جستجوی مقالات مرتبط با کلیدواژه « Hydropriming » در نشریات گروه « اکولوژی »

Drought stress is one of the most important factors limiting growth and crop production in the arid and semi-arid world. Plant response to drought stress depends on the type, severity, and duration of stress, plant species, and stress occurrence stage and farm management.
The sesame, among crop plants, is resistant to drought and heat stress and has great importance in the agriculture development of arid and semi-arid region for summer planting. But this plant is sensitive to drought stress at seedling stage and during flowering to grain filling. To overcome the drought stress, the biological solution is one of the basic strategies that should be considered and can be noted the mycorrhizal fungi. One of the most important types of mycorrhizal is arbuscular rmycorrhizal Fungi, which is important in terms of agriculture; because most crops and horticultural ability to coexist with this type of mycorrhiza. In order to evaluate the effect of irrigation levels and arbuscular mycorrhizal fungi symbiosis on yield and yield components of sesame, an experiment was carried out as split-factorial based on a randomized complete block design with three replications at Agricultural Research Station of Haji Abad, Hormozgan province, Iran during growing season 2014-2015. Experimental factors included: drought stress as main factor in 3 levels: 100% water requirement (normal irrigation), 70% water requirement (moderate stress)and 50% water requirement (Severe stress), the priming as sub factor in 3 levels: without priming (control treatment), hydropriming and osmopriming and the mycorrihizal fungi application as other sub-factor in 3 levels: [without mycorrihizal fungi application(control), mycorrihizal fungi application (Glomus mosseae) and mycorrihizal fungi application (G. intraradices). Analysis of variance data showed that the effect of drought stress had significant effect (P≤0.01) on all traits were studied. The effect of mycorrhizal inoculation was significant on measured plant responses (P≤0.01). Priming treatments were significant on seed number per capsule (P≤0.01) and thousand grain weight and grain yield, biological (P≤0.05). Interaction effects of mycorrhiza × irrigation was only significant on grain yield (P≤0.05), the effects of the interaction of mycorrhiza × priming on seed number per capsule (P≤0.01) and the thousand grain weight (P≤0.05) were significant. The results also showed that the highest grain yield and all measured traits obtained when using irrigation water requirement by 100 percent (normal irrigation). Inoculation with mycorrhizal fungi species G. mosseae and G. intraradices compared to lack of mycorrhizal fungi (control treatment) improved yield by 10.4 and 4.7 percent. Priming treatments compared to non-primed (control treatment) increased seed yield by as much as 2 percent. Drought stress decreased sesame yield, however, the using mycorrhizal fungus can be reduced that effect. The effect of two species of mycorrhizal on sesame yield and their effect on reducing stress damage was different; So that mycorrhizal symbiosis G. mosseae has more than the G. intraradices and avoided the sharp drop in sesame yield in drought stress treatments. The results of this study showed that drought stress and water shortage decreased significantly yield and yield components of sesame. Mycorrhizal fungi improved the absorption of moisture and nutrients under water stress and increased plant resistance to water stress, therefore increased yield and yield components of sesame. The species of G. intraradices fungi compared to G. mosseae was more efficient in terms of resistance to water stress. Thus, it seems that mycorrhizal, in addition to improving the yield due to increased root system development and consequently increasing the availability of moisture and access to nutrients, can have a positive effect on reducing the effects of irrigation deficiency on sesame plants. Seed priming, due to better germination, rapid seedling growth, proper establishment and, finally, the optimal use of nutrients and environmental factors, ultimately increased yield.

Corn (Zea mays L.) is the third most important cereal crop in the world after wheat and rice (Lashkari et al., 2011). Corn production has been extended in to the whole world during the course of the last century due to its compatibility. It has more diversity compare to other cereal. Many corn types are cultivated, including field corn, ornamental corn, popcorn, sweet corn and several different supersweet corns. Sweet corn, considered a vegetable, is a special type of corn with particular characteristics, such as sweet taste, thin pericarp and endosperm with delicate texture, and high nutritional value. It is destined exclusively for human consumption, in fresh form or in processed foods, whereas the straw can be used for silage after harvest (Santos et al., 2014). Sweet corn seeds germinate slowly and exhibit poor seedling vigour. Poor germination in sweet corn has been attributed to low seed vigour and susceptibility to seed and soilborne diseases (Ratin et al., 2006). Seed priming is the one of efficient method to improve germination and emergence. In addition, transplanting provides optimal environmental conditions for seed germination and avoids planting seeds in disease-contaminated soil (Khalid et al., 2012).
To investigate the effect of seed priming and transplanting on morphological characteristics, yield and yield components of supersweet corn a series of greenhouse and field experiments were conducted in a factorial based design on a randomized complete block in 2013. This experiment was conducted in the greenhouse to determine the best seed priming treatments. The treatments were hydro priming, Poly ethylene glycol (6000) -0.4 and -0.8 MPa, Sodium Sulphate 0.1 and 0.5%, Zinc Sulphate 1 and 0.5%, Copper Sulphate 0.1 and 0.5% and Control for 36 hours. After that the seeds washed by distillated water and dried back in laboratory conditions. Then treated seeds were sown in trays that contained by cocopeatand vermicompost. The emerged seeds were counted daily for fourteen days. Based on mean emergence time (MET) and percentages of emergence, the best priming treatments were selected to prime the seeds for transplant production and direct sowing in the field experiment. The factors for field experiment included four treatments of seed priming (hydropriming, polyethylene glycol (PEG) -0.4 MPa, sodium sulfate 0.1% and control) and planting methods in four levels (transplanting the seedlings grown in two different cell sizes (25 ml and 100 ml) and two direct seeding dates (the first one was at the time of planting seeds in the trays (5th June) and the second was at the time of transplanting to the field (26th June)). The determined parameters were established plants, plant height, number of leave, number of leave above ear, ear length, number of rows per ear, number of kernel per row, 1000 seeds weight and grain yield.
The results of greenhouse experiment showed that the highest and the lowest amount of mean emergence time related to control and Sodium Sulphate 0.1% respectively. The highest percent of emerged plant (94%) was observed in the hydropriming treatment while there was no significant difference between hydropriming, Sodium Sulphate 0.1 % and Polyethylen Glycol -0.4 MPa. Therefore, hydropriming, Sodium Sulphate 0.1 % and Polyethylen Glycol -0.4 MPa alongside control were used to prime the seeds sowing in order to produce transplants for the field experiment for further investigation. The results of the field experiment showed that seed priming had no effect on the studied traits in the field. Planting methods had significant effect on crop establishment, plant height, number of leave, number of leave above ear, ear length, number of rows per ear, number of kernel per row and the grain yield. The highest and lowest grain yield were recorded for transplanting in 25 CC cell sizes (10.11 t.ha-1) and direct seeding in 26th June (6.5 t.ha-1) respectively. The result showed there was a high correlation (r =0.64**) between number of established plants and grain yield.
Priming was not useful in field, but farmers could use seed priming to produce seedlings. It seems that the most important benefit of transplanting is obtaining high value of plant establishment in order to achieve optimum plant density.