Cereal Research
Year:2018 | Volume:8 | Issue:1|Papers Count:10

The development of mechanization in the rice production process can play an important role in overcoming the difficulties of producing this product, climate and agricultural constraints. Improving farmer’ s income status, increasing production and positive welfare effects on the rice market are important results of mechanization and paddy mechanized cultivation. In recent years, the number of agricultural machinery active in rice cultivation in the 16 cities of Guilan province has increased significantly. The present study use Granger-causal analysis and panel data series of 16 cities for 16 years from 2011 to 2016, following the evaluation of the stimulus of the number of active machines including tractors, two wheel tractor, transplanting machine, mower machine, threshing machine for two wheel tractors, threshing machine for tractors, cultivation machine and combine harvester on paddy production in different cities of Guilan province, Iran. The results showed that the number of different investigated machines were Granger cause of paddy production in Guilan province. The greatest influence of the types of machines studied on the amount of paddy production belongs to threshing machine for tractors and the least impact on the volume of production of this product belongs to the number of cultivation machine. Considering the severity of the impact of various types of agricultural machinery on the amount of rice production in the cities of Guilan province could provide a suitable framework for planning and prioritizing the development of mechanization in rice cultivation.

Salinity stress is the second major problem and limiting the rice production after drought. To investigate the effects of salinity stress on some important morphological and physiological characteristics of rice, 41 mutant lines from radiation of gama ray to four rice varieties (two Iranian local varieties, Hashemi and Tarom and two improved varieties, Khazar and Fajr) along with parental varieties and two control lines, FL478 (tolerant to salinity) and Teqing (sensitive to salinity) were studied under three salinity conditions (control, 6 and 12 dS. m-1). The experiment was carried out in factorial experiment based on completely randomized design with six replications. The variation among genotypes were also studied using twelve microsatellite (SSR) markers linked to SalTol, a major salinity tolerant QTL. The results of analysis of variance showed significant and considerable differences among the genotypes for all studied traits. The results of cluster analysis of morphological data grouped the studied genotypes into three clusters so that M1, M3, M7, M9, M35, M37 and M40 mutant lines together with the salinity tolerant line FL478 grouped into one cluster, while Hashemi and Fajr varieties and M47, M48, M49 and M56 mutant lines along with the salinity sensitive line Teqqing grouped into a similar cluster. The cluster analysis of molecular data also divided the studied genotypes into three main groups. Accordingly, the mutant lines M35, M37 and M40 together with the control variety FL478 were grouped as salinity tolerant and the mutant lines M36, M47, M48, M49, M54 and M56 together with the control variety Teqing as salinity sensitive genotypes. The Mantel test showed a high similarity of about 65% between two cluster analyses which was due to the use of tigh linked SSR markers to the SalTol, each of them were linked to the several traits studied in this research. As mentioned above, all three salinity tolerant lines identified in the molecular data analysis were also identified in cluster analysis of morphological traits and all four salinity sensitive lines identified in the morphological data analysis were also identified in molecular data analysis. Evaluating the microsatellite markers also showed that the AP3206, RM5, RM3412, RM140 markers were the most suitable and informative markers to assess the genetic variation of salinity tolarance in this research.

The basis of monitoring drought in every region is reviewing the specifications of the occurred drought. In recent years, cutting the distributaries of Sepidrood river due to construction of several dams on the upstream has increased the effect of rainfalls in the province on sustainability of rice fields of Guilan province. This study is aimed at investigating the climate-related drought and studying the characteristics of this phenomenon in Guilan province and the difference between the severities of climate-related drought in different price fields of the region over a 35-year period. For this purpose, standardized precipitation index (SPI) was used. The precipitation data of thirty rain-gauge stations regarding the standardized precipitation in two periods, crop season and whole year periods, related to four regions including the central district of Guilan, east of Guilan, Foumanat, and west of Guilan were investigated. The results showed that a great area of the province has been involved in drought in the crop period in 2013, 2008, 1999, and 2014. The highest severity of drought in the crop period drought was related to Foumanat region during the water year 2007-2008 with a SPI value of-2. 06. The evaluated value of this index in the crop period relative to its value during the whole year showed that in all of the four regions, severity of the drought in the crop period was more than its severity in the year period, and the frequency of drought occurrence in the crop period was over two times more than the year period. Also, calculation of SPI index in the crop period shows a more accurate performance than the 12-month period during which a significant part of the precipitation potential is wasted and lost from the agricultural system of the Guilan province.

