An integrative genetic study of rice metabolism, growth and stochastic variation reveals potential C/N partitioning loci

Studying the genetic basis of variation in plant metabolism has been greatly facilitated by genomic and metabolic profiling advances. In this study, we use metabolomics and growth measurements to map QTL in rice, a major staple crop. Previous rice metabolism studies have largely focused on identifying genes controlling major effect loci. To complement these studies, we conducted a replicated metabolomics analysis on a japonica (Lemont) by indica (Teqing) rice recombinant inbred line population and focused on the genetic variation for primary metabolism. Using independent replicated studies, we show that in contrast to other rice studies, the heritability of primary metabolism is similar to Arabidopsis. The vast majority of metabolic QTLs had small to moderate effects with significant polygenic epistasis. Two metabolomics QTL hotspots had opposing effects on carbon and nitrogen rich metabolites suggesting that they may influence carbon and nitrogen partitioning, with one locus co-localizing with SUSIBA2 (WRKY78). Comparing QTLs for metabolomic and a variety of growth related traits identified few overlaps. Interestingly, the rice population displayed fewer loci controlling stochastic variation for metabolism than was found in Arabidopsis. Thus, it is possible that domestication has differentially impacted stochastic metabolite variation more than average metabolite variation

Evaluation of drought tolerance indices for barley landraces under irrigated and dry conditions

Barley cultivation for drought areas requires reliable assessment of drought tolerance variability among the breeding germplasms. Hence, 121 barley landraces, advanced breeding lines and varieties were evaluated under both moisture non-stress and stress field conditions using a lattice square (11×11) design with two replications for each set of trials. Twelve drought tolerance indices (SSI, TOL, MP, GMP, STI, YI, YSI, HM, SDI, DI, RDI and SSPI) were used based on grain yield under normal (Yp) and drought (Ys) conditions. Analysis of variance showed a significant genetic variation among genotypes for all indices with the exception of TOL and SSPI indices. Yp had a very strong association with Ys (r=0.92**) that indicates high yield potential under non-stress can predict better yield under stress conditions. Yp and Ys were positively and significantly correlated with MP, GMP, STI, YI, HM and DI indices, whereas they were negatively correlated with SSI and SDI. In principal component analysis (PCA), the first PC explained 64% of total variation with Yp, Ys, MP, GMP, STI, YI, HM and DI. The second PC explained 35.6% of the total variation and had positive correlation with SSI, TOL, SDI and SSPI. It can be concluded that MP, GMP, STI, YI, HM and DI indices with the most positive and significant correlation with yield at both non-stress and stress environments would be better indices to screen barley genotypes, although none of the indices could undoubtedly identify high yield genotypes under both conditions

Comparing activated carbon and magnetic activated carbon in removal of linear alkylbenzene sulfonate from aqueous solution by heterogeneous catalytic ozonation process

Activated carbon from pine cone (PCAC) was used as a precursor to prepare Fe3O4/magnetic activated carbon (MPCAC). Here, the removal of linear alkylbenzene sulfonate (LAS) was studied using catalytic ozonation process (COP) in exposure to MPCAC. Subsequently, it was compared with PCAC. Moreover, the effects of solution's initial pH, catalyst dosage, and the time of ozonation on the removal process were comparatively studied in reference to a sole ozonation process (SOP). According to the results of this study, compared with PCAC, degradability could be improved and initial concentration of LAS reduced by COP using MPCAC. Consequently, almost complete removal (>98%) of 25 mg/L of LAS was achieved under the optimum conditions (15 min ozonation time, 7 mg/min ozone flow, 0.3 g/L catalyst dosage and pH=10). Concluding, this nanocomposite is an effective active catalyst for mineralization and degradation of LAS in COP. Keywords:Magnetic activated carbon; Heterogeneous catalytic ozonation process; LAS degradation; Aqueous solutio

