Showing 19 results for mohammadi
Hassan Zare- Maivan, Javad Mohammadi, Hamid Ejtehadi- Bajestani, Karim Pasad,
Volume 1, Issue 1 (12-2014)
Abstract
Kasf forest, with an area of over 12 ha, running in the east-west direction and located at a distance of 20 kilometers in the north of the city of Bardaskan in a mountainous arid region. The minimum and maximum temperature of the area ranges between -10° C and +45° C. The average annual precipitation of the region is 155 mm. The altitude of the forest is about 1600 m above sea level with a 15% slope. The vegetation of this forest was studied using floristic methods 2 years after a devastative fire and life forms and geographical distributions of plant species were determined. Sixty nine plant species belonged to 29 families (25 Dicots, 3 monocots and one gymnosperm). The largest families were the Lamiaceae with 11, Asteraceae with 9 and Caryophyllaceae with 5 species. The percentages of life forms were determined as follows: Therophytes with 36% (25 species), Hemicryptophytes with 29% (20 species), Chamaephytes with 16% (11 species), Phanerophytes with 13% (9 species) and Cryptophytes with 6% (4 species) of total investigated species. The high percentage of Hemicryptophytes indicated the dominance of cold mountainous climate and the presence of Asteraceae species such as harmala (Peganum harmala) showed that a severe disturbance had taken place in the region, which indicated a poor ecological administration in the studied region.
Parisa Mohammadi, Habibian Mahsa , Mohammad Reza Soudi Soudi , Asgarani Ezat ,
Volume 1, Issue 2 (3-2015)
Abstract
Microbial analysis of ground water, as the sole supplying water source in many areas, must be evaluated. Because the treatment of water cannot remove all pathogenic bacteria leaked from domestic wastewater, bacterial analysis of Bojnourd groundwater sources was performed. For this reason, membrane filter (MF) technique and Most Probable Number (MPN) method were used to evaluate the microbial quality of the water. Escherichia coli (E. coli) and Enteroccocus faecalis (E. faecalis) were traced as excremental indices. E. coli was detected from three out of six stations and E. faecalis was only isolated from one station. Although molecular techniques are very rapid and exact methods for detection of microbial community and can identify ‘Viable But Not Cultivable’ (VBNC) bacteria, they are unable to make a distinction between living and non-living microorganisms. By means of a standard technique, it is possible to study living and metabolically active microorganisms. Due to the detection of E.coli and E.feacalis in some stations the sanitization of groundwater must be revised to lessen the microbial population in this groundwater.
Parisa Mohammadi, Sepide Ameri Toorzani, Khadije Kiarostami, Sara Gheravi, Zahra Felahti,
Volume 2, Issue 1 (6-2015)
Abstract
Total petroleum hydrocarbons (TPHs) is one of the most important environmental challenges. Phytoremediation of oil-polluted soil depends on microorganisms of the rhizosphere. This study attempts to evaluate the microbial impact of Zea mays rhizosphere during a 60 day period using three different treatments: control soil, oil-polluted soil and oil-polluted soil including fertilizer (NH4No3, K2HPO4). Then, the rhizosphere bacteria were identified. The results showed that CFU per gram of control soil was higher than other treated soils, an indication of oil stress on microbial population. In addition, more bacterial diversity was observed in soils and different bacteria were isolated from the soils. Finally, the most resistant bacteria to the oil pollution were assayed. The assay of isolates indicated that all of those separated from the oil-polluted soil have the ability to produce biosurfactant in different quantities. Further investigation must be carried out to optimize the degradation of oil by these isolates.
