نشریه زراعت دیم ایران
سال ششم شماره 1 (بهار و تابستان 1396)

In order to study the effect of phosphate solubilizing bacteria (PSB) and mycorrhizal fungi on activities of antioxidative enzymes and physiological characteristics of wheat under dry land conditions, an experiment was carried out using factorial arrangement based on randomized complete block design with three replications at two locations (Agricultural Research Station of Ilam University and Sarableh Agricultural and Research, Recourses Center) during 2013-2014 cropping season. Experiment factors consisted of wheat factor at two levels (Keras Sablan and Saji) and fertilizer sources treatment at eight levels including of 1- without application of phosphorous chemical fertilizer, 2- 50 kg/ha phosphorous chemical fertilizer, 3- pseudomonas putida (PSB), 4- Glomus mosseae (GM), 5-PSB, 6-PSBᣏ kg/ha phosphorous chemical fertilizer, 7- PSB 25 kg/ha phosphorous chemical fertilizer and 8- GM kg/ha phosphorous chemical fertilizer. Results indicated that interaction effect of cultivar×fertilizer sources on some activities of antioxidative enzymes and physiological characteristics were effect at 1% probability level. So that, Saji cultivar×Glomus mosseae kg/ha phosphorous chemical fertilizer had the highest APX (14.6 u/mg protein), POD (15.4 u/mg protein), SOD (23.6 u/mg protein), chlorophyll a (44.3 mg mL-1), chlorophyll b (43.6 (mg mL-1), proline (4.5 μm g-1), RWC (71.3%), WUE (6.3 kg/mm) and decreased MAD (18 μmolg-1d.w) and Keras Sabalan cultivar and check treatment (without application of phosphorous chemical fertilizer) had the lowest APX, POD, SOD and photosynthetic pigment. Therefore, with the selection of suitable and responding cultivar to bio-fertilizers sources can lead to improvement of growth and grain yield by increasing the activities of antioxidative enzymes and physiological characteristics under dry land conditions.

In order to evaluation of bread wheat landraces for uptake and nitrogen use efficiency, this experiment was conducted by using 200 kg N ha-1 N fertilization and control (without using N) by spilit plot design based on RCBD with three replications in 2009-2010. The results indicated high genetic variation between native wheat landraces for nitrogen uptake and use efficiency were found. Use of nitrogen caused increasing of gain yield, number of seed per spike, spike number per m2, nitrogen content in grain and straw, grain nitrogen, nitrogen uptake and use efficiency but decreasing of harvest index and 1000 kernel weight. Analysis of variance showed that significant differences were exsit for genotypes in traits of grain yield, 1000 kernel weight, number of seed per spike, spike number per m2, harvest index, nitrogen content in grain and straw, grain nitrogen, nitrogen harvest index, nitrogen uptake and use efficiency. The interaction of Genotypes and nitrogen for all characteristic were found significantly different, except harvest index. The highest grain yields belong to G19, G26, G29, G37 and G41 compared to others. Landraces of G19, G21, G29 and G40 compared to others had highest reaction for grain N concentration and G12, G15, G28 and G31 for straw N concentration. Among relative contribution of N use efficiency components, nitrogen uptake efficiency contribution was about 85% of variation at both N levels. While Contribution of total N utilization and Harvest Index was (2-15%). The better landraces for N uptake efficiency were G9, G11, G27 and G37. In addition, landraces of G19, G26, G27, 37 and G41 were the better genotypes with their charactersitic and high yielding potential.

Study on differences of barley varieties and genotypes at different P fertilizer rates on grain yields and P uptake under dry land condition was carried out. In this study, experiments were conducted with four levels of phosphorus fertilizer rates as a main plots and ten barley varieties and genotypes as sub plots with split plot design with three replications from 2009 to 2012 in main station of Dryland Agricultural Research Institute. Results showed that with increasing phosphorus application rates, grain and straw yields, P concentration, P uptake of different wheat varieties and genotypes were differently and significantly increased. Phosphorus treatments 30 and 45 kg P2O5/ha compared to control (0 P2O5/ha) had highest grain, straw yields, P concentration in grain and straw, and total P uptake. Barley genotypes and varieties were not significantly different in grain yields, but differed relatively due to selected and evaluated genotypes in cereal section for drought condition. URB81/3, Abidar, Dayton compared to other had highest grain and straw yields. Total P uptake for different varieties and genotypes were differed significantly. Genotype Dari-ERB87/2 had highest P uptake compared to other genotypes and varieties. Barley genotypes and varieties indicated that URB82/9 and URB81/5 had highest P uptake at low phosphorus application compared to other varieties and genotypes, while the other genotypes increased P uptake with increasing P rates. It can be concluded that addition P fertilizer to soil increase barley yields. Varieties and genotypes differed in P uptake and relatively grain and straw yields. Yields of barley and P uptake depend on growth rates, rain fall and its distribution, P application rates and differences of barley genotypes. URB82/9 and URB81/5 can increase P uptake at less applied phosphorus fertilizer.

