Two types of constitutive heterochromatin in the chromosomes of some Fritillaria species

A Giemsa banding technique has been used to study C-banding in mitotic chromosomes in root tips of Fritillaria graeca, F. crassifolia and F. rhodocanakis, all diploids (2n=24) belonging to the graeca group. In the first two the C-bands were of two types, diverging in respect of staining regularly and specifically within chromosomes. In one type it was weak, being intermediate between that of intensely stained ones, representing the other class, and the euchromatin. In F. graeca the pale bands were proximally localized and confined to 5 pairs, whereas in F. crassifolia they occurred only in the 4 M chromosomes, in each within the centromeric constriction as a large inclusion. The interphase nuclei of both species contained pale and heavily stained chromocentres. No pale ones occurred in such nuclei of F. rhodocanakis. The probability is discussed that the two classes of C-band represent distinct types of heterochromatin, differing both in respect of condensation throughout the whole mitotic cycle and in the repetitive DNA sequences they most likely contain. In all 3 species pairs of Giemsa-positive centromeric dots, representing the centromeres, were masked both by proximally or centromerically localized bands, irrespective of the class of heterochromatin they represented.     

Cytogenetic study of certain Tilia species]

The number of chromosomes, and mitosis and microsporogenesis were studied in Tilia europaea, T. tomentosa, T. cordata and T. platyphyllos under natural conditions of Voronezh region. Significant mixoploidy of meristematic tissue cells in seedling root tips, mitotic activity and meiosis have been demonstrated for the first time. The number of chromosomes in somatic cells varied from 28 to 140-146. The number 2n = 82 was modal for all the studied species. The number of chromosomes in T. europaea has been determined for the first time. The numbers of chromosomes in the genus Tilia are analysed on the basis of the literature and our own data. The peak of mitotic activity in seedlings and juvenile leaves (8-10%) fell on the night: 0-1 a.m. according to the winter time. Microsporogenesis is simultaneous and asynchronous. In some individual trees various abnormalities of meiosis were found: lagging in time in 1 to 5-6 chromosomes, bridges, fusions of spindles. Variations in pollen dimensions, shape and pore number were detected in many trees.     

Antimicrobial activity of some Salvia species essential oils from Iran

The aerial parts of Salvia multicaulis, S. sclarea and S. verticillata were collected at full flowering stage. The essential oils were isolated by hydrodistillation and analyzed by combination of capillary GC and GC-MS. The in vitro antimicrobial activity of the essential oils were studied against eight Gram-positive and Gram-negative bacteria (Bacillus subtilis, Bacillus pumulis, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Klebsiella pneumoniae) and three fungi (Candida albicans, Saccharomyces cerevisiae and Aspergillus niger). The results of antibacterial activity tests of the essential oils according to the disc diffusion method and MIC values indicated that all the samples have moderate to high inhibitory activity against the tested bacteria except for P. aeruginosa which was totally resistant. In contrast to antibacterial activity, the oils exhibited no or slight antifungal property, in which only the oil of S. multicaulis showed weak activity against two tested yeasts, C. albicans and S. cerevisiae.     

New chromosome counts in some species of Asteraceae from Iran

Seven chromosome counts of six species from the family Asteraceae are reported. All taxa were collected from Hamedan province, Iran. One count is a new report (viz Inula aucheriana ), three are not in accordance with previous counts (viz Senecio glaucus, Tanacetum chiliophyllum and Tanacetum polycephalum ) and the others (viz Tripleurospermum disciforme, Tanacetum polycephalum , T. parthenium ) are confirmations of very limited (one to eight records) previous data. Most of the studied taxa have the basic number x=9, but Senecio glaucus has x = 10, with ploidy levels ranging from 2x to 8x. Both diploidy and triploidy were found in T. chiliophyllum and may be regarded as a sign of ongoing speciation.     

Cytology and morphometry study of Alhagi (Leguminosae) species in Iran

Karyotypic and morphometric studies were performed on Alhagi species and populations. Morphometric analyses revealed the occurrence of two species in Iran. Both species possessed 2n = 16 chromosome number. Inter-population and inter-specific variation was observed in karyotypic features indicating that such data are not useful in taxonomy of the Alhagi species.     

