Iranian Journal of Rangelands and Forests Plant Breeding and Genetic Research
Year:2003 | Volume:11 | Issue:4|Papers Count:9

For investigation of asexual regeneration in different genotypes of Thuja orientalis, apical buds from adult trees from Gorgan (genotype 1) and Ghazvin (genotype 2) were collected in autumn. The best method for sterilizing of buds was cleaning and brushing of buds with tween and %70 ethanol solution as the pretreatment and sterilizing of buds was dipping in %70 ethanol for 1 minute and cleaning with %0.1 HgCl2 solutions in different times (7 minutes for Genotype 1, 9 minutes for Genotype 2). The suitable medium for establishment was MS with 0.5 mg/l 2ip. Established explants were subcultured in (MS -DKW) medium with 2ip, BA (0.5 and 1 mg/l) + IBA (0.01 mg/l). The rate of shoot regeneration on MS was higher than DKW medium for each of two genotypes. Genotype 1 showed highest proliferation in the same condition. The best medium for shoot regeneration was MS with 1 mg/l 2ip, 0.01 mg/l IBA for genotype 1. DKW medium had better effect than MS medium on elongation in both genotypes.

Nine populations of Festuca arundinacea were investigated in this study. SDS-PAGE method of electrophoresis was employed to perform the study. After extracting the seed storage proteins and running on acrilamide gel, protein bands variation was assessed. At first, different bands locations were recognized on the gel, then presence or absence of the bands for each population and their density were compared.Twenty two protein band locations were observed on the gel. The number of bands in an exotic population named A2210 was more than others. A population collected from Sanandaj had the least in this regard. The results of cluster analysis divided the Pcopulations to two groups. In the grouping, the exotic populations were 106ated in a separate distinct group which indicated their common origin. The most genetic distance was observed between a population from Gorgan and an exotic population.

In cytogenetic studies, preparing well scattered chromosomes within mitotic cells in microscopic specimens for a high resolution is always a bottle neck for cytologists. To overcome this problem, snail digestive system exudates was used instead of commercial enzymes which are routinely used in order to digest the mitotic cell organelles for preparing transparent mitoticcells. This was done to investigate the possibility of substitution of an endemic and easily accessible tool for the commercial enzyme. To extract the exudates, snails were collected from Arasbaran forests and the digestivesystem exudates were extracted. The exudates were centrifuged for 30 minutes at 4000 RPM and the supernatants were kept at zero degree centigrade. In microscopic studies on the species of Agropyron tauri the exudates was applied on root meristem after pretreatment, hydrolyze and staining processes which caused a uniform scattering of the chromosomes on the mitotic cell plate.

Artemisia spp. from Asteraceae (Compositae) family with 34 species is one of the most important genus in Iran. Expantion, Abundance and similarity of Artemisia species cause problems for their identification. They are distributed from caspian area to Jebale Barez mountains. This feature is observed in Artemisia species, evidently. Chromosome numbers of five Artemisia species (A. annua L.,A. scoparia Waldst & Kit, A. spicigera C.Koch, A. vulgaris L., A. absinthium L.) from north of Iran were counted in this research. The specimens collected from different altitudes. The base chromosome number of them x=8 and x=9. The results showed A. annua: 2n=2x=18, A. scoparia: 2n=2x=16, A. spicigera: 2n=4x=36, A. vulgaris: 2n=2x=16,A. absinthium: 2n=2x=18.

Karyotyp of eight species of salsola was studied using mitotic cell of root tip meristems, studied species were Snitraria, Scrassa, Sdendroides, Stomentosa, Srichteri, Srigida, S.Kali, S.incanescens. Considering the chromosome numbers, they were classified to four groups: 2n=2x=18 (4 species), 2n=4x=36 (2 species), 2n=6x=54 (l species) and 2n=8x=72 (l species). In addition, genome analysis including total lengh of chromosomes, long and short arm length, long to short arm length ratio, were determined. Using levan's method, the karyotypic characteristics of the species were identified.

In order to determine the reaction of six sainfoin species to drought stress, an experiment was conducted in a randomized complete blocks design as factorial with four replications in 2002. Experimental treatments were included of six sainfoin species (O. viciaefolia, O. aucheri ssp. Psamophilla, O. melanotricha, O. aucheri ssp. Teheranica, O. crista-galli and 0. sojakii) and four drought levels (0, -0.3, -0.7 and -1.1 MPa), that drought levels were made by polyethylene glycol 6000 (PEG) solutions. Total weight of seedlings, germination percentage, height of radicle and hypocotyle of control and stressed seedlings were analysed. The results showed that the effect of water stress was significant on all traits. There were significant differences between species. The highest germination rate was related to 0. crista - galli species. In general, It could be concluded that O. aucherissp. psamophilla was the most sensitive species to the water stress.