seyyed kamal kazemitabar

Drought stress is the limiting factor for rice growth in rice fields. One of the approaches to dealing with the negative effects of stress on crop production is the use of drought-tolerant cultivars. This research was conducted to investigate the effect of drought stress on changes in antioxidant enzyme activity and amino acid accumulation in a number of rice genotypes. In this research, the number of 6 rice genotypes along with the tolerant (Binam) and sensitive (IR64) control cultivars at the seedling stage in the form of a completely random basic design in 3 replications and 4 drought levels (from polyethylene glycol 6000) zero (Yoshida), -0.5, -1 and -1.5 times were investigated in hydroponic culture medium. The results of the analysis of variance showed that there is a significant difference between the examined cultivars and the level of enzyme activity also increased, and genotypes such as Danesh and LP8, which were more tolerant to drought, had a higher level of enzyme activity. The increase in activity in tolerant genotypes has been greater than that in sensitive cultivars. In the analysis of the amino acid profiles of the genotypes introduced above, the activity of glutamic acid, alanine, arginine, leucine and lysine increased significantly with the increase in drought stress. While no significant accumulation of amino acids was observed in the sensitive IR64 genotype under stress. Therefore, it can be concluded that the accumulation of amino acids is closely related to the drought tolerance of tolerant genotypes.

One of the ways to overcome the limitation of fresh water and lack of sufficient water reserves for agriculture is to use unconventional waters such as seawater. Salinity stress is the most important abiotic stress in seawater application. Identification and planting of salinity tolerant genotypes of a plant species is one of the effective and valuable strategies in reducing the effects of salinity stress. Germination, growth and seedling establishment are among the salinity-sensitive stages in most plants. Therefore, for improvement of abiotic stress tolerance in plants, it is necessary to study the traits and indicators related to tolerance in the germination stage.

A factorial experiment was conducted based on a completely randomized design with three replications at the laboratory of Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in 2020. The first factor included the cultivars and the second included 5 salinity levels (control (no seawater), 3, 6, 9 and 11 dS (deciSiemens per meter) obtained from the incorporation of Caspian Sea and urban water. The number of germinated seeds was counted during eight days of salinity stress. Then, germination percentage, time required for 50% germination, seedling vigor index and germination rate were calculated. On the eighth day, radicle and plumule dry and fresg weights, radicle and plumule length and seedling dry weight were measured.

The results of analysis of variance showed the significance of the effect of different salinity levels, genotype and the interaction of salinity and genotype for all calculated indices at p<0.01. Mean comparison of the interaction of different levels of salinity and cultivars and landraces showed that all the studied traits except for the time to reach fifty percent germination decreased with increasing salinity. Among the studied cultivars, Oltan cultivar had the highest value of germination percentage (100%), germination rate (24.17 seeds per day), seedling vigor index (5.03), plumule length (55.67 mm), radicle length (70 mm), plumule fresh weight (62 mg), radicle fresh weight (45 mg), plumule dry weight (4.77 mg), seedling dry weight (6/23 Mg) and the lowest amount of the time required for 50% germination (24.17 hours) in control treatment. In contrast, Pakistani cultivar had the lowest germination rate (3.06 seeds per day), seedling vigor index (1), plumule length (8.33 mm), radicle length (3 mm), plumule fresh weight (10 mg), radicle fresh weight (2 mg), plumule dry weight (0.57 mg), seedling dry weight (0.84 mg) and the highest time required for 50% germination (24.17 hours) in 11 dS / m salinity level. Using the results of this experiment, among the studied cultivars, Oltan cultivar was selected as the most tolerant and Pakistani cultivar as the most sensitive cultivars to salinity stress at the germination stage.

The studied cultivars and landraces showed different reactions in terms of germination indices when treated with salinity from seawater. The high significant difference in this experiment indicated the high genetic diversity among the studied genotypes. It is possible to choose from these genotypes for salinity tolerance breeding programs in sesame plant.

