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Sayyed Jalil Mirmahmood, Mohammad Javad Ahmadi-Lahijani, Yahya Emam,
Volume 1, Issue 2 ((Autumn & Winter) 2015)
Abstract

Osmotic stress is the most important of the abiotic stresses that lead to limitation of growth and yield in rapeseed. This study was conducted to examine the effect of cycocel seed priming on osmotic stress tolerance in germination and early growth stages of rapeseed, as a factorial experiment based on completely randomized design at Agriculture College of Shiraz University in 2012. The treatments included seed priming in three cycocel concentrations: 0 (without priming as control), 2.5 and 3.5 g L-1 and osmotic stress in five levels: 0 (as control), -0.3, -0.6, -0.9 and -1.2 MPa using polyethylene glycol. The results showed that osmotic stress was significantly reduced germination percentage (15.1%), germination rate (15.3%), radicle length (29.5%), plumule length (31.6%), radicle fresh weight (22.4%), plumule fresh weight (37.6%) and vigor index (39.9%). Furthermore, osmotic stress leads to increase radicle to plumule fresh weight and radicle to plumule length ratio as 6.8 and 24.3 percent, respectively. Seed priming with cycocel reduced the adverse effects of osmotic stress on measured parameters. Although, there was no positive effect on germination percentage and rate under osmotic and nonosmotic conditions for cycocel in both concentrations, but cycocel at 3.5 g L-1 appeared to have a greater positive effect than 2.5 g L-1. Considering positive impact of cycocel seed priming on the reduction adverse effects of osmotic stress further research on cycocel seed priming and osmotic stress tolerance is recommended under field conditions.


Mansour Taghvaei, Neda Aliolad,
Volume 1, Issue 2 ((Autumn & Winter) 2015)
Abstract

Trittipyrum is an important annual grass plant for forage production in arid and semiarid regions. The effects of drought stress on Trittipyrum lines were evaluated in the field experiment in a randomized complete block design with a factorial experiment involving three replications in 2012. Treatments were water stress (field capacity (FC), 75% of FC, 50% of FC and 25% of FC throughout the experimental period and 13 primary Trittipyrum lines ((St/b)(Cr/b)F4, (Ma/b)(Cr/b)F4, (Ma/b)(Cr/b)F3, (Ka/b)(Cr/b)F2, (Ka/b)(Cr/b)F3, (Ka/b)(Cr/b)F5, (Ka/b)(Cr/b)F6, La(4b,4d)/b, St/b, Cr/b, La/b, Ka/b, Az/b). The results showed that drought stress had significant effects on seedling traits. Drought stress significantly decreased shoot length, root length, shoot dry weight, root dry weight, seedling dry weight, seedling length vigor index and seedling weight vigor index. The results of mean comparison revealed that (az/b)(cr/b)F5 and Kz/b lines were the most sensitive and the most tolerant lines to drought stress in early vigor stage, respectively. Although the response of Trittipyrum lines was different to drought stress; but the result indicated that Trittipyrum lines are sensitive to drought at emergence stage.

Hossein Sadeghi, Mohammad Delaviz, Hadi Pirasteh-Anosheh, Gholamhassan Ranjbar,
Volume 3, Issue 1 ((Spring and Summer) 2016)
Abstract

Germination is the first and the most stages for sainfoin (Onobrychis viciifolia) growth; which it has especially sensitivity to environmental stresses such as alkalinity. The current study was conducted to evaluate the effectiveness of seed pre-treatment methods on improving sainfoin tolerance to alkali stress in germination, early growth and its recovery as a factorial experiment based on a completely randomized design in College of Agriculture, Shiraz University in 2013. The first factor was four seed pre-treatment methods (seed with the pod, seed without the pod, pre-chilling of seed without pod and hydro-priming of seed without pod) and the second factor was five alkali stress levels (pH= 6.7, 7.9, 8.9, 9.8 and 10.7). Alkali stress levels were prepared using two neutral salts (Na₂SO4 and NaCl) and two alkaline salts (NaHCO3 and Na2CO3). The results showed that germination percentage was decreased as alkalinity (pH) levels were enhanced; so that, there were no germinated seeds in 9.8 and 10.7 treatments. Alkali stress reduced initial germination percentage (51.9%), final germination percentage (51.8%), plumule length (55.7%) and radicle length (72.2%). Under all alkalinity conditions, the lowest seed germination and seedling growth were observed in with pod seed, followed by pre-chilling treatments; while their highest were achieved in without pod seeds and hydro-priming treatments. The highest recovery was observed in without the pod, followed by hydro-primed seeds. Recovery was observed in Pre-chilled and with pod speeds up to 7.9 and in hydro-primed and without pod speeds up to 8.9.


Farzaneh Fakhari, Hossein Sadeghi,
Volume 3, Issue 1 ((Spring and Summer) 2016)
Abstract

There have been a few studies on removing the seed pods in annual medics, despite its importance. To investigate the role of pod removal on seed germination, seedling growth and antioxidant enzyme activities in annual medic (Medicago scutellata L.) Under salt stress, a factorial experiment was conducted based on a completely randomized design with four replications in 2014. Salinity at 5 levels: 0.62 (tap water as a control), 3, 6, 9 and 12 dS m-1 was applied using sodium chloride. The results showed that salt stress caused changes in the characteristics of germination, seedling growth and antioxidant enzyme activities. With increasing in salinity levels, rate and percentage of germination as well as root length, shoot length and seedling weight was significantly decreased. However, increasing salinity levels increased the activity of antioxidant enzymes. Germination and growth in seed without pod was greater than those in seeds with pod; however, there were no significant differences between antioxidant enzyme activity; except about ascorbic peroxide that was significantly higher in seed without a pod. In general, salinity reduced germination and growth and increased antioxidant enzyme activity of annual medics. The results showed that planting seeds without pod had advantages for better germination and growth, especially under saline conditions.