Cytogenetic comparison of N-genome Aegilops L. species

Differential C-banding and in situ hybridization were employed in a cytogenetic comparison of thee N-genome Aegilops species: diploid Ae. uniaristata, tetraploid Ae. ventricosa, and hexaploid Ae. recta. The formation of Ae. recta was shown to involve only minor functional modifications of the parental genomes, while intraspecific divergence was accompanied by large genome rearrangements, namely, translocations involving the total chromosome arms of all of the three genomes. The formation of tetraploid Ae. ventricosa involved substantial structural chromosome rearrangements, including a partial deletion of the short arm of chromosome 5D, including the nucleolus-organizing region; a redistribution of C bands on chromosomes of the D and N genomes along with a reduction of the heterochromatin content; and a considerable decrease in the hybridization intensity of the pAs1 repeat. Chromosomes of the Ae. ventricosa D genome were more similar to chromosomes of the Ae. crassa D1 genome than to Ae. tauschii chromosomes.     

Karyotaxonomic study of some species ofPeucedanum (Umbelliferae)

A study of morphometric karyotype characters was carried out in 14 species ofPeucedanum s. lat. (Umbelliferae — Apioideae) and in one species of the related genusLomatium. The differences of the species in their karyotype characters are correlated only to a limited degree with their similarities of dissimilarities in morphological (i. a. carpological) characters, and thus with their taxonomic position. The evolution of these two sets of characters seems to have proceeded not synchronously or even in different directions in the group of platycarpousUmbelliferae united in the genusPeucedanum. Therefore, it is unlikely that morphometric chromosome characters revealed by monochrome staining can be used appropriately in the taxonomic revision of the polymorphous genusPeucedanum.     

Numerical taxonomy of some charophytes in Iran

Morphological characters of 10 species of Chara from different localities in northern, western and central Iran have been analyzed, with Nitella hyalina and Tolypella glomerata as outgroups. Phenetic and cladistics analyses of populations belonging to the 10 Chara species were undertaken to reveal their inter‐population morphological variation and inter‐specific relationships. Clustering was based on 54 characters (41 qualitative and 13 quantitative). This produced two major clusters, grouping Chara crassicauliss, C. vulgaris var. longibracteata, C. vulgaris var. vulgaris and C. contraria separate from C. grovesii, C. gymnophylla var. gymnophylla, C. gymnophylla var. rohlenae, C. kirghisorum and C. tomentosa. A smaller cluster of C. socotrensioides, C. fibrosa and Chara sp. was separate from these two clusters. A factor analysis identified the most variable morphological characters as type of cortification, prescence and length of the spine cells, stipulode length, type of branchlet cortication, bract cells length, placement of the gametangia, character of end segment, length of branchlet and internode, development of posterior bract cells, oogonia length and width, oospore length, width and length/width ratio, fossa breath, and number of striae.     

Cytogenetic study of Hapalemur aureus

The karyotype of Hapalemur aureus was compared with those of other Hapalemur species, allowing us to determine the phylogenetic position of this species on the evolutionary tree of the Lemuridae.     

Karyological studies in Hyoscyamus species of Iran

Karyological studies were performed on Hyoscyamus species of Iran. The species studied showed variation with regard to chromosome number and details of karyotype. Two different basic chromosome numbers of x=14 and 17 were recorded for the genus corresponding to the two subgenera of Hyoscyamus . Chromosome numbers of six species are reported for the first time.     

The genus Chaetomium in Iran, a phylogenetic study including six new species

Twenty-one species of Chaetomium known from Iran were compared on the basis of morphological and molecular characters. Six new species are recognized, five isolated from cereals and one from nematode cysts. A combined sequence dataset of the ITS region, partial LSU rDNA, and β-tubulin gene sufficiently resolved five species groups of Chaetomium that are largely concordant with combined features of peridium structure, ascospore shape and germ pore position. Among the new species C. undulatulum is a close relative of C. globosum, C. rectangulare is close to C. elatum, C. interruptum and C. grande are close to C. megalocarpum, altogether forming the C. globosum species group. Chaetomium iranianum and C. truncatulum are members of the C. carinthiacum species group, characterized by spirally coiled ascomatal hairs and fusiform ascospores. A chrysosporium-like anamorph is newly described for C. acropullum.