مجله علوم گیاهان زراعی ایران
سال چهل و ششم شماره 4 (زمستان 1394)

In order to evaluate the effects of intercropping of maize- peanut, weeding and their planting design on weed population dynamics, an experiment was conducted as a factorial experiment in the form of RCBD with three replications at the Research Farm of Agriculture Center of Zabol University (Iran) in 2012. The treatments including sowing system in four levels as first factor (sole maize, sole peanut, 50% maize 50% peanut, 100% maize 100% peanut) and row spacing as the second factor in two levels (40 and 50 cm) and weeding as third factor in three levels (non-weeding, once weeding, twice weeding). The results showed that 100% corn 흍% peanut intercropping patterns had the lowest weed density and dry weight compared to intercropping of 50% corn % of the peanuts. The peanut monoculture compared to other intercropping patterns had the highest density and dry weight of weeds. With the increasing number of weeding, the number and dry weight of weeds decreased. Among the different row spacing, the density and weight of weeds between rows of 40 cm was less than 50 cm. It seems various features of crops such as height and canopy closure will have the most effect on weed control. The results of this experiment showed that the highest weed controlling was obtained from 100% maize 100% peanut, density of 50 cm and twice weeding.

Cell expansion and cell division are two main processes in plant growth and development. Expansin proteins play a role key in cell expansion. These non-enzyme proteins involve in many growth and developmental processes. This protein affects drought tolerance. AtEXPB2 gene belongs to these proteins family. AtEXPB2 gene mainly expresses in the root tissue. In this study the EXPB2 gene, that was isolated from Arabidopsis taliana DNA genomics, transferred to Nicotina tabacum plant. Gene transfer was performed by Agrobacterium-mediated technique. Explants were inoculated by Agrobacterium and then were planted on M.S medium contained antibiotic of kanamycin. Finally, the tolerant seedlings were transferred to pots. Polymerase chain reaction was used to confirm the transgenic plants. Good rooting of transgenic plants suggests that this gene was increased root length and density.The results suggest that the expression of these genes in the aerial parts of the plant can cause undesirable traits such as loss of flower buds and leaf loss.

In order to study of the effects of hydro-osmo priming, bio-priming (biological fertilizer (Barvar-2) and inoculation with Rhizobium japonicum bacteria) on growth & yield of DPX cultivar of soybean (Glycine max L.), an experiment was carried out as factorial based on a randomized complete block design (RCBD) with 4 replications in Agriculture Research Station of Shahrood University of Technology, Iran. Biological fertilizer including 2 levels (check and using of biological fertilizer) and Rhizobium japonicum including 2 levels (check and using of Rhizobium japonicum) and priming including 3 levels [(hydropriming, osmopriming induced by PEG 6000 and check (unpriming)] were used as treatments. The results showed that interaction between biological fertilizer and Rhizobium japonicum significantly affected number of pod per plant, number of seed per plant and oil percentage. Interaction between biological fertilizer and priming significantly affected number of pod per plant. Grain yield for biological fertilizer consumption was 2897.7 kg/ha and for inoculation with Rhizobium japonicum was 2967.2kg/ha. Generally, priming, biological fertilizer consumption and inoculation with Rhizobium japonicum increased grain yield.

Quinoa (Chenepodium quinoa Willd) is a grain-like crop which has a high production potential in Iran. Due to its seeds high nutritional value, it is compared with milk by the FAO. In order to study the effects of temperatures on seed germination of Quinoa seeds under salinity stress conditions, an experiment was conducted in Seed Lab of the University of Tehran in Karaj. Temperatures regimes included 5, 10, 15, 20, 25, 30 and 35°C. At each temperature four salinity treatments (zero, -4, -8 and -12 bars) using NaCl were used. Results showed that increasing salinity stress decreased significantly germination rate but did not affect germination percentage except in 35°C at -12 bar. Basal temperature (Tb) for Quinoa germination was increased in high salinity potentials, but ceiling temperature (Tc) decreased. The germination data indicated that high salinity resulted in the narrow germination temperature in Quinoa seed.

