مجله علوم گیاهان زراعی ایران
سال چهل و سوم شماره 3 (پاییز 1391)

In order to evaluate the effects of seed priming and different levels of nitrogen on yield and yield components of two corn (Zea mays) hybrids, an experiment was carried out as split plot factorial based on a randomized complete block design (RCBD) with four replications in Agricultural Research Station of Shahrood University of Technology. The treatments were urea levels (150, 250, 350 kg/ha) as main factor and seed priming (primed and non-primed) and corn hybrids (SC704, KOSS444) as sub- plots. The results showed that seed yield, number of row per ear, number of seed per row, 1000- seed weight, ear length, ear diameter traits for primed seed of SC704 hybrid were maximum. Urea levels significantly affected yield and yield components and 350 Kg/ha urea produced maximum yield. Number of seed row per ear was maximum at primed seed at all urea levels. Maximum and minimum number of seed per row obtained from primed seed of S.C704 hybrid at 350 Kg/ha urea level and non-primed seed of KOSS444 hybrid at 150 Kg/ha urea level, respectively. Higher levels of urea increased 1000-seed weight in both hybrids and SC704 hybrid at 350 Kg/ha urea level produced maximum 1000-seed weight. Generally, priming improved yield and yield components of hybrids and SC704 was better than KOSS444.

To evaluate the effects of phosphate solubilizing bacteria and chemical phosphorous fertilizer on turnip (Brassica rapa) forage yield under limited irrigation regimes, a field experiment was conducted in Research Farm of College of Agriculture and Natural Resources, University of Tehran, in Karaj/Iran during 2009 growing season. The experimental treatments were arranged as split plots. Five levels of irrigation consisted of: IR0 (no irrigation), IR1 (Irrigation at sowing time), IR2 (Irrigation at sowing time + commencement of tube formation), IR3 (Irrigation at sowing time + commencement of tube formation + commencement of flowering) and IRN (normal irrigation) were assigned to the main plots. Four levels of fertilizing systems viz: F0 (no phosphorous fertilizer), 100% Fch (100% chemical phosphorous fertilizer according to soil test), FBI (seed inoculation by pseudomonas putida bacteria strains 41 and 168), 50%Fch+FBI (50% chemical phosphorous fertilizer + seed inoculation by pseudomonas putida strains 41 and 168) were assigned to the subplots. A randomized complete block design with four replications was employed to analyze the data. The results showed that turnip is very sensitive to water stress in germination and emergence stage of growth. Irrigation at sowing time was the most efficient irrigation in turnip forage production. However, irrigation at stem elongation stage did not affect forage yield. The results also revealed that application of chemical and biological phosphorous fertilizer could moderate negative effect of water stress on turnip forage yield. As the severety of drought stress increased, dry matter digestibility and metabolizable energy of turnip forage followed a decreasing trend, while acid detergent fiber, water soluble carbohydrates and crude protein content followed an increasing trend. Based on the results of the experiment, integrated fertilizer could be a good substitute for chemical fertilizer. Total forage yield of turnip reduced by 8% in integrated fertilizer application compared to chemical fertilizer treatment. However, in integrated fertilizer treatment 50% reduction in chemical fertilizer utilization was achieved. Also integrated fertilizer could moderate the adverse drough stress effects on turnip growth and forage yield.

The effect of late planting heat stress on yield and yield components was studied in 11 barley lines from ICARDA and one cultivar from Iran (Izeh) during two years (2005-2007) in Gachsaran Dry-land Agricultural Research Station. Each line was planted in a 6-rowed plot at two dates: normal planting (middle of November) and late planting (end of December) with three replications using a randomized complete block design. Results showed that heat stress (late planting) significantly decreased the number of spikes per unit area, grains per spike, thousand-grain weight and grain yield by 25.2%, 6.3%, 3.6% and 34.8%, respectively, while grain filling period did not show a significant reduction under heat stress. The number of days to heading showed the highest correlation with yield (-0.65). Mean product (MP), geometric mean productivity (GMP) and stress tolerance index (STI) were the best tolerance indices showing the highest correlation with grain yield under both normal and heat stress conditions. Based on two years data of STI, GMP, MP and yield, line 6 turned to be the most tolerant line and could be recommended for cultivation in tropical areas of Iran.

