مجله علوم گیاهان زراعی ایران
سال چهل و پنجم شماره 1 (بهار 1393)

A field study was carried out at the Islamic Azad University of Arak in 2010 to find out the effects of salicylic acid and water deficit stress on oil yield and some physiological characteristics of different varieties of sunflower. The experiment was laid out in a factorial split plot based on a randomized complete block design with four replications. Treatments consisted of water stress in three levels (I0:100% of required irrigation water (control)، I1:80% of the amount of irrigation water requirement، I2 = 60 % of the amount of irrigation water requirement] in the main plots، and different varieties of sunflower at three levels V1: Azargol، V2: Allstar and V3: Ariflor) and two levels of salicylic acid (SA0: no salicylic acid and SA1: salicylic acid (sprayed)) in a factorial combination in sub-plots. The results showed that the different levels of water stress and different varieties of sunflower had significant effects (P<0. 01) on traits such as: grain yield، test weight، harvest index، relative water content، water saturation deficit and rate of water loss. In addition، application of salicylic acid had significant effect (P<0. 01) on all measured traits except grain yield. The present study indicated that the Alstar variety exhibited the maximum yield of sunflower oil with an average of 1278 kg ha-1. The application of salicylic acid also resulted in 5. 33% higher oil yield in comparison with treatment of no salicylic acid.

In recent years، rye caused heavy damages in wheat farms in Iran. In order to evaluate wheat competitiveness ability against rye، an experiment was conducted in replacement series design. Field experiment was carried out at the Agricultural and Natural Resources Research Station in Miandoab during 2009-2010 (for 2 years). The experimental design was a randomized complete block design with 3 replacements. In this study، treatments include pure wheat sowing and rye replacement by 10% upto pure rye sowing. The result showed that rye replacement decreased wheat yield. Relative density coefficient (RCC) and total relative yield (RYT) was <1، indicating the negative effects of these two plants on each other. The results showed that when rye is the main crop and wheat is the volunteer crop، wheat will damage rye when its density is over 45 plants per m2. However، when wheat is the main crop، the negative role of rye was detected by its density under 45 plants per m2. Therefore، the result showed that rye had better competitive ability than wheat. The planting of these two crops was not recommended because it seems these two had antagonistic effect on each other.

Chickpea fall planting may increase seed yield in comparison with spring planting due to the increased duration of growing period and increased water use efficiency. The most important problem with fall planting is the danger of occurrence of plant death and decreased seed yield quantitatively and qualitatively due to the cold stress. The major strategy in breeding program is development of genotype (s) which is tolerance to cold stress. To achieve that، having genetic variability is necessary. Therefore، the present study was conducted to evaluate morphological variations of 28 Iranian black chickpea (Cicer arietinum L.) genotypes under field conditions in a Randomized Complete Block Design (RCBD) with three replications in fall and spring planting. Traits under study include morphological and phenological traits before harvest and seed yield and its components after harvest. Results of analysis of variance showed significant differences among genotypes and genotype × season interaction for most traits which is an indication of their diversity and different responses of genotypes in both planting seasons. There was a positive significant correlation between seed yield and pods per plant in two seasons. In spring planting، days to 50% flowering with seed yield and pods per plant and also in fall planting، seeds per pod with 100-seed weight showed negative significant correlations. The results of path analysis which was done on the basis of the highest correlations of traits with seed yield، pods per plant had the highest positive direct effect on seed yield in both planting seasons. The indirect effect of this trait through the number of second branches and days to 50% flowering was substantial in both plantings، respectively. These findings showed that in both growing seasons especially in fall planting، pods per plant had the maximum effect on plant growth and seed yield. Thus field studies on genotypes and pods per plant may be used along with physiological and molecular researches to evaluate cold tolerance in black chickpea. The existence of better local genotypes than check varieties supports the efforts on conservation and utilization of landraces in chickpea breeding programs.

Controlled environment may be adopted for a rapid multiplication of a large number of potato seed tubers. The controlled environment prevents seed tuber degeneration which may occur under field conditions. The objective of this study was to introduce new mini-tuber production system with high multiplication rate and low production cost. To evaluate the performance of culture systems in terms of tuberization، a split plot experiment based on a randomized complete block design with 4 replications was used. The main and subplots included culture systems (peat-moss and sand culture) and cultivars (Agria and Sante)، respectively. The results showed that the establishment of plantlets in sand culture was higher than in the traditional system (peat culture). The number of tubers per unit area and per plant in sand culture was increased by 70% and 44%، respectively. Specific gravity of tubers was decreased significantly in the hydroponic sand culture. Tuber germination in all three grades، total nitrogen content and percentage of crude protein of harvested tubers was not affected by culture systems and cultivars. Therefore، hydroponic sand culture due to low initial cost of growth media and high multiplication rate can be recommended as a relatively inexpensive method in potato mini-tuber production.

