فصلنامه تحقیقات غلات
سال هشتم شماره 3 (پاییز 1397)

There is a considerable gap between the amount of water supply and demand in Iran in all sectors, especially in the agricultural sector, as the most commonly water consumer sector. Economic valuation is used as a means for balancing the water supply and demand. In this study, in order to determine the economic value of irrigation water in Guilan province, first farms were divided into two groups based on homogeneity; then, using the production function and the analysis of five flexible and non-flexible functions, the best function was selected by statistical comparisons and finally, the economic value was calculated in each group. The economic value of irrigation water in the first group was calculated with transcendental function being 15218 Rials/m3 and in the second group the generalized Leontief function was calculated to be 17434 Rials/m3. Modifying the present tariff system and reducing the gap between the cost of water and paid water right by the farmers for decreasing water losses in paddy areas and increasing water productivity is an appropriate measure. Establishing local water markets in altering the attitudes of farmers to water is an effective public initiative and brings about the private feature of it.

To study the effect of chemical fertilizer and chicken manure on yield and yield components of rice cv. Hashemi, a field experiment was conducted in randomized complete block design with three replications at Rice Research Institute of Iran (RRII), Rasht, Iran, in 2017. The studied fertilizer treatments were chicken manure (33 t.ha-1), chemical fertilizer (recommended by RRII) and control (no-fertilizer). The studied traits included grain yield, 1000-grain weight, filled grain percentage, number of total tiller per plant, number of fertile tiller, SPAD value, stomatal conductivity and some growth indices. The results indicated that the highest grain yield (3664 kg.ha-1), 1000-grain weight (23.31g), filled grain (96.6 %) and total dry matter (900 g.m-2) were obtained from chemical fertilizer. In contrast, the use of chicken manure produced the highest flag leaf length (40.6 cm) and the highest net assimilation rate (4.6 g.m-2.day-1). Application of chicken manure caused the leaf area index (LAI) to decrease than other treatments. The highest specific leaf area (SLA) was observed in chemical fertilizer. SLA was less in chicken manure at the beginning of the growth period, but over time and reaching next growth stages, it approached to chemical fertilizer. The highest LAI and leaf greenness (SPAD value) obtained from chicken manure application, but the highest stomatal conductivity was observed in chemical fertilizers. According to results of this research, although the application of chemical fertilizers more increased the yield and improved the yield components than chicken manure, but application of chicken manure could be improved the net assimilation rate (NAR), flag leaf length, LAI and SPAD than chemical fertilizer. Probably due to the more greater value of nutrients in chemical fertilizer than chicken manure, the yield produced by chemical fertilizer was higher than chicken manure. In total, according to the harmful environmental effects of chemical fertilizer and the not-significant reduction of grain yield of rice cv. Hashemi in chicken manure treatment, chicken manure instead of chemical fertilizer is recommended.

One of the important objectives in improving rice varieties is improving coocking and eating quality, which plays a key role in it’s marketability and economic value. This research was carried out to indirectly select the high quality linesof a population of F6 generation derived from the cross of Hashemi×Nedarice varieties usingmicrosatellite markers tightly linked to cooking and eating quality traits. In this research, 250 F6 lines in an augmented design together with five prevalent rice varieties as the checks including Neda, Hashemi, Domsiah, Kadus and Ali Kazemi, in a randomized complete block design with three replications were cultivated in two regions, Rice Research Institute of Iran(Rasht, Iran), and ChaparsarRice Station(Mazandaran, Iran),in 2015. Genomic DNA amplification was performedbylinked microsatellite markers tothe genomic regions (genes) controlling rice grain quality traits, includingRM217 and RM225 on chromosome 6, RM234 and RM1364 on chromosome 7 andRM331,RM22804 and RM27181 on chromosome 8.The results of this research showed that among the markers used in current study, the highest accuracy and selection efficiency belonged to the RM331 on chromosome 8 which had the smallest distance with the QTLdetected to amylose content, gel consistency and time to peak viscosity. Afterwards, two SSR markers, RM1364 and RM27181 on chromosomes 7 and 8, respectively, were themost efficient markers.Assessing the genomic intervals among the flanking markers also showed that the flanking markers RM234-RM1364 and RM22804-RM331 were the best marker intervals for the screening of the studied population for the qualitative characteristics.

