فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 42 (تابستان 1396)

Tolerant systems in plants including wheat are affected by several chemical factors, like nano-chelate potassium. Use of nano-chelated potassium under drought stress reduces its negative effects and increase yield. To study protein profiles of wheat under drought stress, a factorial experiment based on completely randomized design with three replications was performed. The first factore was three levels of irrigation (85%, 60% and 35% field capacity), the second factor consisted of three wheat cultivars (Zagros, Chamran and Kuhdasht) and the third factor consisted of four nano-chelated potassium concentrations (zero, 25, 45¡ 65 ppm). The results showed that concentrations of proline and carbohydrates which play a major role in plant defense mechanisms due to nano-chelated potassium treatment were increased. Catalase and butpolyphenol oxidase activity decreased with increasing concentrations of nano-chelate potassium, while peroxidase activity increased. The results of two dimentional electrophoretic studies showed changes of protein expression, due to the effect of nano-chelated potassium as a direct contact with the defensive system against drought stresses, such as 11, 6, 5, 19, 14 bands. Nano-chelated potassium is also associated with proteins involved in the metabolism of carbohydrates and protein and final energy production.

To evaluate relationship between grain yield and its components, two series of wheat`s substitution lines including substitution lines of ‘Timstein’ into genetic background of ‘Chinese Spring’ and ‘Red Egyptian’ into genetic background of ‘Chinese Spring’ and their parents were tested in a randomized complete block design with four replications under water-stress and non-stress conditions in a greenhouse in 2014. Stepwise regression analyses showed that yield components contributions for seed yield variation were not similar under water-stress and non-stress conditions. So that, under non-stress condition biological yield and harvest index and under water-stress condition the number of seeds per spike and number of spikes explained a higher percentage of variations for grain yield. Biological yield and harvest index were entered into model in three cases out of four regression analyses (two substitution lines series and two conditions) and thus it was deduced that these two traits are the most stable traits in explaining the variations observed for seed yield.Path coefficient analysis showed that biological yield and harvest index had direct and equal effects on seed yield at non-stress condition for two substitution line series. The highest direct effects on seed yield under stress condition for ‘Timstein’ substitution line series belonged to biological yield and harvest index and for ‘Red Egyptian’ substitution lines belonged to the number of seeds per spike and number of spikes. Cluster analysis, based on Ward method and by using Euclidian distance, classified two substitution line series under water-stress and non-stress conditions in three groups.

Drought seriously reduces the quality and quantity of agronomic and horticultural plants. In such condition, using factors to reduce these effects on plants is indispensible. To evaluate the effect of water stress and different levels of ascorbic acid on the leaf relative water content, pigments, canopy temprature and dry matter of cress (Lepidium sativum L.) a split plot experiment based on randomized complete block design with three replications at the Agricultural Research Station of Zahak was conducted in 2014 where three irrigation levels (at 100, 80 and 60 percent of field capacity) assigned to the main plots and three levels of ascorbic acid (0, 5 and 10 micromolar) to the sub-plots. The results showed that the effect of irrigation regimes, ascorbic acid and their interaction was significant on the traits under evaluation. Irrigation based on 60% of field capacity as compared with that of 100% F.C. reduced relative water content, chlorophyll a and b, carotenoids and dry matter weight by 20.89, 0.06, 0,034, 0.04 and 57.8 percent respectively and a 20% increase in canopy temperature, while applying of 10 micromolar ascorbic acid relative to control increased 12.22, 0.075, 0.15, 0.05 and 57.8 percent on traits mentioned above respectively and a 3% decrease in canopy temperature. Regression model revealed that application of ascorbic acid at irrigation in 100% field capacity was not effective on these traits, except on chlorophyll b and carotenoids contents, but in irrigation at 60 and 80% percent field capacities, increased amount of relative water content, chlorophyll a, chlorophyll b, carotenoids and dry matter. Although ascorbic acid could not reduce the negative impacts of 20% decrease in irrigation but application of 10 micromolar ascorbic acid in 60% and 80% irrigation at field capacities increased dry matter significantly, as compared to that of ascorbic acid under these conditions.