To study general and specific combining ability of some rice varieties for grain physical properties and milling quality، a diallel design with five parents (Hashemi، Vandana، Kadous، Shahpasand and IR36) was used. Parents and their F1 progenies (25 genotypes) were grown in a randomized complete blocks design with three replications in the Research Field of Rice Research Institute of Iran (RRII)، Rasht، Iran، during 2012، and nine different characteristics were recorded. Analysis of variance showed that there were significant differences among genotypes and also general and specific combining ability for all of studied traits، showing the role of additive and non-additive gene effects. Furthermore، the effects of reverse crosses for all studied traits except، degree of grains whiteness، were significant which indicated the role of maternal effects. The significance of MSGCA/MSSCA ratio، Baker ratio (genetic ratio) near to one and high narrow-sense heritability for physical characteristics showed that the additive gene effects controlling these traits were important than the non-additive gene effects، while non-significance of MSGCA/MSSCA ratio، Baker ratio (genetic ratio) less than one and low heritability for milling characteristics showed the role of non-additive gene effects. Results from graphical analysis based on Hayman method showed that all physical characteristics related to grain quality were controlled by partial dominance effect، while all milling properties were controlled by complete dominance to over dominance gene effect. The results of this research showed that the selection of elite progenies is suitable method to improve the physical characteristics in studied population، while hybrid production method will be suitable to improve milling quality in this population.

Application of biofertilizers is a crucial technique for reducing catastrophic effects of irregular utilization of chemical fertilizers. This experiment was carried out to evaluate the effects of Rhizobium strains and plant growth promoting Rhizobacteria (PGPR) on dry matter partitioning and some growth parameters of chickpea (Cicer arientinum L.)، Arman cultivar. This research was conducted as a split plot based on a randomized complete block design at Zanjan university research farm. Irrigation levels (optimum irrigation during season growth and no irrigation during growth period) were set as main plots and fertilizer level (control or no application chemical and biological fertilizer، seed inoculation with Mesorhizobium ciceri strain of SWRI-3، seed inoculation with Mesorhizobium ciceri strain SWRI-17، seed inoculation with PGPR،Co-inoculation with rhizobium strains SWRI-3+SWRI-17 and Co-inoculation with all biofertilizer، PGPR+SWRI-3+SWRI-17) were sets as subplots. In this experiment، drought stress caused significance reduction of relative water content، net photosynthesis rate، stomatal conductance، chlorophyll content and grain yield. Also، relative water content، net photosynthesis rate، stomatal conductance and grain yield was the highest rate at co-inoculation with rhizobium and PGPR (PGPR+SWRI-3+SWRI-17) treatment. Therefore، our findings emphasis that، co-inoculation of chickpea seeds with rhizobum strains and PGPR resulted better water relations and photosynthesis rate and finally more grain yield in comparison to traditional application of chemical fertilizers.

To study the effect of biofertilizers and manure on yield and yield components of barley (Hordeum vulgare) an experiment was conducted at Research Farm of University of Zabol، Iran in 2012 cropping season. Experimental treatments were arranged in a factorial design based on a randomized complete block design with three replications. Treatments were three manure levels (control، 20 ton/h-1، 30 ton/h-1) and four levels of biofertilizers (control، Azospirillum، Azotobacter and Azospyrilium+Azotobacter). Results indicated that manure levels had a significant effect on plant height، spike length، number of seed in spike and number of spike in plant. Biofertilizers caused significant differences in all measured traits expect for harvest index. The interaction effects showed that integrated application of manure and biofertilizers were more effective on barley growth. The highest economical yield (2. 6 ton/h-1) was detected in 20 ton/h-1manure + Azospirillum and Azotobacter application. Integrated application of manure and biofertilizers could significantly increase seed yield and yield components of barley.

