Iranian Journal of Field Crop Science
Year:2011 | Volume:42 | Issue:2|Papers Count:25

Durum wheat is one of the most important cereals that culture in the west of Iran and dry land from long time. In order to study of chemical stress on germination of Iranian Durum Wheat by coumarin in 5 levels (0, 10, 20, 30, 45 mg/l), an experiment was conducted in randomized complete design as factorial with three replications on 20 Iranian Durum Wheat, which involve two genotypes as control (Karkheh & Yavarus). Coumarins are one of the also chemical substances that widely exist in natural and farming plants communities, and they are considered as strong inhibitor for seed germination.The production of this substance perhaps is considered as an advantage for planting species by reduce competition in adjacent plant species or by delayed germination in desirable condition. The aim of this survey was screening of genotypes aspect of better seedling establishment in stress condition. Results indicated that, coumarin and genotype had significantly effect on evaluated attributes, inhibitory effect was showed in length of root and shoot in all concentrations of coumarin. But inhibitory effect was started in fresh weight of root and shoot and total of fresh weight in seedling at 20 mg/l. While stimulating effect were showed in germination percentage, dry weight of root and shoot. Genotypes evaluation were detected that, genotypes are classified in three groups, furthermore endemic genotypes showed resistance ability against coumarin, in compare with control varieties, and the best genotypes among endemic genotypes are 9, 10 and 12. Also increase of coumarin concentration and time treatment period of genotypes cause decrease in measured traits.

Genetic diversity is one of principle factors to succeed in breeding programs, so its determination is vital in the using of plant genetic resources. With the aim of evaluation of genetic diversity among safflower landraces, 20 lines (14 Iranian and 6 foreign lines) were studied for phenotypic and genotypic variations using agro-morphological traits and RAPD markers. Field study was conducted in RCBD design with three replications in 2007-08. The results of analyses of variance showed that there was significant difference among the studied lines for all agro-morphological traits characters except number of heads. Plant height, number of head and seed germination had significantly positive correlation with grain yield. These traits also showed the most direct positive effects on yield and could explain 43% of total variation of grain yield. Out of 20 primers used in RAPD analysis, 12 primers were polymorphic and produced 104 clear polymorphic bands with average 8.7 band for each primer. Cluster analyses, based on both morphological traits and molecular data, classified the lines into four groups, however, there was not great similarities between two clusters (7.7%). It can be concluded that RAPD is a suitable technique to determine genetic diversity among studied safflower lines. The existence of the great genotypic variation among safflower landraces can be exploited in breeding programs in rainfed area of Iran.

In order to study the weeds frequency and dry matter in corn and cowpea sole cropping and intercropping systems, an experiment using replacement and additive techniques was conducted using different combination of intercropping in seven levels with ratio of 1: 1 (50% corn+50% cowpea), 1: 2 (33%+67%), 2: 1 (67%+ 33%), (100%+20%), (100%+10%), 100% corn and 100% cowpea, two levels optimal and high plant density. A factorial experiment was conducted in the form of randomized complete block design (RCBD) with three replications at the research farm of Agriculture college of Zanjan University on 2007.Results showed that the maximum yield of corn (8844 kg/ha) was obtained from intercropping system with ratio of 20% cowpea additive and the maximum yield of cowpea (640.5 kg/ha) from the mxing ratio of 1: 2 (33% maize+67% cowpea). The plant density and cropping pattern has influenced the dry matter of weeds. Additive intercropping systems and sole of corn was affected on weeds control and dry matter decrease those to cropping systems others. In intercropping pattern of replacement method (33%cowpea+67% corn), was obtained least of weed dry matter. Plant density and cropping pattern levels has significant effect (a=0.01) on weeds dry matter. the study of relative frequency of weed species indicated that red root pigweed (Amaranthus retroflexus) 38% with density was the dominant species and Chenopodium album, Amaranthus albus, Ipomoea hederacea, Acroptilon repens, Sophora pachycarpa, Echinochloa crus-galli, Xanthium pensylvanicum, and Salsola kali respectively were the next category. Values of LER>1 (Land equivalent ratio) more than one in intercropping systems of additive increase 100% corn+20% cowpea and replacement 33%cowpea+67% corn, the advantage to intercropping systems showed a sole cropping.

