Search published articles


General users only can access the published articles

Seyedeh Arhameh Fallah-Shamsi, Hemmatollah Pirdashti, Aliakbar Ebadi, Masoud Esfahani, Mahmood Raeini,
Volume 4, Issue 1 ((Spring and Summer) 2017)
Abstract

In order to study drought stress effect at the reproductive stage on seed germination characteristics of seven rice genotypes, an experiment was carried out at Sari Agricultural Sciences and Natural Resources University in 2014. This study was conducted on drought-stressed seeds and seeds grown under normal conditions. The results of orthogonal mean comparison among non-stressed seeds showed that local genotypes had a lower germination index, germination rate, water percentage of seedling tissue, shoot length and root dry weight than the improved genotypes. Among stressed seeds, however, local genotypes had a higher germination index and germination rates than those of improved genotypes. Comparison of non-stressed seeds of susceptible and tolerant genotypes indicated that susceptible genotypes had a higher germination index, germination rate and germination percentage than tolerant genotypes. On the other hand, the comparison of the stressed seeds of susceptible and tolerant genotypes revealed that drought stress increased the time to 10, 50, 90 and 95% germination, water percentage of seedling tissue and plantlet length in susceptible genotypes, which were higher than those of tolerant genotypes. In conclusion, it seems that drought stress at reproductive stage has a significant effect on germination characteristics of the plant’s following generation. However, their responses are different, depending on the level tolerance of the genotype to stress and genetic origin.

Highlights: 
1-  Drought stress at reproductive stage has a significant effect on germination characteristics of the following generation of the rice plant.
2-  Among stressed seeds, local genotypes have a higher germination index and germination rates than those of the improved genotypes.
3-  Drought stress increases the time of germination in susceptible genotypes, which is higher than that in the tolerant genotypes.

Mahnaz Aghdasi, Pooyan Mehrabanjoubani, Tahereh Nezamdoost, Fatemeh Tamaskani,
Volume 4, Issue 2 ((Autumn & Winter) 2018)
Abstract

The present study sought to compare the effect of seed priming by hydropriming, ascorbate and calcium chloride (CaCl2) versus different concentrations of silver nanoparticles on two Iranian rice cultivars (Hashemi and Shiroodi) under drought stress. The experimental design, which was factorial, was completely randomized. The first factor was control (without priming), hydro-priming, 20 mg.L-1 calcium chloride, 20 mg.L-1 ascorbates and 20, 40 and 80 mg.L-1 of silver nanoparticles. The second factor was the drought stress, including control, -1.48 and -4.91 bars created by polyethylene glycol 6000 solutions. In plants without drought stress, the time required to reach 50% germination (T50) reduced to 34 and 54 percent under ascorbate and CaCl2 priming in the Hashemi and Shiroodi cultivars, respectively.  In the drought stress condition, ascorbate and hydropriming pretreatments decreased T50 and the time required to reach 90% germination (T90) more than silver nanoparticles, especially in the Shiroodi cultivar. On the other hand, in comparison with other pretreatments, CaCl2 had an important role in increasing the growth factors in all of the drought stress treatments. Although 40 mg.L-1 silver nanoparticles increased the growth factors to some extent, it seems that higher levels of silver nanoparticles cause stress in seeds and therefore decrease the seed germination and growth of seedlings. By decreasing reactive oxygen species, Ascorbate improves the germination and by increasing plasma membrane efficiency, CaCl2 enhances the seedling growth under drought stress.

Highlights:

  1. Silver nanoparticles increased the effect of stress on the seedlings of rice cultivars.
  2. Ascorbate and calcium chloride improved the germination and seedlings growth of the rice cultivars, respectively under drought stress conditions.

Nafise Taghizadeh, Gholamali Ranjbar, Ghorbanali Nematzadeh, Mohammadreza Ramzanimoghdam,
Volume 4, Issue 2 ((Autumn & Winter) 2018)
Abstract

Salinity is one of the most important factors limiting agricultural production. Cotton, as an oil-fiber plant, is one of the most important industrial plants and is sensitive to salinity, especially at germination and seedling stages. Therefore, in this study, 14 allotetraploid varieties of commercial and local cotton were selected. The study was carried out as factorial with a completely randomized design and three three replications, using the sandwich method. Germination tests were performed at three salinity levels of 0, 8 and 16 ds.m-1. Afterwards, root and shoot length, fresh and dry weight of root and shoot, germination percentage, allometric coefficient, seedling water percentage and seed vigor index were measured and stress tolerance indices were calculated based on yield (seedling dry weight) in stress and non-stress conditions. Given these indices, all cultivars were aalyzed at two levels of 8 and 16ds.m-1, using principal component analysis and biplot diagrams were drawn. Finally, the dendrogram classification of genotypes was plotted based on STI indices (stress tolerance index), SSI (stress susceptibility index), and the performance (dry weight plantlet) in stress and non-stress conditions. The result of variance analysis for genotype, salinity and salinity×genotype demonstrated that dry weight root, dry weight shoot, fresh weight root, stem length, vigor index seedling, allometric coefficient, dry weight seedling, and length seedling were significant in p-value 0.01, and fresh weight shoot, length root were significant in p-value 0.05. Clustering and the biplot of the genotypes based on STI and SSI indices at salinity levels of 8 and 16 ds.m-1 indicated that the Sepid and Giza genotypes were tolerant and that the Kashmar genotype was sensitive to salt levels at germination stage.
  
