فصلنامه تحقیقات غلات
سال دوم شماره 1 (بهار 1391)

Breeding for drought tolerance is one of the most efficient ways for preventing yield loss in dry conditions. Diallel method is one of the best methods for genetic evaluation of germplasm before starting of breeding program. In this experiment seven bread wheat genotypes including old genotypes and elite lines were crossed in a half diallel mating design. Parents and F1s were planted at stress and normal condition in a RCBD design with three replications. In addition to pheonologic recording, morphological traits and grain yield were measured after harvest. Analysis of variance for diallel experiment showed that the effect of GCA effect was significant for all traits that imply there is significant additive effect in controlling of all traits. Results showed that each genotype is good considering one or some traits. Using biplot analysis, parents with high SCA were recognized for different traits. For spikelets number per ear, ear number and thousand weight crosses Kavir×Shiraz, Sardari×Shiraz and Azar2×WS-82-9 had the highest SCA. Mather and Jinks graphical analysis showed the adequacy of additive-dominance gene action model. Degree of dominance was between from 0 to 1 for most traits which showed the gene action is almost partial dominance. Some genotypes like WS-82-9, Sardari and Kavir can be used for improving of traits thousand weight, ear number and spikelets in ear in both conditions, respectively. Also WS-82-9 is an elite line that can be acceptable genotype for dry condition.

To study genetic diversity of several agronomic and physiologic traits and the effect of water deficit stress on these characters in 34 populations of T. boeoticum, an experiment was conducted as a split-plot using randomized complete block design with three replications in Research Station of University of Tabriz in 2010. The main plots consisted of stress and non-stress conditions and the populations were considered as sub-plots. Analysis of variance showed significant differences among populations for all studied traits, indicating the existence of genetic variation among populations. Phenotypic coefficients of variation for seed weight and leaf area were highest and for days to physiological maturity were lowest in both stressed and non-stressed conditions. Correlation coefficients and stepwise regression showed significant positive associations of seed weight with leaf area and plant height in both stress and normal conditions. In addition, chlorophyll index was also included in the regression model under normal condition. Cluster analysis grouped populations into five and three clusters in stress and non-stress conditions, respectively. In the water deficit condition, populations 114, 118, 176 and 216 by having the highest chlorophyll index and seed weight had superiority over other populations. In the normal condition, populations 3, 10, 12, 120, 127, 257, 277, 320 and 485 in the second group had the highest seed weight, chlorophyll index and leaf area.

The effects of genotype by environment interactions on the sugar yield of 26 promising sugarcane cultivar and 4 standard cultivars (CP48-103, CP57-614,CP69-1062 and NCO310) as checks were investigated for new Plant,first Ratoon and second Ratoon at three locations (Amirkabir, Imam Khomeini and Mian-Ab Agro-Industries) and for three cropping seasons (2008-2010). Combined analysis was done with regard to fixed effects of treatment and location and random effect year. Effect of year, Location, year × location and treatment were found to be significant (P <0. 01) and Effect of treat × location was found to be significant (P <0. 05). To investigate the stability of genotypes were tested, use the Rick, Shukla, Eberhart-Russell, simultaneous selection, AMMI and SHMM methods. Wrick, Shukla, Eberhart and Russell, Simultaneous Selection and SHMM method in their stable clones listed, 8/29 to jointly introduce. Analysis based on AMMI showed that the genotypes /, 1/113, 1/26, 6/60 and 6/8 by assigning the lowest genotype by environment interactions and highest average yield are as the most stable genotypes and clone 6/8 to account very low the interaction among the clones studied were identified as the most stable genotype. Such that the results this method was similar with the results of Eberhart and Russell method and the average rating and standard deviations can proposed rating and Eberhart and Russell methods as a suitable method after two AMMI and SHMM method.

