Crop Production
Year:2013 | Volume:6 | Issue:2|Papers Count:12

Genetic diversity in 22 accessions of Einkorn wheat including thirteen accessions of T. boeoticum, four accessions of T. monococcum and five accessions of T. urartu, evaluated by 24 microsatellite markers originated from AA genome of bread wheat. Twenty of these SSRs amplified showed adequate amplification. Overall 86 alleles were observed for all locus. Polymorphism in locus ranged from 2-9 and with average of 4.1 in each locus. Polymorphism information content was varied from 0.09 (Xgwm99-1A) to 0.86 (Xgwm165-4A). Dendrogram constructed on dice dissimilarity coefficients by Neighbor-Joining algorithm separated accessions in three distinct groups. T. monococcum with two of T. urartu accessions made group I. but T. boeoticum and T. urartu species join together could not be separated and scattered in the other groups, Also these two einkorn wheat species had not genetically and geographically differentiation. The collected accessions from northwestern regions of Iran had too much more diversity than the western regions of country that we could use from this diversity for finding resistant genes about biotic (pest) and abiotic (drought and salt) stress.

In order to study variation of wheat yield and its traits, a field experiment was conducted based on randomized complete block design with 16 treatments and 3 replications at Agricultural Research Farm, Gorgan, Iran in the growing seasons of 2007-2008 and 2008-2009 under well-watered conditions. The results showed that number of nodes, number of tillers per plant, number of grains per spikelet and seed weight were not change during breeding activities. Number of grains per spike and grain number per unit area increased 28.87% and 24.74%, respectively during 38 years of the release, 0.78% and 0.80% improvement per year was observed, respectively. The most important reason for increasing the number of seeds per square meter was increasing grain number per spike. In grain yield, biological yield and harvest index increase has been equal to 24.83%, 16.16% and 8.18% respectively. Also plant height was decreased by 0.25% and spike length was increased by 0.27% per year of release. Generally, more than 89% yield variation was justified by changing variables such as harvest index, biological yield and grain number per spike.

To comparison the photosynthetic parameters and leaf chlorophyll content and fluorescence of safflower (Carthamus tinctorios L.) cultivars under salinity stress, a pot experiment was carried out as factorial arrangement based on completely randomized design with three replications in University of Yasouj in summer 2011. The first factor included four salinity levels (including zero, 75, 150 and 225 mM) and the second factor included six cultivars of safflower (Local Isfahan, Spinned Sina, Isfahan 14, Goldasht, Padideh and Sina 411). Photosynthetic parameters including photosynthesis rate, transpiration, stomatal conductance, mesophyll conductance, chlorophyll content and chlorophyll fluorescence components were measured. Results showed that the interaction of cultivar and salinity for all traits, except for Fv/Fm, were significant. Decreasing trend of chlorophyll and photosynthetic parameters with increasing salinity was different among cultivars. Fluorescence chlorophyll factors, Fm (max fluorescence under dark acclimated condition) and Fo (min fluorescence under dark acclimated condition) were increased with increasing salinity levels in all cultivars. At non-saline condition Padideh cultivar had relative superiority in terms of chlorophyll a, chlorophyll b, transpiration rate, photosynthetic rate and water-use efficiency. At 75 mM salinity, Spinned Sina had relative superiority in terms of chlorophyll b, total chlorophyll, carotenoids, and photosynthesis rate compared to other cultivars. At 150 mM salinity, Padideh cultivar had relative superiority in terms of chlorophyll a, chlorophyll b, the rate of photosynthesis and water use efficiency than other varieties and at 225 mM salinity level, Isfahan 14 cultivar in terms of chlorophyll a, chlorophyll b, carotenoids, assimilation rate and water use efficiency had superiority to other cultivars.

This experiment was carried out to investigate the effect of plant density on growth and seed yield of wheat (Kodasht cultivar) under saline soils and rainfed condition inAnbarolum region of Golestan province in 2008-09. An experiment was conducted in three fields with different salinities (6.73, 9.34 and 11.63 dS m-1) based on randomized complete blocks design. Treatments were four plant densities (125, 250, 375 and 500 plant per m2) in three replications. The results showed that with increasing plant density leaf area index, stems number and fertile stems number per m2 increased. The highest numbers of tillers per m2 was produced at 250 plants per m2, tiller number reduced with increasing plant density. The grain number per spike reduced from 16 numbers in 125 plants per m2 to 8.25 numbers per spike in 500 plants per m2. Increasing plant density reduced thousand grain weights. In contrast, the highest dry matter was observed in the highest plant density. Increasing soil salinity reduced leaf area index, stems number, fertile stems and tillers number per m2, grain number per spike and total dry matter ha-1. The highest 1000 grain weight (38.42 gr) was observed in lowest soil salinity and reduced to 36.99 gr at 9.34 dS m-1 and the highest salinity (11.63 gr) did not have significant effect on this trait. Interaction effect of salinity and plant density on fertile tillers number per m2 showed that with increasing soil salinity probability of adequate growth of tiller for producing seed reduced; then, under the highest soil salinity even under low plant density tillers were not fertile. Seed yield increased with increasing plant density, but plant density role was not equal under saline condition. Increasing plant density from 375 to 500 plants per square meter under 6.73, 9.34 and 11.63 dS m-1 caused 4.46, 7.70 and 10.51 percent increase in seed yield, respectively. Therefore, It is recommended that 375 plants per m2 at soil salinity about 7 dS m-1 and less, and 500 plant m2in soils with about 9 dS m-1 salinity and higher.