Gholamhassan Ranjbar, Hossein Ghadiri,
Volume 3, Issue 2 ((Autumn & Winter) 2017)
Abstract

A controlled experiment was run to quantify emergence of Kochia indica under different temperature, salinity and seeding depth levels at Yazd National Salinity Research Center in 2013. Treatments were five day/night temperature regimes: 20/10, 25/15, 30/20, 35/25 and 40/30 °C, five salinity levels: 2, 6, 10, 14 and 18 dS m-1, and seeding depth on the surface (0 mm), 5, 10 and 15 mm. Final emergence percentage, emergence rate index and elapsed time (days) to reach 50% of the maximum emergence were measured. The results showed that the highest and lowest final emergence percentages were observed at 25/15°C and 40/30°C day/night, respectively. Final emergence percentages at salinity levels of 6, 10, 14 and 18 dS m-1were, respectively, 9, 22, 36 and 57% lower than 2 dS m-1. Final emergence percentages for 5, 10 and 15 mm seeding depths were, respectively, 30, 44 and 72% lower, as compared with the placement of seeds on the soil surface. Regression analysis showed that final emergence percentage linearly decreased with increase in salinity and seeding depth levels. However, elapsed time (days) to reach 50% of the maximum emergence (T50), increased as salinity and seeding depth increased, so that the highest T50 was obtained for 18 dS m-1 and seeding depth of 15 mm. Increase in salinity and seeding depth was associated with a significant decrease in emergence rate index. In addition, using a logistic regression equation, emergence rate of K. indica was quantified on each day after sowing for each temperature-salinity combination to predict the distribution range of the plant in these situations.
 


Zeinab Pirsalami, Asad Masoumiasl, Hossein Shahsevand Hasani, Masoud Dehdari,
Volume 7, Issue 2 ((Autumn & Winter) 2021)
Abstract

Extended Abstract
Introduction: Salinity stress is one of the most important factors in decreasing crop yield. Crossing between cultivars and wild relatives is one of the methods to creating salinity tolerant plants that has led to the creation of new Tritipyrum cereals. Investigation of the effect of salinity stress at the germination stage is a reliable test in assessing salinity tolerance of many species; it reduces percentage and rate germination as well as decreases of root and shoots growth. This research aims to investigate the effects of different levels of salinity stress on germination of promising non-Iranian Tritipyrum lines and two wheat cultivars, Alvand (salinity tolerant) and Ghods (salinity sensitive).
Materials and Methods: The experiment was conducted in factorial based on the completely randomized design at the Faculty of Agriculture, Yasouj University. The first factor consisted of 13 Tritipyrum lines and two wheat cultivars and the second factor consisted of different salinity levels (240, 160, 80, 0 mM NaCl). After surface disinfection and seed culture in a petri dish, germination-related traits were measured until the 14th day.
Results: The results showed that by increasing salinity level, germination rate and percentage, root length, shoot length, dry and fresh root weight, and shoot dry weight decreased. The highest percentage (79.79%) and rate (75.74 seed per day) of germination in stress and non-stress conditions were related to the Az/b line. The germination percentage of the Alvand tolerant cultivar (55.59%) was higher than 5 Tritipyrum lines but less than the other 7 lines, its germination rate (53.69 seed per day) was higher than 10 Tritipyrum lines. The percentage and germination rate of sensitive cultivar Ghods (40.98 and 36.87 seed per day, respectively) were lower than all Tritipyrum lines. Under salinity stress, the La/b line had the highest root length (7.77 cm) which was even longer than the root length of the Alvand tolerant cultivar (4.9 cm). The highest root dry weight (0.027 g) under stress conditions was related to the Ka/b line and the lowest root dry weight (0.013 cm) was related to the Ghods cultivar. Among germination traits, the highest and the lowest heritability were related to shoot length under stress and non-stress conditions and root fresh weight (under non-stress conditions) and root length (under stress conditions), respectively. Genetic variance of shoot length and germination percentage in non-stress conditions was higher than stress conditions and selection under non-stress conditions had a higher yield than stress conditions. Clustering of genotypes by cluster analysis divided the genotypes into four groups under normal and salinity conditions. Under salinity stress, the salt-tolerant cultivar was placed alone in the fourth cluster. The salinity-sensitive cultivar was also in the third cluster with the St/b line. The rest of the Tritipyrum lines were clustered in the first and second clusters, with (Ka/b)(Cr/b)F6 hybrid line in the first cluster. Salt stress condition seems to have separated Qods from all Tritipyrum lines (except St/b), but under normal conditions, it did not indicate clustering accuracy of the studied genotypes.
Conclusion: The results of this study demonstrated salinity tolerance in the most simple and hybrid lines of this plant at the germination stage, among them (St/b)(Cr/b)F3, (Ka/b)(Cr/b)F6, and (Ka/b)(Cr/b)F3 and La(4B/4D)×(b) and the simple lines La/b, Az/b and St/b were better than others. Therefore, these selected lines can be considered in further complementary studies.
 

Highlights:
1. The studied plant is new and needs to be examined at the germination level before introducing.
2. Simple lines with the hybrid lines of this new plant have been studied that can show the effect of crosses.
3. Grouping of lines for tolerance or susceptibility is done solely based on germination traits.


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