Highlights:
  1. The reaction of the cotton cultivars studied was different to levels of salinity stress.
  2. An increase in salt stress caused a significant reduction in the germination characteristics of cultivars of cotton studied.
  3. Bi-plot analysis and clustering based on STI and SSI indices turned out to be a suitable method for clustering cotton cultivars.

Peyman Aligholizadeh Moghaddam, Gholam Ali Ranjbar, Hammid Najafi-Zarrini, Hosein Shahbazi,
Volume 7, Issue 2 ((Autumn & Winter) 2021)
Abstract

Extended Abstract
Introduction: Germination is one of the most important stages of plant growth that determines the durability, establishment and final yield of crops and in regions that due to drought conditions the growth of plant encounters with problem, improving germination traits count as one of the important breeding strategies. The present study was designed to determine the effect of different levels of osmotic stress on germination and seedling traits of some bread wheat cultivars cultivated in cold regions of Iran.
Materials and Methods: In order to investigate the effect of different levels of osmotic stress on germination characteristics of bread wheat cultivars cultivated in cold regions of Iran, a factorial experiment was conducted based on a completely randomized design with 3 replications in which, the first factor consisted of 20 bread wheat cultivars (including rain fed cultivars as well as end-of-season water stress tolerant varieties) and the second factor consisted of 3 levels of osmotic stress (non-stress, -3 and -6 bar stress). Seedling traits such as coleoptile length, shoot length, shoot weight, root length, root weight, root / shoot ratio, root growth angle, germination speed and the germination stress index (GSI) were evaluated. For the experiment concerning the yield comparison, 20 cultivars mentioned above were compared under non-stress and terminal drought stress conditions.
 
Results: The results showed that the ratio of root/shoot length and weight and shoot weight had the highest sensitivity and the lowest number of roots to osmotic stress. Increasing root length as root weight decreased with increasing stress showed that roots became longer and thinner due to stress. Among the genotypes, Saein, Zare, Pishgam, Sadra, Baran and Mihan had desirable traits and CrossMV17, Homa, Orum and Cross Azar2 had no desirable germination traits. In non-stress conditions, 11 genotypes had high coleoptile length including Hashtrood, Azar 2, Saein, CD62-6, CD91-12, Mihan, Baran, Heydari, Homa, Cross Azar 2 and Zare genotypes. At 3 bar stress, 11 genotypes had the highest coleoptile length, with the highest values being assigned to Hashtrood, Heidari and Saein. At 6 bar stress, CD91-12 and CD62-6 lines, Hashtrood, Homa, Pishgam, and Zare had the highest coleoptile length. At 3 bar stress cross Azar 2, Saein, CD62-6, Gascogen and HD2985 demonstrated the highest germination rate. Furthermore, Cross Azar2, HD2985, Gascogen, CD62-6 and Saein led to the best results, respectively. However, in both 3 and 6 bar stress conditions Saein, Cross Azar2, CD62-6 and HD2985 were superior for germination stress index (GSI). For grain yield under normal conditions, Gascogen, Heidari, Pishgam, Orum and Zarrineh had the highest yield and Baran, HD2985, C-88-4, C-9011 and Cross Azar2 were placed next. Under stress conditions Baran, Gascogen, HD2985, Cross Azar2, Heidari and Zarrineh consisted the highest performance. According to STI index Gascogen, Heidari, HD2985 and Zarrineh were the most tolerant genotypes to drought stress. Cluster analysis grouped the studied genotypes into 2 clusters, the first cluster comprising 13 genotypes Heidari, Mihan, HD2985, Baran, Pishgam, Hashtrood, Cross Azar 2, CD62-6, Gascogen, Azar 2, Saein, Sadra and Zare. The second cluster consisted of 7 genotypes C-88-4, Zarineh, C-90-11, Orum, CD91-12, CrossMV17 and Homa. Genotypes of cluster 1 were superior in terms of germination traits such as shoot length, coleoptile length, root length and root weight and reduced root/shoot ratio.
Conclusion: Significant differences in all studied traits among genotypes indicated sufficient genetic variation for selection in germination traits. Results showed that Saein, Zare, Pishgam, Sadra, Baran and Mihan cultivars had desirable germination traits and were superior to other genotypes.

Highlights:
1- The tested genotypes are either newly named or advanced lines and have not been studied for germination traits.
2-The growth angle trait of seed roots through filter paper has received little attention in studies.


Page 1 from 1     

© 2024 CC BY-NC 4.0 | Iranian Journal of Seed Research

Designed & Developed by : Yektaweb


This work is licensed under a Creative Commons Attribution 4.0 International License.