Sesame seeds are a good source for food and health due to their protein and unsaturated fatty acids and secondary metabolites such as lignans. Soil and water salinity is one of the most important factors limiting the growth of this crop. By examining the physiological reactions related to salinity tolerance among different landraces and cultivars, tolerant and sensitive cultivars can be selected and used in breeding programs and cultivation development of this important oilseed. For this purpose, physiological reactions in eight different sesame genotypes in a factorial experiment based on a completely randomized design with the main salinity factor due to mixing Caspian Sea water with normal water at 3 levels(control, 6 & 9 dSm-1) and sub-factor 8 Sesame genotype includes Babol, Dashtestan 2, Oltan, Pakistani, tn-78-389 and tn-78-393, Halil, Naz single-branched genotypes in three replications in pots in the greenhouse of the Plant Breeding Department of Sari University of Agricultural Sciences and Natural Resources in the year 2020 were examined. The results of this experiment showed that at salinity levels of 6 and 9 dS, among the eight different genotypes of sesame studied, Oltan cultivar with the highest amount of total dry weight (8.42 & 5.27 gr), proline (10.35&15 μmol/g fresh leaf weight), membrane stability index ( 82.65&74.14%), relative water content(81.33 & 69.33%), leaf chlorophyll and carotenoid content(based on mg/g fresh weight), chlorophyll a(0.74&0.7),total chlorophyll(1.12&0.95)and carotenoids(0.41&0.46)and antioxidant enzymes activities (based on enzyme unit per gram fresh weight), superoxide dismutase(18.22&29.05), ascorbate peroxidase(14.9&19.21),catalase(1.51), guaiacol peroxidase(4.8&5.43),potassium(6.6%),sodium to potassium ratio index (0.06&0.12) and the lowest amount of sodium(0.41&0.7)was more tolerant of stress than other cultivars. In contrast, Pakistani cultivar with the lowest amount of total dry weight (5.12 & 2.14 gr), proline(5.86&6.7 μmol/g fresh leaf weight), membrane stability index(66.31 & 57.86%), relative water content (58&48.33%), leaf chlorophyll and carotenoid content (based on mg / g fresh weight), chlorophyll a(0.46&0.37), total chlorophyll(0.69&0.5)and carotenoids(0.25&0.27)and Antioxidant enzymes activities (based on unit of enzyme per gram of fresh weight), superoxide dismutase (11.61&10.31), ascorbate-peroxidase (8.61&8.78),catalase(0.84),guaiacol peroxidase(1.77&2.16), potassium(3.68%), sodium to potassium ratio index(0.59&1.12)and the highest amount of sodium(2.15&2.57)was the most sensitive cultivar in stress tolerance compared to other cultivars. Based on the evaluated traits and the response of the studied cultivars to salinity stress, oltan was identified as a tolerant cultivar and Pakistani as a salinity sensitive cultivar compared to the other cultivars. Therefore, these cultivars can be suggested for use in future breeding programs to introduce new cultivars.

Background and objectives Mutational breeding is an effective tool for improvement of agronomic traits in crops. The purpose of this study, mutation induction in local rice varieties using chemical mutagen ethyl methane sulfonate (EMS) to improve their agronomic traits and evaluating genetic variation at M2 generation. Materials and methods In this study the effect of EMS concentrations (0, 0.17, 0.35 and 0.51 percent) was studied on Tarom Mahalli and Tarom Hashemi local varieties. Superior genotypes were selected in M2 generation based on phenotypic status as well as their important agronomic traits were recorded. Results Evaluation of induced genetic variation was done using agronomic traits as well as 12 SSR (Simple Sequence Repeat) markers at phenotypic and molecular levels, respectively. The EMS effectively reduced significantly average of traits like plant height as well as non-filled grains and increased the mean values for 100-grain weight and panicle length. Mutant no. 13 (derived from Tarom mahalli) had superior agronomic characteristics like lower height (147 cm), more tiller number (37), panicle length (29.3 cm) and filled grains (158) in comparison with its control. Also, mutants no. 3 and 10 (derived from Tarom Hashemi) identified as superior lines and their height were 144 and 139 cm, respectively. Discussion Results of the study showed successful induction of genetic variation in mutant lines comparing with respective controls.

Nowadays, biotechnological methods such as transgenic hairy root culture and application of elicitors have become an attractive source for secondary metabolites production. Hyssop species (Hyssopus spp.) having active ingredients including antioxidants such as phenolics, in this plant have shown anti-mutagenic, anti-carcinogenic and antiglycemic effects.

