نشریه پژوهش های کاربردی زراعی
پیاپی 104 (پاییز 1393)

Anther culture application and haploid plant production for releasing new varieties have led to shorten plant breeding cycle. Colchicine is one of the most important materials for doubling chromosomes set and doubled haploid production. The main purpose of this study was to determinate the best colchicine concenteration for doubling rice chromosomes. For this purpose، two pollen-drived haploid plantlets of two hybrid rice (GRH1 and IR69) at the booting stage were selected to treat with colchicine in three concenteration levels (0. 05، 0. 1، 0. 15 g/l) and three time treatments (8،12،18h). The experiment carried out as a factorial experiment complete block design in three replications. Results showed that plantlet percentage of doubled haploid tillers in GRH1 were significantly more than IR69 (53. 33 and 45. 59 respectively). Also the most percentage of plantlets with double haploid tillers were in 0. 1g/l and the minimum of them were in 0. 05 g/l (53. 33 and 37. 77 respectively). The best e time treatment was 12 hours (86. 889). In 0. 1 g/l concenteration level and 12 hours had the most percentage of plantlets with doubled haploid tillers.

In order to study yield and yield components of wheat genotyps (Bahar، Pishtaz،Chamran under the five plant densities (225،300،375،450،and 500 plants per square meter) a split plot design as base of complete randomize block design with four replications was conducted at agriculture، Islamic Azad University of Khorramabad 2006-2007. The results showed that thousand kernel weight seed yield of Chamran was superior for leaf area index، plant height and biological yield. Pishtaz produced the highest seed per spike. Plant densities had significant effect on decreases of plant height and increases of leaf area index، number of spike per unit، seed yield، biological yield and harvest index. Seed yield had positive regression with number of spike m2، thousand kernel weight and negative regression with plant height. Results showed that Bahar with optimum plant density (450 plants per square meter)، produced the highest seed yield than other genotypes.

This experiment was carried out to evoluate the allopathic effects of barely aqueous extracts on germination and seedling electrical leakage of Lolium multif and Avena ludoviciana. The experimental arrangement was factorial included 4 level of aqueous extract concentration of barley (0، 4، 8 and 12 %) and 2 weed seed (Lolium spp and Avena ludoviciana) with 4 replications. Results showed increasing the concentration of barley extracts، decreased seedling dry weight and shoot length in Lolium spp and Avena ludoviciana. Increasing the concentration of barley extracts، increased MDA concentration and seedling electrical leakage in Lolium spp and Avena ludoviciana seedling. In highest aqueous extracts of barley، highest seedling electrical leakage (52%) and lowest seedling dry weight (0/28) obtained from Lolium spp seedling.

In order to evaluation of sowing date effects on forage yield، quality and some yield components of five rape forage (Brassica napus)، a research was carried out at experimental field of Agriculture and Natural Resources University of Ramin during 2007/2008 growing season under Ahwaz condition. An experiment was conducted in factorial form، using a block completely randomized design with three replication. Experimental treatments included three sowing date (5 Nov، 20 Nov and 5 Dec) and five forage rape cultivar (Pac101، Pac102، Pac103، Pac104 and Pac105). In this research، dry matter yield، leaf dry matter yield، stem dry matter yield and leaf and stem crude protein yield in cultivars were determined. Also plant height، branch number per plant and leaf area was measured. Result showed significant difference for sowing date in all traits. The highest total، leaf and stem dry matter yield and highest leaf and stem crude protein yield were obtained from first sowing date (11/83، 8/75، 3. 36، 1. 61 and 0/47 t/ha respectively). Yield and delete yield component of forage turnip cultivars decreased along with delay sowing date. Analysis of variance showed deletes statistically differences among cultivars for all parameters. Pac101 cultivar had a highest total dry matter yield among the cultivars.