To investigate the effect of salicylic acid (SA) on salinity tolerance of two sugar beet cultivars, this experiment was conducted as split factorial based on a randomized complete block design with three replications during growing seasons of 2012 and 2013 in Research Farm of Shahid Chamran University. The studied factors were three levels of SA (0 mM, 0.5 mM and 1 mM), two levels of salinity (150 mm sodium chloride and control) and two sugar beet cultivars (Jolgeh and Shariff). SA was applied as foliar spray along with salinity in the 4-leaf stage. Results showed that foliar application of SA caused significant increase of leaf area (LA), chlorophyll, stomatal conductance, ФPSІІ, Fv/Fm, proline and total soluble sugars, and decrease membrane permeability compared to control under salt stress conditions. Salinity caused a significant decrease in LA, Chlorophyll, stomatal conductance, ФPSІІ and Fv/Fm, while increase proline, total soluble sugars and membrane permeability. Therefore, according to the results of this research, it seems, foliar application of salicylic acid could enhance sugarbeet growth and increases resistance to salt stress.

To study the effects of different tillage systems on yield and some characteristic of wheat and also some soil properties in wheat dry land area, six experiments were performed in cold, moderate and semi-warm climatic conditions of Kermanshah province in west of Iran, in a randomized complete block design with five replications. Experimental treatments were consisted of no-tillage, reduced tillage and conventional tillage systems. The highest seed yield was observed in no-tillage (2365 kg ha-1) and reduced tillage (2373 kg ha-1) systems of moderate climate of the second year. The highest economic value was related to no-tillage (24832 thousand Rials) and reduced tillage (24316 thousand Rials) systems of moderate climate of the second year and no-tillage system of moderate climate of the second year (22753 thousand Rials). In all climates and years, no-tillage system with 11.97% (about two times) following by reduced tillage with 11.16% (more than 1.5 times), preserved large soil moisture in comparison to conventional tillage system (6.2%). Soil organic carbon was not affected by climate type and experimental years, but general trend of differences indicated that no-tillage and reduced tillage systems (except the second year of warm climate) 1.6 and 1.3% were higher than conventional tillage system. The lowest soil bulk density (1.24) was observed in the conventional tillage system. In general, it could be concluded that conservation tillage systems can supply, more yield and economic returns, as well as conserving more water than conventional tillage and its application is a necessary step toward a sustainable agriculture.

In order to study the effects of drought stress and foliar application of iron oxide nanoparticles on sesame plants, a field experiment was laid in Faculty of Agriculture, University of Shahrood in 2014. The design of experiment was in split plot with blocks completely randomized in three replicates. Drought stress, W1=7, W2=12 and W3=17 irrigation time, were randomized in main plots with four concentrations of foliar application of iron oxide nanoparticles, F1 = 0, F2 = 0.5, F3 = 1 and F4 = 1.5 kg at 1000 l water, in sub-plots. Results showed that the interaction between drought stress andiron oxide nanoparticles had significant effect on grain yield, biomass, leafstomatal conductance, chlorophyll "b" and carotenoids content in leaves, and seed nitrogen. The results indicated that the highest grain yield and biomass were obtained at W1F3, stomatal conductance at W1F2, chlorophyll "b" at W1F4, carotenoids at W2F3 and seed nitrogen at the W3F3 treatments. Moreover, the number of branches per plant and the concentration of potassium in seeds were significantly affected by both treatments. However, phosphorus in seeds, and potassium and phosphorous in leaves remained unchanged under treatments. Number of seeds and seed weight per capsule decreased about 12.3 and 27.7%, respectively by worsening the drought condition from W1 to W3. In general, it can be stated that in the drought stress condition, foliar application of iron oxide nanoparticles about 1 kg per thousand liters of water improves the physiological characteristics of sesame and grain yield.

