Pollen Morphology & Endocarp Studies of Rhamnus cathartica L., and Rhamnus pallasii Fisch. & C. A. Mey (Rhamnaceae) in North of Iran

Pollen morphology of Rhamnus pallasii and Rhamnus cathartica from the family of Rhamnaceae in North of Iran was examined under LM and SEM. Polar axis (P). Equatorial axis (E) and P/E were measured under LM. Exile ornamentation and endocarps of seeds were observed by scanning electron microscope. Based on pollen data, Rh.pallasii the shape is spheroidal and subtriangular in polar view; moreover, subprolate and tricolprate shapes were observed in equatorial view. Ornamentation of exine was obscure or indistinctly reticulate in Rh. pallasii subsp. iranica and Rh. X spathulifolia. Fruit of examined species was dropped with 2-3 seeds. All seeds were presented in ovate shape with light-brown color. Ornamentation of endocarp was foveolate and promaninted spotty. The biggest seed was presented in Rh. Pallasii and the smallest was observed in Rh. Pallasii subsp .Pallasii. The results of current research showed that ornamentation of exine is a valuable taxonomic character in the examined species; in addition, endocarp of seeds was to a great extent similar

Micromorphological, anatomical and molecular study of Hedera species (Araliaceae) in Iran

Hedera, with 12 extant species, is a genus of evergreen climbers native to Europe, north Africa, and south Asia. In this study, the micromorphological, anatomical structure and molecular evidences of 11 populations from two species of Hedera (H. helix and H. pastuchovii) have been considered to evaluate the relationships in Hedera. In total, seven quantitative and qualitative characters of pollen were selected and measured. Based on this study, the anticlinal wall and surface sculpturing of seed support for separation of two species of Hedera. Micromorphology of epidermis illustrated two types of epidermal cells: puzzle-shaped and polygonal cells. Using nuclear (nrDNA ITS) marker, we reconstructed phylogenetic relationships within two species of Hedera. This data set was analyzed by phylogenetic methods including Bayesian inference, maximum likelihood, and maximum parsimony. In phylogenetic analyses, all members of two species formed a well-supported clade (PP = 1; ML/BS = 100/100) and divided into two major clades (A and B). Neighbor Net diagram demonstrated separation of the studied populations. The results showed that these taxa differ in taxonomically important micromorphological, anatomical and molecular characteristics and these data provide reliable evidence for separation of these two species

An anatomical study of Rhamnus cathartica L. and Rhamnus pallasii Fisch. & C.A.Mey. (Rhamnaceae) in north of Iran

Rhamnus L. is the genus of Rhamnaceae in Iran with nearly eight species. These species are used as valuable shrubs. This research was carried out in order to investigate the anatomical leaf. Samples from nine populations of Rhamnus pallasii and Rhamnus cathartica were taken. Treatment specimen cover various habitats from north of Iran, moreover herbarium samples were taken into account. The results presented two forms of epidermal cells such as Polygonal and irregular cells in addition, waved and straight anti-clinical walls were observed in R. pallasii subsp. pallasii and R. pallasii subsp. sintensii. Two types of stomata were demonstrated like anemositic and parasitic in two main species. Some characters e.g. thrichome, parenchyma, collenchyma layers were determined to finding some similarity among treatment specimen

Pollen morphology of the genus Rubus L. subgenus Rubus (Rosaceae) in Iran

Pollen grains of 7 species of the genus Rubus L. were investigated using light microscopy (LM) and scanning electron microscopy (SEM). 14 different pollen characters were described, illustrated and compared in the present st-udy. All pollen grains were monad, tricolporate, radially symmetrical, isopolar, and medium in size. As for pollen sh-ape, 3 forms were recognized in the same specimens: prolate, perprolate and prolate-spheroidal. Endopore was located in the middle of colpi. The sculpture of the grains was confirmed to have striate pattern. The size of perforation and the orientation of the muri were compared and appeared to indicate the differences between the species. R.caesius, R. disc-olor, R. dolichocarpus and R. hirtus appear to have steriate-scabrate sculpture; in contrast, R. hyrcanus Juz., R. persicus Boiss. and R. sanctus Schreber. appear to have meandrical and fingerprint-like sculpture. Perforations are of two types. They are either large or often extending to tectal ridges or minute holes. Characters of pollen grains were proved their usefulness for separating taxa at the specific level. It seems that there is a link between the diversity of pollens and the vegetation habitats

Ecology of seed dormancy and germination of Carex divisa Huds.: Effects of stratification, temperature and salinity.

