مجله علوم گیاهان زراعی ایران
سال چهل و پنجم شماره 3 (پاییز 1393)

In this study، 110 samples of bread wheat، Aegilops crassa، Ae. cylindrica and Ae. tauschii were investigated to identify Low-Molecular-Weight Glutenin Subunits. Overall، the four alleles in term of the analysis of SDS-PAGE gels were detected. The ʻaʼ allele with 45% has the greatest frequency، and after that، ʻbʼ، ʻcʼ and ʻdʼ alleles were with 38. 1%، 11. 8% and 9. 1% frequencies، respectively; however، in Ae. crassa، ʻbʼ and ʻcʼ alleles are the highest and lowest frequencies، respectively. The ʻaʼ and (ʻcʼ and ʻdʼ) alleles are the highest and lowest frequencies in Ae. cylindrica; nonetheless، In Ae. tauschii، ʻaʼ and ʻdʼ are the highest and lowest frequencies. In T. aestivum، ʻbʼ are the highest while ʻdʼ shows the lowest frequencies. Genetic diversity (ζ) in populations of bread wheat، Ae. crassa، Ae. cylindrica، Ae. tauschii and total population were calculated 0. 6564، 0. 5792، 0. 6378، 0. 6214 and 0. 6294، respectively. Furthermore، the average genetic diversity (H) for the total population was obtained 0. 6294. The results show that wild wheat relatives have various alleles that can be utilized them in breeding programs to improve glutenin.

Water deficit، ultraviolet radiation and carbon dioxide enrichment are the most important environmental factors in global climate change. This research was conducted in Tarbiat Modares University، Research Greenhouse and the objective of that was to study the effects of three levels of carbon dioxide (500، 900 and 1300 ppm)، UV-radiation (UV-A، B and C with intensity of 18، 25 and 40 µW. cm2 respectively) and water deficit (common irrigation and 40 percent of available water remain in soil) on grain yield، some quality traits of sweet corn (Zea mays L. var. Sacarata). The experiment was conducted as factorial arrangement in randomized complete block design with three replications in one year (2009). The results showed that interaction among UV-C radiation، elevated CO2 and water stress had a significant effect on grain yield and Fv/Fm. The highest grain yield was obtained in water deficit and 900 (µl/l) CO2 concentration. The most content Fv/Fm was obtained under water deficit and 1300 (µl/l) CO2 concentration. Water deficit and elevated CO2 increased proline، and decreased chlorophyll a، chlorophyll b، chlorophyll a+b، carotenoids and flavonoids. Grain protein decreased with wavelength UV reduction. Above result showed that three main environmental stresses reduced plant productivity strategy in most condition and as a result decreased the performance of corn plant.

In this study، the ability of 32 rhizobium strains (26 strain of Sinorhizobium meliloti (SM))، 4 strains of Rhizobium leguminosarum biovar phaseoli (Rlp) and 2 salt tolerance strains of Rhizobium leguminosarum biovar viciae (Rlv) for use of ACC as individual nitrogen source in RMM media was evaluated. Based on the results، 25 strains were found positive for ACC-deaminse، and strains according to growth in the RMM media containing ACC were categorized into three groups of strong، medium، and weak. In the next step، in 2011 a series of greenhouse experiments were conducted for investigating the effectiveness of two strains from strong group (R281Rlp and R103Sm) and one strain from weak group (R29Sm) with control treatment، for the promotion of growth parameters of canola under the salinity levels of 0، 3، 6، and 9 ds/m in factorial format experiment as randomized complete block design with three replications. The Results showed that R281Rlp inoculation، even at higher salinity (9dS/m)، significantly increased wet and dry weight of root (32 and 62. 6%، respectively)، wet and dry weight of shoot (22 and 23. 5%، respectively)، height (49%) and nitrogen uptake (50%) compared to control treatment. Furthermore، at this level of salinity، R103Sm inoculation increased the uptake of Phosphorous up to 34. 5% compared to control. A positive correlation was observed between ACC-deaminase activity of bacterial isolates and plant growth parameters; especially root biomass، (Pearson correlation coefficients > 0. 82). These results revealed that the strains containing high ACC-deaminase activity were more successful in improving the growth parameters of canola seedling، which confirms that using of these strains may be suggested as a biologic alternative to the amelioration of increasingly saline stress.

In order to evaluate the effects of atmospheric CO2 concentration increment on rapeseed salinity tolerance، four levels of salinity (0، 5، 10 and 15 dS. m-1) on three cultivars of rapeseed (Okapi، Zarfam، and RGS) at three levels of atmospheric CO2 concentration (350، 700 and 1050 ppm) were studied. The experiment was conducted at the greenhouse of Tarbiat Modares University at 2010 and 2011 crop season. Three levels of CO2 concentrations have been considered as three environments in which two other treatments (salinity and cultivar) carried out in a completely block design in factorial arrangement. Results indicated that photosynthesis rate of canola increased with increasing CO2 Concentration (about three times in 1050ppm) in the air and decreased with increasing salinity (21% in 15 dS. m-1). Three times concentration of CO2 (1050ppm) reduced the impact of salinity on photosynthesis. Elevated CO2 by increasing photosynthesis rate، reducing transpiration and increasing water use efficiency reduced effects of salinity. Water use efficiency was increased with increment concentration of carbon dioxide and decreased with salinity.