and C. persicus. Among 30 studied characters, five characters (quantitative features such as presence of fiber, presence of cuticle and external xylem) are constant in different species. Twenty four characters 24 are variable in several species and several individuals of the same species. Only one character (i.e. number of palisade parenchyma layer) was variable and useful in separation of species.

In this study leaf and petiole anatomy of 10 species of the genus Pyrus L. belonging to four sections, Pashia, Pyrus, Xeropyrenia and Argyromalon, and one cultivated specimen (close to P. syriaca) is presented. These species include Pyrus boissieriana Buhse, P. kandevanica Ghahreman & Khatamsaz, P. turcomanica Maleev, P. hyrcana Fedor., P. mazanderanica Schönbeck-Temesy, P. syriaca Boiss., P. glabra Boiss., P. oxyprion Woron., P. salicifolia Pall., P. elaeagnifolia Pall. Among 43 studied anatomical characters, 29 characters vary in different localities, seven are constant in all species and four are valuable and can be used in distinguishing species. These characters include number of layers of palisade parenchyma layer, density of palisade parenchyma layers, and presence of lower palisade parenchyma layer between auricles. On the basis of the present study, anatomical characters are useful for separating Zagros species from Alborz ones and also in sectional level.

In this survey, leaf and rachis anatomy of 14 Iranian species of the genus Rosa belonging to two subgenera and four sections was studied. The species examined are including: Rosa persica, R. beggeriana, R. webbiana, R. moschata, R. canina, R. elymaitica, R. orientalis, R. iberica, R. pulverulenta, R. foetida, R. pimpinellifolia, R. hemisphaerica, R. boissieri and R. villosa. On the basis of morphological features of R. canina, eight form-series were distinguished that five of them were studied in this survey. Among 48 anatomical characters examined only 17 characters are valuable at the species level such as presence or absence of fiber in midrib, the number of palisade parenchyma layers, the angle of two parts of blade, presence or absence of spongy parenchyma, shape of auricle in rachis and the distance of auricles.

Duchesnea indica is reported for the first time from Iran, Caspian forests, Nowshahr area, 170-950 m above s. l. Based on the new gathering westernmost distribution of the species extends to Iran as well.