To study the effect of potassium sulfate on seed yield, yield components and traits affecting seed yield of late maturing corn, a split split plot experiment using a randomized complete block design with three replications was carried out in Kashan Desert Research Station. Irrigation levels consisted of complete irrigation and cutting off irrigation at panicle emergence and seed filling stages which were considered as the main factor, three levels of potassium sulfate 200 (recommendation based on the soil analysis), 245 and 290 kg.ha-1 as the subplot, and two single cross of corn, KSC 700 and 704, as sub-sub plots. Effect of irrigation on traits like seed number per row, 1000 seed weight, biological yield, relative water content and relative water loss were significant. The effect of cultivar on all traits, except relative water loss, and the effect of fertilizer on all traits, except number of rows per ear, were also significant. All of the KSC700 traits, except plant highest were better than those of cultivar KSC704. The highest values for the most traits were obtained in full irrigation condition, applying potassium sulfate at the rate of 290 kg.ha-1 for KSC 700. Cutting off irrigation at the panicle emergence of KSC 900 and seed filling of KSC 704 did not cause significant reduction in seed yield. Highest correlation of grain yield were obtained with number of kernels per row, 1000 grain weight and harvest index. Stepwise regression results showed that number of rows per ear, number of kernels per row and 1000 grain weight in KSC 700, and biological yield and harvest index in KSC 704 justified 98.7 and 98.5 percent of changes, respectively.

To identify the effectis traits on grain yield under normal irrigation and water deficit conditions, 65 wheat recombinant inbred lines derived from the crossing of Yecora Rojo American cultivar (a high yielder, dwarf and early) and No.49 Iranian line (medium yielder, tall and late) split-plot experiments based on randomized complete bloks design with two replications was performed at Agriculture Research Station, University of Tabriz, in 2013. Irrigation levels were considered as main factor and lines as sub factor. The analysis of variance showed that the differences among irrigation levels for grain yield, plant height, peduncle length, root volume and root weight were significant. The differences among wheat lines and intraction between line irrigation levels for all of the traits were also significant. Under normal irrigation condition, grain yield had significant an positieve correlation with plant height, highest spike, number of seeds per spike, peduncle length, 1000 seed weight, spike length, straw yield and root length. Under drought stress condition, grain yield had significant and positive correlation with the number of grains per spike, number of fertile spikes, peduncle length, root length and straw yield. Path analysis, based on the stepwise regression method, revealed that the plant height, peduncle length, number of grains per spike, straw yield, number of fertile spike and root length undernormal irrigation condition and number of grains per spike, 1000 grain weight, number of fertile spikes, root length and root weight under water condition were effective traits on seed yield.

To study the effect of corm density on yield and qualitative traits of saffron (Crocus sativus L.) under different biological and chemical nitrogen fertilizers, a factorial experiment based on completely randomized block design with 3 replications was done in 2014 at Shahr-e-Rey region (Ghomi Abad). The experimental factors were: corm density in 3 levels (60, 120 and 180 corm per square meter) and biological and chemical nitrogen fertilizers in 4 levels (without fertilizer application, 150 kg.ha-1 of Urea, 5 L.ha-1 of Nitroxin and 75 kg.ha-1 of Urea L.ha-1 of Nitroxin). The results indicated that the corm density affects number of daughter corm, fresh daughter corm weight, corm diameter, dry stigma and style weight, dry and fresh flower weight significantly. Mean comparisons also indicated that by increasing corm density from 6o to 180, saffron dry yield of saffron improved by 2.7 fold. However, increasing corm density reduced corm diameter, fresh corm daughter weight and their numbers per square meter. It can be concluded that nitroxin as an organic fertilizer, increases vegetative traits and saffron dry yield (stigma style weight) to 2.08 kg.ha-1 and highly improves in qualitative traits like Safranal, Picrocrocin, and Crocin. It can be also said that combined use of nitroxin and urea would be an alternative method to reduce application of urea.