Study of Nickel Nanoparticles in Highly Porous Nickel Metal–Organic Framework for Efficient Heterogeneous Catalytic Ozonation of Linear Alkyl Benzene Sulfonate in Water

Metal–organic frameworks (MOFs), as a relatively new class of crystalline porous materials with large surface area and ultrahigh porosity, are extensively used in heterogeneous catalysts. In this study, the efficiency of heterogeneous catalytic ozonation process (COP) with a new nickel nanoparticle-based catalyst in highly porous carbon derived from nickel-MOF was investigated for Linear Alkyl benzene Sulfonate (LAS) degradation in aqueous solutions. LAS is the most frequently consumed anionic detergent and is used mainly in the household detergents such as washing powder, dishwashing liquid, and other household cleaners. Furthermore, if LAS gets in the water, it can produce eutrophication in water resources. In recent years, emphasis has been put on heterogeneous COP, which is principally based on producing the hydroxyl-free radicals. The influence of important parameters including solution pH (4–10), catalyst dosage (0.1–0.3 g/L), and ozone contact time (10–30 min) on the efficiency of COP were examined. The experimental results showed that catalytic ozonation with Ni/NHPC was the most effective at pH 10 with ozone reaction time of 30 min and the catalyst dosage of 0.3 g. Compared to the sole ozonation process (SOP), the removal percentage of LAS were 98.1% and 32.3%, respectively. These findings show that Ni/NHPC acts as an appropriate catalyst derived from nickel-MOF in COP to remove organic pollutants from aqueous solution

Mapping of Gene(s) Controlling Grain Yield and its Components in Bread Wheat Under Rainfed and Supplementary Irrigation Conditions using Molecular Markers

Water deficit stress is one of the most important abiotic stress reducing wheat yield world wise which affect its sustainable production. To map gene(s) controlling drought tolerance related traits in wheat, 142 recombinant inbred lines derived from a cross between Azar2 (drought tolerant) and 87zhong291 (high yielding) was evaluated under rainfed and supplementary irrigation conditions. The measured traits were grain yield, 1000 grain weight and number of spikelet per spike. Parental polymorphism was assessed using SSR and ISSR markers and 24 SSR marker and 16 ISSR polymorphic markers were used for analysis. Linkage analysis was performed to assign these markers to the population linkage map consisted of 45 SSR and AFLP markers. The linkage map span 1310 cM of wheat genome with 19.55 cM distance between two neighboring markers. Based on composite interval mapping, 10 and 18 QTLs were identified for grain yield, under rainfed and supplementary irrigation conditions, respectively. Under rainfed and supplementary irrigation, five and nine QTLs were mapped for number of spikelet per spike. For 1000 grain weight, four QTLs under rainfed condition and nine QTLs under supplementary irrigation were detected. Two and four QTLs detected for grain yield and 1000 grain weight, respectively, were stable under both conditions. For the studied traits, number of common QTLs were identified which could be due to gene linkage or pleiotropic gene effect. The common QTLs for grain yield and number of spikelet per spike (18.26%) as well as for grain yield, number spikelet per spike and 1000 grain weight on linkage group 2 and the common QTL for number spikelet per spike and 1000 grain weight on linkage group 3 with determining more 15% of these trait phenotypic variance were identified as major QTLs. Some of the markers were tightly linked to the QTLs which could be used for selection of drought tolerant lines

High-Density Linkage Mapping of Agronomic Trait QTLs in Wheat under Water Deficit Condition using Genotyping by Sequencing (GBS)

