فصلنامه پژوهش های تولید گیاهی
سال نوزدهم شماره 4 (زمستان 1391)

To study inheritance of resistance to septoria tritici Blotch in wheat, the generation means analysis method was used. So six generations (P1, P2, F1, F2, BC1 and BC2) were planted under completely randomized design with three replications in greenhouse. Seedlings were inoculated at the second-leaf stage with an isolate of Septoria tritici and Necrosis and Picnidia density and Area Under Disease Progress Curve for both traits (Necrosis and Picnidia) were evaluated. Results of generation mean analysis showed that the additive, dominance and epistatic effects were effective in all traits, but the role of dominance effects and dominance × dominance interactions was more important. The results of the estimated degree heterosis and potance ratio confirmed the more importance of dominance effect in genetic control of studied traits. Average broad sense heritabilities were between 73 and 93.6 for all traits. Degree of dominance being more and less than one, confirmed dominance and overdominance gene effects. Therefore, it is recommended to use the breeding methods based on hybridization and or selection in final generations to improve resistance to Septoria tritic blotch.

Documenting the production process in agriculture includes providing all information and activities that shows the course of production from seedbed preparation stage to harvest stage. For this purpose, in present investigation all management operations performed from seedbed preparation stage to harvest stage were recorded on 95 wheat farms in 2007 and 2008. In this study, the method of doing each management operation undertaken in farms from stages of seedbed preparation to harvest as well as a proportion of farmers applying different method of the management operations were determined through absolute and cumulative frequency distribution. The results showed wheat cultivation was conducted from 5 to 16 December. Depending on seedbed preparation quality and type of planting tool, the rate of used seed was varied from 140 to 250 kg ha-1. The more farmers used urea, triple superphosphate and potassium sulfate fertilizers for supplying nutrient requirement in wheat farms. Traditionally, urea fertilizer was used at stem elongation stage on average with amount of 93 kg ha-1. Due to shortage rainfall during the first year, the most farms were irrigated twice (at flowering and early seed filling) but in the second year it was done once (at flowering). The time of wheat harvest ranged from 7 to 14 June depending on environmental condition. In respect to variation of management operations in farms, the amount of yield varied from 2.5 to 6.3 t ha-1.

Based on the valuable antioxidant activity of citrus fruits, in present study the effect of rootstock (sour orange and citromelo) and fruit tissues (pulp and peel) on total titrtable acid, vitamin C content, total phenols and flavonoids, antioxidant activity as well as the content of hesperidin and naringin of thampson novel and page mandarin was studied. The experiment was conducted as a factorial assay based on a randomized complete blocks with four replications. According to the obtained results, the amount of titrtable acid of thampson novel fruit was higher than that of page mandarin. In comparison with sour orange both fruits produced a higher titrable acid with citromelo. The content of vitamin C of fruits grafted on sour orange was higher than that of citromelo, in which shows a higher nutritional quality of fruit. Antioxidant activity and the content of total phenol, total flavonoid, and hesperidin of thampson novel fruits were significantly higher than that of page mandarin. Contrary to hesperidin, between thampson novel orange and page mandarin the content of naringin of page mandarin was at the highest level. In compare to the sour orange, fruits on citromelo showed a higher antioxidant activity, flavonoid and hesperidin content. On the other hand, results showed no difference on the amount of total phenol and naringin between two different rootstocks. Results showed that the accumulation of measured antioxidant compounds of peel is noticeable. Finaly based on the obtained results it can be concluded that although the concentration of pharmaceutical and nutritional compounds is strongly related to the genotype, it seems that a higher quality and quantity of such compound could be achieved using a suitable rootstock.

In order to effect of application chemical fertilizers (nitrogen and phosphorus), Nitroxin biofertilizer (containing Azospirillum, Azetobacter and phosphate solubilizing bacteria from Pseudomonas genus) and Phosphate Barvar 2 (containing 2 strains of bacteria, 5 p and bacteria 13p) in Pashen sweet corn variety, an experiment was conducted as factorial base on randomized complete block design with three replications in Gachsaran Agriculture Research Center Farm, in 2010- 11. Experimental treatments were contained of 50, 100 and 150 kg/ha of nitrogen, without the use of biological fertilizers and using 1 liter ha-1 Nitroxin as the first factors and 75 and 150 kg ha-1 triple super phosphate, without application of biofertilizers and the application of 100 g ha-1 phosphate Barvar2 with 75 kg ha-1 phosphorus and without application chemical fertilizer as the second factors. Traits were included yield components (cob number per plant, number of rows per cob, grain number per row, number of grains per cob and thousand grain weight), fresh cob yield, biological yield and grain yield of canned, sweet corn cob harvest index and grains. Finally, application of 150 kg nitrogen and 75 kg ha-1 phosphorus with application phosphate Barvar 2 and Nitroxin biofertilizer had the greatest increase in yield and yield components, grain protein and phosphorus content. In grain harvest index, 150 kg ha-1 nitrogen with Nitroxin biofertilizer and 100 g/ha of phosphate barvar2 application have had the most influence.