The present study was conducted to investigate the effect of silver nanoparticles on the growth and antioxidants of transgenic hairy root in two Hyssopus species including H. officinalis and H. angustifolius.

In this experiment, we used silver nanoparticles concentrations of 0, 0.1, 0.2, 0.3 mg/l on transgenic hairy roots and Agrobacterium rhizogenes ATCC15834 strain for induction of hairy roots. Extraction of the samples were performed following ultrasonic method. Total phenolics content were determined using spectrophotometry. The antioxidant activity (AOA) of the extract were evaluated through 2, 2-dipheny l-1-picryl-hydrazy l (DPPH) method.

The results showed that silver nanoparticles as an elicitor had significant effect on the measured traits. The highest dry weight and fresh weight of the transgenic hairy roots were observed as much as 3.8 and 16 g/l in H. angustifolius and 3.2 and 14 g/l in H. officinalis, respectively. Which were caused by silver nanoparticles at the concentration of 0.1 mg/l, The amount of total antioxidants in H. angustifolius and H. officinaliswere 90.81% and 89.84%, respectively. In this study, we could observe relationship between antioxidant activity and plant phenolic content.

In general, we found that 0.1 mg/l silver nanoparticles could improve the growth of transgenic hairy roots and increase their phenolics and antioxidants content.

Ash (Fraxinus excelsior L.) is a forest species with seeds consisting of hard woody skin and high dormancy that complicate the germination. This study was designed to facilitate the growth of ash seed using the in vitro culture of the embryo. Seeds from four regions of Kelardasht, Alandan-Kiyasar (in the Mazandaran province), Aliabad and Galikesh (in the Golestan province) were collected and sterilized using a sterilized scalpel to split tip of an embryo without any damage. Prior to being transferred to the culture medium, the embryo was washed by 70% of alcohol per minute as well as with sterile water under laminar hood. It was then placed in Monier, WPM and MS mediums in three replicates (with five ash seed per each petri dish). All indices studies here in the four geographical regions for the MS medium were significantly higher than the other two media, with the lowest amount observed in Monier culture media. In all four regions, all indices in Alandan and Galikesh were significantly higher than the other two regions, with the lowest amount observed in the Aliabad area. In addition, all indicators showed a significant and positive correlation with each other. Regressions between the length and weight index of vigor with other variables resulted in high R2 values that showed that changes in independent variables are influenced by dependent variables in a close fit. Therefore, it can be concluded that MS medium is more suitable for the in vitro propagation of the embryo plant of the ash.

Effects of salicylic acid and methyl Jasmonate on Hypericin production in callus culture of Hypericum perforatum L. cv Topas were investigated. This factorial experiment was carried out in a completely randomized design with two factors including the four levels of salicylic acid (225,150,75,0 µM) and methyl Jasmonate in three levels (150,75,0 µM) with three replications at the research lab Group of Sari University of Agricultural Sciences and natural resources, deprtment of Horticultural Science. Analysis of variance showed significant differences among treatments. Effect of treatments on total flavonoid Methyl Jasmonate effect was significant. Interaction effect was significant for Hypericin, flavonoids and anthocyanins. According to the results of this study in cell cultures of H. perforatum, low concentration (100 micromolar and lower) of both salicylic acid and methyl Jasmonate elicitors were effective for production of Hypericin. The results of this experiment showed that the highest amount of Hypericin produced from 150 μM salicylic acid (SA) and 225 μM salicylic acid in combination with 75 μM methyl Jasmonate (MJ) after 21 days.