Genetic variation of 20 genotypes (15 exotic collected from ICARDA, and 5 endemic collected from various regions of Iran: Ardebil, Oshnaviyeh, Qazvin, Shahre Kord and Mashhad) were studied during the 2007-2008 growing season, using morphological and phenological traits. The resultant data were examined for normality test and were then analyzed according to randomized complete block design (RCBD) with 3 replications. Mean comparisons were carried out, using Duncan's test. ANOVA showed high significant between-genotypes differences for the most traits studied. The economic yield showed the most significant positive correlations with total pod weight, plant weight during seed harvest and total pod numbers. The same correlations were true between biologic yield and plant weight during seed harvest, weights of total pod and cortex and total pod numbers. Moreover, harvest index showed the most significant positive correlations with economic yield, total pod numbers and weight, and hundred pod weight. Path analysis indicated that the plant weight during seed harvest had a direct and positive effect on either economic yield or biologic yield. The results suggested that breeding strategies for increasing seed yield in Lathyrus should consider the presence of plant weight during seed harvest and for increasing biologic yield should consider the presence of total pod weight. The principal component analysis (PCA) showed that the first 2 components accounted for the 69.1% of total variations. Euclidean distance and group average linkage (UPGMA) phenogram constructed on the basis morphological and phenological data distance showed 3 major clusters. The first comprised of 16 genotypes (G1-G16), the second contained 3 genotypes (G17-G19), while G20 genotype was separated by the third cluster. The resulting genotypes arrangement was fully fited with that obtained from the PCA.

The recent decades emphasis on reducing pesticide use especially herbicide has led to increased interest in alternative weed control methods. The purpose of this study was to evaluate the hilling time and simultaneous interseeding of two cover crops as living mulch to control weeds in potato and to determine the impact of these actions on potato yield. A randomized complete block design as split plot with three replications was used with hilling time (two levels containing 3 and 5 weeks after potato planting) and cover crops (four levels containing barley, persian clover, no-cover and chemical control) as main and subplot treatments, respectively. The barley cover crop in the first hilling time was needed to control using sethoxydim (0.21 Kg ai ha-1).Weed and cover crop numbers were recorded three weeks after hilling time and their biomass was measured at harvest time. Generally the hilling time had no effect on weed and cover crop numbers but was effective on their biomass so that the average weed biomass in second hilling time was less than its first but the cover crop biomass in second hilling time was more than its first because of controlling barley in first hilling time. Barley cover crop was superior to Persian clover in weed control and because of slow growth of Persian clover, its weed biomass was as no-cover crop treatment. However the potato yields were highest with the chemical control but considering to hilling time and cover crop interaction on potato yield, the controlled barley in the first hilling time was to able to provide yields comparable to chemical control. Thus the results suggest that early interseeding of barley as cover crop supplemented with a postemergence narrow leaves herbicide may both control weed adequately with less herbicide and provide yields comparable with conventional potato production systems.

The effects of environmental factors on germination and emergence of hoary cress seeds were examined in laboratory and field experiments. Germinability of hoary cress under light/dark conditions (90%) was significantly higher than when seeds were incubated under continuous dark (78%). Hoary cress could germinate in a broad range of temperatures (15/6, 20/10, 25/15, 30/15, and 35/20oC). The germinability, however, was different depending on the temperature range and the highest and lowest germination percentages were in 15/6 (93%) and 35/20oC (72%), respectively. Salinity showed significant adverse effect on germination of this weed, so that the highest germinability was at 0 concentration of NaCl (92%).Increased salinity levels significantly decreased hoary cress germination and its germination completely ceased at 320 mM NaCl. This study indicated that hoary cress retained its germination percentage higher than 80% in the pH range of 4 to 10, so that the highest and lowest germinability was occurred at pH 10 (98%) and 4 (85%), respectively. Another experiment in which seeds were buried at different depths in the field showed that the effect of interaction between burial depth and duration on seed dormancy as well as their germinability in the field and laboratory was significant and seed germination percentage was remained at high levels during the 10 months of the experiment. Moreover, seed decay was not observed at any burial depths during the experiment and seed placement at burial depth of 10 cm and deeper resulted in a quiescence status of the seeds.