Identification of quantitative trait loci is one of the important issues in breeding program especially under stress condition. Plant material in the present study was a natural population including 72 tobacco genotypes. In order to apply osmotic stress، Mannitol with 0. 33 Molar concentrations was used. The genotyping of individual were performed using 21 out of 35 primer combinations of AFLP markers. After measuring of eight traits including total dry weight، dry weight of shoot، dry weight of leaves، length of highest root، total dry weight of root، length of longest leaf، length of longest stem and dry weight of root to dry weight of shoot ratio، in order to perform association analysis and identify linked markers controlling loci five statistical models were used by TASSEL software. These models were GLM and MLM using data set of phenotype and genotype data، population structure data (Q)، principle components (PC) and Kinship data derived from general similarity in genetic background arising from shared kinship (K). For all eight traits common in all models and the markers with explanation of the most phenotype variations were identified and discussed. For plant total dry weight E110-M160-3، for root dry weight E080-M150-4 and for dry weight of shoot E080-M140-23 with the highest coefficient of determination (19. 9، 23 and 14. 9% respectively) were identified as the most important markers. In total، the numbers of identified markers by GLM were more than MLM model. Considering the results، it will be expected that detected AFLP markers in the present study can be used in marker assisted selection programs after confirmation and specification being specified with high confidence.

West part of Iran is considered as one of the center of diversity for Aegilops triunsialis، therefore، study of its genetic diversity in this area is extremely important regarding evolution of this plant. The genetic variation among 40 accessions of Ae. triunsialis collected from west of Iran were studied using 12 ISSR markers. DNA was extracted، concentrations adjusted and five samples from each accession were bulked. Totally، 118 polymorphic bands were produced using 12 primers that UBC817 primer with 16 and then UBC811 and UBC823 with 14 bands had the maximum number، while UBC825 with 4 bands had minimum polymorphic bands. The PIC value varied from 0. 23 to 0. 40 and the MI value between 1. 1 and 4. 6. Principal Coordinates Analysis showed that the first two could explain the total variation of 23. 72 percent. Cluster analysis using Neighbor Joining، placed the 40 accessions in three clusters that each contain 13، 9، and 18 members، respectively. Discriminate Function via Fisher''s linear confirmed the validity of clustering analysis result (95%).

In order to evaluate and drought tolerance selection in cowpea genotypes and to identify the best indices for drought tolerance، an experiment was conducted at research field University of Tehran in Karaj during 2011-2012 growing season. In this study، 31 cowpea genotypes were evaluated in a randomized complete block design (RCBD) with three replications under normal irrigation (non- stress) and drought stress (non- irrigation from flowering stage until the end of the growing season) conditions. Genotypes were evaluated by indicators of drought tolerance including mean productivity (MP)، geometric mean productivity (GMP)، stress tolerance index (STI)، stress susceptibility index (SSI)، tolerance index (TOL) and yield stability index (YSI). Based on correlation with the yield under stress and non-stress condition، four indices MP، GMP، HARM، and STI were selected as the best indicators for selection of tolerant genotypes. Biplot pattern revealed genotypes No. 6، 10 and 23 as tolerant genotypes and 28، 3، 9، 14، 26، 17، 20، 30، 27 and 12 as drought-sensitive genotype.

In order to examine the effects of silver، zinc، nickel، zinc- copper nanoparticles on germination، seedling establishment، and enzyme activity of alfalfa seeds، a factorial experimental was conducted in a randomized complete design with three replications in the Seed Laboratory، College of Agriculture and Natural Resources، University of Tehran in Karaj. The objective of this study was to determine the potential impact of nanoparticles on alfalfa seed and its tolerance threshold to various nanoparticles. According to the results، maximum reductions were observed in the germination rate and shoot length under 40 mg per liter of zinc-copper and silver treatment. In the growth chamber conditions، only germination rate index was significant at 1% level and 80 mg per liter of Zn-Cu indicated as the lowest treatment. Catalase enzyme in alfalfa plants that treated with nanoparticle levels was significant at 5%، but no significant difference between the control and treated seedling with nanoparticle was detected for superoxide dismutase and ascorbate peroxidase activity. Among the all nanoparticles، the only nanoparticle that absorbed in seedling was Ni under 40mg/l treatment. Based on the results، by comparing laboratory and growth chamber experiments، reduction of nanoparticle injury was observed in the growth chamber experiments that can be related to the kind of media substrate.

