فصلنامه زیست شناسی گیاهی ایران
سال دوم شماره 4 (پیاپی 6، زمستان 1389)

Wild Pistachio is one of the most important trees in Zagros forests. The resistance of P. atlantica to drought, salinity and cold makes this species suitable for reforestation in arid and semiarid zones and also for water and soil conservation. In this research, protein pattern of three populations of P. atlantica Desf. was studied. After extraction of seed storage proteins, concentration of proteins was identified by Bradford method and banding pattern of the populations was determined by SDS-PAGE technique. Average protein concentration of populations was 13.08 percent. Based on the analysis of variance, significant differences were observed among populations for protein percentage. In order to analysis electrophoresis data, presence and absence of the protein bands were scored as one and zero, respectively. Furthermore, the total distances of the bands of each genotype from the beginning point on the gel were summed to get the cumulative distances as a characteristic of each profile. Cluster analysis was performed on the data matrix using SPSS software. Twenty one protein bands were observed in the studied populations. Baneh population showed the highest number of protein bands while Salmas population showed the lowest number. Although the cluster analysis was not able to separate the populations completely it could partly locate the three populations in different groups.

In this research, developmental stages of ovule and pollen grains of Inula aucheriana were studied. The flowers and buds, in different developmental stages, were removed, fixed in FAA70, stored in 70% ethanol, embedded in paraffin and then sliced at 7-10 µm by microtome. Staining was carried out with PAS and contrasted with Hematoxylin. The results indicated that anthers were tetra-sporangiate and anther tapetum type was as secretory type one. Pollen tetrads were tetragonal. Pollen grains, when shed had three colpes and needles on the surface. Ovule was anatropous, unitegumic and tenuinucellate. Endothelium was uni-seriate. Endothelium layer was composed of monolayer cells. Embryo sac development was of monosporic and Polygonum type. The shape of megaspore tetrads was both tetrahedral and T-form. Functional megaspore was the chalazal one. Embryo sac was very small at the beginning of development, so that their nuclei were arranged as linear, but its size was increased in later of development. Antipodal nuclei were massive and exhibited polyploidy. Results of this research showed the presence of needle formed crystals in the epidermal cells of ovary that was species specific characteristic. On the outer surface of ovary long, filamentous and one-celled trichoms were visible.

Ultraviolet radiation is a part of sunlight spectrum and is divided into three bands A, B, and C, due to the wavelength. Plants which are incapable of movements, protect themselves against this kind of radiation, by two enzymatic and non-enzymatic mechanisms. These mechanisms can be used in order to increase medicinal products. In This study, the effects of different UV-B dosages (application of different post harvest illumination durations; 1, 2 and 4 hours) on the content of some antioxidant compounds (i.e., flavonoids, anthocyanin, total phenolic and lecopene contents), activity of PAL and total protein of ripe red tomato fruit (Lycopersicon esculentum Mill.) were studied. The amount of flavonoids increased in comparison with the control, in all treatments. The changes of anthocyanin content was similar to that of the flavonoids. UV treatment of 2 and 4 hours increased total phenolic compounds. Similar results were observed in lycopene content under UV-B. This radiation increased PAL activity, but decreased protein content. Thus, it is concluded that exposure of tomato fruit to UV-B increased antioxidant compounds.

In this investigation, meiotic behavior, morphological and pollen morphological characters of 4 populations belonging to A. macrostachys DC. of Astragalus sect. Malacothrix Bunge in Iran were studied. Results showed that 3 populations were diploid and represented 2n=2x=16 chromosome number and the only tetraploid population showed 2n=4x=32 chromosome number. Although the taxa represented regular bivalent pairing at meiosis, some abnormalities such as laggard and fragmented chromosomes in anaphase/telophase I, II and diakinesis/methaphase I, cytomixis in anaphase/telophase I, II, multipolar cells in telophase II, binuclei cells in prophase I and bridges in anaphase I and telophase II were observed. Data analysis from meiotic study of four populations in the species using UPGMA and PCO methods showed that, in the taxa studied, there were two main groups.

