فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 35 (پاییز 1394)

To study the effects of mycorrhizal inoculation of fenugreek (Trigonella foenum-graecum L.) plants and on its growth and yield under drought stress conditions a greenhouse experiment was carried out in split plot using a randomized complete block design at Zabol University green house in 2013. Treatments were three drought stresses: control, mild stress and severe stress (70, 50 and 30% FC) assigned to main plots, and three species of mycorrhizal treatments (Glomus intraradices, G. versiform, G. mosseae and non-inoculation as control) to sub-plots. The effects of drought on all traits under study were significant, and reduced number of leaves per plant, plant height, root length, chlorophyll b and total chlorophyll by 15.6, 7.6, 10.7, 2.5 and 8.4 % and increased proline and carbohydrates by 38.6 and 17.7 % as compared with the control. Mycorrhizal treatments did not affect the amount of carbohydrates and proline content significantly. Interaction of mycorrhiza and drought stress was significant on grain yield, chlorophyll a and total chlorophyll. Among the mycorrhizal strains G. mosseae affected the traits significantly under drought conditions. The results suggested that mycorrhizal treatments of plants at different drought stresses could improve grain yield of fenugreek and reduce the negative effects of drought by increasing photosynthetic pigments and other quantitative and qualitative traits.

To study variations of osmolytes and nutrient elements in wheat genotypes under drought stress a factorial experiment based on completely randomized design with three replications was carried in both greenhouse and laboratory of Mohaghegh Ardabili University, Ardabil, Iran. Treatments consisted of water deficit in three levels (85%, 60% and 35% of field capacity) and five wheat genotypes (Mihan, C-88D-7, C-88D-17, C88D-19 and C88D-20). Results showed that increasing water deficit resulted in reduced amount of potassium, whereas, elements like sodium, phosphorus, proline and soluble sugar were significantly increased. Drought stress, however, reduced the total protein content in C-88D-19, C-88D-17 and C-88D-20 genotypes and, calcium content in ‘Mihan’ and C-88D-19. In the mean time, protein and calcium contents increased in other genotypes in such a way that total protein content of ‘Mihan’ and C-88D-7 and, calcium content of C-88D-20, C-88D- 17 and C-88D-7 were increased with increasing drought stress. Since C-88D-20 showed lowest proline and soluble sugar accumulation and biomass production than other genotypes it would be considered as a sensitive genotype to water stress as compared to the other genotypes.

Rice (Oryza sativa L.) is the staple food of more than half of the population worldwide. Water deficit stress is one of the harsh limiting factors for successful production of crops. Rice during its growing period comes a cross different environmental hazards like drought stress. Recent advance in molecular physiology are promising for more progress in increasing rice yield by identification of novel candidate proteins for drought tolerance. To investigate the effect of water deficit on rice root protein expression pattern¡ an experiment was conducted in completely randomize design with four replications. With holding water for 24¡ 36 and 48 hours along with control constituted the experimental treatments. The experiment was conducted in growth chamber under controlled condition and root samples¡ after stress imposition¡ were harvested for two-dimensional electrophorese (2-DE). Proteome analysis of root tissue by 2-DE indicated that out of 135 protein spots diagnosed by Coomassie blue staining¡ 14 spots showed significant expression change under water deficit condition¡ seven of them at 1% and the other seven at 5% probability levels. Differentially changed proteins were taken into account for search in data bank using isoelectric point and molecular weight to identify the most probable responsive proteins. Up- regulation of ferredoxin oxidoreductase at first 24 hour after applying stress indicates the main role of this protein in reducing water deficit stress effects. On the other hand ribosomal proteins¡ GAP-3 and ATP synthase were down regulated under water deficit stress. Fructose 1¡6-bisphosphate aldolase¡ glucose- 6-phosphate dehydrogenase and chitinase down regulated up to 36 h of stress imposition but¡ were later up- regulated by prolonging stress up to 48 h. It could be inferred the plant tries to decrease the effect of oxidative stress.

Forage legumes respond differently to limited irrigation regimes. Their evaluation may, thus, help to select drought tolerant types for limited irrigation conditions. In this study four type of forage legume were studied for two years in Tikma-Dash Research Station of East Azarbaijan Agricultural and Natural Research Center, Tabriz, Iran, in a randomized complete block design using split-plot experiment in 2011-2013 years. Irrigation regimes (without irrigation, one irrigation and two irrigations) were assigned to main plots and four forage types (hairy vetch, grass pea, Pannonica sativa and lathyrus) were assigned to subplots. The results of analysis of variance showed that the effect of irrigation on plant height, number of shoots, leaf area and plant fresh and dry weights were not significant. Howere, legume types affected these traits significantly (P≤0.01). The effect of irrigation levels and legume types on protein content of hay were significant (P<0.01). The effects of year and legume type were also significant as to fresh and dry yield of forages. However irrigation, year× irrigation and irrigation× legume type interactions were not significant. Interaction effect of year × legume type was significant (P≤0.01). It seems that under the environmental conditions of this research, differences between no irrigation treatment and irrigation treatments were non significant. Considering the results of variance analysis for all quantitative traits measured and crude protein percentages in fresh and dry forage types and yield hairy vetch and lathyrus can be considered a promising type to introduce for dry lands.

