Iranian Journal of Seed Research

Extended abstract
Introduction: Legumes are the most important source of plant protein and Mung bean has a high nutritional value for humans, as it produces seeds containing high protein percentage. The major problem of salinity in seed germination of higher plants is due to excessive amounts of sodium chloride, osmotic pressure, disruption of nutrient uptake and transport, and direct effects of ionic toxicity on the membrane and enzymatic systems that in turn reduce germination. External use of methyl jasmonate can modulate the effects of various stresses, such as salinity and drought, by increasing the antioxidant activity of the seed. Therefore, the purpose of this research was to evaluate the effect of methyl jasmonate and salinity stress on germination and enzymatic properties of Mung bean.
Material and Method: This study was conducted as factorial based on a completely randomized design with three replications during 2015-16 at the laboratory of Department of Agronomy, Tarbiat Modares University. The experimental treatments included four methyl jasmonate solution (0, 50, 100 and 150 mM) and four salinity stress levels (0, 2, 4 and 6 dS/m salinity from NaCl). Petri dishes were placed in a germinator at 25 ° C and in full darkness for 14 days. In this experiment, germination rate and percentage, time to reach 50% germination, alpha and beta amylase, catalase and peroxidase were measured.
Results: The results of the experiment showed that the lowest rate of slope and final germination percentage were obtained in 50 and 100 mM solutions of methyl jasmonate. In terms of T50, an increase of 4.7 days was observed per one dS/m increase in salinity stress and the lowest T50 was estimated at a methyl jasmonate solution concentration of 78.68 mM. In terms of the activity of germination enzymes, reduction of 0.031 μmol/ml/min per 1 dS.m increase in salinity stress and the highest amount of α-amylase were estimated 72.6 μmol/ml/min at a methyl jasmonate solution concentration of 73.33 mM. Also, the lowest activity of β-amylase enzyme was 0.79 μmol/ml/min at a concentration of 5.6 dS/m salinity stress and the highest activity of β-amylase enzyme was estimated to be 1.7 μmol/ml/min at a methyl jasmonate solution concentration of 86.67 mM. The highest activity of catalase (25.7 ∆A/mg protein/min) was observed at 14.72 dS/m salinity stress and the lowest activity of catalase enzyme (8.9 ∆A/mg protein/min) was estimated at 5.88 mM methyl jasmonate solution. The highest activity of peroxidase enzyme (22.06 ∆A/mg protein/min) was at 24.3 dS/m salinity stress and the lowest activity of the enzyme peroxidase (2.5 ∆A/ mg protein/min) was determined at a methyl jasmonate solution concentration of 266.66 mM.
Conclusions: In general, pre-treatment of methyl jasmonate can reduce the germination time, increase the rate of germination and reduce the oxidative stress in salt stress conditions by improving the activity of germination enzymes, increasing the activity of enzymes, increasing the activity of hydrolyzing enzymes and increasing the easy availability of seedlings to nutrients during germination.

 
Highlights:
1- Germination rate and percentage and morpho-physiological changes of Mung bean seed as affected by methyl jasmonate were investigated.
2- The role of alpha and beta amylase germination enzymes in accelerating the production of Mungbean seedlings under saline conditions were estimated.
3- Methyl jasmonate- induced catalase and peroxidase enzymes activity in resistance to salinity stress were estimated.

Introduction: Today, population growth has placed a significant burden on global agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the most harmful factors in the arid and semi-arid regions of the world that influences crop production. Seed priming is a technology by which seeds are physiologically and biochemically prepared for germination before being placed in their bed and exposed to the ecological conditions of the environment. The aim of this study was to evaluate the efficiency of the effect of chitosan on bean germination indices under salt stress.
Materials and Methods: The experiment was conducted as factorial based on a completely randomized design with four replications in a row (tube or sandwich culture) between filter paper at the University of Mohaghegh Ardabili in 2021. Treatments included four salinity levels (0, 50, 100, and 150 Mm) and four chitosan levels (0, 25, 50, and 75% by weight volume), all of which had been dissolved in 1% acetic acid. The studied traits included germination coefficient, allometric coefficient, daily germination rate, mean daily germination, seedling length and weight index, radicle length, plumule length, seedling length, radicle fresh and dry weight, plumule fresh and dry weight and residual dry weight. Data analysis was performed using the SAS 9.2 software and Duncan's test at p<0.05 probability level was used for mean comparison.
Results: The results showed that salinity stress decreased allometric coefficient (AC), seedling length vigor index (SLVI), radicle and seedling length (RL and SL), and radicle fresh and dry weight (RFW and RDW) and increased daily germination rate (DGS) and residual dry weight (RDW). Seed pretreatment with chitosan increased AC, SLVI, RL, SL, RFW, and RDW. The comparison of the means showed that there was a significant difference between the levels of chitosan so that the highest number of traits was obtained from the use of 75% chitosan and the lowest was obtained from the chitosan-free treatment. SLVI, SL, and RDW in 75% chitosan pre-treatment were higher at about 31, 26, and 27% compared to the control (priming with distilled water), respectively. The highest AC was observed in priming with 50% chitosan. Comparison of the mean for salinity stress also showed that the highest and lowest values of the measured traits respectively were obtained from the application of 0 and 150 Mm salinity levels. Also, with increasing salinity, chitosan increased germination coefficient (GC), seedling weight vigor index (SWVI), plumule length (PL), and plumule fresh and dry weight (PFW and PDW).
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with 75 % Chitosan may be considered an effective way to improve seed germination of bean. It also can reduce the harmful effects of salinity stress on some traits in bean seedlings and improve seedling growth. Also, pretreatment with distilled water is an easy, low-cost and effective way to increase bean seedling germination and growth indices. Farmers can use this method for fast germination and better seedling growth under salt stress conditions.