Salinity stress is one of the main obstacles in crop production in many parts of the world, especially in arid and semi-arid regions. Plant's ability to neutralize the effect of salinity largely depends on the internal state K and Na. In fact, maintaining high Kﳖ ratio in Cytosol is a key element for tolerance to salinity. Rice, one of the most important food crops, a primary food source for more than one-third of the world’s population. Rice is sensitive to salinity stress, so that, salt effects will extensively damage rice metabolic activities. This study has presented the effects of salinity on some physiological characteristics and genes expression patterns that coded for a number of ion channels in rice. In order to seed germination, the seeds of some cultivar (IR29, Sangtarom, and Jelodar) sterilized and then were placed in germinator. Salinity treatment (120 mM NaCl) were applied 14 days after culture. The leaf and root samples were collected at six time-courses (0, 6, 24, 72, 120 and 168 hours) after sodium chloride stress. Results of physiological assessments showed that the effects of genotype, sampling period and their interactions were significant at 1% level of probability on all measured traits including malondialdehyde (MDA), chlorophyll a, chlorophyll b, carotenoids and proline contents. The concentration of chlorophyll a, b and carotenoid of leaves were reduced in early hours of encountering with stress and then increasing the hours of stress, leaf thickness (leaf rolling) caused chlorophyll per leaf unit and increases the amount of chlorophyll. The measurement of MDA in the leaves showed that the greatest increase occurred in sensitive cultivar (IR29). Proline content analysis showed that there was no significant difference between proline content of sensitive and tolerant cultivars under normal condition (no stress), but by exposure to salinity stress, proline content was increased in susceptible more than tolerant cultivar. Proline content in Sangtaroom, as a salt tolerant genotype, has significantly increased in comparison with the control cultivar in 72, 120 and 168 (h) times. Consequently, the responses of sensitive and tolerant rice cultivars to the salinity stress are different from each other and measuring of some parameters such as MDA, chlorophyll a, chlorophyll b, carotenoids, and proline can help to improve the salt tolerance of plants.

Sesame (Sesamum indicum L.) is one of tropical plants that sensitive to cold. In order to evaluate the tolerance of different genotypes of sesame to cold stress and effect of cold on their physiological characteristics, an experiment was conducted using a completely randomized design on ten genotypes including Varamin, Qa’im, Ultan, Yekta, Dashtestan 2, Darab 1, Naz Takshakheh, Naz Chandshakheh, Jahad and Nishapur with three replications. The genotypes exposed three days in 8˚C and the leaf samples were prepared at 0 (pre-stress), 6, 12, 24 and 48 hours. The highest amount of chlorophyll a was measured in Naz Chandshakheh, and the lowest amount was in Varamin and then was in Nishapur genotype after 48 hours. About chlorophyll b, the Naz Chandshakheh and after it, Jahad genotypes had the highest and the Nishapur genotype had the lowest amount after 72 hours. The amount of carotenoids, just in time zero and the beginning of stress (6), a significant difference was observed among genotypes and with advancing the stress, changes in ten genotypes carotenoids in such a way that no significant differences were found. The process of proline changes was incremental and proline accumulation found during cold stress in all genotypes. The difference between genotypes in stress and non-stress (time zero) conditions was significant and the highest amount of proline accumulated in Naz Chandshakheh and the lowest found in the Nishapur genotype at all times. The changes of malondialdehyde (MDA) was different in the genotypes at all times and the Nishapur and then Darab 1 genotype had the highest and the Naz Chandshakheh genotype had the lowest amount of MDA at the end of cold stress duration, which represent respectively the maximum and minimum damage to the membrane. The cold stress leads to loss of intracellular water of leaves and thus, the concentration of photosynthetic pigments increased. On the other hand, the lost water is used to interactions, such as the synthesis of proline and its levels has increased under the stress. As well as damage to the membrane, causing exit substances such as MDA that due to these factors finally, the Naz Chandshakheh and the Nishapur genotype introduced respectively as cold tolerant and cold sensitive cultivar.

Sesame (Sesamumindicum L.) as an ancient plant has traditionally used for centuries as a medicinal plant due to its natural antioxidants and plenty of medicinal properties. Seeds from different cultivars of sesame have various nutritional values and different genotypes showing different response to mature shoot buds meristems. In present experiment callus induction and plant regeneration of sesame cultivar (Single Branch Naz) have been considered using different hormonal combinations in a factorial experiment based on completely randomized design with three replicates. In order to evaluate callus induction¡ 2¡4-D in three levels and NAA in four levels were used as auxinsources. In current study¡ percentage¡ fresh weight and diameter of induced callus were compared. Results in different environments showed that the highest percentage of callus was obtained using 0.4 mgl-1 2¡4-D hormone. Also¡ in terms of fresh callus weight maximum result was belong to combination of 0.2 mgl-1 2¡4-D and 0.16 mgl-1NAA hormones. Furthermore¡ in callus diameters the highest amount was allocated to combination 0.2 mgl-1 2¡4-D and 0.12 mgl-1 hormones. However¡ kinetin played a significant role in increasing the percentage of regeneration¡ so that. The best response was belonged to combination 2 mgl-1 Kin and 0.4 mgl-1 NAA hormones.