Water resources shortage threatens the sustainability of continuous flooding rice culture. To investigate the effect of initial flooding duration on herbicide efficacy and rice yield loss, a field experiment was conducted at Rice Research Institute of Iran, Rasht, Iran, in 2015. The experiment was arranged in a factorial arrangement based on randomized complete block design with three replications. The experimental factors were two rice cultivars (Hashemi and Gilaneh) and five initial flooding durations (flooding for 2, 4, 6, 8 and 12 weeks after transplanting and then applying intermittent irrigation). Consistent with the paddy fields irrigation method in northern Iran, 12-week flooding duration was considered as continuous flooding irrigation. Results showed that there was no significant difference in herbicide efficacy between Hashemi (87. 9%) and Gilaneh (85. 6%) cultivars. No significant reduction in herbicide efficacy was observed when initial flooding duration reduced from 12 to 6 weeks, but with further reduction in initial flooding duration to four and two weeks, herbicide efficacy was significantly reduced. The highest paddy yield (3989. 2 kg. ha-1) was observed in permanent flooding (flooding for 12 weeks) + herbicide application treatment and the paddy yield was decreased about 10% by reducing the initial flooding duration to six weeks but it was not statistically significant. With further decrease in initial flooding duration to four and two weeks, rice paddy yield reduced significantly by 16% and 31%, respectively. In conclusion, results of this experiment revealed that under water shortage conditions, it is necessary to apply initial flooding duration at least for 6 weeks after transplanting for obtaining favorable herbicide efficacy (more than 90%) without paddy yield loss compared to permanent flooding treatment.

Drought is the main abiotic stress seriously influencing wheat production and quality in Iran. Information about genetic controlling drought tolerance inheritance is necessary to determine the type of breeding program as well as develop tolerant cultivars. In this study, Bayesian inference using LASSO method used to identify the most important gene effects related to drought tolerance in context generation mean analysis. For this purpose, field experiments consist of two pairs of crosses with nontolerant and tolerant cultivars and generations derived from them were carried out across two years as split plot designs based on RCBD with three replications in which main plots assigned to irrigation treatment consist of two levels (well watered and cessation of irrigation at pollination stage) and subplots given to the generations. Bayesian inference is an alternative approach which combines available prior knowledge (prior distribution) with the information contained in the data. The result is the posterior distribution containing all information to interpret genetic structure. LASSO is an effective method to apply shrinkage and selection on model variables. Non-important effects in the model shrunk toward zero and excluded from the model. While for important effects, less shrinkage will be achieved. Since the additive, dominance and epistatic gene actions involved in drought tolerance inheritance, methods which utilize all type of gene effects, like recurrent selection followed by pedigree method may be useful for drought tolerance stress improvement.

Determining adaptability and stability of crop varieties is one of the most important stages in plant breeding programs, which it is costly and is not easy to do due to genotype × environment (G×E) interaction effects. To study G×E interaction for grain yield in durum wheat, an experiment with 16 durum wheat genotypes was carried out in a randomized complete block design with three replications under rainfed and supplemental irrigation conditions at research field of Dryland Agricultural Research Sub-Institute (Sararood Station), Kermanshsh, Iran, during three growing seasons (2011-14). The GGE (G + G×E) biplot was applied to study G×E interaction. Combined analysis of variance showed significant differences (P<0. 01) between genotypes, environments and G×E interaction effects. The G×E interaction variance was greater about two times than genotypic variance, indicating the possibility of existing environmental groups for genotype adaptation. The GGE biplot analysis indicated that the environments were classified into three mega-environments with winning genotypes. Biplot analyses identified the breeding line G13 (2169 kg. ha-1) as the best genotype with high yielding and stability performance. The breeding lines G3 and G15 with 1960 and 3041 kg. ha-1, respectively, had the highest mean yield under rainfed and supplemental irrigation conditions, indicating the superiority of these two lines than the check cultivar in the both rainfed and supplemental irrigation conditions. In conclusion, positive increase in yield and yield stability is attributable predominately to genetic improvement in durum wheat breeding lines under variable environments.

Polyamines are oxidatively deaminated by amine oxidases (AOs), including copper amine oxidases (CuAOs) and FAD-dependent polyamine oxidases (PAOs). PAOs are associated with polyamine catabolism in peroxisome, apoplast and cytoplasm. In plants, increasing evidences support that PAO genes play an essential roles in growth and developmental processes such as organogenesis, senescence, and also responses to abiotic and biotic stresses. The availability of the maize genome sequences has provided an excellent opportunity for whole-genome annotation, classification and comparative genomics research. In this study, through bioinformatics analysis approaches, nine putative PAO (ZmPAO1– ZmPAO9) were identified in maize genome. According to Phylogenetic analysis ZmPAOs can be divided into three major groups as found in their orthologous in Arabidopsis and rice. It is also demonstrated that maize PAO proteins are more closely related to rice than those in Arabidopsis. Gene structural analysis showed that the ZmPAOs have zero to nine introns and they are distributed across 4 out of 10 chromosomes in maize. Duplication pattern analysis shows that segmental and tandem duplication are the main reasons for maize PAOs expansion. Using public microarray data, the roles of ZmPAOs in growth and development processes were assessed. These results have been provided evidences regarding the important functions of the gene family in maize developmental regulation. These results provide a basis for further functional characterization of ZmPAOs at the tissue/developmental level and in response to stresses. Using public microarray data, ZmPAO expression profiles strongly suggested that ZmPAOs have a role in growth and development processes.