In arid and semi-arid regions of the world including Iran, soil salinity is one of the major abiotic stresses. One of the ways to achieve high performance in these areas is using salt tolerant varieties. Also, study on relationships between yield and its components will improve the efficiency of a breeding program with appropriate selection criteria. In this study, 110 bread wheat genotypes were evaluated in two conditions (non-stress and saline stress) at the research field of the National Salinity Research Center (NSRC). The salinity of water used in irrigation in saline and non-stress conditions was 10 and 2 dS.m-1 respectively. In this study was used of stress tolerance index (STI) as the best indicators for evaluating of tolerant to salinity stress of bread wheat genotypes. Based on stress tolerance index (STI)and seed yield in non-stress and saline stress conditions, the linesSalt18, Salt19, Salt20, Salt21, Salt22, Salt23, Salt24, Salt25, Salt26, Salt27, Salt28, Salt29, Salt30, and varieties Arg, Bam, Rushan, Sorkhtokhm, BumiYazd, Kavir, Moghan 1, Sardari, Sharyar, Shirazhad had a high yield in the non-stress and saline stress conditions and these genotypes were selected as the most tolerant genotypes to salinity.The highest grain yield under non-stress and saline stress conditions was produced by Salt29 line (178.13 gr) and Salt24 line (164.33 gr), respectively which had more grain yield than control cultivars (Arg, Bam, Rushan, Sorkhtokhm, Bumi Yazd and Karchia). Also, based on the results of sequential path analysis, kernel weight per spike and number of fertile tillers in non-stress conditions and spike weight, number of fertile tillers, days to headingand peduncle weightin saline stress conditions were selected as first order variables.Therefore, it seems that these traits could be used as a suitable criterion in wheat breeding programs for increased seed yield in both non-stress and salinity stress conditions.

To determine yield stability of 16 bread wheat promising lines along with two commercial check cultivars,Chamran and Aflak, were studied in six experimental field stations for two successive cropping seasons (2012-2014). The experiments were conducted using randomized complete block design (RCBD) with four replications. The analysis of variance showed that 80.9, 3.2 and 15.9 percent of total variation were related to the environment (E), genotype (G) and G×E interaction effects, respectively. The results of additive main effects and multiplicative interaction (AMMI) model showed that the first four principal componentsof AMMI were significant and described 78.4% of the variance of G×E interaction. The AMMI1 model analysis indicated that S-91-9, S-91-14, S-91-13 and S-91-15, with an average grain yield higher than total mean, were the most stable lines. Based on AMMI2 model, S-91-13 was the most stable line. The shifted multiplicative model (SHMM), classified the environments in three groups. The first group consisted of Darab (first and second years), Iranshahr (first year), Khorramabad (first and second years) and Dezful (first year), while Dezful (second year), Ahwaz (first and second years), Zabul (second year) and Iranshahr (second year) were classified in the second group andZabul (first year)was only into the third group.The presence of Darab and Khorramabad in the same group indicates the relative similarity of these stations and existence of an additive or non-crossover interaction. Finally, the S-91-13 line with high yield and broad adaptability was selected as superior line for further investigation to introduce the new commercial bread wheat cultivar.

Zn deficiency in the soil reduces plant yield and grain Zn content. The regulation of ZIP (ZRT/IRT-like protein) family genes is one of the main mechanisms of plant to confront to Zn deficiency stress. To investigate the expression of ZIP1, ZIP3 and ZIP6 genes in roots and leaves of Zn-efficient and inefficient wheat cultivars under Zn deficiency conditions, a factorial experiment based on completely randomized design (CRD) with three replications was conducted in greenhouse. Bayat and Niknejad (Zn-efficient) and Hirmand and Karaj 1 (Zn-inefficient) cultivars were grown under Zn deficiency and adequacy conditions and the relative expression of the genes were measured in root and leaf at two growth stages, 28 days after germination (vegetative) and 30% of flowering (reproductive). The results revealed a significant (P≤0.01) increase in expression of all three studied genes in Zn-efficient than -inefficient cultivars under Zn deficiency conditions. The expression of the ZIP1 in root was significantly more than that of leaf in both vegetative and reproductive stages, while ZIP3 and ZIP6 genes were expressed in both root and leaf. A significant (P≤0.05) and positive correlation was observed between ZIP6 expression in leaves and seed grain Zn content at reproductive stage. In conclusion, with regard to the increased expression of ZIP1 in root and ZIP3 and ZIP6 in both root and leaf, it may be resulted that ZIP1 have a major role in Zn uptake from the roots, while ZIP3 and ZIP6 probably involved in Zn uptake and translocation.

A large amount of the world lands under the cultivation of wheat is under drought stress. In cereals, the reproductive stage is the most sensitive phase to drought stress. Despite the importance of drought stress in reproductive stage and its role in wheat yield reduction, the mechanisms involved in it have been less studied. In the present study, the expression of miR166 and miR167 in mature anthers of two tolerant (Dezfoul or D-10) and susceptible (Shiraz) wheat genotypes under drought conditions in reproductive stage was investigated. Stress tolerance index (STI) for grain number per spike, grain set and pollen viability was higher in tolerant genotype, Dezfoul, compared to susceptible genotype, Shiraz. Drought stress induced expression level of both miRNAs in both genotypes. The amount of miR166 increase in the susceptible genotype, Shiraz (over 14 times compared to the non-stress conditions) was about twice more than the tolerant genotype,Dezfoul (about 8 timesmore than the non-stress conditions). Under drought stress conditions, expression of miR167 in Dezfoulgenotype was more than two fold and in Shiraz genotype more than four timeshigher thanthe non-stress conditions. Both miR166 and miR167 regulate development of floral organs such as microspore development. In conclusion, the effect of drought stress on their expression changes can affect male sterility in wheat, and modifying the expression of these two miRNAscan lead to efficiency of pollen development and successful anther dehiscence which is rooted in signal transduction.

