CROP PHYSIOLOGY
Year:2018 | Volume:10 | Issue:3 (39) |Papers Count:8

In order to investigate the physiologic and biochemical changes of drought tension in chickpea, a split-plot experiment based on randomized complete blocks design with three replications at the research farm of Campus of Agriculture and Natural Resources of Razi University of Kermanshah was conducted. The main factor was the moisture regimes including: 1-normal irrigation, 2-water deficient tension at podding stage and 3-flowering and the sub factor, including: five chickpea cultivars (Arman, Azad, Bivanij, Hashem and ILC482). The obtained results indicated a high effect of the moisture content of chickpea, on grain yield and biological yield, and among cultivars under intense moisture tension, ILC482 cultivar with seed yield of 715 (kilogram per hectare) and in non-tension conditions, Arman cultivar with the yield of 1355 (kilogram per hectare) showed the best performance. Based on the results, the photochemical efficacy of the photo cysteine II and the relative water content of the leaf had a positive and significant relationship with the amount of water available and the moisture restriction reduced these significant traits and in resistant cultivars including Azad, ILC482 and bionic, higher values of these traits were observed during drought tension. The content of soluble sugars and proline in chickpea leaves increased with decreasing moisture content, so that the amount of soluble sugars in the ILC482 and Azad cultivars and the amount of proline in ILC482 and Bivanij cultivars were higher, but on the contrary, the concentration of soluble proteins increased with increasing moisture content and was the highest in Hashem and Arman cultivars.

This research was carried out in order to investigate the reaction of canola cultivars to salinity tension in a factorial experiment based on randomized complete blocks design with four replications in the research farm of Islamic Azad University, Shoushtar, during 2016-17 cropping year. In the present experiment the reaction of four canola cultivars (Hyola 320, Hyola 330, Option 500 and Sarigol) in vegetative growth stages was investigated in four salinity levels zero(control), 50, 100 and 150 mmol NaCl). The results showed the highest and lowest shoot dry weights were seen at the highest level of salinity tension in Hyola 320 (2. 8 g) and Option 500 (1. 5 g) and Sarigol bushes cultivars were eliminated at this salinity level. Salinity tension significantly reduced photosynthesis and chlorophyll a and b concentrations of canola cultivars, however at 150 mmol NaCl salinity level, the highest photosynthesis was observed in Hyola 320 and Heyola 330 (9. 3 and 8. 9 μ mol Carbon dioxide per square meter of leaf area per second). Salinity tension reduced sucrose synthase enzyme activity in canola cultivars leaves, while cell membrane degradation in response to salt tension increased and the highest concentration of malondialdehyde was observed in salinity level of 150 mmol NaCl in Option 500 cultivar (0. 051 nanomol per gram leaf). The results showed that Hyola 320 and Heulla 330 cultivars had more stability in cell membrane stability, photosynthesis, antioxidant enzymes activity and sucrose synthase enzyme activity compared to Option 500 and Sarigol cultivars.

The present research was carried out as factorial experiment based on randomized complete blocks design with three replications on forage corn hybrid ZP600 in Mashhad in 2017. The experimental factors included Paclobutrazol with concentrations zero, 10, 20 and 30 milligram per liter and drought tension levels including irrigation after 50 millimeters (without tension), 70 millimeters (mild tension), 100 millimeters (moderate tension) and 150 millimeters (severe tension) evaporation from evaporation pan class A. Foliar application of Paclobutrazol was applied in two steps (at 6-8 leaf stage and was repeated 2 weeks later). The results showed that plant height, leaf number, leaf area index, leaf dry weight and fresh forage yield decreased by drought tension and proline content of leaf and insoluble fiber in neutral detergent increased significantly, but protein percentage and protein yield did not change significantly. Application of Paclobutrazol in medium and severe tension increased plant height, leaf area index, leaf dry weight and fresh forage yield, and decreased proline and insoluble fiber content in neutral detergent. Paclobutrazol also increased protein yield under tension and non – tension conditions. The highest fresh forage yield (103 tons per hectare) was obtained in 20 milligram per liter Paclobutrazole treatment under severe tension conditions and the lowest fresh forage yield (72 tons per hectare) in non-application of Paclobutrazol in severe tension. Application of Paclobutrazol at a concentration of 20 milligram per liter in moderate and severe tension could reduce the effect of drought tension by 24 and 43 percent, respectively.