To evaluate the effects of biological phosphorous, chemical fertilizers and limited irrigation regime on quantitative and qualitative characteristics of two different grain sorghum cultivars (Kimiya and Speedeh), this experiment was conducted in research farm of College of Agriculture, University of Tehran during 2009 growing season. The experimental treatments were arranged as split split plot based on a randomized complete block design with three replications. The irrigation regimes viz: full irrigation (IRN) and limited irrigation (IRS) were assigned to the main plots and the grain sorghum varieties viz: Kimiya (KI) and Speedeh (SP) were assigned to the sub plots. Four phosphorous fertilizing systems viz: control, no phosphorous chemical fertilizer application and no biological fertilizer, (P0), complete phosphorous chemical fertilizer as triple super phosphate according to soil test (P100), seed inoculation by Pseudomonas bacteria and mycorrhiza fungi (M+Ps) and seed inoculation by Pseudomonas bacteria and mycorrhiza fungi + 50% of chemical phosphorous fertilizer(P50+M+Ps), were assigned to sub sub plots. The results indicated that in full irrigation system the highest biological yield was produced by integrated application of P50+M+Ps while at limited irrigation system the highest biological yield was achieved by both integrated fertilizer (P50+M+Ps) and biological fertilizer. The highest grain yield under full irrigation system was produced by complete chemical fertilizer (11694 kg/ha). However, under limited irrigation system, biological fertilizer (9479 kg/ha) and integrated fertilizer (9186 kg/ha) produced the highest grain yield. Across two studied varieties, kimiya variety produced almost 8 percent higher grain yield. The phosphorus content in Kimiya variety was higher than Speedeh.However, Speedeh produced more protein than Kimiya. The application of limited irrigation tend to decrease the phosphate content in Speedeh variety, while Kimiya showed no significant response to limited irrigation in this regard. The overall grain yield decreased by 17% in limited water application while water saving in the same treatment was 41% compared to complete irrigation. This result indicated the profitability of limited irrigation system in grain sorghum production in Iran.

In order to study the effect of spraying of abscisic acid on yield and yield components of chickpea (Cicer arietinum L.) under rainfed and supplementary irrigation, a field experiment was conducted in 2010 in Agricultural Research Station of Ilam University. A split factorial experiment based on a randomized complete block design was conducted. Main plots were composed of two levels of irrigation (rainfed and supplementary irrigation in pod formation stage). Also, abscisic acid treatments (0, 20 ppm) and cultivars (Azad & Bivanij) were assigned as factorial to sub plots. Results showed that supplementary irrigation leads to significant increase in yield, number of pods per plant, 100 grain weight and biomass yield. For other traits including length and width of pod, days to 50% flowering and days to 50% pod, cultivar was only effective and abscisic acid and supplementary irrigation had no significant effect on these traits. Under rainfed conditions, treated plants with abscisic acid had higher plant height, branch number per plant and number of pod per plant than control plants. Also, abscisic acid spraying led to significant increase in yield and biomass yield of rainfed conditions similar to supplementary irrigation conditions.

Main objective in wheat breeding programs is to improve high yielding and stable varieties possessing desirable morpho-physiological traits. This study was conducted to determine the stability of 18 winter and facultative bread wheat genotypes. The experiments carried out in 9 experimental stations (Karadj- Arak- Ardebil- Jolgerokh- Miandoab- Hamedan- Mashad- Qazvin- Khoy) using a randomized complete block design with three replications during 2006-2008 cropping seasons. Result of combined ANOVA showed highly significant effects for genotype, year × location and genotype × location × year interactions. Using method of simultaneous selection for yield and stability (YS) revealed that genotype 3 (C-85-3) and 8 (C-85-8) with YS=13 were the most superior genotypes. Genotype 5 (C-85-5) had the lowest grain yield and its YS was -8 which selected as the least stable genotype. Based on AMMI analysis, genotype 9, 13, 18 and 8 were more stable than the others and had general adaptability. AMMI was able to categorize the environments into different groups, so that in each environment genotype (s) with specific adaptability can be determined. Results of contribution of pre-anthesis assimilate to grain (CPAAG) showed that genotype 17, 5, 8, 18 and 3 had the highest remobilization among the genotypes. Correlation coefficients between the traits showed that correlation of grain yield with biomass weight at anthesis and maturity, spike weight at maturity and grain number per spike were significantly positive, however, correlation between grain with CPAAG was significantly negative.

