جستجوی مقالات مرتبط با کلیدواژه "خصوصیات بیوشیمیایی" در نشریات گروه "زراعت"

This study was conducted to investigate the effects of different levels of cut irrigation on yield and quantitative and qualitative characteristics of cultivars wheat in the crop year 2017-18 in Shahriar region. This research was carried out as split plots design a randomized complete block with two cut irrigation and cultivars factors in 63 treatments and three replications. The main factor of irrigation treatment in three levels including: normal irrigation I0, cut irrigation in flowering stage I1 and cut irrigation in grain filling stage I2 and cultivars in 21 levels as a sub-factor including; Chamran, star, Sirvan, Sivand ,Arg, Parsi, Barat, Narin, Heidary, Ofogh, Rakhshan, Baharan, Sepahan, Aflak, Mihan, Zare, Gonhad, Orum, Saison, Gascogen and Mehregan. The results of analysis of variance showed that 1000-seed weight, grain yield, total yield, stomatal conductance, canopy temperature, leaf proline, cell membrane stability, grain gluten, SOD antioxidant enzyme and MDA degradation biomarker were affected by the main effects of irrigation levels and cultivarsand interactions were significant at the level of 5% and 1%. The highest grain yield (10857.2 kg.ha-1), total yield (44092.8 kg.ha-1) and stomatal conductance (236.08 molH2o. m2.s-1) were allocated to Normal irrigation and Rakhshan cultivar treatment. The lowest grain yield (1467.9 kg.ha-1), total yield (11496.7 kg.ha-1) and stomatal conductance (44.81 mmolH2o.m2.s) were obtained from cut irrigation at flowering stage and Ofogh cultivar treatment. However cut irrigation treatment at flowering stage and Ofogh cultivar obtained the highest canopy temperature (19.827 C), proline leaf (0.994 µg.gFw-1) and the lowest canopy temperature (13.126 C), leaf proline (0.416 µg.gFw-1) and cell membrane stability (171.14 µmos.cm) was observed from normal irrigation and Rakhshan cultivar treatment. The highest antioxidant enzyme superoxide dismutase SOD (19.06 U.mgprotein) and MDA (40.68 Ƞmol. gFw-1) were achieved from cut irrigation at flowering stage and Gasgogen cultivar treatment. The results showed that the tolerant cultivars were less affected by drought stress. And by less producing organic matter such as proline and degrading enzymes and biomarkers, they maintained their yield at an acceptable level.

To study the effect of 5- aminolevulinic acid (ALA) on some physiological responses of sweet pepper under drought stress, a factorial experiment in a randomized complete block design with 5- aminolevulinic acid and water deficit stress treatments was carried out in the greenhouse of the agricultural faculty of Ilam University. Levels of water deficit stresswere stress free conditions (irrigation within the field capacity), moderate stress (irrigation within the 60% field capacity) and severe water deficit stress(irrigation within the 30% field capacity). Four concentrations of AL Aincluding 0 (control), 0.25, 0.5, and 1 mM were applied as foliar application at three to four-leaf stage. The results showed that with increasing ALA concentrations, catalase activity, proline content, relative water content, dry weight, flower and fruit number increased but electrolyte leakage (EL) decreased. The lowest EL and the highest proline content, relative water content, fruit number and shoots fresh weight were observed at 1 mM of ALA while the highest catalase activity, dry weight and flower number were obtained with application of 0.5 mM ALA. Water deficit stressdecreased relative water content, fresh and dry weight, flower and fruits numbers, but increased EL, proline content and catalase activity. ALA with increasing of catalase activity and reducing of EL reduced the stress effects on plant growth and yield. According the results of this experiment, through the impact on growth characteristics and biochemical and physiological parameters, ALA provides better water deficit stresstolerance in pepper plants.

In order to study some physiological responses of saffron under saline conditions, three landraces of saffron which were collected from Gonabad, Ferdows and Torbat-e-Heydarieh were compared under 0, 3, 6, 9 and 12 dS/m electrical conductivity of saline water during two years under a rain shield in pots in a randomized complete block design with three replications at the Research Center of Yazd which three levels of the landraces and five salinity levels were distributed as factorial. After uniform emerging of the buds, NaCl solutions with the above mentioned levels of salinity were used gradually for pots irrigation with 30% leaching fraction in order to control soil water salinity in desired levels. The results showed that with increasing salinity, relative water content 6.26%, dry weight 19.80%, the total number of leaves 17.042%, the dry weight of corm 49.42%, the concentration of sugars in the leaves and corms 43.36 and 23.72% were reduced and corms and leaves ion leakage 34 and 27%, sodium concentration70%, sodium to potassium ratio 66.66% and proline in leaves 2.88 times were increased that in most cases these fluctuations were observed in 3dS/m of irrigation water.

Fire blight caused by Erwinia amylovora (Burr.) Winslow et al., has the highest importance among different diseases of pome fruits in many countries. Use of resistant or tolerant cultivars has been suggested as the most economic and effective method to control the disease. In this research different isolates of fire blight causal agent bacterium were isolated and evaluated biochemically and pathologically to select the highly virulent isolates for subsequent use in screening of quince (Cydonia oblonga Mill.) genotypes to the disease. Five isolates out of 25 primary isolates successfully passed all biochemical and phytopathological identification tests. Two isolates obtained from Zanjan province (Z1 and Z2) and one isolate from Tehran province (K2) expressed more virulence that shows their appropriateness in the screening of genotypes. Modeling of carbon source utilization by isolates confirmed homology of the isolates and revealed potential of bacterium to metabolize sucrose, glucose and fructose faster than other carbohydrates. Regarding to the dominance of sucrose and glucose in Rosaceae family, it seems that limited host range of bacterium at least in part, is depending on the accessibility of an appropriate carbon source in the members of this family. Test of resistance to the antibiotics revealed existence of an eventual high streptomycin resistance in K1 isolate that is the first report in country