Safflower as an original crop in Iran has high adaptability to different environmental conditions. Iran is one of the original areas of safflower as a drought and salinity tolerant crop. Therefor, safflower can be a suitable alternative crop for cultivation in marginal areas. The aims of research were studying the late season drought effects on seed and oil yields and its components of fall safflower genotypes in marginal border areas of Oroumieh lake. The study was carried out in East Azarbaijan Research Center for Agriculture and Natural Resources, Iran (46o and 2” E, 37o and 58” N) during 2008-9. A factorial experiment including 2 irrigation levels (non stressed and drought stress during seed filling stage) and 5 safflower genotypes (Padideh, Zarghan, Varamin 259, KW5 and KW8) based on randomized complete block design with 3 replications was used. During stress period relative water content (RWC), leaf temperature and finally seed and oil yields and its components were measured. The results showed that RWC, Paniculum diameter, panicula per plant, seeds in paniculum, seed and oil yields were significantly decreased and leaf temperature was significantly increased by water deficit. Significantly negative correlations among leaf temperature with RWC, seed and oil yields were seen.Also significantly positive correlations among RWC, seed and oil yields were achieved. Therefore, it is concluded that these indices can be used for determining late season drought effects on fall safflower genotypes. Among seed and oil yields with plant and capitulum formation height, capitulum diameter, capitula per plant, seeds in capitulum and 1000 seeds weight significantly positive correlations were seen, also between capitulum diameter with seeds in capitula, positive correlation achieved. Safflower plants with having higher capitulum diameter, indicated more seeds in capitulum and finally produced higher seed yield. Among studied genotypes, KW8 with having 3189 and 913 Kg ha-1 seed and oil yields respectively, showed higher yields. KW5, Padideh and Varamin295 were in next ranks respectively. It seems that these genotypes are suitable for cultivating in border areas of Oroumieh lake with marginal soil and late season drought and areas with similar climate.

In order to study the effect of nitrogen level on physiological characteristics, grain yield and yield components of tetraploid wheat genotypes, a split plot Randomized Complete Block Design field experiment with three replications was conducted in 2007 at Research Farm of Isfahan University of Technology. Four levels of nitrogen fertilizer (20, 80, 140 and 200 kg/ha) were chosen as main plots and eight tetraploid wheat genotypes, consisting a group of six hulled wheat (Singerd, Shahekord, Jooneghan, Khooygan, Zarneh and Ozonbolagh), T.turgidum subspp. dicoccum, and a group of two free-threshing durum genotypes (Shoa and Ostagata), T. turgidum subspp durum, as sub plots. Measurements were made on physiological characteristics such as LAI, chlorophyll fluorescence and leaf chlorophyll content. After harvest, yield and yield components, total dry weight, harvest index and percent of protein were evaluated. Results showed that there were significant differences between nitrogen levels in LAI, grain yield and protein content. There were statistically significant differences between genotypes for all measured characteristics except for total dry matter, chlorophyll B and protein content. Significant interactions of genotype X nitrogen were detected for LAI, chlorophyll content, ear per m2, number of grain per ear, yield and grain protein. The interactions between groups and nitrogen on LAI, number of grain per ear, grain yield and protein content were significant. Maximum 1000 grain weight (45.2g), number of grain per ear (36.4), grain yield (5028.8 kg/ha) and harvest index (28%) were seen in durum groups and maximum leaf chlorophyll content (0.097 mg/ml), number of ear per m2 (941.2) and protein content (16%) were observed in hulled groups of genotypes. All of the measured characteristics except for number of grain per ear, grain yield and harvest index decreased with nitrogen deficit in durum wheat genotypes. Grain yield and number of ear per m2 for hulled wheats increased with decreasing nitrogen level. It was concluded that at least with hulled wheat group used here, the latter wheats could be more resistant to environmental constrains such as nitrogen deficit, compared to the modern durum genotypes. In addition, hulled tetraploid genotypes may have the potential for food producing purposes in marginal and stressfull conditions.