Improvement of grain yield is the ultimate goal for wheat breeding under water-limited environments. In the present study, a high-density linkage map was developed by using genotyping-by-sequencing (GBS) of a recombinant inbred line (RIL) population derived from the cross between Iranian landrace #49 and cultivar Yecora Rojo. The population was evaluated in three locations in Iran during two years under irrigated and water deficit conditions for the agronomic traits grain yield (GY), plant height (PH), spike number per square meter (SM), 1000 kernel weight (TKW), grain number per spike (GNS), spike length (SL), biomass (BIO) and harvest index (HI). A linkage map was constructed using 5831 SNPs assigned to 21 chromosomes, spanning 3642.14 cM of the hexaploid wheat genome with an average marker density of 0.62 (markers/cM). In total, 85 QTLs were identified on 19 chromosomes (all except 5D and 6D) explaining 6.06–19.25% of the traits phenotypic variance. We could identify 20 novel QTLs explaining 8.87–19.18% of phenotypic variance on chromosomes 1A, 1B, 1D, 2B, 3A, 3B, 6A, 6B and 7A. For 35 out of 85 mapped QTLs functionally annotated genes were identified which could be related to a potential role in drought stress

QTLs for root traits at mid-tillering and for root and shoot traits at maturity in a RIL population of spring bread wheat grown under well-watered conditions

Root system traits have positive effects on wheat grain yield, particularly in drought environments. Root traits are difficult to manipulate using conventional selection procedures. Marker-assistedselection (MAS) could be helpful for the improvement of root morphological traits. A recombinant inbred line (RIL) population of 168 lines derived from the cross Iran #49 9 Yecora Rojo was used to map quantitative trait loci (QTLs) for root traits at midtillering stage for one season and for root and shoot traits at plant maturity for two seasons using two different subsets. The RILs were grown in sand-tube experiments in a glasshouse under well-watered conditions. Longest root (LR), total root length longer 30 cm (TRL30), shallow root weight (roots between 0 and 30 cm, SRW), deep root weight (roots bellow 30 cm, DRW), total root biomass (RBio), ratio of root to shoot (RTS) and to plant (RTP) biomass were measured at mid-tillering. At maturity, number of days to booting (DTB), to heading (DTH), to anthesis (DTA), and to maturity (DTM), plant height (PH), flag leaf area (FLA), number of tillers (NTP) and spikes (NSP) per plant, number of grains (NGP), grain weight (GW), grain yield (GY) per plant, LR, SRW, DRW, RBio, PBio, and RTP were measured. At mid-tillering, a total of 18 putative QTLs were detected with individual QTL accounted for between 6.5 and 26.5 % of the variation in the traits. The QTLs were distributed on chromosomes 1B, 2A, 2D, 4B, 6B, 7A, and 7D. A major and two minor QTLs were identified for LR, with the major QTL (qLR-2D) explaining 26.5 % of variation. Two QTLs were detected for DRW on chromosome 4B between markers Gwm6 and Sukkula.1220 that together explained 23.1 % of variation. One region between marker Wmc198 and Cfa2263 on chromosome 2A contained four QTLs affecting PH, SRW, RTS, and RTP. At maturity, 70 putative QTLs were detected across the two seasons with a single QTL accounted for between 7.7 and 40.6 % of variation in the traits. Three major colocalized QTLs for SRW, DRW, and RBio were identified on chromosome 2D between markers Wms515 andWms102 that accounted for 19.8, 20.5, and 22.4 %0f variation, respectively. Two major colocalized QTLs for SRW and RBio were detected on chromosome 3A that explained 17.8 and 13.4 % of variation, respectively. One major QTL for DRW was identified on chromosome 1B that accounted for 20.3 % of variation. Chromosome 2B harbored major QTLs for GY, NGS, and NGP. A major QTL cluster was detected on chromosome 2D and on chromosome 4A relating 11 and eight QTLs for phenological periods, root traits, RTS, and RTP, indicating pleiotropic effects on these traits. Of the four common root traits studied at mid-tillering and at maturity, only SRW had linked QTLs on chromosome 2A at both stages of plant growth, indicating selection for root traits at seedling stage alone may not be effective in changing root morphological characteristics at later stages of plant growth. It appeared that chromosome 2A, 2D, and 4B harbored genes regulating growth of root traits at early and later stages of plant growth. The molecular markers closely linked to QTLs for root and shoot traits may be used in wheat breeding program using MAS procedures.The research was financed by The California Wheat Commission, The University of California- Riverside Botanic Gardens, and the California Agricultural Experiment Station