In order to investigate the effect of superabsorbent polymers use on some biochemical traits and relative water content of bean cultivars under drought tension conditions, an experiment was carried out as split-split plots design based on randomized complete blocks design with three replications in Kaleybar city in 2015 cropping year. The main factor included irrigation after 70, 140 and 210 millimeter water evaporation from class A evaporation pan, bean cultivars (red beans, cowpea, pinto bean and white beans) as sub plots and four levels of 50, 100, 150 and 200 kilogram per hectare superabsorbent application as sub-sub factor. The obtained results of analysis of variance showed that the interaction of drought tension and superabsorbent on the activity of superoxide dismutase enzymes, glutathione peroxidase, chlorophyll a, total chlorophyll and proline concentration was significant. The results of the comparison of the mean interactions of drought tension and superabsorbent showed that maximum activity of antioxidants enzymes and proline obtained by treatment 50 kilogram per hectare super absorbent application at drought tension level of 210 millimeter evaporation. The results showed that with increasing drought tension, the activity of antioxidant enzymes increased and chlorophyll a, chlorophyll b, total chlorophyll, carotenoids and relative content of water decreased. In four assessed cultivars, cowpea had the most frequent photosynthetic pigments, the relative water content of leaf, proline content of leaf and the highest activity of antioxidant enzymes. According to the results, superabsorbent has reduced damages caused by dry land.

In order to evaluate the effect of physiological and biochemical traits on tolerant water deficit of 15 imported genotypes soybean, a pot experiment with 15 imported genotypes was carried out in a factorial arrangement based on randomized complete blocks design with three replications in Damavand city in 2017. The first factor contained 15 soybean genotypes and second factor included two levels of normal irrigation and irrigation disruption at 50 percent podding time to seed filling stage. The results of analysis variance showed that that there was a variety of genotypes under abnormal conditions and normal irrigation. The results of the mean comparison showed that in non-tension conditions, genotypes 3, 5 and 13 had the highest chlorophyll a, genotype 15 the highest total chlorophyll, genotype 5 most carotenoid genotypes, 13 and 14 genotypes the highest protein content, genotypes 7 and 13 the highest number of leaves, genotypes 2 and 10 the highest dry weight of plant and genotype 13 had the highest harvest index and grain yield. Low irrigation tension reduced yield and some physiological and morphological traits. Under the present conditions, some traits also increased. Genotype 3 had the highest chlorophyll b and chlorophyll b to a ratio, genotype 5 and 8 had the highest flavonoid, genotype 5 had the highest proline content and genotype 14 had the highest yield. The main components analysis showed that under normal irrigation conditions, the first four components explained 67. 85 percent of the total variance, so that the contribution of the first to fourth components were 38. 81, 20. 65, 15. 62 and 10. 57 percent. Under tension application conditions, the first four components explained 82. 26 percent of the total variance, so that the share of the first to fourth components was 35. 58, 25. 20, 13. 66, and 7. 80 percent, respectively.

