فصلنامه زیست شناسی گیاهی ایران
سال چهاردهم شماره 4 (پیاپی 54، زمستان 1401)

In this study, the effect of salicylic acid and sodium nitroprusside on the toxicity of zinc oxide nanoparticles (ZnONPs) and zinc sulfate (ZnSO4) in Phlomis tuberosa was investigated. The purpose of this research was to investigate new methods of increasing the tolerance threshold of Phlomis plants under the influence of zinc oxide and zinc sulfate nanoparticles toxicity. This experiment was conducted in the form of a completely randomized design with three replications in the form of pot cultivation in a perlite bed, and the plants were harvested after 21 days of treatment. The measured factors included total chlorophyll, carotenoid, total phenol, flavonoid, the activity of phenylalanine ammonia lyase, catalase, superoxide dismutase, and ascorbate peroxidase. The results of the analysis of the variance of the data in the laboratory showed that the application of 1000 mgL-1 of zinc oxide nanoparticles or zinc sulfate caused more toxicity. The interaction effect of salicylic acid and sodium nitroprusside pretreatments on zinc oxide nanoparticles in Phlomis seedlings was significant and salicylic acid pretreatment increased the amount of proline in the treatment of zinc oxide nanoparticles. Phenol antioxidants increased significantly under the effect of zinc oxide and zinc sulfate nanoparticles, which was associated with an increase in the activity of the phenylalanine ammonia lyase enzyme. Salicylic acid pretreatment showed the greatest effect in the Phlomis plant compared to the combination of salicylic acid and nitric oxide.

Due to its great medicinal value, the Moldavian dragonhead, belonging to Lamiaceae, is naturally distributed in Europe, Siberia, and Central Asia and planted in different Iranian provinces. This research studied the development of male/female reproductive organs. Flowers and buds in different stages of development were fixed and preserved in order to prepare microtome sections using appropriate solutions and embed them in paraffin. Hematoxylin-eosin was used to stain the slices. Based on the results, despite the relative simultaneity of the formation of stamen primordium and carpel, stamens develop faster than ovules. Nurses’ cells in secretory and plasmodium types are rectangular, spindle-shaped, and often mononuclear or more. The microspore’s tetrads had tetrahedral ornamentations, and mature pollen grains were hexacolpate with reticulate ornamentation of the exine. The ovules were anatropous, unitegmic, and tenuinucellate. The functional megaspore has a micropillar position, and the embryo sac development belongs to the Polygonum type.

In order to investigate the effects of salinity, vermicompost, and methanol on the trend of changes of chlorophyll fluorescence components and some physiological traits of triticale, this experimental study was conducted as factorial based on randomized complete block design with three replications in greenhouse research of the Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili in 2022. Factors experiments included salinity in three levels (no salinity as control, salinity 50 and 100 mM by NaCl), application of vermicompost at two levels (without vermicompost as control and application of vermicompost), and methanol foliar application in three levels (foliar application with water as control, foliar application 15 and 30% volume). The results showed that the highest salinity level (100 mM) and both vermicompost and foliar application of 30% volume of methanol increased chlorophyll index (27%), nitrogen index (20.5%), stomatal conductance (38.9%), relative water content (26.7%), maximum fluorescence (27.6%), variable fluorescence (70.7%), and quantum yield (33.8%) compared to no application of vermicompost and methanol under the same of salinity level. In addition, the highest grain yield (5.4 g per plant) was obtained due to the application of vermicompost and methanol 30% volume under no-stress conditions. Based on the results of this study, it seems that the application of vermicompost and methanol can be used to mitigate the adverse effects of salinity stress due to the improvement of chlorophyll fluorescence components and some physiological traits in triticale.

The genus Ceratophyllum L. is a submerged aquatic plant of the Ceratophyllaceae family, with six species recognized worldwide. So far, two species, C. demersum and C. submersum, have been reported for the flora of Iran. Considering the importance of this plant from an environmental and ecological point of view, its taxonomic and molecular studies have been carried out in this study to investigate the species diversity of this genus. Following the identification of species by assessing morphological features in individuals from different populations, 7 ISSR primers and 3 pairs of SRAP primers were used to confirm the identifications and study the genetic diversity of distinct populations. Molecular investigations showed the number of 5 genetic groups, whose intra-population diversity (52%) was higher than inter-population diversity (48%) with P<0.05. Furthermore, the data revealed that the populations of this plant in Iran have relatively the same genetic pool. Based on this, it can be concluded that several elements, including the connectedness of aquatic ecosystems, particularly in the north of the country, as well as the high adaptability of this submerged plant with aquatic habitats, can be effective in producing such conditions. Recent droughts have increased the sexual reproduction of this plant, and as a result, the species diversity within the populations has increased.

The factorial experiment conducted in this study aimed to induce somatic embryogenesis in tomato cultivar Money Maker using different culture media and growth regulator combinations. The experiment was done in a completely randomized design with three replications. Three types of culture media, namely MS, B5, and MS + Vitamin B5, were used in combination with three hormonal combinations: 2,4-D (2 mg/L) + BA (1.5 mg/L), 2,4-D (8 mg/L) + BA (6 mg/L), and IAA (2 mg/L) + BA (5 mg/L). Additionally, three types of explants (cotyledon, hypocotyl and root) were utilized to induce somatic embryos. To promote embryo maturation, the explants were transferred to a hormone-free culture medium. The results revealed that the highest number of immature embryos was obtained from cotyledon explants cultured in MS medium with the hormonal combination of 2,4-D (2 mg/L) + BA (1.5 mg/L) and in hypocotyl explants in MB medium supplemented with the hormonal combination of 2,4-D (8 mg/L) + BA (6 mg/L), with an average of 20.33 embryos per explant. Also, the highest percentage of embryogenesis (93.33%) was in hypocotyl explants at MS culture medium with the hormonal combination of IAA (2 mg/L) + BA (5 mg/L). After two weeks of cultivation, the presence of globular embryos was visible on the surface of the explants under binoculars. By transferring the explants to light conditions and subsequently to a hormone-free culture medium, the embryos further developed and matured.

Identification of plant species in each region is a reflection of its various ecological factors. Malat Storage pool of Langarud city is a stable water ecosystem in the north of the country, which plays an important role in supplying water to paddy fields. In this study, floristic composition, life form, geographical distribution of plants and soil characteristics of Malat Storage pool area of Langarud city were investigated. First, plant samples were collected from this Storage pool, surrounding lowlands and plains and forest areas overlooking it. Then, soil samples were taken from the surface horizon of habitats and some of their physical and chemical properties were determined. Based on the results, a total of 250 plant samples were collected, which belonged to 60 families, 127 genera and 146 species. The plant families Poaceae with 22 genera and Asteraceae with 11 genera formed the most populous plant family in terms of genera. Also, Poaceae and Fabaceae had the highest species richness with 24 and 15 species. The highest percentage of plant species in the region had the predominant life form of therophyte (29.7%) and hemicryptophyte (26.2%) and the highest frequency of chorological type was Pluriregional vegetative elements (31.5%). Examining the properties of the soil showed the uniformity of the soil texture (medium to light class) and the absence of salinity with electrical conductivity less than 1 (dS/m). The range of soil pH ranged from neutral (6.78) to strongly acidic (4.03), the range of organic carbon was in the medium to optimal class, and the amount of N-P-K was in the medium to rich class. The present floristic study can provide the basis for more comprehensive studies and management practices in this touristic area.