This field study was conducted in a factorial split plot experiment based on randomized complete block design with three replications to evaluate the effect of irrigation and nitrogen fertilizer levels on physiological characteristics of four varieties of barley (Hordeum vulgare) during 2012 in Azad University of Miandoab. Irrigation levels were full irrigation, cutting off irrigation at boot stage (code 40 scale zadoks) and cutting off irrigation at flowering stage (code 60 scale zadoks). Nitrogen levels were 20, 40, 60 and 80 kg ha-1. Varieties under study were ‘Makuyi’, ‘Valfajr’, ‘Sahra’ and ‘Jonoob’. Traits studied were seed yield, flag leaf area, chlorophyll content of flag leaf and proline content of flag leaf, and peducle length. The results showed that highest grain yield, flag leaf area, chlorophyll content of flag leaf and proline content were obtained by using 80 kg.ha-1 nitrogen. Data collected also showed that at 80 kg.ha-1 nitrogen and full irrigation, the highest and lowest grain yield, flag leaf area, chlorophyll content of flag leaf belonged to ‘Makuyi’ and Jonoob, respectively. However, cuuting off irrigation at boot stage resulted in highest and lowest grain yield, flag leaf area, chlorophyll content of flag leaf to Jonoob and Valfajr, respectively. Cutting off irrigation at flowering stage decreased grain yield and increased proline content in ‘Makuyi’ and ‘Valfajr’. However, lowest reduction in grain yield, and highest increase in proline content were measured in ‘Sahra’ and ‘Jonoob’ varieties. Decreasing slope of regression curves was higher in ‘Makuyi’ and ‘Valfajr’. This indicates that cutting off irrigation at flowering stage reduced yield and increased proline content of these varieties compared to ‘Sahra’ and ‘Jonoob’.

To investigate the effect of vermicompost, chemical fertilizers and their application methods on tuber yield and some morphological traits of potato (Agria cultivar) an experiment was carried out in Mahidasht Agricultural and Natural Resources Research Center in Kermanshah Province during 2012-2013 cropping season. The experiment was carried out in a split plot factorial using a randomized complete block design with four replications. Levels of vermicompost (0, 1.5, 2.5, 3.5 t/ha) were assigned to main plots, and chemical fertilizers with three levels (0, 50 and 100 % chemical fertilizer recommended) of the amount of 225 kg/ha of urea, 150 kg/ha of potassium sulfate, 105 kg/ha of triple super phosphate and 52 kg/ha zinc sulfate and on 50% level respectively 112.5, 75, 52.5 and 26 kg/ha and fertilizer application methods at 3 levels (broadcast, one band and two band application) to subplots. The results showed that increasing the amount of vermicompost about 3.5 t/ha and reducing chemical fertilizer by 50% and applying it in two band increased plant height, number of stems per plant and tuber yield. The highest tuber yield was obtained from application of 3.5 t/ha of vermicompost, 50% chemical fertilizer and two band fertilizer applications (37 t/ha). This study indicated the positive effect of vermicompost on potato tuber yield. Thus, it can be suggested that combined application of chemical fertilizers and organic fertilizers may reduce chemical fertilizers usage and reduce also the environmental pollutions.

To study effects of nitrogen fertilizer and sowing date on some agronomic traits of canola cultivars, a factorial split plot experiment based on randomized complete block design with four replications was conducted during growing season 2013 – 2014 at the Research Farm of Gonbadkavus University, Iran. Treatments were four canola (Brassica napus L) cultivars (C1=Hayola 401, C2=Zarfam, C3= Hayola 308, and C4=RGS003), two planting dates (D1=17 Nonvember and, D2=28 December) and three levels of nitrogen fertilizers (N1=0, N2=%50 of recommended fertilizer, N3=%100 recommended fertilizer). In this study the treatment of nitrogen fertilizer levels and planting dates were asseigned to main plots and canola cultivars to sub plots. The results of analysis of variance showed that the interaction effects between nitrogen fertilizer × planting were significant at 0.01 probability level on all evaluated traits. Interaction of planting date × cultivar effects on all yield components except seed per silique were also significantly. The fertilizer × cultivar interaction did not affect yield components significantly. The highest yield, 4.2 t/ha, was produced by the open pollinated cultivar of RGS003 using %100 recommended rate of nitrogen fertilizer at sowing date of 17 November, which represents a high potential of this cultivar under this nutrients level and sowing date.