Mansour Afsharmohammadian, Mohsen Sharifi, Seyyede Narjes Abolghasemi, Narjes Mohammad,
Volume 2, Issue 2 (9-2015)
Abstract
Dittrichia graveolens (Asteraceae) is an aromatic and annual plant. The aim of this study is the evaluation of total phenolic, flavonoid and flavonol content, the antioxidant activities and other important medicinal secondary metabolites of this plant. According to the results, the total amount of phenols and flavonoid in different plant organs of D. graveolens were different in a way that the content of total phenols and flavonoid in the flowers and leaves were significantly more than the stems and roots. The content of flavonol in the flowers, leaves and stems were not significantly different, and the lowest content was observed in the roots. In addition, the linear and significant correlation coefficient was found between the antioxidant activity and the phenolic compounds in the extracts of different organs of the plant. The main components in different extracts were Bornyl acetate and α-Cadinol in flower extract, Borneol, Bornyl acetate, Thymol and Calarene in leaf extract and PMAMOMPE, Safrole, Carvacryl acetate, Vulgarone B and Bornyl acetate in root extract. On the whole, the current results compared with the results of other researchers indicates the remarkable impact of plant habitat on the quality and quantity of pharmaceutical compounds in different organs of the plant
Zahra Noormohammadi, Bahar Ghasemzadeh, Farah Farahani,
Volume 5, Issue 1 (6-2018)
Abstract
Aloe barbadensis is perennial, monocotyledonous, fleshy plant belongs to
Aloaceae family. In this study, somoclonal variations of regenerated
A. barbadensis plants were investigated. The plantlets of forth subculture transferred to the soil for further study. The genomic DNAs of 40 regenerated plantlets were extracted and genetic variations were studied using SPAR markers including RAPD and ISSR primers. The amounts of Aloe gel also were extracted from regenerated
A. vera plants. Average percentage of polymorphism, Shannon index, Nei's genetic diversity and number of effective alleles based on RAPD data were higher than genetic parameters obtained from ISSR data. NJ cluster and STRUCTURE plot based on molecular markers grouped regenerated plants to distinct clusters. AMOVA analysis also showed a significant (P = 0.01) genetic distinction between studied groups. This result also confirmed differentiation of regenerated plants. The amount of Aloe gel in the four groups (based on clustering method) was compared by using analysis of variance (ANOVA). The results showed no significant (P = 0.746) differences between the amount of gel in four group. In total, our findings showed somaclonal variations on genomic level while no significant differences were observed in amount of gel among regenerated Aloe plantlets.
Masoud Nazarizadeh, Mohammad Kaboli, Hamidreza Rezai, Jalil Imani, Alireza Mohammadi, Saeid Khaki,
Volume 5, Issue 2 (9-2018)
Abstract
Abstract. Eurasian Nuthatch (Sitta europaea), with 18 subspecies, has a wide distribution in deciduous forests of Eurasia. The subspecies S.e.persica is a resident bird in the Zagros Mountains, from north-west to south-west of Iran. The aim of this study was to evaluate the taxonomic and phylogenetic relationships of this subspecies to European, Asian, as well as Caucasian clades. For this purpose, 10 individuals of two populations from Zagros forests in Kermansha and Kohgiluyeh and Boyer-Ahmad provinces were captured and blood samples were collected. Furthermore, we used ND2 sequence data (1041 bp) for 136 sequnces from GenBank. were used from Then genetic variations and Genealogical analysis was calculated using complete ND2 gene sequence (1041bp) and TRN+G model, Bayesian trees and maximum likelihood, respectively. Also, median joining algorithm showed the relationships among haplotypes. We found four new haplotypes for the Zagros populations. Our phylogenetic analysis revealed that the genetic distance between Zagros population and Caucasian clade was significantly small, demonstrating Zagros populations are part of the Caucasian clade. FST statistical values, resulted from Analysis of Molecular Variance (AMOVA), represented significant variations in genetic structure among Eurasian Nuthatch populations. Moreover, FCT revealed significant variation among European, Asian, and Caucasian clades. Overall our result suggests that Eurasian Nuthatch populations in Eurasia comprise three phylogenetic species, and likely biological species. Hoewever, the previous nomenclatured subspecies, S.e.caucasian and S.e.persica, can be considered as a common phylogenetic species.
Mansour Afshar Mohammadian, Shirin Kordi,
Volume 5, Issue 4 (3-2019)
Abstract
Nowadays, the use of a wide range of medicinal herbs such as saffron and its aromatic compounds is increasingly being regarded as natural sources of antioxidant properties. In addition to saffron stigma, saffron petal is a rich herbal source of antioxidant compounds. The present study was conducted in a completely randomized design with three replications to study some of the enzymatic and non-enzymatic antioxidants of two species of wild saffron in Guilan Province compared with agronomic saffron (C. sativus). The results of this study showed that total phenol, flavonoids and anthocyanins in agronomic saffron were significantly higher than those in the other two species. The amount of flavonel in C. speciosus and the level of antioxidant activity (DPPH) in C. caspius were significantly higher than other species. The level of PPO activity in C. sativus and C. speciosus was significantly higher than that in C. caspius. However, there was no significant difference in the level of POD activity among the three studied species. Therefore, according to the results of this study, petals of different species of saffron are good sources of non-enzymatic and enzymatic antioxidants and can be used as an available natural antioxidant in the food and pharmaceutical industries.