This study was performed to evaluate relationships among morphological traits and use of the traits to describe Iranian Cannabis accessions. Results of the ANOVA for the measured traits excluding the number of lateral inflorescent, displayed significant differences among accessions. The lowest plant heights were observed in Sero and Saqez (respectively 81.20 and 78.80) and the highest values were in Desht-e-moghan, Ramhormoz, Dezful2 and Boshruye (respectively 203, 222.40, 198.40 and 195.30). Also the earliest flowering dates were found in Ardabil, Sero, Kermanshah, Saqez, Saadat-shahr (respectively 91, 89, 88.40, 84.10 and 88.20) and the latest flowering accessions were Qazvin1, Ramhormoz and Shiraz (respectively 108.80, 111.50 and 114.30). Associations among the traits revealed positive significant correlations between some traits such as the height of the first alternative node indicating the beginning of reproductive phase with stem diameter, number of node and mean length of internode. The least coefficient of variation was observed in number of days to seed formation (2.27%) and the highest amount was in the length of main inflorescence (29.31%). Factor analysis based on the measured traits showed that the three first factors explained 80.67% of total variance. According the factor loadings, the most of vegetative traits had higher values in the first factor while the phonological traits along to plant height were effective traits in the second factor.

Salinity is one of the abiotic stresses and exploitation of heterosis could increase the crop yield and extend the stress tolerance, especially in salinity stress. In this research, a set of full diallel design involving 7×7 crosses from cultivars including Flat, Bam, Ghods, Roshan, Arg, Kavir and Pishtaz were conducted in a randomized complete block design with three replications under both normal and salt stress conditions in Yazd, Iran. The results of heterosis and graphical analyses using GGE biplot approach indicated high narrow and broad sense heritabilites and heterosis of crosses for yield and biomass traits, especially in saline condition. Graphical biplot determined two different heterotic groups for yield and biomass characteristics in saline condition. The ranges of heterosis for yield trait were between -18.5 to 24.1% in normal condition and -21.3 to 60.1% in saline condition, respectively. Also, the ranges of heterosis for biomass were between -22.2 to 16.1 % in normal condition and -19.7 to 55.3 % in saline condition, respectively. The results of this research showed that under saline conditions there were significant crosses for negative and positive heterosis for studied trait. High heterosis and great narrow and broad sense heritabilites for yield and biomass traits indicated that finding a better line along with a fixed relative heterosis is possible using selection methods from the progenies in saline condition.

Stem reserves of barely can be an important contributor to grain filling particularly under condition is limited such as salinity stress. The aim of this research was to study dry matter accumulation and remobilization ability in different internodes of some Iranian Barley varieties and promising lines under salinity and normal conditions. The research was set up as two Randomized Complete Block design with three replications at the agriculture research station of Neishabur, Khorasan Razavi, during 2013-2014. The amount of dry matter accumulation and remobilization were determined using method. The relationship between length and specific weight of internodes with dry matter accumulation and Remobilization was investigated. The results showed that lower internodes had maximum dry weight and specific weight in both of experimental conditions. Maximum remobilization was obtained from penultimate and lower internodes in normal and salinity conditions, respectively. A positively significant correlation was observed between seed weight per spike and the amount of Remobilization from all of internodes in saline condition. Results indicated that dry matter accumulation and remobilization ability are two different mechanisms that inherent from parents to progeny. Also in this study it was found that new tolerant promising lines compared to old tolerant varieties, had internodes specific weight, dry matter accumulation and remobilization ability.

In order to evaluate the effects of drought and salinity stresses on growth parameters and essential oil of lemon balm, two experiments with three replications in a randomized complete block design were applied. Five levels of salinity including zero, one, two, three and four dS/m of sodium chloride solution, and five drought stress treatments including 50, 62.5, 75, 87.5 and 100% as available water for plants were used. Parameters including morphological, dry matter, and essential oil percentage were measured in each experiment separately. Drought and salinity stress, with the exception of essential oil percentage, decreased all measured parameters and the effect of salinity stress was higher. The highest and lowest growth characteristics were achieved from the 100 and 50% available water treatments, and the maximum and minimum essential oil was achieved from 50 and 100% available water, respectively. In salinity experiment, growth parameters declined with increasing salinity. The level of salinity from zero to one dS/m increased the essential oil percentage. However, compared to control, treated plants showed higher essential oil percentages. Salinity and drought stresses reduced the growth parameters and essential oil percentage was somewhat increased.

