Journal of Plant Biological Sciences
Year:2012 | Volume:4 | Issue:12|Papers Count:8

The concept of plant biodiversity is closely related to flora composition and is one of the important characteristics of plant communities which is always used as an index for ecological assessment of forest ecosystems. In this research, plant biodiversity in Afratakhteh Yew (Taxus baccata L.) habitat was studied by 30 sample plots (400 m2 area) with 3 times repetitions in land form units, 3 plots were taken by selective procedure in representative stand of each land forms. At each plot, plant biodiversity indices such as: richness, evenness and diversity with respect to physiographical factors were investigated. One way ANOVA, Duncan's multiple comparison tests and t-test were used to study differences among physiographical classes. The results indicated there was no significant difference between altitude and species diversity. Duncan's results showed that the average measure of richness, Diversity indexes of Shannon and Mc-Arthur and Pielou Evenness were highest towards the west. Also, the average measure of richness, the Diversity indexes of Shannon and Mc-Arthur were highest in 10 to 35% slope.

Citrus fruit has high nutritious, medical and economical values. Seediness is considered as a weakness in selecting high quality citrus fruits. Among polyploids, triploids produce seedless fruits. In order to produce triploid fruits, there must be a tetraploid plant, therefore, in this research, the production of tetraploid plant was highlighted in Citrus ourantifolia using a chemical material named colchicine through dropping method.60 days after treatment by 0.2, 0.6, 1.0 and 1.4% concentrations of colchicines, the flow cytometric investigation on treatment plants were conducted. The morphological and anatomical characteristics of tetraploid plants were investigated. Comparison of the leaves of tetraploid with diploid plants indicated that the leaves of tetraploid plants in length and width were smaller than the diploid ones. The height of tetraploid plants was reduced significantly compared with that of the diploid ones. Comparison of the density and the size of stomata and secretory sacs showed that the density of stomata and secretory sacs in tetraploid plants decreased but, the size of stomata and secretory sacs increased, significantly, compared with the diploid ones. The amounts of chlorophyll a, chlorophyll b, total chlorophyll and carotenoids in treatment plants showed no significant increase in tetraploid and diploid plants.

Studies have shown that salicylic acid (SA improves the resistance of the plant to environmental stress (heat, cold, drought and salt stress). In this research we studied the effect of salicylic acid on lipid peroxidation, sugars and the quantity of Na+, K+ ions in leaf and root of Ocimum basilicum under salinity stress. The plants were grown in pots until 4 leaf stages. Then, the leaves were sprayed with one of three concentration of salicylic acid (0, 0.01 and 0.1 mM SA) for 5 days and salt stresses at 3 levels (0, 100 and 200 mM NaCl) were treated for 5 days. Lipid peroxidation in leaf and root decreased significantly after treating with salicylic acid and salt water, but malondealdehyde increased significantly in root in 200 mM NaCl under the condition of the combination of the treatment with salicylic acid and salt water. Sugar and Na+ in leaf increased significantly with increasing salty stresses. Not only had the amount of sugar and Na+ decreased significantly under the combination of the treatment with salicylic acid and 100 mM NaCl, but also the amount of sugar increased with 200 mM NaCl in this condition. The amount of sugar and K+in root increased significantly in the condition of salinity stress with 100 mM. The combination of the treatment with salicylic acid and salt water increased significantly the amount of sugar in root under salty stresses condition. Both 100 and 200 mM NaCl, as well as the combination of the treatment with salicylic acid and salt water, decreased K+ significantly, that is, the presence of salicylic acid enhanced the effect of salinity.

The genus Artemisia (Asteraceae) with about 200-500 species, is one of the largest genus in Anthemidae. In order to study intraspecific diversity in Artemisia spicigera in the North-West of Iran, D.S.S. method was used in this research work. Eight special stations were determined using D.S.S. method for A. spicigera and floristic-ecologic data collected from each special station. In the survey of all special stations, 75 plant species were distinguished as associated species. As the result of analysis of floristic data, as floristic marker, 6 groups were determined. This groupment distinguished the existence of intraspecific diversity in A. spicigera. Analysis of ecologic data was also confirmed the above mentioned groupment.Seed storage proteins were subjected to electrophoresis to determine the level and kind of intraspecific diversity. The results were also in accordance with the results of floristic and ecological results. Existence of differences regarding number and density of the protein bands indicated the intraspecific diversity in the populations ofA. spicigera. Therefore, in this species, the groupment that introduced by floristic marker, was confirmed by ecological and electrophoresis data as well. This means that floristic groupment can only be used as a cost effective and efficient method to stud intraspecific diversity.