In order to study the effect of nitrogen, vermicompost and nitroxin biofertilizer on growth indices and phenology stage of sesame, a field experiment was carried out at Behbahan based on randomized complete block design in factorial arrangement with three replications in the summer of 2009. First factor was three rates of nitrogen fertilizer (50, 75 and 100% of region recommended nitrogen rate,) and second factor was three rates of vermicompost (0, 5 and 10 t ha-1) and third factor was two levels of nitroxin biofertilizer application (seed inoculation and non-inoculation). The result showed that nitroxin inoculation and the use of 5 and 10 t ha-1 vermicompost increased 7.1, 23.11 and 31.19% of maximum LAI of sesame, respectively. With increasing nitrogen fertilizer application, vermicompost and nitroxin inoculation, the maximum CGR of sesame increased significantly. Result also showed that vermicompost and nitroxin application had a positive and significant effect on phonological stages of sesame. So that use of vermicompost decreased rate of GDD requirement for sesame emergence significantly. Also inoculation with biological fertilizer nitroxin reduced emergence 17.4%. With vermicompost application the period of planting to appearance of capsule increased and reached to the highest level (5 t/ha). Nitroxin application increased grain yield 8.5%. Interaction of nitrogen and vermicompost showed that the most grain yield (1352 kg/ha) was obtained with applying 10 t/ha vermicompost and 75% nitrogen rate based on regional recommended.

In order to investigate the effect of row spacing and cocklebur (Xanthium strumarium) densities on yield and its components of two sesame cultivars, a Field experiment was conducted at Research Farm of University of Agricultural Science and Natural Resources of Gorgan, Iran in 2009-2010 growing season. The experiment was established as factorial arrangement using a randomized complete block design with three replications. The factors included different densities of cocklebur (0, 2, 4, 6 and 8 plant m-2) and two cultivars of sesame (Oltan, Yekta) and three sesame row spacings (35, 45 and 55 cm). The results showed that number of capsul per plant, seed per capsul, and 1000-seed weight were significantly affected by cocklebur density, sesame cultivars, and their interactions. Harvest index was only affected by weed density. Row spacing affected significantly on all yield components except of 1000-seed weight. Grain yield and biomass of sesame cultivars reduced significantly with increasing cocklebure density and Oltan cultivar was less sensitive than Yekta cultivar. Grain yield was affected more than biological yield in competition with cocklebur. According to regression analysis, I parameter (yield reduction with entering the first weed) was estimated as 44.7, 43.91 and 46.39 for Oltan and about 48.68, 53.4 and 51.66 for Yekta in 35, 45 and 55 cm row spacing, respectively.

In order to investigate the effect of water stress at heading stage on grain yield and yield components of eight wheat cultivars, in 2008, and experiment was conducted in the two regions, Isfahan and Ardestan by using split plot arrangement based on randomized complete block design with three replications which that two irrigation treatments included custom irrigation and terminal water stress were main factors and 8 wheat varieties were as sub factors. In Isfahan region at adequate moisture conditions, SW-82-9 line and Pishtaz cultivars produced 10500, and 10630 kg ha-1 yields, respectively and they produced significantly higher yield than other cultivars, but effect of water stress on yield reduction were 8 and 14.9 percent, respectively. In water stress condition of Ardestan region, yield reduction of SW-82-9 line and Pishtaz cultivars were 16.3 and 15.8 percent, respectively. In water stress condition of Isfahan and Ardestan regions in SW-82-9 line, number of grains per spike were 33.8 and 28.3 and harvest index were 0.49 and 0.44, respectively. Stress tolerance index range was 0.71 to 1.34 in Isfahan region and 0.56 to 1.22 in Ardestan area. According to the results of all three indicators, stress tolerance index, mean productivity and geometric mean of yield, SW-82-9 line could be produced grain yield similar to Pishtaz cultivars, and therefore had the potential to culture in both Isfahan and Ardestan regions.

In this study, the effects of weed control treatments and plant density on lentil (Lens culinaris) yield and yield components as well as weed control efficacy were investigated. The study was conducted according to a split-plot arrangement based on randomized completely block design in three replicates in Karaj in 2007-2008. The weed control chemical treatments in four levels (Trifluralin herbicide with hand weeding, Alachlor herbicide, hand weeding, control) were selected as the main factor while the plant density in four levels (80, 160, 240 and 320 p/m2) was chosen as the sub-factor. Results showed that the effects of weed control on the biological and seed yields of lentil and the harvest index were significant. Also, the effect of plant density on the biological and seed yields, harvest index, number of branch and number of pods per plant were significant. The results showed that the biological and seed yields and harvest index were increased by increasing the plant density. According to the significant effect of plant density on the dry weight and the weed control efficacy, the results showed that by increasing the plant density, the weed control efficacy increased, and the best weed control efficacy was obtained in 320 plant/m2. In addition, the complete weeding and Alachlor herbicide were the best methods based on the weed control efficacy among the weed control treatments.