Zink deficiency in calcareous soils of arid and semi-arid regions is a limiting factor for crop yield. Bean is considered as one of sensitive plants to zinc (Zn) deficiency. To study the responses of various bean genotypes to soil zinc deficiency, a greenhouse experiment was carried out. A factorial completely randomized design with three replications was conducted. The first factor was two levels of Zn (0 and 10 mg Zn kg-1 soil) and the second factor was 12 genotypes of beans. Zn uptake was found to be significantly correlated with Zn level, however, zinc concentrations of both old and young plant portions had lower correlation. Therefore, zinc uptake is a suitable characteristic to identify zinc efficient genotypes compared to Zn concentration. Adequate Zn supply in studied genotypes enhanced shoot dry matter production of bean genotypes compared to plants cultivated under low Zn condition. Under low Zn condition, dry matter production of young part of shoot was lower in the Zn inefficient genotypes, but in the old portion of the shoot exhibited higher dry matter. In addition, compared to efficient genotypes, responses of inefficient bean genotypes were higher to zinc application.

A study was conducted to investigate the genetic variance components and the combinig ability of sunflowers lines at the Seed and Plant Improvement Institute, Karaj, IRAN in 2006. A total of 41 genotypes including 2 CMS, 13 restorer and their 26 corresponding hybrids were evaluated in a line × tester approach. The analysis of variance indicated that significant differences existed among genotypes for all of the studied traits except the days from sowing to emergence. The significance of the parents vs crosses variance indicated the presence of heterosis for days to maturity, diameter of head, grain yield and oil yield. The effect of parents was significant for most of the traits except for number of leaves, grain and oil yield. The effect of lines was significant for days to 5%, 50% and 75% flowering, days to maturity, number of leaves, length and width of leaf, plant height and grain yield. The testers effect was significant for plant height, grain yield, 1000 ‎grain weight and oil content. The effect of line × testers was significant only for 1000 ‎grain weight and days to 5% flowering. Based on general and specific combining abilities, CMS19 (tester) and CMSB × R7 were the best line and hybrid, respectively. The additive genetic effect was important in controling grain yield while dominance gene effect was important in controling 1000 grain weight and oil yield.

The objective of this experiment was to investigate inheritance and gene action for resistance to sunn pest (Eurygaster integriceps) and related traits in bread wheat including F1, F2 and backcross generations derived from a cross between line 15 as resistance and line 12 as susceptible parents. Parents along with F1, F2, BC1 and BC2 generations were evaluated in a randomized complete block design (RCBD) with three replications in the field of College of Agriculture and Natural Resources of University of Tehran in Karaj. Results of weighted variance analysis showed significant differences between 6 generations in all traits including weight of damaged seed, weight of total of seed in damaged spikes, weight of 50 damaged seed, weight of damaged spike and damaged seed percentage. Generation mean analysis by joint scale test showed that additive, dominance and epistasis components play a major role in resistance to sunn pest, but dominance component is more important. In damaged seed percentage as the most important trait to resistance, additive (d), dominance (h), and dominance×dominance (l) components were more important than other components. For damaged seed percentage, broad heritability and narrow heritability were relatively low and high, respectively. This result showed the more important role of dominance component.

Pinto bean is a susceptible plant to drought stress. However, there is genotype variation for this trait in this plant. In order to investigate the effects of drought stress on physiological traits and grain yield of pinto bean genotypes cultivated in Zanjan province, an experiment was conducted as spilt plot based on a completely randomized block design with four replications at Zanjan university research farm. Irrigation levels (control and drought stress) and genotypes (Talash, G14088, Khomein and COS16) were set in the main and subplot, respectively. Results indicated that COS16 showed maximum photosynthesis rate, cell membrane stability and relative water content under drought stress. Also, COS16 genotype exhibited the least reduction for photosynthesis rate and relative water content reduction under drought stress in comparison to control. In addition, this cultivar had maximum seed yield and minimum seed yield reduction under drought stress in comparison to control. Thus, it seems that under drought stress, cultivars with stable cell membrane will produce higher seed yield because of higher photosynthesis rate.