International audiencepermanent grassland on the French Atlantic coast. This study treated three storage regimes (wetcold, dry-cold and dry-warm), burial in soil, fluctuating temperature and salinity on seed germination of C. divisa. The seeds were dormant at maturity. No seed germinated after 2 and 6 weeks of dry storage under laboratory conditions prior to the onset of the stratification treatment. Thus, the effect of after-ripening was not evident in C. divisa. Germination rate of 11.3% started only in the wet-cold stratification treatment after 2 months. Seeds that had been stored under wet-cold conditions for 8 months had a higher germination than seeds stored under dry-cold and dry-warm treatments for the same length of time. Seeds of C. divisa tested at 10-20 °C in light had no marked dormancy cycle, but in darkness under a fluctuating temperature regime (10-20 °C), C. divisa seems to exhibit annual dormancy cycles. There were no differences in germination between fluctuating temperatures 10-20°C and 15-25 °C after 12 months in the wet-cold treatment. No germination occurred at fluctuating temperatures 0-10 °C. The highest percent germination was observed in distilled water, followed by 50 mM L-1 NaCl. The highest NaCl concentration (250 mM L-1) was found to inhibit seeds germination

Ecology of seed dormancy and germination of Carex divisa Huds.: Effects of stratification, temperature and salinity.

International audiencepermanent grassland on the French Atlantic coast. This study treated three storage regimes (wetcold, dry-cold and dry-warm), burial in soil, fluctuating temperature and salinity on seed germination of C. divisa. The seeds were dormant at maturity. No seed germinated after 2 and 6 weeks of dry storage under laboratory conditions prior to the onset of the stratification treatment. Thus, the effect of after-ripening was not evident in C. divisa. Germination rate of 11.3% started only in the wet-cold stratification treatment after 2 months. Seeds that had been stored under wet-cold conditions for 8 months had a higher germination than seeds stored under dry-cold and dry-warm treatments for the same length of time. Seeds of C. divisa tested at 10-20 °C in light had no marked dormancy cycle, but in darkness under a fluctuating temperature regime (10-20 °C), C. divisa seems to exhibit annual dormancy cycles. There were no differences in germination between fluctuating temperatures 10-20°C and 15-25 °C after 12 months in the wet-cold treatment. No germination occurred at fluctuating temperatures 0-10 °C. The highest percent germination was observed in distilled water, followed by 50 mM L-1 NaCl. The highest NaCl concentration (250 mM L-1) was found to inhibit seeds germination

Phenotypic variation and leaf fluctuating asymmetry in natural populations of Parrotia persica (Hamamelidaceae), an endemic species from the Hyrcanian forest (Iran)

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variacion fenotipica y fluctuacion de la asimetria de la hoja en una poblacion natural de parrotia persica hamamelidaceae una especie endemica del bosque hircaniano iran

Se evaluó la variación fenotípica en cuatro poblaciones naturales de Parrotia persica (Hamamelidaceae), una especie endémica considerada como un fósil viviente del bosque hircaniano, a través de un análisis morfométrico y multivariado de las hojas. Asimismo, se estudiaron la plasticidad y la asimetría foliar fluctuante (AFF). Nuestros hallazgos mostraron claramente una divergencia significativa entre sitios. El tamaño más pequeño de la lámina foliar, la plasticidad más grande y los valores más pequeños de AFF fueron registrados en los sitios más xéricos de la parte oriental (Ghorogh y Daland), por lo que parece que estos sitios están sujetos a un mayor estrés ambiental. Obtuvimos resultados interesantes, pero hace falta realizar nuevos estudios de la diversidad de aloenzimas y ADN