To evaluate general and specific combining ability for resistance to bolting and Cercospora leaf spot, 36 hybrids derived from crosses between 9 sugar beet lines along with four checks were planted in Safiabad Agricultural Research Center (Dezful) in 2008-2009. The experimental design was a triple lattice design with three replications. Analysis of variance showed significant differences among genotypes for all of the traits with exception of sugar content, sodium, white sugar content and purity. Analysis of combining ability using Griffing's method II indicated that general combining ability of the lines was significant for all of the traits in probability level of 1%. Also, specific combining ability was significant for root yield, sugar yield, white sugar yield and potassium in probability level of 1% and for resistance to bolting and Cercospora leaf spot in probability level of 5%. In general, both additive and non-additive effects were effective in controlling the resistance to Cercospora and bolting, root yield, sugar yield and white sugar yield. However, resistance to bolting, root yield, sugar yield and white sugar yield were found to be mainly determined by the non-additive gene effects. The best parent for resistance to Cercospora and bolting was RR607, however, its root yield was not suitable. The best hybrid for resistance to Cercospora, root yield, sugar yield and white sugar yield was F1 of RR607x452. Furthermore, the best cross for resistance to bolting was SB-FIROZ x 261. Nonetheless, cross of RR607×436 produced the best hybrid for resistance to bolting and Cercospora.

This research has been done for studying the effect of split application of Nitrogen fertilizer on growth indexes and yield of three hybrids of grain corn in Shahrood. A split plot experiment based on randomized complete block design with four replications was carried out in 2007. Three hybrids of corn (double cross 370, single cross 447, single cross 499) were placed in main plots and split application of nitrogen which was containing the six treatments (N1: 45 Kg Nitrogen/ha in planting time, 135Kg Nitrogen/ha in flowering time, N2: 90 Kg Nitrogen/ha in planting time, 90 Kg Nitrogen/ha in flowering time, N3: 135 Kg Nitrogen/ha in planting time, 45 Kg Nitrogen/ha in flowering time, N4: 45 Kg Nitrogen/ha in planting time, 67.5 Kg Nitrogen/ha three weeks before flowering, 67.5 Kg Nitrogen/ha three weeks later flowering, N5: 90 Kg Nitrogen/ha in planting time, 45 Kg Nitrogen/ha three weeks before flowering, 45 Kg Nitrogen/ha three weeks later flowering, N6: 135 Kg Nitrogen/ha in planting time, 22.5 Kg Nitrogen/ha three weeks before flowering, 22.5 Kg Nitrogen/ha three weeks later flowering) were placed in sub plots. In total, in each treatment 180 Kg/ha pure Nitrogen (392 Kg/ha Nitrogen) has been used.Results show that hybrid of 499 and fourth fertilizer treatment has had the highest total dry matter (TDM). Also, the highest leaf area index (LAI) has been shown in hybrid of 447 and fourth fertilizer treatment and the highest crop growth rate (CGR) and net assimilation rate have been achieved in sixth fertilizer treatment. In third fertilizer treatment the highest relative growth rate (RGR) has been obtained. Analyses of data variance showed that hybrids had significant effect on grain yield in hectare, number of ear in bush and ear weight. Fertilizer treatments had significant effect on grain yield in hectare, number of ear in bush, ear weight, biological yield and weight of 100 grains.Also the effect of interaction of hybrid-fertilizer treatments has significant effect on grain yield in hectare, number of ear in bush and ear weight. The highest grain yield in hectare was shown in hybrid of 499 with first and forth fertilizer treatments. Based on obtained results, the highest number of single-ear bushes has been shown in hybrid of 499. The highest weight of ear was achieved in hybrid of 499 with first fertilizer treatment. Finally, in total, application of hybrid of 499 with first and forth fertilizer treatments is suggested for shahrod climate condition.

In the present experiment, the effects of nitrogen and phosphor fertilizer application in two methods of furrow and trickle irrigation on the yield and quality of sugar beet seed cultivar 7233 were studied. The experiment was conducted as a split factorial in a completely randomized block design with three replications during 2003 and 2004 in Hamedan province. Main plots were allocated to irrigation methods (furrow and trickle irrigation systems) and sub plots to four nitrogen levels (0, 60, 120, 180 kg/ha) and three phosphor levels (0, 30, 60 kg/ha). Yield, quality and technological particular of sugar beet seed were evaluatged. The results of combined analysis showed that total consumed water in trickle irrigation system relative to furrow irrigation decreased about 50%, however, water use efficiency in trickle irrigation was 0.59 kg/m3 and twice as much as furrow method. By increasing nitrogen in trickle irrigation relative to furrow irrigation, the highest sugar beet seed yield and sugar beet seed yield standard was achieved. In trickle irrigation, nitrogen application did not reduce significantly germination percentage of sugar beet seed. However, by increasing nitrogen level in furrow irrigation method no significant difference for germination percentage was detected. Yield seed was affected by nitrogen and also by the interaction of nitrogen x year and irrigation x phosphor x year interaction. The interaction between irrigation systems with nitrogen levels and interaction effect of irrigation x phosphor x year were significant. Seed phosphor concentration was not affected by any treatment. Seed potassium concentrations were affected by nitrogen levels and the interaction effect of phosphor and year. Sodium content of sugar beet seeds were affected by irrigation method, interaction of irrigation x year and the interaction of irrigation x nitrogen x phosphor x year. In conclusion, to produce maximum standard sugar beet seed with good germination percentage under high water use efficiency, trickle irrigation systems with application of 120 kg/ha, nitrogen fertilizer may suggest for similar conditions.