Plant breeders use rye (Secale cereale L.) as a foreign genetical resource tool in increasing wheat genetical variations. 1R chromosome and especially its short arm, 1RS has been introduced into wheat genome frequently. 1RS studies and effective selection is used in cytogenetical, chemicals techniques and DNA markers. Present study was conducted to investigate the presence of rye chromosome segments in some species of Poaceae family using specific pair primer 1RS (RyeR3/F3). For this, genomic DNA of rye, wheat and some species of the genus Aegilops were extracted and polymerase chain reaction performed with TaKaRa Ex TaqTM enzyme. The results of this study showed the expected amplified sequence of the gypsy-like retrotransposons (1451bp length) in rye, bread wheat, Ae. biuncialis, Ae. crassa, Ae. cylindrica, Ae. kotschyi, Ae. speltoides and Ae. taushii samples on agarose gel, and their bands accuracy was confirmed by using the sequencing data. By drawing phylogenetic trees, bread wheat and rye were in a cluster and Ae. crassa, Ae. taushii, Ae. speltoides, Ae. cylindrica and Ae. biuncialis were located in other cluster, and Ae. kotschyi had the most genetic distance from wheat and rye based on the sequence of retrotransposons. These results indicate that this retrotransposon specific sequence is inside of many genomes of the Poaceae family.

In order to study the effect of water deficit stress at different growth stages on yield and seed oil quality of rapeseed cultivars, a field experiment was conducted as split-plot in a randomized complete block design arrangement with three replications in 2009-2010 growing seasons in Abarkouh in Iran. Four levels of irrigation were located in the main plot including, (I1) normal irrigation based on 40 percent accessible water, (I2) irrigation based on 80 percent accessible water from stem elongation stage to maturity, (I3) irrigation based on 80 percent accessible water from flowering stage to maturity, (I4) irrigation based on 80 percent accessible water from seed filling stage to maturity and five rapeseed cultivars including, Hayola 401,Zarfam, Modena, Sarigol and Option 500 were considered as sub plot. The analysis of variance showed that there were significant differences between cultivars and different levels of irrigation for seed yield, oil content, protein content, meal glucosinolate content and fatty acids (P<0.01). In this study, water deficit stress reduced seed yield (I2:¬28%¬, I¬3:26%¬ and I4:10%), oil content (I2:¬5.6%¬, I¬3:6.2%¬ and I4:4.3%)¬, oleic acid¬ (I2:¬1.1%¬, I¬3:0.1%¬ and I4:0.7%) and linolenic acid (I2:¬7.4%¬, I¬3:6.7%¬ and I4:7.5%)¬ and increased protein content (I2:¬0.2%¬, I¬3:1.6%¬ and I4:3%)¬, meal glucosinolate content (I2:¬155%¬, I¬3:109%¬ and I4:171%)¬ and linoleic acid (I2:¬6.3%¬, I¬3:5.4%¬ and I4:5%). Also, cultivar × irrigation effect were significant on meal protein, oleic acid and linolenic acid. The highest meal protein content (50.2%) and linolenic acid (19.4%) was detected in I3 level os Zarfam and the highest oleic acid content (70.7%) was detected for Modena cultivar under control irrigation treatment. The lowest meal glucosinolate content was obtained in Hayola 401 cultivar (19/93 Μmol/g−1). Among the five cultivars, it was shown that Hayola 401 and Zarfam cultivars produced the highest seed yield (3991 and 4006 kg/ha, respectively). Overall, Hayola 401 and Zarfam cultivars were superior due to high seed yield, oil and protein yield. But the superior quality oil (due to low saturated fatty acids (6%)) was detected in Modena and Sarigol cultivars.