Mitra Mohammadi Bazargani,
Volume 5, Issue 4 (3-2019)
Abstract
Epilobium minutiflorum belongs to the genus Epilobium with important medicinal properties. In this study, the natural variation of phytochemical compounds of E. minutiflorum at different altitudes has been investigated. Aerial parts of plants were collected at flowering stage from natural habitats at different altitudes of 2387, 2569 and 2813 masl. The plant extracts were obtained with 80% methanol and several phytochemical properties were measured. The properties included the total flavonoid content (TFL), total phenol (TPH), antioxidant capacity (AOX) and anthocyanin content (ACY) measured by the AlCl3, the Folin-Ciocalteu, the Ferric reducing antioxidant power (FRAP) and the differential PH methods, respectively. In addition, phytochemical components were identified by the GC/MS method. The results of photometric analysis indicated that the population of Shemshak, located at the highest altitude showed the highest content of TFL, TPH and AOX with 30.39 mg/gr DW, 938.91 mg/gr DW and 77.77 mM/gr DW, respectively. The TFL, TPH and AOX values showed a positive correlation with altitude. The results of GC/MS analysis revealed the presence of 41 compounds in E. minutiflorum, which were separated into flavonoids, phenolic acid and its derivatives, steroids and terpenes groups. Shemshak population showed the highest value in all identified compounds. A positive correlation was also observed between altitude and 30 compounds identified by the GC/MS method including mainly flavonoids and phenolics. The results of this study indicated that environmental factors at higher altitudes may influence the elevation of the flavenols and phenol content in E. minutiflorum. The identification of these influential factors on phytochemical content at higher altitudes requires further studies.
Elham Seidmohammadi, Saeed Abbasi, Mohammadreza Asef, Samad Jamali,
Volume 6, Issue 1 (5-2019)
Abstract
Through a survey of macrofungi in Ghalajeh heights and its surrounding plains, conducted from 2014- 2017, twelve specimens of macroascomycota were collected. The specimens were identified on the basis of macro- and micro-morphological characteristics. The internal transcribed spacer sequences of the selected specimens were analyzed to confirm the morphological identification. Based on the results, five species, including Terfezia claveryi, Tirmania pinoyi, Helvella acetabulum, Picoa juniperi and Picoa lefebvrei were identified. T. claveryi and T.pinoyi species had been previously reported from Kermanshah Province, but H. acetabulum, P. juniperi and P. lefebvrei species were reported for the first time.
Rezvan Mohammadi, Parto Roshandel, ,
Volume 6, Issue 1 (5-2019)
Abstract
In order to study the effects of magnetopriming on the physiological and phytochemical characteristics of Hyssopus officinalis plants, this research was conducted as a factorial experiment in a completely randomized design. Results showed that magnetopriming (particularly at 200mT/5 min) increased the level of shoot dry weight (82.6 percent), root dry weight (86.5 percent), total chlorophyll (32.8 percent), carotenoids concentration (32.4 percent) and polyphenols content (2 folds) in 60-day-old Hyssopus officinalis. Also, electrolyte leakage and lipid peroxidation decreased by 27.6 and 45 percent, respectively. In addition, reducing power, DPPH and superoxide anion scavenging activities significantly augmented. However, higher activities of superoxide dismutase (76 percent), catalase (4.2 folds), ascorbate peroxidase (2.4 folds) and guaiacol peroxidase (48 percent) were found at 90 mT. Results suggested that the application of magnetopriming promoted growth in H. officinalis through augmentation of cellular membrane integrity as well as biomass and photosynthetic pigments content. Furthermore, it was found to enhance the antioxidative system. Magnetopriming might apparently improve the medicinal properties via increasing the level of polyphenols and antioxidant capacity in H. officinalis.
