فصلنامه زیست شناسی گیاهی ایران
سال دوازدهم شماره 3 (پیاپی 45، پاییز 1399)

Most of Lorestan is mountainous. Precipitation in the mountainous areas of the province is mostly snow (750 to 950 mm). Snow plays a role as a natural reservoir. Its gradual melting has led to the emergence of humid areas and the presence of more plants in mountainous areas. In this study, habitat factors of 5 mountainous sites of Lorestan province were identified and investigated. The collected parameters were analyzed by GGE biplot software. The results show that water regime, substrate and the EC have the greatest effect on the distribution of the species, pH did not show significant differences in habitats. The most ideal habitat is the Sumach Valley, and the Nozian are closer to ideal conditions. By identifying the super environments and their subdivisions, there are two distinct groups of wet mountainous areas: Wet mountainous areas above the timberline (Garin, Oshterankouh and Rimeleh highlands) and wet mountainous areas below the timberline (Neujian and Samag Chegeni Valley). In the region above the timberline, Iranian-Turanian elements have the highest proportion. The plant species of this group of wet mountainous areas are highly dependent on the cold and humidity of the snowfalls. The ecosystems in which they live are often very limited, fragile, small, and isolated. Due to the effects of climate warming and intensive grazing in highlands, they need strong conservation management and maintenance.

Saffron is the most perennial plant species considered as valuable medicinal and aromatic plant worldwide. Dried stigmas (saffron) of Crocus sativus is commonly used as a flavor, food coloring and a drug and comprises several beta carotenes including a yellow pigment Crocins, a bitter-tasting substance Picrocrocin and a good perfume Safranal which not only exerts a hypoglycemic effect but also expressions antioxidant and anti-inflammatory properties. this study evaluated the effect of PEG 6000 on some secondary metabolite content and morphophysiological traits. The results showed that the highest and lowest levels of proline, relative water content, hydrogen peroxide and chlorophyll a, b and total pigments were obtained in 12% polyethylene glycol treatment and control treatment, respectively. The highest content of Crocins, Picrocrocin and Crocetin were obtained using PEG 12% by 29.04%,24.17% and 0.04% respectively. The highest and lowest IC50 inhibitory potency was observed in 12% polyethylene glycol and control treatments, respectively. The optimum enzyme activity (unit/mg) of superoxide dismutase, catalase and Ascorbate peroxidase were also triggered by the application of PEG 12%. The results of the present study showed that the application of polyethylene glycol elicitor improves the content of important secondary metabolites and morphophysiological characteristics of saffron plant and this solution can be suggested to increase the economic productivity of saffron.

Paspalum is one the largest genera of Poaceae in tropical and subtropical habitats from sandy coastal zone to salt marshes. In Iran, there is only two species mainly distributed in southern coasts of the Caspian Sea. These are cold and flood resistant plants and are cultivated as turf grass. The flooding and drought caused some anatomical modifications in this genus. In this project, for the first time in Iran, Paspalum is studied morphologically, micro-morphologically and anatomically. Studies were done on 11 natural accessions by use of qualitative and quantitative features. Multivariate statistical analyses including principle component analysis (PCA) and cluster analysis by WARD method were done. Leaf, lemma and palea studies by scanning electron microscope showed salt galnds on dorsal epidermis. Results of this study showed that selected morphological and anatomical features are capable of species separation.

Several studies have been conducted focusing on antioxidant capacity of medicinal plants; however information is lacking on the daily rhythm of antioxidant capacity as well as photochemical reactions in medicinal plants under natural conditions. Thus, in this study, changes in phenolic acids, PSII functioning and antioxidant enzymes activities in response to low (1,100 m) and high (2,200 m) elevation sites in Marrubium vulgare L. were investigated. Plants were harvested and analyzed in a temporal manner; and for the latter analysis, leaf samples were frozen immediately in liquid N2 and stored in it until assay. High-altitude plants exhibited higher phenolics and carotenoids than that in low-altitude plants, which was associated with higher phenylalanine ammonia-lyase (PAL) activity. Results indicated that the absolute amounts of antioxidant enzymes activities were considerably greater in high-altitude plants than low-altitude plants. High-altitude plants showed the rapidly reversible inhibition of PSII reaction centers (dynamic photoinhibition) associated with an increase in non-photochemical rate constant (kN), which was important photoprotection mechanism under high-mountain conditions. Surprisingly, the activities of antioxidative enzymes, the accumulation of hydrogen peroxide (H2O2), & the free radical scavenging activities using DPPH radical-scavenging in the leaves of high-altitude plants showed diurnal rhythm during the course of day. Finally, we found that the ability of dynamic photoinhibition was an important photoprotection process during periods of high solar radiation in the high-altitude Marrubium vulgare plants.

This study aimed to investigate the effect of different levels of sodium fluoride stress on germination and early seedling growth stages of Rumex seeds was conducted in a completely randomized design. The results showed that germination percentage was significant at 5% probability level, but germination rate was not significant. Plumule and radicle length, fresh weight of plumule and radicle, radicle and plumule dry weight were significant at the 5 percent level. Stress caused by sodium fluoride affects the germination of Rumex and seeds are sensitive to sodium fluoride. In the morphological study, harmful effects of sodium fluoride as necrosis, chlorosis, and wounds in the leaf, premature aging and wilting treated plants were observed. In roots and petioles, by increasing the concentration of sodium fluoride up to 0.5 mg L-1, the thickness of the xylem and phloem decreased and increased with increasing concentration due to plant consistency. By increasing the concentration of sodium fluoride to 0.5 mg L-1, the thickness of the xylem and phloem of root and petiole thickness decreased and with increasing the concentration of sodium fluoride due to plant adaptation increased. Also, by increasing the levels of sodium fluoride concentration to 0.5 mg L-1 sodium fluoride, the thickness of the mesophilic and total leaf thickness decreased and then increased with increasing sodium fluoride concentration, which can be said decrease the leaf thickness due to increasing of fluoride due to reducing plant ability in the absorption of water leads to reduced growth.

In order to study the effect of uniconazole and bio fertilizers on activity of some antioxidant enzymes and compatible osmolites of wheat (Triticum aestivum L var Zagros.) in soil salinity conditions, a factorial experiment was conducted based on randomized complete block design with three replications in a research greenhouse of the Faculty of Agriculture and Natural Resources of Mohaghegh Ardebili University in 2018. Treatments were included soil salinity in four levels (no application of salinity as control and application of 40, 80 and 120 mM soil salinity), by NaCl and application of uniconazole, mycorrhiza fungi (Glomus intraradicese) and pseudomonas putida strain 186 in seven levels. Means comparision showed that both application of mycorrhiza with uniconazole and pseudomonas under 120 mM salinity increased soluble sugars and proline contents, antioxidant enzymes activity such as catalase, peroxidase polyphenol oxidase (93.98, 47.33, 63.88, 75.67, 69.35% respectively) in comparison with no application of bio fertilizers under without salinity. Also, both application of mycorrhiza with uniconazole and pseudomonas under without salinity increased leaf proteine, plant height and grain yield (72.36, 41.85 and 108.84% respectively) and decreased electrolyte leakage (39.02%) in comparison with application of bio fertilizers under at the highest soil salinity level. It seems that the mentioned bio-fertilizers and uniconazole application can increase grain yield of wheat due to improve biochemical and physiological traits of wheat under soil salinity condition.