Highlights:

Extended Abstract
Introduction: Lallemantia royleana is an annual herbaceous plant of Lamiaceae family in different parts of Europe, the Middle East, and especially Iran. Cyamopsis tetragonoloba L. is a plant of the legume family. A common feature between these two plants is hydrocolloid gums, which stabilize some food emulsions by absorbing water and increasing the viscosity or forming a gel in the aqueous phase. Due to its diverse and rich vegetation, Iran can produce countless types of plant gums, and many seeds such as Lallemantia royleana and Cyamopsis tetragonoloba contain valuable gums. Considering the important therapeutic and industrial applications of C. tetragonoloba and L. royleanaplants and the need for more information and reports on determining the best humic acid level and salt stress tolerance of these plants, the purpose of this research is to investigate the tolerance of two L.  royleana and C. tetragonoloba plants to salinity stress in the germination stage and the initial stages of the growth of two plants under the humic acid application.
Materials and Methods: The experiment was carried out as factorial in a completely randomized design with three replications at the seed laboratory of the Faculty of Agriculture of Zabol University in 1400. In this experiment, salinity stress was investigated using sodium chloride at control (no salinity), 70, 140, 210 mM levels and humic acid at (0, 40, 80, and 120 mg/L) levels. Humic acid solution at different salinity levels was added to each petri dish containing 25 seeds.
Results: The results showed that salinity stress decreased germination percentage, radicle length, plumule length, seedling length and seedling dry weight of C. tetragonoloba. In this plant, the germination percentage decreased by 35.34% compared to the control as the salinity stress level increased to 210 mM, and with the increase of the stress to more than 140 mM, a significant decrease in the germination percentage was observed. The maximum plumule length of L. royleanaplants was obtained in 70 mM salinity treatment and 40 mg/L fertilizer level. The maximum radicle length in the L.  royleanaplants plant was obtained in the treatment of 40 mg/L of humic acid at a 70 mM salinity stress level. Also, the results showed that the maximum radicle length (1.46 cm) in the C.  tetragonoloba plant was related to humic acid pretreatment at 70 and 140 mM salinity and fertilizer levels of 40 and 80 mg/L.
Conclusion: In general, it can be stated that the germination indices significantly decreased under stress conditions, and this indicates that humic acid is a suitable pretreatment that can improve the growth indices of C. tetragonoloba and L.  royleanaplants under stressed and non-stressed conditions. With the application of humic acid at all salinity levels except 210 mM, the germination indices in the two mentioned plants were in a favorable condition.

Highlight:
1- The salinity stress tolerance threshold was studied in Cyamopsis tetragonoloba and Lallemantia plants.
2- Humic acid fertilizer in this study mitigated the destructive effects of salinity stress in Cyamopsis tetragonoloba and Lallemantia plants.

Extended Abstract
Introduction: At present, the drastic increase in population has created an additional burden on the world's agricultural resources. As a result, meeting global food demand and increasing farmers' incomes has become a challenging task. Salinity is one of the abiotic stresses that strongly affect the germination, growth, and yield of crops. Seed priming is a simple technology that hydrates seeds to the point where the metabolic activity for germination is initiated without radicle emergence. In fact, the seeds are physiologically and biochemically prepared to germinate before being placed in their bed and exposed to environmental conditions. This research was conducted to investigate the effect of seed priming with chitosan on germination indices and biochemical traits of beans under salt stress.
Materials and Methods: This experiment was conducted at the University of Mohaghegh Ardabili in 2021 as a factorial in the form of a completely randomized design with four repetitions. The treatments included four levels of salinity (0, 50, 100, and 150 mM) and four levels of chitosan (0, 0.25, 0.50, and 0.75% w/v), all of which were dissolved in 1% acetic acid.
Results: The results showed that salinity stress decreased germination percentage (GP), peak value (PV), and germination value (GV). However, seed priming with different levels of chitosan, especially 0.75% chitosan, improved GP, PV, and GV by 7, 21, and 17%, respectively, compared to the control. Proline content and polyphenol oxidase enzyme activity went up with increasing salinity. However, the application of chitosan 0.75% increased these traits by 34% and 43%, respectively, compared to the control (priming with distilled water). Electrolyte leakage in priming with 0.75% chitosan decreased by 31% compared to the control, which indicates the maintenance of the cell membrane stability. The content of soluble sugars in the treatment with 0.75% chitosan and 150 mM salinity showed an increase of about 78% compared to the control. The highest correlation among traits was observed between peak value and germination coefficient (r²=0.99) and between proline and polyphenol oxidase enzyme (r²=0.92).
Conclusions: The results of this study show that among the different treatments, pre-treatment of seeds with 75 % Chitosan may be considered an effective way to improve germination indices and biochemical characteristics of beans and it can be used as a treatment to deal with salinity conditions in bean seedlings and improve their seedling growth.

Highlights:

1. Seed priming using chitosan improved germination indices of common bean seeds under salt stress.
2. Priming with chitosan increased proline and polyphenol oxidase enzyme.
3. A chitosan concentration of 0.75 V/W showed a better effect on germination indices and biochemical characteristics.
4. Priming with chitosan can be a suitable method to mitigate the negative effects of salinity, increase germination indices, and improve the biochemical characteristics of beans.