To evaluate the effect of different application methods of different strains of PGPR on sorghum forage production, a field experiment was conducted in Research Farm of College of Agriculture of University of Tehran in Karaj during 2009. The treatments were arranged factorially and the data was analyzed based on a complete block design with three replications. The treatments comprised of three Pseudomonas putida (strains: 34, 53 and 100) and three Pseudomonas fluorescence (strains: 82, 162 and 169) which were applied either by seed inoculation, foliar spray application or integrated application (inoculation and foliar spray). The results showed that the integrated application over yielded the forage production over other application methods for all different bacteria strains.The results supported the synergistic effects of integrated application method on forage yield as well as leaf area, leaf dry weight and stem dry weight. The highest forage yield was obtained by bacteria strains of 87, 100 and 162 in integrated application method.

In order to study the gene actions and heritability of the physical and chemical characteristics associated with appearance and cooking quality of rice grain, generation mean analysis was performed using a cross between two Iranian rice cultivars, Deylamani and Sepidroud, having different quality characters. Seeds of the parental lines and F1, F2, BC1 and BC2 generations were grown in randomized complete block design with three replications in farm. Twelve chemical and physical traits including: paddy length, paddy width, paddy length to width ratio, head rice percent, broken rice percent, white grain length, white grain width, white grain length to width ratio, 100-grain weight, amylose content, gelatinization temperature and protein content were measured. The analysis of variance showed significant differences between generations for all studied traits. According to generation mean analysis, additive dominance model was fit for all traits and the epistatic effects were not significant. Degree of dominance showed that the paddy length and white grain width were controlled by over-dominance, white grain length to width ratio and gelatinization temperature by complete dominance and the other traits by partial dominance effect. Average broad-sense heritability ranged from 0.36 to 0.93 for paddy width and gelatinization temperature, respectively, and average narrow-sense heritability varied from 0.32 to 0.76 for paddy width and amylase content, respectively. In conclusion, the results of this study showed that to improve paddy length, paddy width, white grain length to width ratio and gelatinization temperature in population resulting the cross between Deylamani and Sepidroud, the heterosis and hybrid production method will be suitable, but for other studied traits, selection after crossing can be used at first to increase the favorable genes and then hybridization between the lines with good performance will be performed to utilize the dominance gene effects.

Sainfoin (Onobrychis viciifolia Scop.) is a perennial forage legume has recognized for its feed value and high stability. This experiment was conducted to investigate the relationship among morphological and agronomic traits using multivariate statistical methods including correlation, regression and factor analysis. Twenty one accessions of Sainfoin were evaluated in a randomized complete block design with 6 replications during 2008 and 2009. Analysis of variation showed that there was significant variation for forage yield and its components. Results indicated that dry yield was positively correlated with fresh yield, stem percent and number of stem per square meter while it was negatively correlated with flowering date, leaf percent and leaf to steam ratio.Forage yield had no correlation with plant height but plant height was correlated with number of stems per plant (as a component of forage yield). The result of path analysis indicated that number of stem per plant, stem percentage and plant height had the most direct and positive effects on dry matter yield.On the basis of stepwise regression analysis, stem percentage and plant height justified the majority of dry matter yield variation and can be used for indirect selection of forage yield. Factors analysis identified five hidden factors which justified more than 75 percent of the total variation. Results indicated that there was a wide genetic diversity for forage yield in this germplasem and indirect selection based on number of stem per meter square, stem percentage and plant height would be effective for improving forage yield.