Zahra Noormohammadi, Mahnoosh Mohammadzadeh-Shahir, Donya Fahmi, Seyed Mohammad Atyabi, Farah Farahani,
Volume 6, Issue 3 (10-2019)
Abstract
Catharanthus roseus is widely cultivated around the world. Cold atmosphere plasma (CAP) has been used to improve crop plants seed germination, and plant growth. In the present study, three different times of CAP (40, 50 and 60s) were used for the treatment of C. roseus seeds, and the changes in morphological traits, antioxidant enzymes and the genetic content of the treated plants were examined. Cold plasma (50s) markedly raised the seed germination, length of the leaves and the stem length of the plants in comparison with those in the control group. The catalase and peroxidase enzyme activities had the highest value in 60 and 40 s CAP treated plants, respectively. The sequence related amplified polymorphism (SRAP) markers showed the highest degree of genetic diversity in 50s cold plasma treated plants (Ne = 1.388, I = 0.316, He = 0.217, uHe = 0.237 and P % = 50.08). Based on Neighbor Joining, principle coordination analysis (PCoA) and analysis of molecular variance (AMOVA) test, four significantly distant groups were formed. The 40s and 50s cold plasma treated plants stand far from the control plants due to genetic difference. The results indicate that cold atmosphere plasma could be used as an economic and environmentally safe tool in increasing C. roseus growth characteristics in addition to inducing genetic variations.
Shiva Shahsavari, Zahra Noormohammadi, Masoud Sheidai, Farah Farahani, Mohammdreza Vazifeshenas,
Volume 7, Issue 4 (2-2021)
Abstract
The pomegranate fruit is one of the most important horticultural products due to the presence of polyphenolic, antioxidant and anti-fungal compounds. In the present study, morphological and phytochemical compounds diversity was investigated in eight Iranian commercial pomegranate cultivars. Fourteen morphological characters and 10 chemical compounds were measured. Based on PCA analysis the most variable morphological characteristics among Punica cultivars studied were the wood surface, the leaf tip, the leaf incision, growth power and rained condition. High-performance liquid chromatograms of chlorgenic acid, caffeic acid, Para Coumaric acid as well as titrable acidity, total soluble solid, total phenolic contents, antioxidant activity in juice and peel of cultivars differentiated the cultivars studied. Comparing the two UPGMA dendrograms of Punica cultivars based on morphological data and chemical contents indicated certain disagreement between them. The correlation between morphological and chemical compounds and geographical distances of Punica cultivars was not statistically significant by the Mantel test. These findings indicate that Punica cultivars studied differ in their genetic content, however, this genetic difference is not correlated with their geographical distance.
Hiba Zedan, Seyed Masoud Hosseini, Ali Mohammadi,
Volume 9, Issue 1 (3-2022)
Abstract
The aim of this study was to increase the shelf life of traditional yogurt, to improve its consistency and to prevent whey syneresis by adding tarragon essential oil. Yogurt was produced by industrial procedures and then the essential oil was inoculated into yogurt in different concentrations (10, 25, 30 ppm). Samples were examined for water storage capacity and microbial evaluation during 3 weeks of storage at two temperatures (refrigerator temperature and room temperature). The results showed that different concentrations of tarragon, temperature and storage time had a significant effect (p <0.05) on water holding capacity as well as the number of starter bacteria, molds, and yeasts. Tarragon essential oil reduced the number of bacteria, molds, and yeasts that spoil yogurt. The final results showed that the use of tarragon was not effective in water retention of yogurt samples, but it affected the number of initiator bacteria and yeast. Yogurt samples with high concentration of tarragon had the highest score in terms of consistency and sour taste. While samples with low concentration of tarragon, in terms of yogurt taste, had the highest sensory score.