Abiotic stress are the main factors causing low growth and yield in crops. Osmotic stress is an important stress and in case of salinity stress is presuming at the first step. There are different experimental and computational methods to study plant response to stress and lead to better understanding of mechanism involved in these conditions and improvement of plant tolerance to stress. Upstream analysis of genes including regulatory sequences can improve our relative knowledge about gene response to stress. To study the scope of adaptation between experimental and computational analysis and also co-regulation and co-expression ability of interested salt-response genes, we analyzed upstream regions of eight salt-response genes TSA,GCS,SOD,Tpis,AtpE,FBA,ps16 and 14-3-3p in rice and examined their expression profiling via semi-quantitative RT-PCR in bread wheat under salt stress. Our results showed two distinct groups of genes according to their expression pattern similarities. In spite of deficiency in regulatory element databases and different analyzer programs, our results showed expective adaptation between the methods.

In order to evaluate efficiency of nitrogen fertilizers consumption in a sugar beet monogerm hybrid variety of Zarghan, a field experiment was conducted in a loamy soil during 2007 in the research farm of Sugar Beet Seed Institute located in Karaj. Five levels of nitrogen fertilizers including 0 (check), 120, 160, 200 and 240 Kg/ha of net nitrogen from urea fertilizer (46 percent of pure nitrogen) and three levels of phosphor including 0 (check), 50 and 100 Kg of P2O5 per hectare from the triple super phosphate were arranged in a factorial experiment (5×3) in a randomized complete block design with four replications. The results showed that the effect of nitrogen application was significant for nitrogen uptake of both top and root parts of sugar beet, and also for nitrogen uptake efficiency of whole crop. However, nitrogen uptake of sugar beet was not affected by phosphor fertilizer and by the interaction of nitrogen × phosphor application. The highest nitrogen uptake by whole crop in this experiment was equal to 447 Kg ha-1 from the treatment of 240 Kg ha-1 nitrogen application. In the check treatment, nitrogen uptake by whole crop was 250 Kg ha-1. In Zarghan sugar beet variety, for one t ha-1 beet root production about 4 Kg nitrogen was used and from the total nitrogen uptake by whole crop, 44% was allocated in the top part and 56% in the storage root of sugar beet. There was no significant difference between the treatments for nitrogen uptake efficiency, whereas nitrogen utilization efficiency for sugar yield in the treatment of N0P0 was 35% greater than that in the treatment of 240 Kg ha-1 nitrogen application. On average, nitrogen utilization efficiency was equal to 40 Kg sugar for each Kg of N uptake by the crop. Thus, for the production of sugar beet close to actual yield potential it is necessary to consider 5 Kg of N for each t of beet root. Consequently, in order to prevent the environmental pollution, improve nitrogen efficiency, and taking into account the best quality and quantity of sugar beet yield, nitrogen application must be recommended based on the soil analysis and expected root yield and quality of sugar beet.

Efficient use of natural and biological cycles such as nitrogen fixation by legumes may stimulate yield of non-legumes crops in an intercropped system. In order to evaluate spring barley (H) and annual alfalfa (M) intercropping, a study was conducted in the research field of University of Tehran (located in karaj) during 2009-2010 growing season. In this research, a randomized complete block design with 4 replications and 14 treatments were used. Treatments include: H1:1M, H2:2M, H4:4M, H6:6M, H6:2M, H4:2M, H2:4M, H2:6M, H100%:20%M, H100%:40%M, H40%:100%M, H20%:100%M and two additional treatments of barley and alfalfa sole intercropping were established. The highest cumulative dry forage yield was achieved from treatment H1:1M (2934 Kg/ha). The maximum forage crude protein (CPf=30.87%), dry matter digestibility (DMDf=76.57%) and silage crude protein (CPs=17.88%) was detected in sole culture of alfalfa. Also, the highest silage dry matter digestibility (DMDs=31.37%) and silage ash (18.73%) belong to H4:2M, H6:2M, respectively. The highest land equivalent ratio (LER=1.232), and relative crowding coefficient (RCC=2.60) was detected for H1:1M mixture. Our results suggested that the best mixture is H1:1M for quantity yield. For achieving better quality, more percentage of alfalfa in mixtures is necessary.