Understanding of physiological responses of salt tolerance might be lead to identify main salt tolerance mechanisms and essential approaches for improving grain yield stability, and also to select salt tolerant wheat cultivars. Thus, the effects of salinity were investigated on grain yield and some of the characteristics related to salt tolerance. Six wheat cultivars (Roshan, Kavir, Karchia, Gaspard, Shiraz and Qods) differing in salt tolerance at three salinity levels (0, 100 and 200 mM NaCl) were used in a pot experiment, using a factorial experiment based on a randomized complete block design with three replications. Salt stress caused to decrease grain yield, biomass production, chlorophyll content, and catalase activity, while it caused to increase the activity of peroxidase, ascorbate peroxidase and glutathione reductase and malondialdehyde (MDA) content. Cultivars showed different responses to salt stress. Cultivars Roshan, Kavir and Karchia showed lower yield losses. With increasing salinity treatment levels, MDA content and antioxidant activity increased except for catalase. Cultivars Roshan and Kavir were showed the highest antioxidant enzyme activity, but the lowest MDA content. Cultivars Qods and Shiraz were showed lowest antioxidant enzyme activity, but the highest MDA content in flag leaf blade. In salt tolerant cultivars, a higher antioxidant enzyme activity was accompanied with lower MDA content, resulting higher capacity to eliminate active oxygen species and yield stability. Correlations coefficient analysis exhibited increasing of antioxidant enzyme activity in salt stress condition with no considerable effect on grain yield, while chlorophyll and MDA content illustrated negative correlation with grain yield and so a main role in yield.

Drought stress is one of the most important abiotic stresses which can affect the growth of a plant, thereby curbing crop yield. Identification of effective morphological traits is the main aim of each breeding program. Our objective was to identify agronomic traits associated with changes in grain yield of wheat under irrigated and drought conditions. To address this objective, grain yield and its components of 81 Iranian wheat genotypes were tested using two simple lattice designs with two replications under irrigated and drought conditions at research farm of Agriculture College, University of Tehran, Karaj during 2007-2008 and 2008-2009. Drought stress was imposed when plants were at the heading stage by withholding watering. Grain yield, biological yield, harvest index, kernel weight per spike, 1000 kernel weight, number of kernels per spike and plant height were evaluated. Five statistical procedures including: simple correlation, multiple linear regression, stepwise regression, factor analysis and principal components were used to study the relationship between wheat grain yield and its components under irrigated conditions and drought stress. Results revealed that biological yield and harvest index were the most effective variables influencing grain yield. Based on the results, biological yield and harvest index were found to be the most important agronomic traits for selecting high-yielding cultivars under irrigated and drought stress conditions. The effects of these traits under irrigated and drought stress conditions were not similar. The role of biological yield was less sensible than harvest index under drought stress. However, yield increase in wheat cultivars could be attributed to partitioning enhancement of photo-assimilates to the grain (higher harvest index) under drought stress.

The effect of concentration and time of supplementary nitrogen fertilizer spray application on grain yield and nitrogen use efficiency in rapeseed (Hyola 401) as a second crop in paddy fields were evaluated in a field experiment conducted in randomized complete block design with 3 replications at Rice Research Institute of Iran (Rasht) in 2008. In this experiment two factors, concentration of solution containing nitrogen fertilizer (urea) at two levels (5 and 100.00) and application time in seven levels: 1-seedling stage at 6-8 leaves (1.06-1.08 Sylvester-Bradley and Makepeace coding system), 2: beginning of stem elongation (2.01-2.03), 3: pre-flowering (3.9), 4: 1.06-1.08+2.01-2.03, 5: 1.06- 1.08+ 3.9, 6: 2.01-2.03+3.9, 7: 1.06-1.08+2.01- 2.03+3.9, plus two control treatments a: zero nitrogen fertilizer b: conventional fertilization (180 kg.ha-1) at seed sowing, stem elongation and prior to flowering in equal rates.Plant characteristics (grain yield and oil content) were measured and nitrogen agronomic efficiency (NAE), nitrogen use efficiency (NUE), nitrogen apparent recovery fraction (NRF), nitrogen physiological efficiency (NPE), nitrogen harvest index (NHI), nitrogen uptake efficiency (UPE) and nitrogen utilization efficiency (UTE) were calculated. Results showed a significant difference between concentration and times of nitrogen spray application effect on grain yield, agronomic efficiency, and harvest index of nitrogen. Spray application of nitrogen (100.00) in 2.01- 2.03+3.9 stages (Treatment #6) produced the maximum grain yield (4221.7 kg.ha-1), agronomic efficiency (17.94 kg.kg-1), use efficiency (23.45 kg.kg-1) and harvest index (77.39%) of nitrogen. Spray application of nitrogen (100.00) at all growth stages produced the maximum Apparent recovery Fraction and uptake efficiency (70.71% and 87.12 kg.kg-1, respectively) of nitrogen. According to the results of the present experiment, it seems the spray application of supplementary nitrogen fertilizer at beginning of stem elongation and prior to flowering stages, may help to provide fertilizer needs and help to nitrogen fertilizer use efficiency and grain yield enhancement.