Atefeh Shahraki, Mrs Maryam Mohammadi-Sichani, Mrs Monireh Ranjbar,
Volume 9, Issue 3 (12-2022)
Abstract
Rhizospheric bacteria are among the beneficial soil microorganisms that improve plant growth. These bacteria increase plant growth through various mechanisms such as the production of various phytohormones and the ability to solubilize phosphate. The aim of this study was to investigate the effects of rhizosphere bacteria on the growth of Carthamus tinctorius to improve its physiological and biochemical indicators. Carthamus tinctorius seeds were inoculated with five isolates of rhizosphere bacteria and were then planted the seeds in pots. Subsequently, the physiological and biochemical parameters of the plants, including the rates of auxin production, phosphate dissolving, photosynthetic pigments and the contents of proline and malondialdehyde were measured. For this purpose, a factorial experiment were conducted using a completely randomized design with three replications. The ANOVA was performed and a comparison of the means was carried out using Duncan’s multiple range test. The results indicated that the largest stem fresh weight, root fresh and dry weights observed in the treatments of using Pseudomonas fluorescens (auxin concentration of 23.55 μg/mL) and Bacillus muralis (auxin concentration of 22.27 μg/mL). In addition, all bacterial species increased the safflower seed germination rate compared to the control group. The largest malondialdehyde content was recorded in the treatment with Bacillus albus, and MDA content decreased in the treatments that produced larger amounts of auxin. In general, the finding of this research suggested that bacterial inoculation was capable to significantly affect the growth of safflower and improve its qualitative and quantitative growth parameters.
Mehri Farzadi, Reza Khakvar, Abolghasem Mohammadi, Thomas Rattai,
Volume 9, Issue 4 (3-2023)
Abstract
Urmia Lake is the largest lake in the Iranian plateau and the second largest Salt Lake in the world. This study was conducted to identify hypersaline bacteria in the lake through the screening with molecular markers. For the molecular study of the bacterial microbiome of the lake, samples were collected from water, sludge and soil of the different parts of the lake during different seasons of 2018 and 2019, and then transferred to the laboratory under standard conditions. Bacterial isolates were purified from the samples using universal culture media. ERIC molecular marker was used to study the species diversity. After clustering analysis of the species on the basis of their genetic markers, one bacterium from each cluster was selected as the representative of each cluster and then identified by DNA barcoding method using the 16srDNA. Biochemical tests were performed to confirm the molecular results. In total, 102 bacterial isolates were isolated and purified from the samples, of which only 29 isolates were extremely-halophilic. The molecular diversity of isolates, based on ERIC molecular marker, showed that isolates can be assigned to five different clusters. Five isolates selected from each cluster were selected and their 16SrDNA region were amplified and sequenced with 16SrDNA-specific primers. The results showed that the five selected isolates with 99% similarity belonged to the species Microbulbifer halophilus, Halomonas salina, Bacillus sonorensis, Salinivibrio costicola and Bacillus aquimaris. The results of molecular identification were consistent with the results of biochemical tests.
Mostafa Hosseinpour, Mohammad Mohammadi, Gholam Reza Ghezelbash,
Volume 10, Issue 3 (12-2023)
Abstract
Biological cementation is a new process in which urea hydrolysis bacteria or free urease enzyme decompose urea and increases the pH of the environment and chemical interactions in the presence of calcium ions to form calcite. Nowadays, nano-calcite is widely used in engineering, such as increasing the strength of soil and concrete, as well as in medicine, such as drug delivery and cancer treatment. This study aimed to investigate the laboratory conditions for producing nano-calcite particles with appropriate quality, size and purity by Sporosarcina pasteurii enzyme extract for use in medical and engineering studies. This investigation aimed to make calcite by S. pasteurii enzyme extract and optimize influential factors in calcite production. For this purpose, the bacterium S. pasteurii was cultured in nutrient broth containing urea and nickel, and upon reaching the appropriate time, the cells were separated and washed. Then, their enzyme extract was prepared by sonication, and calcite precipitation was studied in different amounts of urea, calcium chloride, enzyme and temperature. The quality of produced calcite crystals and their ratio compared to other crystals were investigated by XRD and SEM analyses. According to the results of XRD analysis, it was found that in 0.5 M urea and 0.25 M calcium chloride, the highest amount of calcite is produced with 96%, and the least side products are produced. Examining the particle size histogram in the sample containing 0.5 M urea and 0.25 M calcium chloride revealed that the range of particles were between 50 and 100 nm. The nature and type of crystals were studied by electron microscopy, and EDX analysis showed the presence of calcium, oxygen, and carbon. According to the results, it was found that by the increase of the concentrations of urea and calcium, the range of particle size became larger. Also, the percentage of calcite produced in low urea and calcium chloride concentrations is higher than those in high concentrations.