To study the effect of plantingdate and method on ear yield, water use efficiency and some phenological characteristics of sweet corn, an experiment was carried out as split plot based on randomize complete blocks design with three replications in research farm of the Faculty of Agriculture, Azad University of Yasouj, Iran, in 2016. The main factor of the experiment included planting date in five levels (4 and 19 May, 4 and 19 June and5 July) and the sub factor wasplanting method in three levels including seed cultivation, 15-day seedling (three leaf stage) and 20-day seedling (four leaf stage) cultivation.The results showed that the effect of planting date and method interaction on ear yield and water use efficiencywas significant. Mean comparison of data indicated that 15-day seedlingcultivatedat May 4th had the highestcanned grain yield (16 t.ha-1) and 20-day seedlingat July 5thhad the lowest ear yield (8.24 t.ha-1). The highest water use efficiency (2.93 kg.m-3) was also obtained from 15-day seedling cultivation at May 4th, which was 66% higher than the 20-day seedling atJuly 5th. The effects of planting date and method on vegetative period and days from planting to harvest were significant. The vegetative period decreased with delay in planting date, so that the highest vegetative growth period was obtained in the planting date of May 4thand the lowest in the July 5th.Also, the duration of vegetative period in the seedling cultivation method was less than the seed cultivation method, so that the seed cultivation with growth period of 87.4 days and 20-day seedling cultivation with77.1 days had the highest and lowest growth period, respectively. In addition, the seedlings cultivation method increased grain sugar content.In total, the results of this research showed that the application of seedling cultivation method can accelerate the maturity of the plant, and therefore, when the plant may be exposed tounfavorable weather conditions, the growth period can be reduced by the application of seedling cultivation.

To investigation the management of winter cover crops on weed control in corn, an experiment was carried out as split-plot in randomized complete block design with three replications at the Agricultural and Natural Resources Research Center of Moghan, Iran, during 2016-2017. Cover plants (wheat + crimson clover mixed culture, wheat single culture and rye + wheat mixed culture) were considered as the main factor and their management methods (removing residues from the soil surface and remaining residues on the soil surface as mulch) as the sub-factor together with a control treatment (without cover plants). The results showed that the lowest total dry weight of weeds was obtained from rye + wheat treatment with mulch management. In general, total dry weight of weeds was reduced by 65% under mulch conditions and 35% under removing residues conditions compared to control treatment. The highest grain yield (4 t.ha-1), biological yield (15.1 t.ha-1), number of rows per ear (14 rows) and number of grains per row (26 grains) was obtained from clover + wheat mixed culture in the management of removing residues. The results showed that dry fodder produced by wheat single culture, rye + wheat mixture and wheat + crimson clover mixture was 1960 kg.ha-1, 1933 kg.ha-1 and 1800 kg.ha-1, respectively. In total, the results of this research indicated that the accurate management of cover plants, in addition to more efficient use of resources and livestock nutrition, can be considered as an important component of the sustainable weed management strategy.

In this research, the genetic analysis of some of the important agronomic traits in a number of barley cultivars was investigated under favorable irrigation (non-stress) and drought stress conditionsusing Griffing’s secondmethod and GGE-biplot. The plant materials consisted of seven barley cultivars (Valfajr, Makuei, Kavir, Reyhan, Gorgan-4, Nosrat and Nimrouz) and 21 hybrids derived from their half diallel crosses that were evaluated using a randomized complete block design with three replications under two favorable irrigation and drought stress conditions in 2015-2016. Genotypic mean squares for all studied traits except for harvest index and plant height undernormal irrigation conditions and harvest index, plant height and awn length under drought stress conditions were significant. Specific combining ability (SCA) was also significant for all traits except for stem diameter and seed length under normal conditions and biological yield, spike length, 100-grain weight and peduncle length under drought stress conditions. GGE biplot graph for grain yield explained 83.1% and 86.5% of total varianceunder favorableirrigation and drought stress conditions, respectively. Evaluating the general combining ability (GCA) of the studied lines under both favorable irrigation and drought stress conditions showed that Nusrat, Valfajr, Kavir, Nimrouz, Makuei, Reyhan and Gorgan-4 lines had the higher GCA, respectively. Assessing the SCA also showed that Nosrat, Reyhan and Gorgan-4 lines under favorable irrigation conditions and Nosrat and Valfajr lines underdrought stress conditions had the higher SCA than the other lines.Also, Valfajr × Nosrat and Kavir × Nosrat hybrids under favorable irrigation conditions and Valfajr × Nimrouz and Kavir × Nosrat hybrids under drought stress conditionswere the best hybrids in this research.