To study the effects of planting patterns on yield and yield components of two maize cultivars, an experiment was conducted in 2011-2012 cropping season at Dehloran Agricultural Station, Ilam, Iran, as a split plot based on a randomized complete block design with three replications. The treatments were two maize cultivars (S.C. 704 and 677) asseigned to main plots and five planting patterns (planting on alternate ridges, planting at furrow bottorn at row 55 cm apart, two planting rows per ridge and conventional planting on ridges 75 cm apart) as sub plot. The results showed that there were significant differences between cultivars for plant height, ear hight, seed row per ear, number of seeds per ear and harvest index. Highest plant height (208.3 cm), ear hight (96.1 cm), seed rows per ear (14.26 rows), seeds per row (37.3 grains) and harvest index (51.1%) belonged to S.C. 704 cultivar. Planting pattern affected plant height, ear height, seed rows per ear, seeds per ear and harvest index, significantly. The highest ear hight (93.8 cm), seed rows per ear (13.9 rows) belonged to two row plantings per ridge. Interaction effect of cultivars × planting patterns were significant on grain yield, 1000 grain weight and biological yield. The highest grain yield (10116 kg.ha-1), 1000 grain weight (234 g) and biological yield (19600 kg.ha-1) belonged to S.C. 704 cultivar at planting pattern of two rows 20 cm apart per ridge and the lowest grain yield (9201 kg.ha-1) and biological yield (19289 kg.ha-1) at planting patterne of two rows per ridge to S.C. 677 and conventional pattern at planting.

To evaluate the integrated management of weeds in red kidney bean, a split-plot experiment using randomized complete block design with three replications was conducted in 2013 in the Damavand County. In this experiment, the mechanical control treatments consisted of two levels (no cultivation and one cultivation) asseigned to main plots and controlling chemical treatments consisted of six levels (non-application of herbicides, pre-emergence herbicide application of Pursuit with full dose of 1 liter per hectare, pre-emergence herbicide application of Pursuit a dose decreased 0.5 liters per hectare, post-emergence herbicide application of Pursuit dose reduced to 0.3 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit with a reduced dose of 0.5 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit full dose of 1 liter per hectar 2 thousand citogate) to subplots. The results showed that the effects of interaction between herbicide application and cultivation for traits of carotenoids, chlorophyll a, chlorophyll b and total chlorophyll contents, density of weeds and their dry weights were significant at 1 %, and grain yield at the 5% probability levels. The highest bean seed yield with an average of 5461.6 kg.ha-1 and lowest weed dry weight with an average of 345.9 kg.ha-1 were related to pre-emergence herbicide and cultivation with a dose of 1 liter per hectare treatment. The difference between full and reduced doses of chemical weed control was non-significant. It could be concluded that integrated mechanical and chemical weed control not only may increase seed yield but also reduce, environmental hazards.

To investigate the possibility of improving seedling emergence, stand establishment and yield of late sown ribwort plantain (Plantago lanceolata) by seed priming pot and field experiments were conducted at the Islamic Azad University, Tabriz, Iran during 2013. The ribwort plantain seeds were differently treated by ultrasonication, laser, magnetic field, gamma and beta irradiations all for 3.5 and 5 min. and were sown on 5th and 20th of May. All of the seed priming treatments reduced seedling emergence time, 50 % of seedling emergence and mean emergence time as compared with control. Highest seedling dry weight (0.49 g.plant-1) resulted from magnetic field treatment for 5 min. followed by magnetic field for 3.5 min. and ultrasonic treatments (0.40 g.plant-1). A further reduction in exposure time of magnetic field from 5 to 3.5 min. decreased seedling vigor index. When seeds were sown in 5th and 20th May, maturity period of plots treated with magnetic field and ultrasonic happened to range between 112.2 and 99.7 days after sowing, respectively. Leaf area index remained statistically unaffected due to a delay of 15 days in sowing date. Under field conditions, there was not significant difference between seed yields from sowing dates, and the yield ranged from 176 kg.ha-1 in control, gamma and beta irradiations up to 211 kg.ha-1 in magnetic field and ultrasonic treatments. It can be concluded that priming ribwort plantain seeds by magnetic field and ultrasonic waves would effectively be used to improve the crop performance and yield especially in late sown plants.

To study the effect of nano iron and solupotass on agronomic and physiological traits of two onion cultivars, a factorial experiment was conducted in complete randomized block design with 32 treatments and three replications in Joghatai of Khorasan-e- Razavi province, Iran. Treatments consisted of two onion cultivars (red, yellow) and four levels (0, 1, 2, 3 kg per hectare) of nano iron chelat and four levels of solupotass (0, 5, 10, 15 kg per hectare). Results showed that the effect of nano iron and solupotasse on fresh weight, dry weight, pyrovic acid and macro element (N, P, S) contents were significant at %1 levels. Application nano iron, solupotasse to red onion cultivar increased dry weight significantly at the %5 level. Highest onion weight was obtained by using 2 kg nano iron and 15 kg solupotasse (17.3 g). Use of nano iron and solupotasse highly increased the pyruvic acid percentage (1.07 mM). Highest rate of pyruvic acid obtained by application of 3 and 15 kg nano iron and solupotasse respectively. Application of nano iron on the sulfur and nitrogen contents of onion were significant. Use of 2 kg/ha of nano iron exhibited highest increase in these elements. Thus, soil application of 10 kg/ha solupotasse, 3 kg/ha nano iron would highly increase red onion traits mentioned above.