A study was set up in the research station of rice research institute of iran (RRII) to rate plant double haploids anther culture-derived plant F1. Anther cultures of a genotype to put on two medium Chu، N6 were treated with or without (0،20،40،60 mg/l) colchicines for 7 days and then the anthers from culture media containing colchicines transfer to medium without colchicines. The effect of media، colchicines concentration and their intractions on callus iniation، regeneration and double haploidy، the compelet random factorial design with three replication was formed. The results indicated to be affected significantly between callus induction medium for four manners case evaluation (callus induction، green plants، total regeneration) but not to be between on callus induction media for double haploidy affected significantly. Also means comparison at P= 0/05 based on Duncan،s multiple range test، indicated culture media N6 (5/102) was considerably better for callus induction and for green plants، total regeneration and double haploidy. The most percentage of double haploids were in 60 mg/l colchicine concentration (68/19) that with other concentrations was doubling rate control 0 mg/l (31/98) affected significantly. Also callus induction media Chu with 60 mg/l concentration (69/17) and callus induction media N6 with 60 mg/l concentration 67/22) had the most double haploids. culture media N6 was the least with control 0 mg/l colchicines (30/00). In fact of to be between different concentration in callus induction media affect significantly.

In order to investigate the effects of nitrogen fertilizer type and split application of fertilizers، an experiment was conducted in experimental field of Lorestan University as split plot experiment based on complete randomized block design with four replications. In this experiment seven nitrogen treatments were in the main plots and two corn hybrids (short season and full season) were in the subplots. The Results showed that by increasing the amount of both nitrogen fertilizers grain yield and biological yield of corn hybrids increased. Using urea in comparison with ammonium nitrate has higher effects on grain yield of corn hybrids. For both of corn hybrids and especially for full season hybrid split application of nitrogen fertilizers have positive effects on grain yield. Based on results split application of urea has higher positive effects on grain yields of corn hybrids.

To investigate the relationship between yield and its components in wheat under non stress and drought stress conditions an experiment was conducted in on Agricultural Research Station at Bahonar University of Kerman. Experimental trial was split-plot (non-stress and drought stress as main plots and 15 cultivars as sub plots) in randomized complete block design with three replications. The measured traits were relative water content، yield and its components (number of spikes per m2، number of grain per spike and 1000 grain weight)، biological yield and harvest index. The results showed that the effects of drought and cultivar were significant on all traits، and drought stress decreases all traits. Correlation coefficients between grain yield and harvest index under both conditions was positive and highly significant. Correlations of harvest index with the number of spikes per m2، number of grains per spike and 1000 grain weight under drought stress، were significant. However، under non-stress condition was non significant. Correlation between 1000 grain weight and grain number per spike was significant under drought stress and was not significant under non-stress conditions. Under drought stress and non stress conditions، the correlation between 10 grain weight and grain yield was positive and significant. Correlation coefficient between grain yield and relative water content under non-stress condition was not significant; however under stress condition was significant. Based on path analysis، under stress and non stress conditions، harvest index had the highest and positive direct effect on grain yield. Under non-stress condition number of spike per m2 and under stress condition number of grains per spike had the highest direct effect. The number of spikes per m2 via by the number of grains per spike had the highest indirect negative effect under non-stress condition. Under stress condition، the 1000 grain weight by harvest index had the highest indirect negative effects.

Planting pattern and plant density affect growth characteristics and yield of sunflower via changes in space available for growth of each plant. To evaluate these effects in sunflower cv.، Hisun-36 hybrid، an experiment was conducted in the spring 2006 at The Agricultural Research Station، Isfahan University of Technology، using a split-plot layout within a randomized complete block design with three replications. Row distance (60 and 75 cm) was the main plot and plant distances over the row (12، 14، 16، and 18 cm) were the sub-plots. Plant height and stem diameter were significantly increased، as row distance increased. Dry weights of stem and leaves per unit area، seed and biological yield per unit area and harvest index were decreased as row distance increased، but these decreases were only significant for dry weight of leaves and seed yield per unit area and harvest index. Stem diameter and head diameter were significantly reduced and plant height was significantly increased as planting distance decreased. Dry weights of stem and leaves per unit area were significantly increased، but seed yield per unit area and harvest index were significantly reduced as planting distance decreased. The results obtained in this experiment indicate that the combination of 60 cm row distance and 14 cm between plants (11. 9 plants m-2) might be suitable for production Hisun-36 hybrid under the conditions similar to this study.

