PLANT ECOPHYSIOLOGY (ARSANJAN BRANCH)
Year:2011 | Volume:3 | Issue:9|Papers Count:11

Stem-stored carbohydrate from pre-anthesis period had an important role in supporting assimilates for growing grain in drought stress during grain filling period. An experiment was conducted in 2007-8 in experimental farm of Islamic Azad University of Arsanjan, to investigate the quantity of stem reserves in different wheat cultivars of different heights. The randomized block, split-plot design was used in the experiment. Main plots consisted of three irrigation regimes (full irrigation, only one irrigation in post-anthesis and without irrigation during post-anthesis period) and subplot consisted of six wheat cultivars (Marvdasht, Falat, Ghods, Karaj3, Adl and Kaveh). At physiological maturity, grain yield, biological yield, yield components, plant height and stem weight were measured. The results showed that water holding in post-anthesis period significantly reduced grain yield, biological yield, grain weight and stem weight. Grain yield, biological yield, harvest index, number of ear m-2, number of seed ear-1 and plant height were significantly different in different cultivars. The interaction effects of cultivars and irrigation indicates that different cultivars respond differently to reduction of irrigation. By withholding post-anthesis irrigation the adverse effects of drought on grain weight and grain yield in tall cultivars were lower in comparison with dwarf cultivars. Losses of stem weight with irrigation withholding were higher in tall cultivars. These results indicates that tall cultivars have more stored reserves in stem, which can be used in unfavourable condition for grain filling. In other words, remobilization is higher in tall cultivars and this trait can be used for developing drought tolerance in breeding programs.

The relationship between vegetation and soil of the semi-arid areas in management and planning, especially when the goal is to reform, regenerate and protect the soil cover. For this purpose, a study of pasture species Galium verum in phenological phases in three different soils in the valley of the martyrs was carried out in 2011. Plant and soil samples from an area in the north with three types of soil with three replicates were randomly collected systematically. Average of data using variance analysis and Duncan test, and correlation between soil and plants through a single linear regression was performed using SPSS by Stepwise method. Factors measured in soil samples included: Saturation, Organic carbon, N, P, K, Ca, pH, EC, Lime, Clay, Sand, Silt and elements in plant samples were (P, K, Ca, N, DM). The results showed a correlation between soil factors and plant So that the different phenological stages, phosphorus plant lime, sand, clay, silt and soil saturation were sensitive and the reduction of silt, clay and soil saturation, and the lime and sand reduced the phosphorus plant. In the active growth phase, reduction of silt and soil saturation and increasing the lime and sand reduced nitrogen in plants and decreased sensitivity in flowering phase. Therefore, the only effective agent in reducing the nitrogen plant is reducing the silt. The highest seed yield factor influencing plant nitrogen-phosphorus soils is So that the reduction of nitrogen and phosphorus on plant-soil interactions. Therefore it is concluded that different plants react differently to changes in soil properties and can be represented as a habitat for forage quality.

Brassinostroids are group of plant hormones that have significant biological effects on plant growth and development including increase in plant tolerance to environmental stresses. In this study the effects of 28 - Homobrassinolide on growth parameters, yield and essential oil percentage in the dill (Anethum graveolens) under drought stress, were studied in greenhouse of arsanjan training and vocational teaching organization. Factorial experiment in randomized complete block design with four replications and 12 treatments were used. Total number of test pots 12×4=48 was the number. Treatments randomly were placed in each pot. The first treatment included drought factor (S) in three irrigation levels based on values of field capacity (FC), mild stress (LS-2 / 3 field capacity) and high stress (HS-1 / 3 field capacity) and the second treatment, included steroid hormone factor that 28 - Homobrassinolide four levels, control (zero), M 10-10, M-810 and M 10-6 in solution, before drought treatments were applied. The plants in pots containing clay loam soils planted. Young plants in 4 to 5 leaf stage with a solution of 10-8 M 28 Homobrassinolide containing 20 had been sprayed. After establishing plants in stage six branches drought stress treatments were applied. Results showed that different levels of drought stress reduced shoot and root dry weight, plant height and Essential oil yield but percentage of Essential oil significantly increased. Use of 28- Homobrassinolid improved, dry weight root and shoot, Essential oil yield and percentage of Essential oil under mild stress and high stress condition treatment. As a result, plants treating with Article 28 - Homobrassinolid percent significantly increased oil yield and the damage caused by the deficit irrigation stress reduced.

Allelopathic compounds display an important role in biodiversity, stability and ability of ecosystems production. This phenomenon that has not been considered in range improvement is of important concerns in restoration of rangelands. Artemisia aucheri due to having chemical properties may contain allelochemical components. In this study, allelopathic effect of mentioned species was tested on Festuca arundinacea and Dactylis glomerata of seed germination. To do so, aerial part powder of Artemisia aucheri (stem, leaf and seed) collected from habitats in flowering stage (end of November). Also a control treatment (distilled water) was used. A completely randomised design was carried out using six treatments and four replications in laboratory. Results showed a significant effect of aqueous extract of Artemisia aucheri on seed germination indices. The percentage of germination, seed germination rate and plumule and radicle length, and seed vigor of Festuca arundinacea, and Dactylis glomerata significantly reduced under aqueous extract of Artemisia aucheri.

