نشریه علوم پایه
سال بیست و یکم شماره 2 (1387)

The effect of fruit maturity (immature green, mature green, turning red or red, ripe fruits) on the seed germination of tomato (cvs.‘Norma’ and ‘Falkato’) were investigated for plants growing in hydroponic culture. Manual extraction from fruit pulp was done and seeds were washed. Experiment was arranged in a completely randomized design (in factorial arrangement)with four replicates, each plot consisting of 100 seeds. Means were compared using LSD test (P< 0.05). Seeds from immature green fruits gave the lowest germination whereas harvesting of fruits at the turning red and ripe stages recorded the highest seed germination. Speed of germination (mean time of germination and rate of germination) increased with increasing maturity. Speed and rate of germination (means of days for germination) were superior in seeds extracted from fruits harvested at the turning red or ripe stages. It was concluded that seeds with the best germination potential could be extracted from turning red or red fruits. Fruit maturity caused changes in fruit juice pH that probably affected the seeds germination.

Polypogon genus comprises weed grass which are also efficient in soil remediation. This Mediterranean element is recognized with four species in Iran. P. fugax and P. monspeliensis are two morphologically similar species with a lot of difficulties in species recognition. In this project 12 accessions of these two species are gathered and studied from different parts of Iran. Qualitative and quantitative morphological characters and leaf dorsal epidermis were studied. Results of statistical analysis revealed that with studied characters set these two species are clearly separated from each other. Lemma apex status, Translucant Hairs on lower third of lemma, lemma texture, hairs of dorsal epidermis, caryopsis shape and its groove are of great diagnostic importance in these species. Some anatomical features like subsidiaries shape and long cells between stomata are distinctive in these two species.

H. pylori infects more than half of the world-population. Infection can be detected by the invasive and non-invasive methods and serological detection of the specific-antibodies is the easiest. Our purpose was to evaluate the rates of infection in 98 students (aged 19-27) and in 29 employees (aged 19-27) at Alzahra-University. Sera was collected one-day before the test and a questionnaire based in presence of recurrent abdominal-pain, history of infection and/or treatment, gastric or duodenal ulcer in them as well in their families was prepared. Anti-H. pylori IgG, were detected using a commercial kit (Pishtaz-teb, Iran) and the results were classified as negative, intermediate, and positive from (+) to (+++). The rates of total positive, intermediate, and negative was 30%, 27% and 43% respectively, but the higher positive-rate (59%) was found for the employees. No global relationship was observed between positivity of the test and clinical symptoms; the rates of non-symptomatic positives was higher in two groups. Thirty-two percent of the employee group and 5% of the student group had the history of infection and/or treatment and 34% of the student had the symptoms in their family, of which 22% were the H. Pylori-positive ones. A history of gastrointestinal-cancer in the family have been noted for 15% of the students of which 8% were the H. pylori-positives. So development of gastro-duodenal cancer related to H. pylori can be prevented by eradication of infection.

In this research we describe three methods of saponin extraction from wild Cyclamen coum. This chemical compounds were extracted from dried powder of tubers under reflux by soxelet in a fractionation method with three different solvent systems and introduced best extraction method among them. The results showed that use of various solvents such as ethanol, diethyl ether, n-butanol, petroleum ether, methanol and chloroform are significant effects on remove artifact compounds and increasing isolation of the saponins from cyclamen tubers. In the first, saponin content of the 15 fractions which obtained during three methods was determined at 473 nm. By the first method (with ethanol, diethyl ether and n-Buthanol solvent, respectively) extracted the highest percentage of saponins (7.8%) without artifact compounds. Therefore, it was the best choice for saponin extraction from Cyclamen coum tuber. Also, TLC was performed for isolation of the saponin components. The results showed 7 saponin spots, a spot with Rƒ = 0.48 was major saponin compound of Cyclamen coum.

Avena fatua is one of the widespread weeds in wheat farms, and influences wheat growth and yield by means of water and mineral elements uptake. Phenolic acids are the main allelopathic compounds of wheat that affect germination, growth and development of another plant. The present study was conducted to investigation the effect of vanilic, syringic and m-coumaric acid with 0, 1, 3 and 5 mM against Avena fatua in order to study biological control of Avena fatua. Seed germination, seedling growth rate, photosynthetic pigments amount, reducing sugars, polysacarides and proteins contents were studied. A negative relationship was detected between seedling growth and the increasing phenolic acid concentration. By increasing phenolic acid levels, percentage of seed germination,shoot and root length, fresh and dry weight, carotenoid and chlorophyll content reduced. phenolic acids increased shoot and root proteins content. The influence of phenolic acids on reducing sugars and polysacarides were different and the reduction was significant with 5mM vanilic acid.

Cross sections of petioles in 10 species of Vicia L. belonging to sections Variegata, Cracca and Ervum were studied to circumscribe natural groups within the sections and determining the species relationships. The following characters were informative: shape and diameter of the cross section as a whole, number, size and diameter of vascular bundles, diameter of scleranchymatous vascular bundle sheath, the number of collenchymas layer under the epidermis and the number of cell layers in the pith. These characters confirmed the situation of the species within the sections. Our results show the petiole anatomy is useful in circumscribing the species and can be used along with morphological characters to distinguish the species groups, sections and species relationships.

In this work 18 genotypes of Iranian Pomegranate (Punica granatum) were studied. Twelve quantitative and qualitative morphological trait considered. In hierarchical cluster analysis, based on Ward’s method, genotypes were clustered into four groups based on the similarity of coefficients. In factor analysis of traits, four independent factors explained 75% of total variation in data and confirmed cluster analysis. The results of morphological and molcular markers (SSR) data indicated there is no significant correlation (0.22), between these data. The results can be considerd in future programs for improvement and conservation of Iranian Pomegranate.