A Study on the Quality of Study Skills of Newly-admitted Students of Fasa Medical University, 2012

Introduction: Some students attribute their academic failure to such factors as low aptitude, unavailability of resources, and bad luck. However, we can dare to say that the most important factor playing a role in academic success is students’ little acquaintance with learning and study skills. This study aimed at examining the quality of study skills in newly-admitted students of Fasa Medical University so that the results can be used in holding teaching courses in study skills. Methods: The present study is a cross-sectional descriptive study. The sampling was done of all the newly-admitted students in the first semester of 2012 academic year including 94 students of Medicine, Nursing and Laboratory Technology. The data were collected through a questionnaire, consisting of two parts. The first part included items on demographic information of the subjects (such as sex, field of study, number of hours dedicated to studying, student’s rank in Konkour, and the National University entrance exam. The second part was composed of 19 special items on such domains as ‘Time management’, ‘Concentration’, ‘Class note-taking’, ‘Studying’ and ‘Taking exams’ with 4, 5, 4, 3, 3 items, respectively. The checklists were filled in using Likert scale. The collected data was then analyzed using an SPSS 14, through which descriptive statistics as mean, standard deviation and multiple regressions were obtained. Moreover, the data were analyzed using Independent Sample t and ANOVA tests. Results: The results showed that the range of the students’ study skills was 2.35, being rather below the normal level; the highest mean belonged to ‘concentration’(2.56), but the lowest mean was that of ‘time management’ (2.05). Through ANOVA test, it was also shown that there was no significant difference between the students of Medicine, Nursing and Laboratory Sciences regarding their scores on ‘study skills’ as (p=0.646). In addition, through independent sample t-test, it was shown that there was no significant difference between the subjects’ ‘sex’ and ‘study skills’ as the p-value was 0.584. On the other hand, through multiple regressions, the results indicated that there was a significant difference between ‘Taking exams’ and ‘Studying’ (p=0.003), between ‘Class note-taking’ and ‘‘Taking exams’ (p=0.004), between ‘Concentration’ and ‘Taking exams’ (p=0.002), and between ‘Time management’ and ‘Taking exams’ (p=0.001). Conclusion: Regarding the very important role of study skills in learning, it is recommended that ‘study skills’ and ‘study habits’ courses be included in the students’ curriculum formally or implemented as workshops for students

An Integrative Genetic Study of Rice Metabolism, Growth and Stochastic Variation Reveals Potential C/N Partitioning Loci.

Studying the genetic basis of variation in plant metabolism has been greatly facilitated by genomic and metabolic profiling advances. In this study, we use metabolomics and growth measurements to map QTL in rice, a major staple crop. Previous rice metabolism studies have largely focused on identifying genes controlling major effect loci. To complement these studies, we conducted a replicated metabolomics analysis on a japonica (Lemont) by indica (Teqing) rice recombinant inbred line population and focused on the genetic variation for primary metabolism. Using independent replicated studies, we show that in contrast to other rice studies, the heritability of primary metabolism is similar to Arabidopsis. The vast majority of metabolic QTLs had small to moderate effects with significant polygenic epistasis. Two metabolomics QTL hotspots had opposing effects on carbon and nitrogen rich metabolites suggesting that they may influence carbon and nitrogen partitioning, with one locus co-localizing with SUSIBA2 (WRKY78). Comparing QTLs for metabolomic and a variety of growth related traits identified few overlaps. Interestingly, the rice population displayed fewer loci controlling stochastic variation for metabolism than was found in Arabidopsis. Thus, it is possible that domestication has differentially impacted stochastic metabolite variation more than average metabolite variation