This study was conducted in okra in Damghan condition in order to understand their effect on yield and yield components in the form of factoriel experiment with three factors, the first factor was two varieties of okra (Iranian native variety, CLEMSON), three planting densities (80000, 40000 and 30000 plant/ha) and two planting patterns (Unilateral and Bilateral) in the form of randomized completely block design. The highest amount of function was gathered from the foreign type with the mean of 1801.4 kg/ha, so it was the highest number of fruit with the mean of 212.78. The Iranian varieties with the mean of 8091 kg/ha had the highest amount of biomass and it hat the highest wet weight with the mean of 15020 per ha. Among the Studied planting patterns, the Unilateral pattern with the mean of 13519 kg/ha was the heaviest and it had the highest amount of biomass with mean of 7200 kg/ha. The density of 80000 bushes per hectar with the mean of 13084 was the heaviest and it had the highest amount of biomass with mean of 2467.44 Kg/ha. So it had the highest number of fruits with the mean of 13450.4.

The effect of salicylic acid on yield and yield components of salt-tolerant and salt-sensitive wheat cultivars in saline conditions was investigated in Factorial experiment based on randomized block design with 3 replications in Islamic Azad University farm research in 2009-2010. Factors included: cultivar (Akbari and falat, salt-tolerant and salt-sensitive, respectively) and salicylic acid application method (seed treatment, foliar application, seed treatment+foliar application and control). 0.5 gkg-1 salicylic acid for seed treatment and 0.5 mM for foliar application were used. Foliar application was done in booting stage. The result showed that salicylic acid application method had significant effect on yield and yield components of wheat in saline condition except Na+ and K+ content. Seed treatment+foliar application had more effect on all parameters. The highest economic yield was achieved with seed treatment+foliar application of salicylic acid. Biological yield, economic yield, number of seed per ear and 1000 seeds weight were significantly different between the two cultivars. For all parameters Akbari cultivar was better than Falat in saline condition. There was no significant difference between cultivars for other parameters. Overall, in saline conditions, the use of Akbari cultivar with seed treatment+foliar application of salicylic acid is appropriate to achieve the best yield production.

In order to study the effects of salinity on yield and yield components of rapeseed varieties and identify the best cultivars, an experiment was conducted in the greenhouse of Islamic Azad University, Arsanjan branch as factorial based on completely randomized design with three replications. Experimental treatments included five varieties of rapeseed (Opera, Okapi, Madonna, Kobra and Talayeh) and five levels of sodium chloride salinity (0 control, 3, 6, 9 and 12dS m-1). The number of pods in main and secondary stems, the number of seeds in the pod in main and secondary stems, 1000 seed weights in the main and secondary stems and yield of the main and secondary stems were measured. The results showed that the highest value of the yield and yield components, main stem and branches were related to the control salinity treatment. Increasing salinity negatively influenced all traits. Kobra CV showed the highest value of all measured traits. Therefore it could be introduced as salt tolerant variety. Talayeh and Madonna varieties were introduced as semi-tolerant and Oprah and Okapi as sensitive cultivars to salinity. The interaction impact of variety and the salty surface was significant. the 12dS m-1 had the highest salty surface impact. Salt decreased the yield of the main stem for 81% and secondary stem for about 87% among the yields of the components, the main and secondary pod showed the highest decrease.

Desertification means land degradation in arid, semi-arid, and semi-humid areas, which happens due to changes in climatic conditions and human activities. Sistan plain is a dry area in the eastern part of Iran that is suffering from desertification as the main problem. The main purpose of this two-year study is to assess changes in the vegetation of the region within the time period from 1990 to 2006. Field sampling, satellite images, and related software were used to conduct the present study. First of all, field sampling method was randomly and systematically performed in 26 well-known sites. For each site, nine 10×10 m plots were recorded. In the next stage, the required processes were conducted on the satellite images and vegetation indices were generated. Correlation analysis was performed between data related to land coverings and spectral values of corresponding pixels. The highest correlations obtained among 83 estimated indicators were related to indices of WDVI, NDVIab, TSAVI2 and MSAVI1, respectively. The obtained images were classified into two coverage and non-coverage groups. Then the precision of plots were evaluated and the highest precision of 83.27% was related to the plot taken for WDVI which had the highest correlation coefficient (p<0.01 and R2=0.89) as well. Based on these plots, vegetation rate was determined as 101247 acre for 1990 which decreased to 26475 acres for 2006.