Maize (Zea mays L. ) as a model plant is important from agricultural, feed and industrial point view. Most of economically important traits and morphological traits are controlled by several genes and also influenced by environment effects and hence possessed complicated genetic control. This research was aimed to study the genetic control and identification of genomic regions controlling agro-morphological traits in maize germplasm using association analysis approach. Maize inbred lines were evaluated based on morphological and 16 ISSR primers. Results of morphological and genetically evaluations trials revealed existence of genetic variability in the studied germplasm which is mandatory item for successful association analysis study. Analysis of population structure using 81 ISSR loci divided the population into 2 sub-populations. Among studied lines, lines 1387/193/chase (Mashhad population) and 66*1388 (Mashhad population) showed maximum genetic admixture. Association analysis using MLM model represented 25 ISSR loci which possessed significant relation with studied traits. Positive markers identified in this research, could effectively applied in marker assisted selection programs to achieve suitable parental lines and also improvement of trait of interest. Also, this is resulted that inter simple sequence regions have acceptable ability and performance in association mapping of maize.

Selecting quantitative characteristics, division of their expression ranges and selecting the check varieties are key issues on preparation of DUS test guidelines, so that based on these characteristics can evaluate three conditions of a new variety; distinctness, uniformity and stability (DUS). To prepare national DUS test guidelines in maize (Zea mays L. ), a randomized complete block design was conducted with three replications and 28 varieties and lines at Seed and Plant Certification and Registration Institute (SPCRI), Karaj, Iran, during 2014 and 2015. First, a total of 49 qualitative and quantitative morphological and phenological characteristics proposed by international union for the protection of new varieties of plants (UPOV), community plant variety office (CPVO), India (PPV&FRA) and Philippines (PVPO), were selected and evaluated. Then, ten quantitative characteristics based on within-variety uniformity by using coefficient of variation, correlation among characteristics, heritability, stability in two years and principal component analysis, were selected for the national DUS test guidelines. The expression ranges of these ten selected quantitative characteristics were divided into different situations using the descriptive statistics and frequency distribution of the varieties. The plant height with two peaks in the frequency distribution chart of the varieties was categorized as grouping characteristic, while other nine selected quantitative characteristics had only one peak and were selected as standard characteristics. Finally, KSC704 hybrid and two maternal lines Fajr and Mobin were determined as the check varieties for plant height using box plot. It is also proposed to use this method as an efficient method for preparing DUS guidelines for other plant genera.

To agroecological zoning of current agricultural lands in Gorgan township and determination of the suitable planting date for hull-less barley cultivation, a research was carried out in the spatial and temporal steps. In the first step, geographic information system (GIS) and analytical hierarchy process (AHP) were applied to agro-ecological zoning of agricultural lands in Gorgan township for hull-less barley cultivation. The results showed that extend areas of Gorgan agricultural lands are suitable for hull-less barley production. So, about 20, 899. 35 ha (32. 64 percent) of agricultural lands were located in the high suitable class (S1) and 25, 759. 13 ha (40. 24 percent) in suitable zone (S2). The high suitablezone (S1)was observed in the northwesternparts toward central and northeast regions of this township. Also, about 17, 730. 54 ha(27. 17 percent) areas were identified as less suitable (S3) and nonsuitable (NS) zones for hull less barley production. In the second step, a field experiment was conducted with six planting dates (29 October, 12 and 28 November, 12 and 28 December and 11 January) in the randomized complete blocks design with 3 replications at Gorgan University of Agricultural Sciences and Natural Resources, during 2013-2014. Statistical analysis showed that effects of planting dates were significant onall studiedtraits except 1000 grain weight. The first and secondplantingdates (29 October and 12 November) had the highest grain yield, harvest index, biological yield and SPAD. In general, we can be concluded that hull-less barley cultivation in 29 October and 12 November dates in 20, 899. 35 ha of Gorgan agricultural lands with high suitable degree, lead to the highest production of grain yield and biological yield.