In order to investigate the effect of salinity on resistance indices, the present experiment was conducted in a randomized complete blocks design with three replications and three years in two saline and normal fields in Astara. Commercial genotypes and lines included K3615. 1, S. C704, B73, S. C302, Waxy, K3546. 6, K3653. 2, and Zaqatala-68. Soil salinity reduced the index of chlorophyll content, chlorophyll a, plant height, ear weight, number of seeds per ear, 100 seed weight, plant dry weight and yield in genotypes. The results showed that the highest amount of chlorophyll a was in S. C704 hybrid in normal medium and there was no significant difference between this hybrid and S. C302 and B73. Different traits including chlorophyll index, chlorophyll “ a” , plant dry weight and yield per plot were measured. The results showed that the highest amount of chlorophyll “ a” in S. C704 and in normal conditions and was observed no significant difference between this hybrid with S. C302 and B73. Salinity caused a sharp reduction in chlorophyll index so that the least amount of chlorophyll was seen in Zaqatala-68 in salty. Interactions between varieties and environment was significant and different cultivars showed different reactions to salinity. Zaqatala-68 had the highest 100 grain weight in normal and salty conditions. The highest grain yield in normal conditions was observed in Zaqatala-68 that no significant differences with the K3653/2 and S. C704 but with other cultivars were significantly different. SC704, and Zaqatala-68 produced the highest grain yield in saline conditions, were selected as resistant genotypes. Indicats of resistance and sensitivity, according to grain yield was measured in different environmental conditions and based on STI S. C704, Zaqatala-68 and S. C302 genotypes were selected.

In order to eliminate the overlapping time of rapeseed harvesting and rice transplantation in Guilan province, and to provide appropriate solutions to reduce yield losses through seed loss, the present experiment was conducted as a factorial plots in a completely randomized blocks design with three replications at the Rice Research Institute of Iran in Rasht. The main plots in the present experiment consisted of the interaction of two ethephon foliar application factors at two levels (non-consuming and consuming 280 gram per hectare) and foliar application time at three levels ( podding, early grain filling, grain filling completion) and subplot including harvesting time in three phases, physiological maturation, 10 and 20 days after the physiological maturity. The results showed that ethephon foliar application with a mean time of 192 days reduced 8 days growth period compared to control treatment with an average time of 200 days. Also, erosion time (194. 6 days) was higher than early grain filling (196. 3 days) and seed filling completion with 197. 1 days for early maturity traits. The effect of harvest time on number of pods per plant, one-thousand grain weight, grain yield, oil percentage was significant. According to the results, ethephon foliar application caused 12 percent increase in grain yield and 0. 7 percent increase in oil in later harvestings. The interaction effect of foliar application, foliar application time and harvest time on seed yield was significant. Ethethenol soluble foliar application at the time of podding, with the lowest grain loss, was 202. 8 kilogram per hectare as the best experimental treatment.

According to information extracted from Iran's soil resources and talent map, about 44. 5 million hectares of Iran's area are salty lands. Salicylic acid is a plant growth regulator that increases plant tolerance to environmental tensions and improves plant metabolic activity. Therefore, the present experiment was conducted in order to investigate the effect of salinity tension on lands without drainage system and the role of salicylic acid in modifying its effects. This experiment was carried out as combination analysis in a randomized complete block design with three replication in the crop year of 2016-17 in agricultural lands of Shadegan city. Understudied treatments consisted of wheat under cultivation with two types of environments: 1-cultivation on normal lands (with drainage system) (first experiment) 2-cultivation in salty lands (without drainage system) (second experiment), and the second factor was the six method for the use of salicylic acid included non-use of salicylic acid (control), seed inoculation with salicylic acid, foliar application at the beginning of tillering, seed inoculation with salicylic acid in addition to foliar application at the beginning of tillering, foliar application at the end of tillering and seed inoculation with salicylic acid in addition to foliar application at the end of tillering. The results showed that the effect of cultivated land type on plant height, leaf area index, total dry matter, crop growth rate and net assimilation rate were significant at one percent probability level. The effect of salicylic acid on all measured traits was significant at one percent probability level. The interaction between environment and the method of salicylic acid application in terms of growth rate was significant at five percent probability level and was not significant for other traits. The maximum and the minimum amount of the investigated traits were observed in normal and salty lands, respectively, and among the various methods of using salicylic acid, the highest and lowest amount of traits was obtained in seedlings inoculation method with salicylic acid, in addition to foliar application at the beginning of tillering and without the use of salicylic acid (control).