In order to find suitable ratio of chemical fertilizer and compost, to increase economic yield of onion, a study was carried out at the Malekan Agricultural Farm and Natural Resources Research and Education Station in 2013. The experiment was done in split plot using RCBD with three replications. Fertilizers (A) were asseigned to main plots with six levels (recommended dosage of chemical fertilizers as control (a1), ¾ of the control 4 ton ha-1 of compost (a2), ½ of the control 8 ton ha-1 compost (a3), ¼ of the control 12 ton ha-1 compost (a4) and the compost alone (16 and 20 ton ha-1) (a5 and a6)) and cultivars to subplots with five levels , (B) (Zanjan Qoli Qissa (b1) and Red Azarshahr (b2)). Red Azarshahr was superior to Qoli Qissa in all traits. Fertilizer levels had significant effects on all traits, except number of edible layers, and a1 was highest amount in these traits compared to other fertilizer rates. The interaction of fertilizer × cultivar was not significant in all traits. Combined use of chemical fertilizers and compost had significant positive effect on vegetative traits, bulb diameter, yield per plant and total yield as compared to that of using compost alone. Using ¾ a1 and ½ a1 along with the rate of 4 and 8 t.ha-1 (a2 anda3) of compost had no significant decreasing effect on bulb weight per plant and yield as compared with chemical fertilizer application alone (a1). Thus use of ¾ the control treatment 4 ton ha-1 of compost (a2) and ½ of the control treatment 8 ton ha-1 of compost (a3) can be recommended to the region.

To investigate the effects of nitrogen foliar application at different growth stages of soybean on the yield and yield components this experiment was performed in Shush, north of Khuzestan, Iran, during growing season of 2014. The experiment was in split plot based on randomized complete block design with three replications. Experimental treatments consisted of four levels of nitrogen fertilizer foliar applications as control (no nitrogen foliar application), 25, 50 and 75 kg/ha pure nitrogen from urea source (46% pure nitrogen) assigned to the main plots and spraying times in three levels, at vegetative stage, flowering stage and podding stage to the subplots. Results showed that the effects of nitrogen foliar application on traits measured in this experiment like leaf area index, number of pod per plant, number of seeds per pod, thousand seed weight, seed yield, biologic yield, harvest index, protein percent and protein yield and also interaction of different levels of nitrogen foliar application and different growth stages, were significant. Oil percent and yield were only significant under the effect of nitrogen foliar application treatments at different growth stages while the interaction of different levels of nitrogen foliar application and different growth stages, were not significant. In this experiment nitrogen foliar application increased seed yield. The highest seed yield amounted to 2466 kg/ha when 50kg/ha of foliar nitrogen applied at vegetative growth stage and lowest seed yield amounted to 1295 kg/ha in the control treatment at the stage of podding. In general, results demonstrated that 50 kg/ha treatment could be considered as the best management option of nitrogen foliar application for soybean at vegetative growth stage.

Intercropping of forage cropsand the combined use of organic, chemical,and biofertilizers is of great importance. To evaluate quantitative and qualitative characteristics of corn and grass pea intercropping under organic and chemical fertilizers factorial experiments in a randomized complete block design with three replications were conducted in Yalian Farm of Qazvin, Iran, in 2013 and 2014. Levels of intercropping consisted of: corn sole croppings, intercropping of maize and 25% grass pea, intercropping corn and 50% grass pea, and grass pea sole cropping. Fertilizer levels were chemicals (base and top dress), cow manure (base) and avian manure top dress, cow manure (base) and chemical top dress, and cow manure (base) and chemical (top dress and spraying). In the last three treatments corn and grass pea seed inoculated with Azotobacter and mycorrhiza. The results showed that the highest corn forage yield with 84230 kg/ha produced from grass pea corn treated with 50% chemical manure. Intercropping is a suitable method for crop production and increasing quantity of crop as compared with sole croppings. The highest forage with 46020 kg/ha was produced by grass pea chemical manure treatment because of more light penetration to the canopy and the lack of competition with corn. Highest carbohydrates %30.5 belonged to the use of chemical fertilizer in sole cropping of corn and the highest crude protein with %24.75 is produced from chemical fertilizer in pure grass pea sole cropping and the highest dry matter digestibility and higher quality forage with %68.08 from the use of manure %25 grass pea/corn intercropping. Intercropping and mixed application of chemical and organic fertilizers improve the quality and quantity of forage yield.