Transgenic plants are often produced by tissue culture-dependent methods that require careful preparation and selection of explants, selection of transformed cells and regeneration of transgenic plants. In this in planta transformation method, the mature embryos of soaked seed were pierced by an Agrobacterium tumefaciens -coated needle or scalpel. The inoculated seeds were germinated and grew under no sterile conditions. In order to evaluate the effects of cultivars (Hashemi and Gerdeh), A. tumefaciens strains (EHA105 and LBA4404) and Three methods of inoculation (0. 5 mm Ø needle, 0. 5 mm Ø needle together with vacuum infiltration, Wounding with a scalpel) on transformation efficiency. A CRD based factorial experiment with three replications was applied. Integration of the transgene into the genome of transformed plants (T0 and T1) was confirmed using PCR method, resistance of leaf tissues to hygromycin and histiochemical GUS assay. Accordingly, the highest significant transformation efficiency (11. 72 %) was obtained in Hashemi cultivar wounded with a scalpel. Transformation efficiency of the same cultivar inoculated by a needle under vacuum infiltration was significantly higher than treatment of inoculation in the absence of vacuum. Seventy T0 seedlings were selected randomly and analysed further at T1 generation, which ~19 confirmed to be positive.

To investigate the effects of on-farm seed priming and weed control on some traits in corn (single cross 301), an experiment was arranged in a factorial experiment based on randomized complete block design with three replications at experimental field of the Bu-Ali Sina University, Hamedan, Iran, in 2010. Experimental factors included, on-farm seed priming in four levels (non-primed, priming with urea solution, priming with zinc sulfate solution and priming with tap water) and weed control in three levels (non-weeding, weeding in 20 days after planting and weeding in 20 and 40 days after planting). For on-farm priming the seeds were placed for 16 hours in solutions of urea (6 g.l-1), zinc sulfate (0.34 g.l-1) and tap water, and after surface drying were planted. The results showed that priming with urea and zinc sulfate solutions had highest emergence rate and lowest time to 50 percent emergence (E50) using urea solution caused the most emergence percentage and emergence energy. The maximum emergence index was observed in urea solution. All treatments compared to non-primed non weeding treatment had higher leaf area index. In other words priming could compensate decreasing effect of weeds on leaf area index. Priming treatments with zinc and urea solutions had highest crop growth rate and total dry weight (Crop Growth Rate: 21.76 and 18.99 gr.m-2.d-1, respectively), (Total Dry Weight: 1086.76 and 1080 gr.m-2, respectively). Corn leaf area index duration was not affected by priming, but increased under once and double weed control respectively 22% and 23.9%. Crop growth rate increase with weed control and priming treatments showed most increase. Urea-once weed control and Zinc Sulfate-once weed control treatments had most biological yield. Zinc sulfate and urea treatments showed respectively, 14 and 12% higher yield than the control. Generally results showed that emergence rate and vigor increased by priming with urea and zinc sulphate solutions, also weed control in companion with seed priming increased the studied growth indices and biological yield.

A field study was performed at the research farm of the Faculty of Agricultural Sciences science at the University of Guilan, Rasht during the season growth in 2009 for investigating the effects of deficit irrigation and nitrogen fertilizer on quantitative and qualitative yield of forage corn. SC70. The experimental design was conducted as randomized complete blocks with factorial arrangement in three replications. The experimental treatments consisted of two factors, irrigation in two levels (50% and 75% available water depletion from soil) and nitrogen rates in three levels (0, 100 and 200 kg.ha-1). The obtained results depicted the fact that the irrigation had no significant effects on the traits of the case study excluding the protein yield. On the other hand, the nitrogen had significant effects on all traits of the case study excluding the fiber yield. No significant statistical effects were observed on the interaction of irrigation × nitrogen on the traits measured. The results obtained by the comparison of the average of different levels of irrigation on the application of protein showed that the complete irrigation, the treatment of 50% available water, had a better protein yield in comparison with 75% available water. Comparing of the levels of nitrogen also depicted that the application of 200 Kg.ha-1 had significant effects on the most traits of the case study in comparison with the application of 100 Kg.ha-1 but their difference was not statistically significant on the application of dry mater yield(DMY) and wet mater yield (WMY). The interaction of irrigation per nitrogen effected on the DMY, but it was not significant so that the highest amount of DMY (1014.2 gr.m-2) and the lowest amount (723.3 gr.m-2) were obtained at 200 kg.ha-1 N with full irrigation and without fertilizer and 75% available water depletion, respectively. The obtained results from this research indicated that the treatment of 75% available water together with 100 Kg.ha-1 N is the suitable for quantitative forage yield, but the treatment of 50% available water together with 200 Kg.ha-1 N is needed for the protein yield.