مجله تولید گیاهان زراعی
سال پنجم شماره 3 (پاییز 1391)

In order to determine the genetics of barley lines for freezing resistance based on crown survival percentage an experiment was carried out as a split plot design on the basis of randomized complete blocks with two replications. Forty barley lines were assigned in subplots and five freezing temperatures (-8، -11، -13، -15 and -17 ˚С) were allocated in main plots. The results showed significant differences among lines at the temperatures -8، -11 and -13 ˚С. Analysis of variance of the data based on randomized complete block design showed significant differences among lines for LT50، leaf fresh weight، percentage of leaf dry weight، percentage of crown dry weight، percentage of leaf water content، percentage of crown water content، percentage of seedling water content، leaf relative water loss and the amount of proline after hardening. The heritability of LT50، percentage of leaf dry weight، percentage of leaf water content، percentage of seedling water content and amount of proline after hardening were high and amount of proline after hardening had the largest squared genetic coefficient of variation. Grouping of barley lines based on LT50 and survival percentage at the temperatures -8، -11، -13 and -15 ˚С، determined line 36 (Schulyer cultivar) as the most freezing tolerant and based on physiological characters indicated the lines 9 (with the pedigree of Alger/(CI10117/Choyo.. )، 31 (Makouee cultivar) and 15 (with the pedigree of K-096M3) as the more desirable genotypes.

Global warming and global climatic changes have attracted many concerns. The objective of this research was to examine greenhouse gas emission and its resultant global warming potential (GWP) in wheat production in Gorgan، north-east of Iran. To do this، six wheat fields were selected and during three consecutive growing seasons، data were gathered on input and energy use in all production practices. The production practices were classified into eight categories، i. e. seed bed preparation، plant protection، weeds control، irrigation، harvesting and transportation for storage. Results showed that GWP for wheat production was between 268 and 923 kg equivalent CO2 per ha which was equal to 104 to 272 kg eq-CO2 per t wheat production. Among different production activities، nitrogen fertilizer with GWP of 291 kg eq-CO2 ha-1 had the greatest contribution. Using fuels in field operations with a GWP of 213 kg eq-CO2 ha-1 occupied the next position. Comparisons showed that wheat production in Gorgan results in more GWP than some other locations around the world.

To investigate the relationship between different traits، discover factors affecting this relationship and to identify components of seed yield in cultivated and wild safflower genotypes، this investigation was conducted at Isfahan University of Technology research farm under two different water regimes during 2008. Significant differences were observed between genotypes belonged to the two species for drought tolerance. Wild genotypes were more tolerant than the cultivated genotypes. In cultivated genotypes under normal moisture condition، number of seed per head، days to flowering، head weight and plant height had a positive correlation with seed yield. Under water deficit condition، seed yield showed non-significant correlation with number of seed per head. Similarly in wild safflowers number of heads per plant and seed weight per head had positive correlation with seed yield under normal condition. Under stress; seed yield was correlated with plant height، number of head per plant and thousand seed weight. Results of step wise regression showed that the kind and order of seed yield components in cultivated safflower was more affected by drought condition. Path analysis indicated that moisture stress changed direct and indirect effects of traits on seed yield. Under normal irrigation regime development of reproductive system (increasing number of head per plant and number of seed per head) directly affect yield، while under deficit irrigation، thousand seed weight was the effective parameter. Results indicated that wild species had high drought tolerance which can be used for breeding of cultivated safflower.

In order to evaluate drought tolerance of cultivars and advanced grain sorghum lines، an experiment was conducted as split-plot on randomized complete blocks design with three replications at experimental field of seed and plant Improvement Institute، Karaj in 2009. Three levels of irrigation regimes including normal irrigation (IR0=60 mm)، moderate stress (IR2=120 mm) and sever stress (IR3=180 mm evaporation from the surface evaporation pan) were the main plot and the subplots were ten cultivars and advanced lines including (Kimiya، payam، sepeede، KGS27، KGS32، KGS23، KGS19، KGS15، KGS36، KGS25). Results using stress susceptibility index (SSI) and tolerance index (TOL) revealed that Payam and Sepeede cultivars and KGS19 and KGS15 lines are more tolerant than others. Stress tolerance index (STI) and geometric mean productivity (GMP)، that their higher values indicate the tolerance of cultivars under stress، revealed kimiya cultivar with grain yield 12026. 7 Kg ha-1 in non-stress conditions and grain yield 7663. 3 Kg. ha-1 in stress conditions and KGS32 line with grain yield 12973. 9 Kg. ha-1 in non-stress conditions and grain yield 8830. 6 Kgha-1 in stress conditions، as genotypes with highest yield in both optimum irrigation and drought conditions.

Drought stress is one of the most important factors limiting the productivity of crop plants around the world. Genotype-by environment (G×E) interactions are common under drought and make breeding progress difficult. For this reason twenty genotypes of bread wheat were evaluated in a randomized complete block design with 3 replications at 2 locations (stress and non-stress environments) in two growing seasons. Stability of genotypes were evaluated by using of several methods such as coefficient of regression and deviation from regression in method of Eberhart and Russell، stability variance of Shukla، simultaneous selection for yield and stability، Rick ecovalance and ranking method. The object of this study was to compare the results of above methods and to introduce the simplest method for determining stable genotypes. In the most methods genotypes 9 and 12 selected as stable genotypes. Coefficients of correlation between different methods were calculated using Spearman''s coefficient. Regard to strength significant correlation between mean yield and mean of ranks in ranking method، strength significant correlations between deviation from regression and most of used methods and its highly significant correlation with standard deviation in ranking method، it''s concluded that the simple method of ranking was enough for determining stable genotypes.