In order to evaluate the effects of convention and conservation (no-tillage and reduced tillage) tillage methods on wheat and chickpea yield and yield components and soil physical properties under rainfed conditions in Kermanshah (N: 34°19', E: 47°17'), some experiments were performed in Sararood Dryland Agricultural Research Station during three cropping seasons (2011-2014). In the first year, chickpea was planted in a randomized complete block design (RCBD) with five replications, covering the three tillage methods. In the second and third years, split plot experiments were performed based on RCBD with five replications. The tillage systems located in the main plots while crops, were in sub-plots. Results in the first year showed that, except of soil organic carbon, all studied traits were affected by tillage system (P≤0.01). In the second year, the highest soil moisture was observed in no-tillage plots of chickpea, and the highest yield and yield components were observed in the reduced tillage system of the third year. The no-tillage and reduced tillage systems produced the maximum yield, thousand grain weight and plant height in bread wheat. In general, most of the traits were influenced by tillage types. Regarding the results of the experiments and the other benefits of conservation tillage, reduced tillage recommended as a good replacement for conventional tillage in dryland areas of Kermanshah.

In this study fertilizing potential of municipal solid waste (MSW) compost was investigated by the distribution behavior of heavy metals, nutrient elements and salinity content among the different size fractions. Therefore, 3 compost samples (each composed of 6 subsamples) were collected from Sanandaj MSW Composting Plant. Then, the samples were physically divided into seven fractions of different particle size including >2, 1.2-2, 0.8-1.2, 0.4-0.8, 0.2-0.4, 0.1-0.2 and 2 mm). Overall, the results suggest that the size fractions less than 0.4 mm with highly heavy metals and salinity content and size fractions more than ­2­ mm with high impurity (glass, 21.2 times over the permissible limit) were responsible for lowering the quality of the produced compost, thus, removal of selected fractions particle size could significantly improve the compost quality and allowed us to use and its safe recycle in agriculture.

Application of organic fertilizers increases quality and yields in the sustainable crop production and considerably replaces or reduces chemical fertilizers. In order to study the effects of different manure and vermicompost rates on yield and essential oil contents of dragonhead, an experiment was conducted as a randomized complete blocks design with eight treatments and three replications in the field of Pakdasht city in 2012. The treatments were 10 and 20 t/ha manure, 5 and 10 t/ha vermicompost, 5 t/ha manure 2.5 t/ha vermicompost, 10 t/ha manure 5 t/ha vermicompost, chemical fertilizer (70 kg/ha nitrogen) and control (without fertilizer). The results showed that the highest herbage yield, essential oil contents and yield, geranyl acetate percentage and geraniol percentage in essential oil were obtained by using 10 t/ha manure, 5 t/ha vermicompost and integrated application of 10 t/ha manure and 5 t/ha vermicompost, respectively. The highest geranial percentage, neral percentage and neryl acetate percentage in essential oil were obtained by using 10 t/ha vermicompost application. Generally, the highest herbage and essential oil yields were obtained by using 10 t/ha manure application and the highest essential oil contents with vermicompost application.

In order to increase drought tolerance in bread wheat, an appropriate breeding program based on inheritance of drought tolerance is recommended. In the present study, nine bread wheat cultivars and their F2 progenies were evaluated in a randomized complete block design under normal and drought stress conditions. Nine sensitivity/tolerance indices were calculated for studied genotypes and stress tolerance score (STS) was calculated using all indices. Inheritance of drought tolerance indices (STI, DRI and STS) were evaluated using half diallel design. Low Baker ratio for these indices showed that none-additive effects are more important than additive effects in genetic control of these indices. In addition, broad sense heritability was relatively high and narrow sense heritability was low for evaluated indices. Results of this research showed that selection for increasing drought tolerance in bread wheat should be postponed till late generations. Based on these results, bulk, single seed descent and double haploid are recommended methods for breeding for drought tolerance in this population.