Microsatellite loci and peroxidase alleles correlation in somaclonal variation of Eucalyptus microtheca F. Muell

The aim of this study was to investigate the correlation between biochemical and molecular markers in Eucalyptus microtheca F. Muell. under in vitro culture. For this mean, twig-derived explants obtainedfrom Eucalyptus microtheca 1-year-old seedling were cultured on modified MS medium, supplemented with different concentrations of NAA, Kin and TDZ. POD (peroxidase) alleles patterns were studied among regenerated plantlets to investigate the effect of TDZ concentration on POD activity. A dimer locus, a tetramer locus and two epigenetic bands were observed. Genome variation among somaclonal plantlets were investigated using microsatellite markers. SSR (Simple Sequence Repeat) markers revealed polymorphism among the studied population. Nonparametric statistical analysis showed significant effect of simple sequence repeats loci on peroxidase alleles. Correlation of two similarity matrix POD and SSRs loci was 0.18 using Mental test. Results showed less stability of dimer locus indifferent concentrations of TDZ compared to tetramer locus. Tetramer alleles showed more correlation to SSRs than that of dimmer ones

Lead and Cadmium Concentrations in Throughfall of Pinus eldarica and Cupressus arizonica Plantations in a Semi-Arid Polluted Area

This research was carried out in order to quantify throughfall (TF) and interception loss (I) and to compare the chemical composition of TF, i.e. lead (Pb) and cadmium (Cd) as well as electrical conductivity (EC) and pH beneath Pinus eldarica and Cupressus arizonica plantations and the open field rainfall. The research was accomplished in the Chitgar Forest Park, a semi-arid polluted urban area, around Tehran, Iran. Gross rainfall (GR) was measured using ten collectors located in an open field. TF was quantified by randomly manual TF collectors placed beneath each plantation. Measurements were recorded on an event basis from 15 April 2010 to 15 February 2011. During the measurement, eighteen rainfall events with cumulative GR value of 114.8 mm were recorded. Interception loss was 35.3 mm by P. eldarica plantation and 30.4 mm by C. arizonica. There were strong correlations between I:GR and GR ((r2 Pinus = 0.686, r2 Cupressus = 0.766, p value ≤ 0.01). Pb and Cd concentrations as well as EC of TF were significantly different among P. eldarica and C. arizonica and the open field. The results demonstrated that interception represents a considerable portion of GR in P.eldarica and C. arizonica plantations and, therefore, it should be considered while choosing trees for plantations in semiarid climate zones of Iran. Our results showed that P.eldarica and C. arizonica plantations have good potentials for filtering the polluted air with Pb and Cd

Physiological responses of Celtis caucasica L. and Robinia pseudoacacia L. to the cadmium and lead stresses

Afforestation of contaminated areas is considered as a possible strategy for reduction of contaminations. In the present study, the effects of lead (Pb) and cadmium (Cd) were investigated on chlorophyll fluorescence parameters (Fv/Fm, Fo, and Fm), photosynthetic pigments (chlorophyll a, b, and total chlorophyll), and proline in one-year-old seedlings of Celtis caucasica and Robinia pseudoacacia. The seedlings were treated 2 times during 10 days, with different concentrations of Pb and Cd (0, 250, 500, 1000 and 2000 mg L-1). Saline solutions containing Pb and Cd were sprayed on the leaves. Chlorophyll fluorescence was measured every other day. Chlorophyll and proline were also measured at the end of experiment period. The results indicated that chlorophyll fluorescence of C. caucasica and R. pseaudoacacia was affected by Pb on the last days and by Cd on the first days. The chlorophyll a content of C. caucasica at 250 mg L-1 of Pb and the chlorophyll a of R. pseudoacacia at 1000 and 2000 mg L-1 of Cd increased. With increasing Cd and Pb concentrations, proline of C. caucasica increased significantly while proline of R. pseudoacacia was not affected by Cd and Pb. Our results suggested fairly similar photosynthetic responses of C. caucasica and R. pseudoacacia to Cd and Pb concentrations. We concluded that physiological sensitivity of the both species to Pb and Cd were weak and can be used for afforestation in semi-arid areas contaminated by Pb and Cd

Diversity of arbuscular mycorrhizal fungal spores associated with Sorbus torminalis (L.) Crantz

This study aimed to investigate the diversity and types of arbuscular mycorrhizal fungi (AMF) associated with the wild service tree, Sorbus torminalis (L.) Crantz in spring and autumn followed by identifying similarities among the different study sites. Three different sites were selected including Kheiroud, Lalis, and Tarkin, in the Hyrcanian forests, north of Iran. Five rhizosphere soil samples were collected from each site, and the spores were extracted. Based on their morphological features, five species of AMF belonging to two families, i.e., Claroideoglomeraceae (two species) and Glomeraceae (three species) were identified. The species richness of the studied sites was identical with only the Kheiroud site presenting an additional species. Glomus badium was the most common AMF species in Kheiroud and Lalis in spring and autumn. However, the most common species in Tarkin was Septoglomus constrictum. The Shannon–Wiener indices of diversity and evenness and Simpson’s index of dominance (Ds) showed no significant differences among the studied sites in the two seasons. In sum, it is recommended that the colonized wild service tree seedlings be produced with the more relevant species identified in this study than with commercial sources