Rice as one of the most important agricultural crops has a putative potential for ensuring food security and addressing poverty in the world. In the present study, in order to provide basic information to improve rice through breeding programs, Inter Simple Sequence Repeat marker (ISSR) was used For DNA fingerprinting and finding genetic relationships among 32 different cultivars. In this study, 12 out of 17 used primers amplified 184 distinct and reproducible fragments with high value of polymorphism (88%). also, for fingerprinting the cultivars 29 loci were used that generated high polymorphic bands among the cultivars. Results indicated that similarity index varied between 39% and 88.4 %, furthermore, PIC value with an average of 23% ranged between 0.1 (for primer #3) to 0.34 (for primer #2). Clustering based on Jaccard coefficient similarity index and UPGMA algorithm divided the cultivars into 6 main sub-clusters in cut-off point of 64% similarity index. The two Italian rice cultivars ‘Ribe’ and ‘Roma’ were the closest cultivars in addition, ‘Vialone nano’ and ‘Anbarbu’ showed the highest dissimilarity. In total, high genetic divergence was observed among the cultivars also, poly (GA)-containing 3-anchored primers amplified the highest number of bands. According to similarity and cluster analysis, it could be inferred that crosses involving Anbarbu cultivar are the most promising ones to improve rice through breeding programs. In fact, results of this study would be promising as a genetic marker for the identification of rice cultivars and an important source of knowledge for subsequent rice researches.

Mutation has been accepted as a useful tool in plant breeding programs to provide inheritable variability for selection. In this research, the effect of chemical mutagen Ethyl Methane Sulfonate (EMS) at three levels, 0.17%, 0.35% and 0.51% was studied to create the variation on morphological characteristics of Tarom Mahali, Sange Tarom and Tarom Hashemi varieties. The M1 generation was examined using a factorial experiment based on randomized complete block design with three replications and the agronomic traits including plant height, number of tiller, panicle length, number of filled and unfilled grains per panicle, number of total grains per panicle, grain width and length and 100 grain weight were measured. Analysis of variance showed that the interaction effect of cultivar×EMS concentration was significant for total number of grains per panicle, number of unfilled grains per panicle and grain length at 5% probability level and for filled grains per panicle and 100 grain weight at 1% probability level. The effect of variety was significant for plant height and 100 grain weight at 1% and for panicle length at 5% probability level, while the EMS concentration was significant for the number of tiller, total number of grains and number of filled and unfilled grains per panicle at 5% probability level. Results of the comparison of means indicated that the application of EMS lead to increase in grain length, number of grains per panicle and 100 grain weight and decrease in plant height in rice varieties. Generally, results of current research showed that the EMS had considerable and significant effect on the 100 grains weight and plant height of rice varieties in M1 generation. Thus, EMS as the mutagens can be utilized for increasing of the variation and genetic improvement in breeding programs.

Gamma irradiation was used at different doses (80, 160 and 240 Gy) on Glycine Max (L.) Merrill cv. Hill homogenous seeds. A single suitable M2 plant was selected and evaluated at M3 and M4 along with its parent and three other varieties as control in RCBD experiment in Sari Agricultural Sciences and Natural Resources University’s experimental field. M-80-709 and M-160-3429 mutant lines were significantly shorter (55.05 and 72.04 cm respectively). Their branch numbers were however significantly more (8.70 and 11.53 respectively) compared to the parent cultivar (80.82 cm and 6.10 respectively) and other genotypes (p≤0.05), when calculated on per plant basis. Besides, the M-160-3429 was characterized by highest grain yield and oil content (38.25 g and 19.22% respectively), in compare with its parent (12.73 g and 19.09% respectively) and all others control cultivars (p≤0.05). The M-160-3429 mutant line with high grain yield and oil content accompanied with some other favorite morphological traits can be considered as a new promising line of soybean for future studies. Results from this study suggested that mutation breeding procedures at the ranges of 80 to 160 Gy is a capable me­thod for breeding higher grain yield including increasing the oil content as well.