Siamak Yari, Sayeed-Hikmatullah Anis, Mohammad-Hossein Mohammadi-Mahdiabadi-Hasani,
Volume 10, Issue 3 (12-2023)
Abstract
Cisplatin (CP) is one of the most effective chemotherapeutic drugs, however, its clinical use is limited due to possesing nephrotoxicity, hepatotoxicity and hemotoxicity side effects. α-lipoic acid (ALA) is known as a powerful antioxidant with anti-inflammatory properties. The aim of this study was to evaluate the effect of ALA on cisplatin-induced hemotoxicity. In this experimental study, 35 NMRI mice were divided into five groups (7 mice/group) of Group 1 (Control), group 2 (CP), group3 (CP+ALA low dose), group 4 (CP+ALA high dose) and group 5 (ALA). ALA was administrated orally for 7 consecutive days and CP was injected intraperitoneally. At the end of the experiment, blood samples were collected and blood parameters were analyzed. Spleens belong to different groups were evaluated histologically. The data were revealed that erythrocyte count, White blood cells count and hemoglobin level were increased significantly in group2 in comparison with other groups. However, ALA administration improved CP induced changes in blood parameters. CP treatment induced histological changes such as increase in megakaryocytes count and accumulation of hemosiderin and collagen in red palp of spleen. ALA treatment improved CP induced histological alteration in groups 3 and 4. Results of the present study showed that ALA exerts protective effects on CP-induced hemotoxicity and histological alteration of spleen.
Bahare Asgari, Dr Ali Mohammadi, Dr Bahare Attaran,
Volume 11, Issue 1 (6-2024)
Abstract
The aim of the present work was to produce a stable nanoemulsion containing clove (Syzygium aromaticum) essential oil (PCLO) and evaluate its antimicrobial activity. The effect of the preparation technique, the type of surfactant and the ratio of surfactant to oil was evaluated to optimize the preparation formula of oil-in-water nanoemulsion. The optimized formula prepared by low energy production method containing 4% w/w PCLO and 12% w/w mixed surfactant (SDS + Tween 80) produced a clear and stable nanoemulsion for 90 days with an average particle diameter below 150 nm. The antibacterial activity of pure PCLO and its nanoemulsions (NCLO) was investigated by disk diffusion, agar well, and broth methods in 3 indicator bacteria of gastrointestinal infections, Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium. Minimum inhibitory concentration (MIC) and bacteriocidal concentration (MBC) as well as dynamic killing time were determined in the tested bacteria. Strong antibacterial activity of PCLO and NCLO was revealed in the concentration range of 1000-2000 ppm. The killing kinetics study showed that during the first 15 minutes of exposure to NCLO at the MIC concentration, there was a rapid and extensive reduction in the amount of viable microorganisms. The presented data, considering the optimal performance of antimicrobial substances in food, cosmetics and chemical industries, can help in the rational design of nanoemulsion-based essential oil delivery systems.
Dr Seyed Mehdi Razavi, Mrs Neda Delir, Dr Sareh Abrahimi, Dr Mansour Afshar Mohammadian,
Volume 11, Issue 2 (8-2024)
Abstract
Using the allelopathic property of some plant species is one of the proposed methods to reduce the use of chemical poisons. Anthriscus nemorosa is an aromatic plant belonging to the Apiaceae that grows naturally in the western and northern parts of in this study. Considering that so far the biochemical and allelopathic properties of this plant have not been investigated in Iran, in this study, the roots of this plant were collected from Khalkhal county and after drying in the shade, the essential oil was extracted by hydro-distillation. The essential oil was analyzed by GC and GC-MS. 52 compounds were identified from the essential oil, representing 80.21% of the total oil. The main constituents were Myristicin (16.92%), Heptane (12.98%), Elemicin (12.54%), Gamma-Terpinene (12.50%), Decane (3.08%), Beta-Eudesmol (2.95%) and Beta-phellandrene (2.52%) and these compounds were remarkably different with that of A. nemorosa native to Serbia. To investigate the allelopathic effects of this plant, an experimental design was factorial experiment in a completely randomized design with four replications. The results of examining the effects of n-hexane, dichloromethane and methanolic extracts (with concentrations of 0, 0.001, 0.01, 0.1 and 1 mg/ml) of the root of this plant on lettuce (Lactuca sativa L. var.capitata) showed that all three extracts had an inhibitory effect on the germination percentage (%), shootlet growth and rootlet growth of lettuce. However, the hexane extract in all treated concentrations had a more inhibitory effect on the germination and shootlet growth of lettuce seed.