Flower development is a mystery and provides a useful means for understanding cell differentiation and genetic mechanisms needed for organogenesis. Tajetes patula is an annual herbaceous ornamental species belonging to the family Asteraceae. In this study, the structure and development of inflorescence, flower and pollen grains and their characteristics related to pollination were assayed. The inflorescence was capitulum in which involucral bracts primordial were subtend inflorescence meristem and then floret primordial was initiated centripetally on flatten generative meristem. A dimple appeared on the top of floret primordium, and a corolla was produced first. Inside the developing corolla 5 staminata primordial and two-lobed pistillata primordium arise. Five staminata primordia surrounded the pistillata primordium.Gynomonoecious inflorescence consisted of high number of fertile bisexual tubular florets and sterile female ray florets. Both florets consisted of small bract like sepals, inferior ovary, bifid stigmas containing numerous papillate cells and single styles which were of the closed type with a filled stylar canal. The anthers were synatherous, tapetal layer was of secretory type firstly but finally its cells enter the anther locule and was converted to amoeboideus type. The endothecium was fibrous and anther dehiscence was longitudinal and extrose. Cytokinesis was simultaneous and mature pollen grains were yellowish, 31u m in diameter, triapertures (tricolporate) and echinate with small pores in base. Fruit was elongated and black achen. Traits such as the formation of capitulum inflorescence, its color, secretory (papillate) epidermis on the adaxial surface of petals, color and sculpture (echinate) of pollen grains, grown and bifid stigmata attract insects as pollinators and improves pollination.

The seeds of two salt sensitive (Y3000 and Hayola 420) and relatively salt tolerant cultivars of canola were cultivated as a completely randomized block in a split plot. The experiment was conducted in Haji Abad village, Qom, Iran. Salicylic acid (SA) treatment was carried out with 0, 0.5 and 1.0 mM of SA solution in the early morning when the plants fourth leaf completely expanded. The samples were taken at 130 (vegetative phase), 160 (flowering phase) and 190 (harvesting phase) days after germination for analysis. The growth parameters of Hayola 420 was more affected by SA treatment, whereas 1000 seed weight increased much more in Y3000 SA did not influence carotenoids content in the treated plants. A significant increase in chlorophyll content was observed in Y3000 by the level of 0.5 mM SA, however in Hayola 420, the level of 1.0 mM SA was the most effective. Proline content tended to increase in SA treated plants but no significant difference was observed as compared with the control plants. MDA content decreased significantly in Hayola 420. SA application reduced Na+ and K+ content in roots and leaves of Y3000 respectively. In contrast, the level of Na+ was increased in leaves and decreased in roots. SA by the level of 0.5 mM increased the rate of Na+ and K+ in Hayola 420. In brief, the level of 0.5 mM SA was the most effective level and its application reduced the damaging action of salinity on canola plants especially in Hayola 420.

Taxol is one of the most important anti-cancer drugs and is obtained from yew (Taxus sp.). Currently, plant cell culture is counted as one of the most important methods to obtain taxol across the world. In this context, determining optimum composition of the medium to acheive maximum growth and productivity is particularly important. This study was carried out to investigate and determine the best basal medium for production of taxol from taxus cell culture. For this purpose, four different basal medium including WPM, B5, MS, and SH containing similar hormonal compounds of 2 mg/l NAA, 0.2 mg/l 2, 4-D, and 0.2 mg/l Kinetin were tested and the produced taxol during 21 days period were analyzed by HPLC. Significant difference was observed between different mediums with respect to the total amounts of produced taxol. The maximum yield of taxol (16.58 mg/l) was achieved from WPM medium. Afterward, the highest amounts of taxol were 8.66, 6.42 and 5.82 mg/l that were obtained from MS, B5, and SH mediums respectively. Significant difference also was observed between different mediums with respect to the amounts of produced taxol secreted from the cells into mediums that were 7.68, 4.28, 3.59 and 3.31 mg/l taxol respectively for WPM, B5, SH, and MS mediums. These amounts included 46, 67, 62 respectively and 38% of the total volume of produced taxol in the mediums. According to the results, it could be concluded that the basal medium not only affect the taxol yield but significantly affect on the amounts of taxol secreted from the cells.