Biofertilizer is a substance which contains living microorganisms which can use instead of chemical fertilizer in sustainable crop production. The effects of phosphate solubilizing bacteria; root endophytic fungi (EF) Piriformospora indica، and Arbuscular mycorrhizal fungus (AMF) Glomus mosseae on growth and nutrient uptake of sunflower plants grown in mixture with two clover species، Persian clover and berseem clover، were investigated at the experimental farm of Ilam agriculture center. The treatments were consisted of sunflower colonized and non-colonized by P. indica or Glomus mosseae، inoculated by phosphate solubizing bacteria (Bacillus lentus + Pseudomonas putida)، non-fertilizer soil، non-sterilized and sterilized soil، and two cropping system which consisted of mixture clover of Persian clover and brseem clover at the ration of 1:1 under sunflower canopy. Result indicated the benefits of colonization of sunflower plants with mycorrhizal and endophytic fungi as well as inoculated with bacteria on increasing growth، nutrient uptake and yield compared with their non-application of sunflower. Sunflower cultivation covered with a mixture of two clovers spices achieve increased yield and shoot nitrogen and phosphorus of sunflower seeds، but no effect on shoot phosphorus، grain yield and biomass yield. According to the results، the use of phosphate solubilizing bacteria، mycorrhiza and endophytic fungi and legumes cultivated under canopy cover could be a mechanism for designing sunflower farming under system with low input.

This study was performed in order to evaluate the effects of spraying micronutrients iron، zinc، calcium on yield and yield components of seven sesame varieties on 2007 cropping season in research farm of Shahed University. The experiment was performed as split-plot based on randomized complete blocks design with three replications. The main factor included FeSo4، ZnSo4، CaNo3 and control (water) solutions. The sub-main factors were seven varieties (Yekhta، Varamin 237، Karaj 1، Borazjan 2، Jiroft 13، Bushehr 2 and Darab 14) of sesame. The results of variance showed significant differences among micronutrients on seeds per capsule، 1000-seed weight، oil percent and grain and oil yields. The cultivar×micronutrient interactions were not significant for all traits exception for oil percent (P<0. 01). Zinc was highly affected grain yield (1. 37 fold)، seeds per capsule (1. 30 fold) and oil yield (1. 41 fold) in comparison with control treatment. The highest significant correlation observed between grain yield with seeds per plant (0. 95) and grain yield with capsule per plant (0. 93). According to stepwise regression analysis four traits، seeds per plant، 1000-seed weight، Secondary branches number and seeds per capsule were entered in regression equation. In final conclusion، this survey showed that zinc and calcium were the best micronutrients to increase oil and grain yields of sesame and the cultivars Bushehr 2 and Borazjan 2 were introduced as the best cultivars with high grain yield (27. 5 and 24. 1 gr. plant-1) and high oil yield (13. 8 and 12. 6 gr. plant-1).

Chemical fertilizers are threat in hman life and today application of biological fertilizer find more important. This study performed in order to evaluate the effects application of biofertilizers with urea fertilizer on yield، protein percentage and numbers of eyes in plant، plant height and chlorophyll SPAD in potato var. Marphona. A factorial experiment was conducted based on randomized complete block design with four replications. The traits were consist of nitragin biofertilizer in two application levels and not application (application with seed)، HB-101 biofertilizer in complete organic soluble (whit three levels of application، control، one spray application and tow spray applications) and urea fertilizer in tow levels (application and not application). The results showed that highest tubre yield (46526 kg). Heigth plant (70. 2 cm) and chlorophyll SPAD (55. 2) were founded in nitragin biofertilizer with urea fertilizer and tow application of HB-101 treatment. Also highest protein percentage and lowest number of eyes in tubre were founded in application of nitragin biofertilizer with urea fertilizer and two applications of HB-101. In final، the results showed that inoculation of biofertilizer with chemical fertilizer increased yield and quality of potato.

Waterlogging is one of the problems of cotton-growing in rainy regions which affects adversely plant growth in the early stages. So that rainfall causes waterlogging in early to mid spring in the fields without proper drainage. Also، rainfall declines soil and environment temperatures. To investigate the effects of waterlogging period duration and temperature on vegetative properties and glycolytic-fermentative enzymes activity in cotton، an experiment was carried out in laboratory and green house at Gorgan University of Agricultural Sciences and Natural Resources. Experimental treatments were the waterlogging period duration (0، 24، 48 and 96 h) and temperature (16، 20 and 25 ˚C). The results showed that increasing waterlogging period duration from 0 to 96 h and decreasing temperature from 25 to 16 ˚C led to decrease of leaf area، plant height and dry weight، chlorophyll and Fv/Fm ratio. However، the interaction of waterlogging period duration and temperature was significant only on leaf area، plant height and dry weight. The results showed that alcohol dehydrogenase and fructose-1،6-bisphosphate aldolase enzymes was affected by waterlogging period duration and temperature; but the interaction of waterlogging period duration and temperature was significant only on fructose-1،6-bisphosphate aldolase activity. So it can be concluded that in waterlogging conditions، decreasing temperature led to decrease cotton growth. Also، according to that alcohol dehydrogenate and fructose-1،6-bisphosphate aldolase enzymes activity show an increasing trend in waterlogging conditions، we can use from both enzymes as proper marker in order to determination of tolerant genotypes to waterlogging.