Guilan province is a suitable area for growing second crop after rice in autumn. Growing a crop in a field of rice after it is harvested in addition to creation of job and increasing farmer’s income, can be used to produce a winter crop for the second six months of year. One of the most consequences of producing one or two crops is to conserve water and soil resources and reduces pollution caused by excessive chemical inputs and also maintaining and improving soil fertility in the long term. To investigate the effect of remains of fertilizers used in faba- bean on rice yield in faba bean- rice cropping system a research concering growing two crops in one year, namly rice var. Hashemi (June- September) and a second crop, faba bean var. Barkat (November- May) was performed with 15 fertilizer treatments for faba bean in the form of a factorial randomized complete block design with three replications in the Research Field of Rice Institute of Iran during years of 2012- 2015 (growing two crops of rice and three crops of faba bean). Experimental factors for faba bean consisted of five nitrogen rates (0, 25, 50, 75 and 100 kg.ha-1 N) from urea and three phosphorus levels (0, 50 and 100 kg.ha-1 P) from triple superphosphate fertilizer. The results showed that faba bean yield increased up to 2003 kg.ha-1 and 285 kg.ha-1 by increasing nitrogen and phosphorus levels respectively. The highest seed yield (4833.8 kg.ha-1) was observed in the treatment N100P100 where the difference with that of N100P50 treatment (4744.5 kg.ha-1) was non significant. The results also showed that nitrogen and phosphorus used in faba bean increased soil nitrogen by 0.147% to 0.178% and 0.209% and soil phosphorus by 24.2 ppm to 40.59 and 37.51 ppm in the first and second years of rice production, respectively. The average yield of two- cycle production of rice (without chemical fertilizers and after faba bean cultivation) was about 2770.95 kg.ha-1.

To evaluate the effect of different planting dates on yield and yield components of Chickpea) Cicer arietinum( in sole cropping and intercropping with Cumin (Cuminum cyminum), an experiment was conducted in completely randomized block design with three replications at Research Farm of Agriculture, Ferdowsi University of Mashhad in 2013. The Treatments consisted of three sole cropping and intercropping dates as foloows: chickpea sole cropping in 13 February 2013 (PP1125), chickpea sole cropping in 22 February 2013 (PP1210), chickpea sole cropping in 16 March 2013 (PP1226), chickpea and cumin intercropping in 13 February (PC1125), replacement intercropping in 22 February (PC1210), replacement intercropping in 16 March 2013. The result showed that the highest chickpea seed yield (1435 kg.ha-1), plant height (38.5cm), number of stems (5.7), R.S-1 (3.166) and 1000-seed weight (377g) were obtained in chickpea sole cropping in 13 February planting date (PP1125). The results in intercropping treatments also showed that the highest LER (2.33) was obtained in March 16 relay intercropping treatment (PC1226) and lowest LER (1.24) in February 13 intercropping treatment (PC1125). According to the result the best dates in this region for sole cropping and intercropping with cumin, whould be second and third week of February.