The increasing demands for agricultural products and pressure on the water and land resources also the problems to generate new data specify the necessity of using suitable models to predict the performance of agricultural products. In this situation, computer models provide the possibility to investigate different management strategies. The objectives of this study were to determine the least important computer input parameters which affecting the silage maize yield using artificial neural networks in different levels of water and nitrogen applications. The experiments included four irrigation levels (0.7, 0.85, 1.0, and 1.13 of crop evapotranspiration, ETc) and three nitrogen fertilization levels (0, 150, and 200 kg N ha-1). The results of artificial neural network analysis showed that when at least three parameters of irrigation, fertilizer and growing degree days (GDD) were introduced as the input of ANN, the model could predict the performance of silage maize with high accuracy. The best validation performance of the model was at step 10 with mean square error of 0.0032. Also the results of sensitivity analysis indicate that the growing degree days with the coefficient of sensitivity of 9.96 is the most important parameter for predicting of silage maize performance and after that is the amount of irrigation with the sensitivity coefficient of 2.07. The results showed that adding the solar radiation and average relative humidity to the input parameter cause reduction in MSE and increasing the accuracy of the model in the process network training.

This research were conducted on 2007-8 and 2008-9 cropping years in Agriculture Research Center of Khuzestan in split plot experiment using complete randomized block design with four replications in which main plots were consisted of three planting dates (Nov11, Dec11 and Jan11) and sub plots were included three canola cultivars (Hayola 401 Shirali, and R.G.S). Results showed that planting date delaying caused dry matter reduction in response to growth duration, which reduced plant height and consequently reduced stem and leaf dry matter pod and grain weight. According to two years mean comparison to Nov11 planting date total and leaf dry matter reduced 41.6 and 74.9, and 47.2 and 83.1 percent in Dec11 and Jan11 planting dates respectively. Planting date delaying caused stem and pod dry matter and grain weight reduced 58.1 and 87.5 and 42.1 percent respectively. Vegetative growth duration and flowering period reduced %15.6 and %26.2 and %20.3 and %35.2 respectively in Dec11 and Jan11 planting dates comparison to Nov11 planting date. Heat unit accumulation reduced vegetative growth duration(%21.6 and %29.5), flowering period (%6.1 and %14.6) and ripping (%6.6 and %12.2) in two delayed planting dates in compare to optimum planting date for high yield Potential early growth canola cultivars and November planting date recommended, it must be avoided from delayed planting date.

Dutch elm disease is the most important disease of elm trees in most planting regions. The use of tissue culture of plant under in vitro condition, to make easy study of interaction elm trees and Dutch elm disease agent and help for control disease via selection, improvement and reproduction resistant genotype. For this purpose during years 2004 until 2006, samples were collected from Ulmus campestris and Ulmus parvifolia in Golestan and Mazandaran provinces forest. In order to study ability and value of callus growth this two species, after use sterilized treatment, samples cultivated on MS media with different treatments from growth regulator. Growth callus from U. parvifolia and U. campestris were inoculated with different concentration of culture filtrates of Ophiostoma novo-ulmi. Fresh weight callus and vital cells after exposed to different concentration of culture filtrate was measured. Results showed the weight callus on two species was different and growth of callus of U. parvifolia (Chinese elm) was more significant (P= 0/05) than U. campestris. As thought the rate of weight decrease of callus in U. parvifolia and U. campestris, at 10% concentration was 13/3 and 28% respectively. Rate of cell vitality at 50% concentration of culture filtrate in U. campestris was 2 % but in U. parvifolia in the same concentration was 23 %. So it could concluded that the rate of tolerance and viability Chinese elm cells was more after exposed to media culture filtrate. On the basis of this study, U. parvifolia (Chinese elm) show most resistant to Dutch elm disease. Therefore, this method can fast of screening with select of tolerant calli.

There is no report on the nitrogen nutrition status of wheat fields using nitrogen nutrition index (the ratio of the total actual N to critical N concentration at any time course of the crop growth period) method in Iran. Hence, this study was carried out to evaluate the N nutrition status of 16 selected wheat fields in Gorgan during 2006-2007 growing season. Plant sampling were conducted in six growth stages during wheat growing season to determine dry matter yields, actual N concentration, critical N concentration and NNI. Soil samples were provided from 0 to 30 and 30 to 60 soil layers to determine some of physical and chemical characteristics, and NO3-N and NH4-N at the early season. Based on the obtained results, dry matter yields of fields were varied from 0.38 ton ha- at the beginning tillering to 12.51 ton ha- at the harvesting maturity. The mean of N concentrations (%) in plant dry matter were 3.09 at beginning tillering, 2.60 at complete tillering, 1.62 at stem elongation, 1.56 at boot stage, 1.14 at the beginning watery ripe stage and 1.08 at harvesting maturity. These results indicate that the most reduction in N concentration occurred in stem elongation stage, and that N concentration in plant dry matter decreased as plants developed. Actual N concentrations in dry matter were substantially less than critical N concentrations at all development stages; The means of critical N concentrations at above mentioned development stages were 4.38, 4.33, 2.88, 2.32, 1.95 and 1.72, respectively. Then, the means NNI for 16 wheat fields were very lower than optimum (NNI=1) at all development stages; 0.71 at beginning tillering, 0.59 at complete tillering, 0.57 at stem elongation, 0.68 at boot stage, 0.59 at the beginning watery ripe stage and 0.61 at harvesting maturity. Based on these findings, N nutrition status in studied wheat fields was unsuitable through growing season, and that N can be considered as one of the limiting factors for wheat growth and yield in these fields. Finally, the obtained results indicated that achieving potential yield of this region using current N management is impossible.