Intercropping is a beneficial farming system to intensify and sustain farm productivity. In order to evaluate forage production of maize and seed yield of bean in maize/bean (maize var 704 and bean var Goli) intercropping، a field experiment was conducted at Research Farm، Faculty of Agricultural Sciences and Engineering، Tehran University during 2006. Sowing dates of plants with three levels، simultaneous sowing for both plants، 20 day delay in sowing of bean and 20 day delay in sowing of maize were arranged in main plots. The five planting ratios (100/0)، (66. 7/33. 3)، (50/50)، (33. 3/66. 7) and (0/100) were the percentage of bean/maize arranged in subplots. Results showed that the bean seed yield / plant and bean pot number / plant were affected by interaction of sowing date and planting pattern. Delay cropping of bean in maize under planting ratio of 66. 7/33. 3 of bean/maize produced the highest dry weight of maize among intercropping treatment. Pure maize had the highest plant height and produced maximum dry weight /ha. The highest pod number per plant، yield per plant and hectare، and the lowest seed number per pod were observed in pure bean.

Quality of produce is as much important as quantity in all stages of life and particularly in direct consumption of commodities. In order to evaluate some rice grain physicochemical properties in different irrigation regimes in two varieties (Tarrom and Shiroodi)، a field experiment was carried out on randomized complete block design at rice research institute of Mazandaran in 2010. Treatments includes five irrigation regimes، viz.، T1: permanent flooding with 3-5cm height throughout growing season، T2: irrigation with 5cm height after disappearing water from soil surface، T3: irrigation with 5cm height 2 day after disappearing water from soil surface، T4: irrigation with 5cm height 5 day after disappearing water from soil surface and T5: permanent saturation during growth period، with three replication. In each treatment، yield and some grain quality parameters were measured. The statistical analysis showed that، there was a significant differences in yield between treatments (α<0. 01)، with highest yield in continuously flooded treatment، 4210kg/ha and 6799. 7kg/ha in Tarom and Shiroodi، respectively. There were significant differences in grain hardness، broken rice percentage، elongation ratio، elongation after cooking، Amylose content and Gel consistency in different irrigation levels. Based on the results of the different irrigation methods، the best grain hardness amount (13. 1 Nioton) and reduced broken rice percentage (15 %) in Tarrom variety were obtained by the permanent flooding method، but for Shiroodi variety، the best grain hardness amount (17. 8 Nioton) and reduced broken rice percentage (19. 5 %) were gained by the permanent saturation method.

In this study 512 wheat accessions and three cultivars، named Kavir، Roshan، Mahooti (as check varieties) were evaluated in a field experiment of National Plant Gene Bank of Iran (NPGBI) during 2009-2010، using augmented design in 16 block، in which each block contained 35 samples. Agronomical، morphological and phenological characters such as germination percentage، days to heading، days to flowering، days to maturity، days from heading to maturity، days from flowering to maturity (duration of grain filling)، plant height، spike length، stem thickness، number of nodes، spike density، awn of spike، glume color، glume hairiness، number of spikelets/spike، number of flowers/spikelet، number of seeds/spike، hundred seeds weight، seed weight of 5 spikes and seed weight/ plot were evaluated according to IPGRI descriptors. Results of descriptive statistics for quantitative traits revealed the most value of coefficient of variation (CV) on seed weight / plot (30%) and seed weight of 5 spikes (23%)، respectively. Minimum value of CV was detected for phenological traits such as days to maturity (2%)، days to heading (3%) and days to flowering (3%)، respectively. Results of Shannon index for qualitative traits revealed the most variation on awnletted of spike (H0. 92='') and minimum variation was observed on glume hairiness (H0. 37=''). The strongest correlation with seed weight/ plot were observed with plant height (r = 0. 23**) and hundred seed weight (r = 0. 23**)، respectively. Number of seeds/spike and hundred seed weight، explained 95. 2 percentage variation of seed weight on 5 spikes in stepwise regression analysis. Path analysis revealed that direct effects of seed number /spike and hundred seed weight on seed weight on 5 spikes were 0. 77 and 0. 66، respectively. Factor analysis according to principal components analysis and varimax rotation revealed that overall 74. 1% of total variation could be explained by 5 factors. Cluster analysis by Ward method grouped the germplasms from 21 countries in three clusters.

