Iranian Journal of Seed Research

Extended Abstract
Introduction: Salinity is one of the most harmful factors in the arid and semi-arid regions in the world that influences crop production. Micro-organisms can play an important role in adaptation strategies of plants to stress and by producing of plant growth promotion hormones such as cytokinin, gibberellic acid, auxin, amino acids, and vitamins of B groups help to more growth of the plant and have an important role in increasing of tolerant in plants in unsuitable environments.
Material and Methods: This experiment was established as factorial in a completely randomized design with three replicates at Shahed University of Tehran. The treatments included salinity in four levels (0, 40, 80, and 120 mM NaCl) and biological pre-treatment at eight levels (control: non-inoculation), inoculation with Trichoderma harzianum fungus strain BI, with inoculation with azotobacter bio-fertilizer, inoculation with phosphate bio-fertilizer, inoculation with both bio-fertilizer, a combination of fungus and azotobacter bio-fertilizer, a combination of fungus and phosphate bio-fertilizer, inoculation with fungus and both bio-fertilizer). In this experiment, germination indices, photosynthetic pigments, proline, sodium, and potassium amount, starch, carbohydrate, electrical conductivity, and soluble protein were studied.
Results: The result showed that the interaction effect of biological pre-treatment and salinity was significant on all indices except chlorophyll b and anthocyanin. Treatment of phosphate bio-fertilizer had maximum positive effect on germination percent with increasing salinity. In the co-application of fungus and azotobacter bio-fertilizer treatment, the amounts of chlorophyll a, b, and total chlorophyll in different levels of salinity were more than the other treatments and were incremental with further increasing of salinity level. The highest amount of potassium (4.10 mg/g FW) obtained in the co-application of a fungus with azotobacter bio-fertilizer under 40 mM of salinity and showed 22.02 percent increase in comparison to control. With rising salinity, fungus treatments were the most effective in preventing more increasing sodium amount and azotobacter bio-fertilizer in preventing more reducing potassium. The number of soluble proteins was the highest amount (13.09 mg/g FW) in the co-application of fungus and both bio-fertilizer and showed 38% increase compared to control at the same level of salinity.
Conclusion: The uses of microorganisms reduced the negative effect of salinity and led to the increase of potassium in shoots. Also, utilization of microorganism led to lower electrical conductivity at the highest salinity level compared to control and thus, positively affected germination.
 

Highlights:
1- The effect of bio- primed bacteria and fungus on physiological traits of Pumpkin was investigated seedlings under salinity.
2- Threshold of tolerance of pumpkin seedlings to salinity was improved by increasing K content and reducing Na under bio- primed treatments.
3- Osmolite components of pumpkin seedlings increased under bio- primed treatments.

Extended Abstract
Introduction: Due to the fineness of parsley seeds, several problems may arise, such as the impossibility of using planting machines and the displacement of seeds by water, reduced germination and growth due to increased planting depth or lack of seed establishment in the soil, and consequently, increased seeding rate. Therefore, it is necessary to use methods to increase germination ability and improve the establishment of parsley seeds and seedlings in the soil. This experiment aimed to determine the most effective biopriming and gibberellin treatments for better germination and establishment of parsley seeds.
Materials and Methods: In order to determine the best biopriming and gibberellin priming treatments on germination characteristics and establishment of parsley seed, three experiments with four replications were conducted in the seed science and technology laboratory of Yasouj University in 2015 and 2016. The first biopriming experiment was carried out using growth-stimulating bacteria in a completely randomized design with eight treatments including bacterial isolates Pseudomonas fluorescens strain 21, Bacillus biosobetyl strain, Enterobactercus cloac strain 5, also two and three compounds of these bacteria along with control treatment. The second experiment was carried out with five treatments of Trichoderma harziarum (T36, T39, T42, and T43) isolates with control treatment. Finally, the third experiment was performed as a factorial in a completely randomized design with concentrations of gibberellin hormone (0, 50, 100, and 200 ppm) and prime times (6 and 12 hours). The measured traits were seedling length, seedling dry weight, germination percentage, and seedling length vigor index.
Results: The results showed that the best treatments for the first experiment were biopriming with Enterobacter + pseudomonas, for the second experiment biopriming with T36 fungus strain, and for the third experiment 50 ppm of gibberellin prime for 6 and 12 hours. The results showed that the majority of biopriming and hormone prime treatments improved the quality of parsley seeds so that the germination percentage in control seeds was 70%. This value increased by 31% compared to control treatment following priming with growth-stimulating bacteria (Pseudomonas+ Enterobacter), which showed the highest rate among all treatments applied in this study. The use of 50 ppm of gibberellin priming for 6 and 12 hours increased germination by 19% and 14% compared to the control treatment, respectively.
Conclusion: The results of this study showed that biopriming with Pseudomonas + enterobacter had the greatest effect on improving the quality and germination characteristics of parsley seed. In general, biopriming except for T42 fungi, and also gibberellin priming showed improvement in the quality and germination properties of parsley seed.

Highlights:
1. The effects of using biopriming and hormone prime are common, while it is not clear for parsley.
2. Biopriming with Pseudomonas+ enterobacter had the greatest effect on improving the quality and germination characteristics of parsley seeds.
3. Priming with T42 fungus reduced the quality and germination characteristics of parsley seeds.

Extended abstract
Introduction: Seed germination and emergence are the most sensitive stages of growth and development of rice plants. In this regard, the use of growth-promoting fungi in the form of seed biological pretreatment (bio-priming) for germination and optimal growth of seedlings can be feasible. Therefore, this study aimed to investigate the effect of isolated root symbiotic fungi on the improvement of germination and growth components of two traditional and bred rice (Oryza sativa L.) cultivars.
Materials and Methods: This experiment was done as a factorial-based completely randomized design with three replicates at Sari Agricultural Sciences and Natural Resources University in the summer of 2021. Experimental treatments included 22 isolates of root symbiotic fungi (isolated and identified from previous experiments) and control (without inoculation) and two native (Hashemi) and bred (Roshan) rice cultivars. After the end of the germination period, the number of normal seedlings was counted and five normal seedlings were randomly selected to measure the length of the root, stem, and seedling as well as the fresh and dry weight of the root, stem, and seedling.
Results: Based on the results of cluster analysis the fungi were divided into four and three groups in Roshan and Hashemi cultivars, respectively. In both cultivars, group I was selected as the best group. In this group, the highest positive effect on vegetative traits varied from 5 to 59% compared to the control in fungal treatments was related to Bjerkandera adusta (ST1), Trichoderma atroviride (SF1), Monosporascus cannonballus (B3) and Trichoderma atroviride (SN1) in Roshan cultivar and Bjerkand adusta (ST1) in Hashemi cultivar. The best fungal treatments in germination traits of Roshan and Hashemi cultivars were Chaetomium globosum (SE2) and Bjerkandera adusta (ST1), respectively.
Conclusions: Overall, the results indicated the positive effect of most symbiotic fungi on the growth and germination characteristics of rice in both Roshan and Hashemi cultivars. These results show that symbiotic fungi use different mechanisms to increase growth and improve germination indicators in plants.

Highlights:
1- Growth-promoting fungi in the form of seed biological pretreatment were used (bio-priming) for optimal growth and germination and of rice seedlings.
2- The effect of native fungi isolated was investigated for the first time in two native (Hashemi) and bred (Roshan) rice cultivars.