One of the effects of reducing water levels in soil is reduction of in growth and development of seedlings. It is found that seed priming improves some properties of seed and seedling and the next plants. The effect of seed priming by salicylic acid on some properties of rapeseed cv. RGS300 in early growth stages under water shortage conditions was evaluated. Factorial experiment in completely randomized design was performed. The treatments were soil moisture in field capacity (control) and 70% and 50% field capacity and priming with SA at zero, 750, 1500 and 2250 µM levels. The results showed that the priming effects by SA on percent of emergence, emergence index, fresh and dry weight of seedling leaves, leaf and cotyledon area, mean emergence time (MTE), time speared of emergence (TSE), shoot length and specific leaf weight (SLW) were significant and the highest emergence percentage, emergence index, fresh and dry weight of seedling leaves, leaf and cotyledons area, plant height, SLW and lowest MTE and TSE were found to be 1500 µM concentrations of salicylic acid. In fact, SA through reducing days of planting to uniform emergence of seeds and inducing vigourius seedlings could lead to maximize the amount of dry weight of seedlings. Also, results showed the lowest values observed in non primed seeds and treated seeds with 750 µM SA concentrations. Leaf number affected only by soil water levels and priming by SA had not any effects on this character.

The Chickpea (Cicer arietinum L.) is a particularly important crop in semi-arid and arid regions of world and is highly sensitive to salinity stress. Recently, priming of seed has been reported to be a simple technique for enhancing seedling establishment and crop production under stressed conditions. In this study, the changes in percentage and speed of germination and growth parameters in osmo (mannitol 4%) and hydro (water) primed chickpea seedlings under salt treatment (0, 25, 50 and 75 mM) were investigated. Results showed that compared to controls, salinity caused the reduction of speed and percentage germination of seeds, length, fresh and dry weights of shoots and roots of plants. In general, a salt dose- dependent decrease was observed in nodule number seedlings. Data on the effect of water and mannitol (4%) priming of chickpea seeds (12h at 25˚c) showed higher number of nodules in osmopriming seed compared to hydro priming and control seeds. Seedlings obtained from primed seeds with mannitol (osmopriming) and water (hydropriming) showed more growth with respect to fresh and dry weights root and shoot in comparison with seedling obtained from non-primed seeds under salinity stress conditions.

Cadmium is a non-essential divalent heavy metal cation. The toxic level of Cd may be caused by natural soil charscteristics or by human activity. Cd has been shown to cause many morphological, physiological, biochemical and structural changes in growing plants. Meanwhile, some plant species can grow in Cd-contaminated soil and are able to uptake and accumulate this element in their tissues. Matthiola chenopodiifolia, is a plant that is able to grow in heavy metals contaminated soils in Irankouh mining area. In this study, in order to determine the potentiality of this plant to accumulate of Cd, it was grown under different concentration of Cd in laboratory conditions. The seeds of M. chenopodiifolia were collected from plants grown on contaminated soils (Irankouh) and uncontaminated soils (Soffeh) around Isfahan. Plants were grown in hydroponic system with modified Hoagland nutrient solution for 10 days. Then, the plants were treated with Cd concentrations of 0, 2.5, 5, 10, 20, 30 and 40 ppm for 24 days. Results showed that the root and shoot dry weight in both populations were decreased with increasing concentration of cadmium. Also root tolerance index in both populations significantly decreased (P<0.05). In addition, both populations of M. chenopodiifolia were able to accumulate cadmium in their roots and shoots under all concentration of Cd. Uptake and accumulation of Cd were increased by increasing Cd concentration. Also, both populations had no significant differences in response to Cd, therefore, M. chenopodiifolia had an innate tolerance to Cd and was a very useful plant for phytoremediating of Cd from contaminated soils.