Boron is considered as a micro-element with essential roles in plant metabolism, including cell wall construction in high pectin content cell walls, malic acid synthesis and cell division. Another possible role attributed to boron is carbohydrate translocation, as sucrose, inside the plant organs. The former role was kept in mind to conduct the evaluation of the single or combined foliar application of boron and sucrose on biochemical parameters measured in shoots, leaves and fruits of strawberry plants. The highest level of chlorophyll a, b, total leaf chlorophyll and carotene content were recorded following application of sucrose (10%) combined with boric acid (0.2%). The total leaf carbohydrate content was also recorded in the same treatment but highest glucose percentage was observed following spraying sucrose (10%) combined with boric acid (0.1%). The highest level of estimated carbohydrate, fruit glucose content, leaf sucrose content were measured following application of sucrose (10%) combined with either 0.1 or 0.2% of boric acid. The same treatments also yielded higher fruit ascorbic acid and sucrose contents. These findings demonstrated a typical rise in leaf chlorophyll as well as carbohydrate contents following treatment and as result significant increasing fruit carbohydrate content. Furthermore, high boric acid levels may lead to phytoxicity and consequently significant decreasing leaf and fruit chlorophyll and carbohydrate levels. The positive correlations were also calculated among estimated biochemical composition of leaf and fruits.

In order to evaluate the effect of soil salinity on characteristics of rice cultivars (IR54447-3B-10-2, IR58443-6B-10-3 Gil repented and native Dom Seiah) an experiment was carried out at Gonbad University in 2008. The experiment was factorial of salinity levels (0, 4, 8 and 12-dSm-1) and rice cultivars using randomized complete block design. The germinated seeds cultivated in pots with 5 kg of soils. The treatments of salinity were applied according to the International Rice Research Institute instruction 30 days after planting. Filled seed and unfilled seed per plant, filled and unfilled panicle per plant, seed weight, Na and K were measured. The effect of salinity, cultivar and interaction between them had a significant effect on all measured characteristics. There was a significant effect on filled and unfilled seed per plant, between Dom Seiah and other cultivars and Dom Seiah also had minimum filled seed and unfilled seed number per plant. Maximum filled panicle number per plant observed in Dom Seiah (16.75) between cultivars. The effects of salinity had the same trend on filled and unfilled seed number per plant, filled and unfilled panicle per plant and seed weight. The maximum potassium observed in cultivars of Dom Seiah and IR58443-6B-10-3

Seedless grapes are widely grown all over the world. Iran has very rich germplasm of seeded as well as seedless grape genotypes. One of the most important grape breeding purposes is to obtain high quality and seedless grapes. The embryo rescue technique is one of the main methods for producing seedless grapevines. In this study putrescine, cadaverine, spermidine and spermine (each with three concentrations) were added to media to rescue embryos of grape cv. Flame Seedless. In order to improve this technique, ovules were excised from berries 45 days after pollination and cultured in NN medium supplemented with 3.0% sucrose, 0.2% activated charcoal and 0.6% agar. Embryos were removed from the ovules after 10 weeks and transferred onto MS medium supplemented with 3.0% sucrose, 0.2% activated charcoal and 0.7% agar. Results showed that putrescine, spermidine and spermine at 1, 0.5 and 1 mm could increase growth and development of embryos, percentage of embryo germination and plant production, respectively. Application of cadaverine only at 0.5 mm could increase development and germination of embryos. However, it was not significant.

The karyotype of two Trigonella species from Ardabil was investigated. Chromosome characteristics of Trigonella caerulea was reported for the first time in Iran. AcetoChromosome characteristics including number, long arm, short arm lengths, total length of chromosome set, arm ratio index and relative chromosome length were made from 7 enlarged well-spread metaphases. The difference between the species and chromosomes were tested using factorial statistical model, based on completely randomized design. Results showed that these species were different in karyotype formula and karyotype characteristics. In the view point of stebbin’s symmetry class, Trigonella caerulea showed the most symmetric karyotype.

Crop residues mixed with soil recycles a considerable amount of potassium. This research was conducted to evaluate the effect of crop residues incorporation with soil on leaf and spike potassium concentration. In this experiment, four crop residues (cotton, maize, wheat, alfalfa) and control were used in a four replicated Completely Randomized Block Design. Results indicated the highest and lowest values of leaf (2.66% and 2.43%) and spike (0.69% and 0.56%) potassium content were seen in alfalfa residue and control treatment, respectively, but their difference was not significant. The value of leaf potassium content declined (with rate of 0.027% per day) after stem elongation stage. The most and least grain yield (8695 and 6962 kg.ha-1) were observed in alfalfa residue and control, respectively.