Uniparametric, non-parametric methods and AMMI model (Additive main effects and multiplicative interaction) were used to evaluate the yield stability of ten cotton cultivars at six regions of Golestan and Mazandaran provinces (Baye kola, Gharakheil, Kalaleh, Khan bebein, Karkandeh, Hashem Abad) during two successive years (2005 & 2006). The experiment was conducted in randomized complete block design (RCBD) with 4 replications. The results of varied methods were different. The main effects of genotype, environment and Genotype x Environment interaction effect were statistically significant, and 81.75% of variation was explained by the first two interaction principal components (IPC1, 2). Biplot of IPC1 and the mean of traits for cultivars and locations had good efficiency for detecting of Genotype x Environment interaction effect patterns. Based on biplot diagram of genotypic and environmental components, IPC1 and IPC2 interaction with mean yield of the genotypes and environments, computation of stability criterions of AMMI model (SIPC1), genotypic reaction pattern analysis, and also cluster analysis results, the Gukorova, Sepid and Tabladila cultivars had the most yield stability over environments. Gukorova had the lowest IPC1. Khordad, 43200 and Sahel showed the most interaction effects.43200 and khordad cultivars were identified with specific adaptation for Karkandeh and similar regions.Varamin, Nazily, Tabladila and Sahel cultivars had specific adaptation for east of Golestan (Kalaleh, Khan bebein) and Mazandaran province (Baye kola, Gharakheil). Sepid and 43200 were identified as high yielding cultivars with general and specific adaptation, respectively. Inverse, Sahel cultivar with lowest yield had broad stability with non-fertile regions. Gukorova was the most stable cultivar with moderate yield all over Golestan and Mazandaran.

Malaria disease is caused by unicell of Plasmodium falsiparum. The unicell attacks to red blood cells and destroyed them. Nowadays, malaria has been reported in more than 100 countries. The artemisinin is a sesquiterpene that is produced by two isoprenoid and mevalonate pathways in Artemisia annua. Artemisinin as a new and effective drug is been used for various applications. Artemisia annua is an annual plant and native to Asia and most probably China. In this study, six different Artemisia annua genotypes were collected from Golestan province. Amorpha-4, 11-diene synthase (ADS) promoter was analyzed by using different cis-elements database of PLATcare, TRANSFAC and PLACE. The result showed that there are different cis-elements responding to plant hormones and abiotic stress in ADS promoter. We also identified two new putative transcription factors in EST library of Artemisia annua then studied the expression of ADS gene and three transcription factors by using real time PCR technique. The results showed that WRKY transcription factor has more important role than other transcription factors.

Drought stress as the most important abiotic stress plays a significant role in reduction of crops yield. This study was conducted at six agricultural experimental stations (Karadj, Ardebil, Arak, Mashhad, Jolgerokh and Miandoab) during 2006-08 cropping seasons. Experiments were carried out under normal irrigation and post-anthesis drought stress conditions using 18 wheat genotypes.Experimental design in all locations at both conditions was RCB with three replications. Results of combined ANOVA in normal and stress conditions showed significant effect for genotype and year, and also for location* year, and genotype* location* year interactions. Mean grain yield of the genotypes under normal irrigation was from 5969 to 7073 kg ha-1, however under stress condition this range was between 4041 to 5676 kg ha-1. Based on stress tolerance and susceptibility indices per se and ranking parameters (R and SDR) of the indices for each genotype, C-85-3 with mean grain yield of 5676 kg ha-1 under drought stress condition, and R=1.2 and SDR=0.44 was determined as the most tolerant genotype. The most susceptible genotype was C-85-10 with mean grain yield of 4041 kg ha-1 and R=17 and SDR=1.22.