To study the effect of different fertilizing systems on the seed yield and phosphorous absorption in annual medic (var. Robinson)، an experiment was conducted based on a complete randomized blocks design with three replications in two locations in Kermanshah province، Iran. The treatments consisted of Control (no fertilizer application)، Chemical fertilizer (urea chemical fertilizer + triple superphosphate fertilizer)، Urea chemical fertilizer + phosphorous solubilizing bacteria، urea chemical fertilizer + mycorrhiza، Urea chemical fertilizer + phosphorous solubilizing bacteria + mycorrhiza، Nitrogen fixing bacteria + triple superphosphate fertilizer، Nitrogen fixing bacteria + phosphorous solubilizing bacteria، Nitrogen fixing bacteria + mycorrhiza، Nitrogen fixing bacteria + phosphorous solubilizing bacteria + mycorrhiza. The results of this research showed that under the conditions of this experiment The highest content Phosphorus content in pods (0. 47 %) and Soil seed bank (838 pods/m²) was found in treatment T6 (nitrogen fixing bacteria + phosphorussolubilizing bacteria). The highest content Phosphorus content in pods (0. 47 %) and Soil seed bank (838 pods/m²) was found in treatment T6 (nitrogen-fixing bacteria + phosphorus-solubilizing bacteria). It seems that inoculation annual medic var. Robinson withnitrogen fixing + phosphorous solubilizing bacteria،، indicating the synergistic interaction between these groups of bacteria to increase، soil seed bank as well as seed phosphorous content of annual medic var. Robison was found in control treatment.

There are a lot of evidence on the effects of potassium and Zinc to increase wheat yield and improving seed quality and reducing of cadmium uptake by plant. An investigation carried out to study the effects of these two elements in the process of Cd uptake by wheat and effects of these elements in other growth parameters. The statistical design was split plot with three main factors (without potassium، potassium consumption based on soil test potassium and potassium consumption tow time more than soil test potassium) and four sub plots (control Zn، soil Zn consumption، foliar Zn application and، Zn in Soil and consumption combined with foliar application). The experiment was done in a wheat field in southern of Tehran، which many years were irrigated with wastewater. The results of experiment showed that the main effects (potassium effects) on grain yield، straw yield، spike length، number of grains per panicle and grain weight is significant. The above characteristics increased by use of potassium based on soil test recommendation significantly and extra use of potassium did not any effects on these parameters. Secondary effects (Zn) on the above traits were significant. Grain yield، straw yield and grain weight were not affected by different methods of Zn application، but combined use of Zn as soil application and foliar، produced the greatest amount of panicle length and number of seeds per ear. The main effects of zinc and potassium was significant on the concentration of mean grain cadmium. Consumption of these elements significantly reduced grain cadmium concentration. Use of potassium tow time more than soil test recommendation was the highest decrease in cadmium concentration by 34 percent. Use of Zn in soil combined with foliar application was the highest effects on seed cadmium decrease by 17. 8 percent in compare to other method. The concentration of cadmium in seed was affected by Potassium and Zinc interaction and decrease significantly. Use of potassium tow time more than soil test recommendation and Use of Zn in soil combined with foliar application decreased seed cadmium concentration by 48. 6 percent significantly. Data also showed that there were a significant correlations between seed potassium and seed zinc concentration and the amount of seed grain cadmium with the quadratic equation، so with increasing concentrations of potassium or zinc، cadmium concentrations of grain declined. On the whole، to reach maximum yield with minimum grain cadmium concentration، Use of potassium tow time more than soil test recommendation and use of Zn in soil combined with foliar application، eventually in lands the same place of research experiment، was recommended.