Genotype × environment interactions make it difficult to release high yielding durum varieties for diverse environmental conditions. The main purpose of this study was to achieve high yielding durum wheat genotypes with higher yield stability in different environmental conditions, tolerance to environmental stresses such as cold damage, terminal drought, and heat stresses. Hence, 16 durum wheat lines were evaluated for grain yield stability and morphological traits in Maragheh, Sararood, Qamloo, Ardabil and Urmia Agricultural Research Stations in 2012-15. In each location, the experiments were conducted in a randomized complete block design with three replications. Based on combined ANOVA, there were significant differences among the environments (E), genotypes (G) and G×E. GGE-biplot analysis showed that the 14 environments belonged to 3 mega-environments, and different genotypes had higher yield in each mega-environments. The AMMI and GGE results also confirmed that genotypes 2 (G-1252) and 3 (61-130/414-44//…) were the most high-yielding durum lines with reasonable yield stability across environments. Also, genotype 10 was the most adapted genotype to Ardabil. Line 61-130/414-44//… had 60, 11, 31, 10 and 17% more yield than check line (Saji) in Maragheh, Sararood, Qamloo, Ardabil and Urmia under rainfed conditions, respectively. Hence, these lines can be candiates to release as new durum varieties for cold and moderate rainfed areas. Complementary irrigation could increase grain yield up to 14 and 68% in Maragheh and Sararood, respectively. It can be concluded that finding new stable high-yielding durum lines, with better performances, as compared to the existed varieties, is a great progress in durum breeding programs in cold rainfed areas. Moreover, the GGE biplot and AMMI analysis had good performance in adaptability and yield stability analysis in durum genotypes and could be used to evaluate durum genotypes at different locations over the years in durum breeding programs.

Due to genotype×environmental interaction, seed yields of genotypes are usually evaluated in broad range of environmental conditions to obtain efficient information concering cultivar selection and introduction. For this purpose, an experiment was conducted based on RCBD with three replications, using 20 bread wheat cultivars to study seed yield stability of cultivars introduced during the past several years to cold, and moderate areas of Iran. This experiment was carried out at the Agriculture Research Station of Islamic Azad University, Tabriz branch during 2009-2012, for 4 years. Because of significant genotype×environmental interaction, stability analysis was performed by all possible methods to obtain stable and high potential cultivars. The result of stability analysis showed non parametric, AMMI, GGE biplot and simultaneous selection stability methods introduce lower, high, and higher yielding cultivars to be stable. On basis of all stability methods, Bahar (spring type introduced in 2008), Mahdavi (facultative type released in 1995), and Azadi cultivar (winter type introduced in 1989) respectively with 7.27, 7.13 and 6.88 (t/ha grain yield) were stable and were highly potential cultivars among other cultivars. These cultivars could be introduced to researchers as stable cultivars to be used as parental ones in breeding programs for production of highly stable and seed yielding lines.

Using live mulches is one of the biologic methods for weed control in potato. This research was conducted as a factorial experiment based on RCBD with four replications at the Research Field of Fereydunshahr of Esfahan during 2015. The treatments consisted of two cultivars: Arinda and Agria and three planting systems of potato: weedy sole cropping, weed-free sole cropping and potato inter cropped with maize. Analysis of variance showed that all traits like plant height, plant dry weight, tuber number per plant and tuber yield, except average weight of tuber, were influenced by variety at five percent level of significance. However, plant height and tuber number per plant were influenced by planting system at the level of one percent and plant dry weight, average weight of tuber and tuber yield at the level of five percent significance. The results also showed that potato intercropped with maize reduced highly weed density. The highest and the lowest penetration light were related to weed-free and maize, respectivey. The highest reduction in potato height was found in maize. This might be due to correlation of height and competitiveness of species, because by increasing plant competition height was increased. The highest plant dry weight of potato (121.79g) was related to weed free condition and following by maize, weedy sole cropping. The highest average tuber weight (65.33 g) and tuber yield (677.44 g) belonged to maize, weed free treatments, and lower values of these traits were founded in weedy sole cropping treatment. Overall, live mulches by reducing density of Amaranth (plants per 38.4 m2) was able to control weeds in potato field. This could be attributed to its effects on shading and/or higher competitivness.