Genetic diversity is necessary for breeding program and increasing selection efficiency. With the onset of spring growth, spring cold stress is a problem for wheat crops at heading and also may be damaged some other parts of the plant. The aim of this study was the investigation of genetic diversity duo to artificial cold stress on the physiological traits, chlorophyll a, chlorophyll b, total chlorophyll, carotenoid and cytoplasmic membrane stability at the reproductive stage. For this purpose an experiment with 20 cultivars of bread wheat and four levels of cold stress, (8 (control), +2, 0 and -2 Celsius) was performed in factorial arrangement in a completely randomized design. Results of variance analysis showed that cultivars and cold stress interaction effect was significant at the 5% level which showed the existence of genetic diversity among cultivars. There were significant correlations between chlorophyll a, b, total and carotenoid. In order to determine genetic relationship among cultivars, cluster analysis with Ward method was performed and cultivars were divided into 5 groups at -2oC and 4 groups at +8oC. Discriminate function and principal component analysis confirmed the results of cluster analysis. The third group of -2oC including of GHODS, TAJAN and PISHTAZ had the lower level of ion leakage and higher level of plant pigments.

In order to evaluate the effects of different sowing dates on leaf area index, dry biomass weight and panicle dry weight and also yield of rice cultivars, harvest index, fertility rate, and 1000-grain weight an experiment was as spilt plots arrangement based on  RCBD design with three replications for one year in the north region of Khozestan. Main plot factor was the date of planting at three levels (26 May, 10 Jun, 26 Jun) and the sub plot was three cultivars of red Amber (long and short grains) and Champa. The results of analysis of variance indicated that there was a significant difference between different sowing dates and cultivars at all traits at %1 level. Except panicule dry weight and fertility rate (difference among different planting dates was significant at 5% level), other properties did not have any significant difference in the interaction of both factors. The highest leaf area index (LAI) and biomass dry weight was related to the first sowing date and the highest grain yield and panicle dry weight was related to the third sowing date. Evaluation of LAI and dry weight trend showed that with increasing heat stress at 26 May sowing date they reached the maximum growth in a shorter period of time; of course, after that, the leaf area index was rapidly reduced, while panicle weight particularly on the last two weeks of the last sowing date had the minimum increase due to infertility of more seeds in this time span. Among the cultivars, short-leg Amber had the minimum changes and Champa had the maximum yield with an average of 3795.4 kg/ha.

In order to evaluate different sources and rates of nitrogen on dry matter yield, concentration and uptake of primary macronutrients (nitrogen, phosphorous and potassium) in forage sorghum (Hybrid of Speedfeed), three levels of nitrogen (80, 160 and 240 kg N ha-1) from three N sources (urea fertilizer, cattle manure and equal combination of urea fertilizer+cattle manure) and the control (no fertilizer) were compared in a randomized complete block design with three replications at the research farm of Shahrekord University in 2010. Results showed that dry matter, concentration and uptake of nitrogen, concentration and uptake of phosphorous and potassium uptake of aboveground organs, were significantly influenced by N amendment. The greatest nitrogen uptake was gained in 240 kg N ha-1 as urea fertilizer and urea fertilizer+cattle manure, because of their treatments have high nitrogen concentration (17.5 and 15.4 g kg-1, respectively) and dry matter (14.4 and 16.3 Mg ha-1, respectively). The highest dry matter production (15.7 and 16.3 Mg ha-1), phosphorus uptake (32, 34.2 kg ha-1), and potassium uptake (254, 272 kg ha-1) were obtained in 160 and 240 kg N ha-1 as urea fertilizer + cattle manure, respectively. In general, application of 160 kg N ha-1 as integrated fertilizer resulted to improvement of nutrients uptake (phosphorous and potassium) and desirable forage production. Thus, it can be helpful for development of sustainable agriculture by decreasing the consumption of urea fertilizer.

Damage of the pathogens is one of the main limitations for cultivating and production of safflower. This study was performed to investigate reaction of safflower genotypes to Pythium ultimum during 2009 and 2010 under field conditions. The study was done in two parts, selection and evaluation of parents (part 1; 2009) and evaluation of the progenies (part2; 2010). In the first year, the experiment was performed as a randomized complete block design including selected seeds (seeds obtained on plants at infested soil) and unselected seeds (obtained seeds at sterilized soil) of 6 genotypes in 8 replications. In the second year, experiment was conducted in 3 different conditions. These conditions were included of two infested environments (environment 1 and 2) and one sterile environment. The suspension of 105 per ml zoospore was used for infection. Results showed that P. ultimum damping-off decreased speed of emergence. Selection increased percent of emergence of genotype Zargan from 29.25% to 40.75%, of Syrian from 37.0% to 46.0% and of 34074 from 41.7% to 64.2%. Improving of percent and speed of emergence in infested soil with P. ultimum showed that selection is an effective way for breeding resistance to this disease in some of safflower genotypes.