This field experiment was done as split plot based on randomized complete blocks with three replications at Urmia University in 2013-14. Rainfed (I1) and supplemental irrigation (I2) arranged as main plots and different cropping patterns included T1=plots without chickpea with every 10-day regular-irrigated, T2=plot without chickpea, T3=chickpea planting with no empty rows with hand weeding, T4=chickpea planting with no empty rows and without weeding, T5=one row of chickpea and an empty row as alternate, T6, T7 andT8=two rows of chickpea and two, three and four empty rows, respectively, T9=three rows of chickpea and two empty row, T10=four rows of chickpea and two empty row as subplots. The results showed that chickpea with no empty rows (T4) and without weeding under rainfed conditions decreased 92.17, 92.18 and 90.33 percent dry matter of common cocklebur, common lambs quarters and wild radish, respectively, compared to the supplementary irrigation. In the plot without chickpea, supplemental irrigation increased 41 percent the total biomass of weed compared to the rainfed condition. Also, results demonstrated that the highest yield components of chickpea were observed under irrigation that led to increase 40 and 37 percent grain and biological yield as compared to rainfed conditions. In comparison of T3 and T4 treatments, results showed that the weeds competition with chickpea cause to decreasing 35.5 and 29.57% of chickpea grain and biological yield. Overall, with planting of chickpea by filling the ecological nest, in addition to the reduction of inputs, we can cause the weed control in irrigated farms and provided the agro-ecosystem sustainability.

Biofilmed bacteria that possess growth promoting properties can help crops such as wheat to survive in water stress conditions. In this regard, a factorial experiment with randomized complete block design (RCBD) was carried out to evaluate the effects of biofilm bacteria on yield and its components of wheat in rain-fed condition. Factors were including biofilmed bacterial isolates (including no bacteria, and isolates 16-1, 38-2 and 1-54), different wheat varieties (Kohdasht and Chamran), and water application (applying 20, 50, and 80 % of available water content) which were applied in 3 replications in research greenhouse of university of Maragheh. Studied isolates were selected among 120 biofilm isolates which were isolated from Graminae’s roots resistant to drought in the Hashtrood region. Results revealed that bacteria had positive effects on yield component of wheat in all applied water conditions. Bacteria’s application also prevented the deduction in some of yield components which usually occurs due to water stress condition. However, the results revealed that the effects of bacterial application were higher in Chamran variety compared to Kohdasht variety. Root’s wet and dry weights, root’s tissues density, water holding percentage of root and root/shoot ratio were affected by water stress condition. Bacterial inoculation decreased root’s wet and dry weights and tissues density. In contrast, Bacterial inoculation considerably increased water holding percentage. In general, the results suggest that biofilmed bacteria are suitable to deduct the effects of drought stresses.

In order to zoning of planting and harvesting dates and the length of growth stages of rainfed wheat in Golestan province, daily data of maximum and minimum temperatures and precipitation of 30 meteorological stations were used during the statistical period of 1991-2015. Due to the dependence of rainfed cultivation on the meteorological parameters, zoning maps were produced based on the probability level of 75%. Planting date and length of growth stages were determined based on the occurrence of the first precipitation equal to or more than 25 mm during a 10- day period in December and concept of Growing Degree-Days (GDD), respectively. To verify and check the validity of the results, zoning maps were compared with the various research findings obtained from farm-scale studies in Golestan province. Results showed that the highest frequency (area) and weighted average of rainfed wheat planting date in different regions were between 7th to 16th and 12th of December and for harvesting date were between 11th to 21th and 16th of June, respectively. Time duration of planting to emergence was between 34 to 89 days with a weighted average of 47 days, emergence to flowering was between 106 to 147 days with a weighted average of 122 days, flowering to maturity was between 31 to 68 days with a weighted average of 37 days and planting to maturity (total growing season) was between 170 to 244 days with a weighted average of 187 days. Regarding the occurrence of more and earlier precipitation and early appearance of cold season in the southern half and highlands of province compared to the northern plain areas, earlier planting and later harvesting dates in the southern half seem reasonable. Verification of these results with the findings of farm scale research showed that the prepared zoning maps had a good accuracy.

In order to study genetic diversity and identification of QTL controlling seed germination and seedling establishment traits in wheat 148 bread wheat RILs and their parents (RojoYecora and No.49) were studied based on an alpha lattice design with two replications under normal and drought stress conditions in 2016. In this research final germination percentage, germination speed, root and shoot length, root and shoot dry weight and seedling dry weight and vigor index were measured. Analysis of variance showed that between genotypes for all traits, there were significant differences. Under normal moisture conditions the highest heritability was observed for stem length, stem weight and final germination percentage. The highest heritability under drought conditions was found for root length. QTL analysis using composite interval mapping (CIM) for each trait in each environment and mean of two environments were performed. Under normal conditions16 QTL were detected. Phenotypic variance explained by the identified QTLs varied from 11.49 to 21.57 percent. The highest and lowest phenotypic variation belonged to shoot dry weight and root dry weight, respectively. The estimated LODs were in range of 3.15 to 6.76. Under stress conditions 20 QTL were detected. Phenotypic variance explained by these QTLs varied from 11.89 to 24.65 percent. The highest and lowest phenotypic variation were observed fot root dry weight and shoot length respectively. Furthermore LODs were in range of 3.11 to 9.67. Considering the average of two environments, 14 QTL were detected. Phenotypic variance explained by the identified QTLs varied from 11.41 to 23.20 percent, and belonged to root dry weight and shoot dry weight, respectively. The estimated LOD was in range of 3.12 to 7.25. In two different environmental conditions and their average QTL located on chromosome 4B interval markers of Wms121-Sukkula.1300 which control of shoot dry weight and seed vigor and QTL located on chromosome 2D between markers of Gwm349-Wmc445 Which is controlled vigor index was quite stable in all conditions that can be used for marker assisted selection.