Despite the importance of drought stress in early stage of growth and plant establishment، it has usually been neglected as selection criteria in breeding programs. Therefore، a population of recombinant inbred line derived from the cross “Babax/Seri M82” and their two parents were studied. The experiment was conducted in two randomized complete block designs with two replications under osmotic (-8 MPa) and non-osmotic stress conditions in 2012. Germination percentage، promptness index، shoot and root length and their proportion، shoot and root fresh weight، shoot and root dry weight، number of root، seed vigor، water soluble carbohydrate، relative water content and germination stress index were measured. QTL analysis was conducted by composite interval mapping method separately for each trait under each condition and mean of two conditions. A molecular genetic linkage map including 249 AFLP، 74 SSR and 264 DArT markers was used for QTL analysis. Based on combined analysis of variance، the main effect of genotype was highly significant for all studied traits and transgressive segregation in both directions (positive and negative) was observed. Thirty four QTLs were found for the studied traits. Phenotypic variation that were explained by these QTLs، varied from 15. 86-28. 81%. The highest and the lowest phenotypic variations were related to RWC and GSI. QTL of 25. 20 cM location of chromosome 1B، controlling RWC، was quite stable، therefore، may be used in marker assisted selection. MAS for RWC may enhance the plants'' ability to maintain the growth of them in drought-prone soils at the critical early developmental stages.

Chickpea is commonly grown in large scales in the western part of Iran (Kermanshah، Hamedan، Lorestan and Chahar Mahal & Bakhtiari) and it forms a symbiotic relationship with rhizobia which promotes legumes growth through nitrogenfixation. Therefore، it is important to evaluate the population genetic structure of rhizobia nodulating chickpea in various areas to manage extension of chickpea cultivation. In this study، the characterization of chickpea nodulating rhizobia was carried out by PCR-RFLP analysis and nucleotide sequence determination of 16S rDNA region in addition to tracking and sequencing of nodC and nifH genes، which directly affected on Rhizobium- legume symbiosis. The results indicated that the diversity of rhizobia isolated from chickpeas in different sites is limited and they mainly belonged to Mesorhizobium cicer. Few strains of Agrobacrium tumefaciens were isolated from root nodules of chickpea growing in Lorestan soils indicating the absence of nodC and nifH genes in these isolates raising doubt about their nitrogen fixation capability. It seems that the long history of chickpea cultivation in western provinces and the specific relationship of chickpea with its symbionats are the main factors in predominance of M. cicer and absence of other Misorhizobium sp. in symbiosis with chickpea in Iran.

To assess the radiation use efficiency (RUE) of different rice cultivars under transplanting (TP) and direct-sowing (DS) systems and scrutiny of weed effect، a split-plot factorial experiment was conducted based on a randomized complete block design with three replications in 2011 at Haraz Extension and Technology Development Center in Mahmoudabad city، Mazandaran. The main plots were two planting systems (TP and DS) and subplots were factorial combinations of three rice cultivars under weed infested and weed free conditions. The results showed that RUE and grain yield of rice cultivars significantly reduced in weed infested plots especially in DS system. The average RUE of line 843، Khazar and Tarom in weed-free conditions were 3. 18، 3. 22 and 2. 69 g MJ-1، respectively، while it reduced to 3. 08، 2. 57 and 2. 35 g MJ-1، respectively، under weedy conditions. The differences of yields were mainly due to differences in biomass and harvest index، and were not associated with RUE. Light extinction coefficient (K) of line 843، Khazar and Tarom were 0. 44، 0. 45 and 0. 71، respectively. Under high weed interference (as seen under DS method)، Tarom could better suppress weeds and had lower yield loss due to its taller plant height and greater K. Under no or low weed interference (as seen under TP method)، line 843 was ranked higher in terms of final yield due to its smaller K، greater leaf area and higher harvest index.

In this study the effect of salt stress on banding patterns of superoxide dismutase (SOD)، catalase (CAT) and peroxidase (POX) in 18 genotypes of white common bean (Phaseolus vulgaris L.) were examined under two levels of NaCl)0 and 400 mM) stress. For each isozymic band the “density × area” scores on gels were evaluated by MCID software and considered as enzymatic activity. Three isozymes were observed for SOD، one for CAT and three for POX. According to analysis of variance the difference between genotypes and between salinity levels were significant (P≤0. 001) for all isozymes except for POX2. The genotype by salinity interaction for SOD1، SOD2 and POX3 were significant (P≤0. 001). According to mean comparisons in common bean genotypes، SOD3 showed the most activity increment in first، third and fifth genotypes، CAT in eight، ninth and eighteenth genotypes، and POX1 in sixth، seventh and tenth genotypes. Genotype by salinity interaction analysis showed that the most increment activity of SOD1were observed in seventh، eighth، ninth، and twelfth genotypes، SOD2 in fourth، seventh، eighth، ninth، and thirteenth genotypes and POX3 in first، second and fourth genotypes under salt stress. Correlation estimates between antioxidant isozymes in normal، salt stressed condition and total (both normal and salt stressed conditions) showed only one positive and significant correlation between CAT and POX3 under salt stressed condition. Finally the results indicated that salt stress increased activities of all studied antioxidant enzymes.