Dissection of the genetic basis of genotype-by-environment interactions for grain yield and main agronomic traits in Iranian bread wheat landraces and cultivars

Understanding the genetic basis of performance stability is essential to maintain productivity, especially under severe conditions. In the present study, 268 Iranian bread wheat landraces and cultivars were evaluated in four well-watered and two rain-fed conditions for different traits. According to breeding programs, cultivars were in a group with a high mean and stability in terms of GY, GN, and SW traits, while in terms of PH, they had a low mean and high stability. The stability of cultivars and landraces was related to dynamic and static stability, respectively. The highest number of marker pairs and lowest LD decay distance in both cultivars and landraces was observed on the B genome. Population structure differentiated indigenous cultivars and landraces, and the GWAS results for each were almost different despite the commonalities. Chromosomes 1B, 3B, 7B, 2A, and 4A had markers with pleiotropic effects on the stability of different traits. Due to two rain-fed environments, the Gene Ontology (GO) confirmed the accuracy of the results. The identified markers in this study can be helpful in breeding high-performance and stable genotypes and future breeding programs such as fine mapping and cloning

Dual pillars of hotel restaurant food quality satisfaction and brand loyalty

Purpose: The purpose of this paper is to investigate the impact of service quality (physical quality and staff behaviour) and brand equity (brand quality, brand awareness and brand image) on hotel restaurant food quality satisfaction and brand loyalty among international and local travellers in Malaysia. Design/methodology/approach: A total of 354 valid questionnaires were collected to assess the measurement and structural model for reflective latent constructs using the two steps of covariance-based structural equation modelling. Findings: The research findings suggest that while travellers’ nationality moderates the path between physical quality, staff behaviour and brand image on food quality satisfaction, it does not moderate the relationship between brand quality and brand awareness on food quality satisfaction. This finding further suggests that towards enhancing service quality and brand equity on food quality satisfaction and brand loyalty, managers should understand the important distinctions between international and local travellers. Originality/value: Previous studies have mostly examined the impact of brand equity and service quality towards tourist satisfaction and very few studies have examined the impact of restaurant service quality and brand equity on consumer satisfaction and brand loyalty specifically among international and local travellers. This is one of the first few studies providing empirical evidence and discussions in this area

Genome-Wide Association Study (GWAS) and genome prediction of seedling salt tolerance in bread wheat (Triticum aestivum L.)

Background: Salinity tolerance in wheat is imperative for improving crop genetic capacity in response to the expanding phenomenon of soil salinization. However, little is known about the genetic foundation underlying salinity tolerance at the seedling growth stage of wheat. Herein, a GWAS analysis was carried out by the random-SNP-effect mixed linear model (mrMLM) multi-locus model to uncover candidate genes responsible for salt tolerance at the seedling stage in 298 Iranian bread wheat accessions, including 208 landraces and 90 cultivars.Results: A total of 29 functional marker-trait associations (MTAs) were detected under salinity, 100 mM NaCl (sodium chloride). Of these, seven single nucleotide polymorphisms (SNPs) including rs54146, rs257, rs37983, rs18682, rs55629, rs15183, and rs63185 with R-2 >= 10% were found to be linked with relative water content, root fresh weight, root dry weight, root volume, shoot high, proline, and shoot potassium (K+), respectively. Further, a total of 27 candidate genes were functionally annotated to be involved in response to the saline environment. Most of these genes have key roles in photosynthesis, response to abscisic acid, cell redox homeostasis, sucrose and carbohydrate metabolism, ubiquitination, transmembrane transport, chromatin silencing, and some genes harbored unknown functions that all together may respond to salinity as a complex network. For genomic prediction (GP), the genomic best linear unbiased prediction (GBLUP) model reflected genetic effects better than both bayesian ridge regression (BRR) and ridge regression-best linear unbiased prediction (RRBLUP), suggesting GBLUP as a favorable tool for wheat genomic selection.Conclusion: The SNPs and candidate genes identified in the current work can be used potentially for developing salt-tolerant varieties at the seedling growth stage by marker-assisted selection

Characterization of Dynamic Regulatory Gene and Protein Networks in Wheat Roots Upon Perceiving Water Deficit Through Comparative Transcriptomics Survey

A well-developed root system benefits host plants by optimizing water absorption and nutrient uptake and thereby increases plant productivity. In this study we have characterized the root transcriptome using RNA-seq and subsequential functional analysis in a set of drought tolerant and susceptible genotypes. The goal of the study was to elucidate and characterize water deficit-responsive genes in wheat landraces that had been through long-term field and biochemical screening for drought tolerance. The results confirm genotype differences in water-deficit tolerance in line with earlier results from field trials. The transcriptomics survey highlighted a total of 14,187 differentially expressed genes (DEGs) that responded to water deficit. The characterization of these genes shows that all chromosomes contribute to water-deficit tolerance, but to different degrees, and the B genome showed higher involvement than the A and D genomes. The DEGs were mainly mapped to flavonoid, phenylpropanoid, and diterpenoid biosynthesis pathways, as well as glutathione metabolism and hormone signaling. Furthermore, extracellular region, apoplast, cell periphery, and external encapsulating structure were the main water deficit-responsive cellular components in roots. A total of 1,377 DEGs were also predicted to function as transcription factors (TFs) from different families regulating downstream cascades. TFs from the AP2/ERF-ERF, MYB-related, B3, WRKY, Tify, and NAC families were the main genotype-specific regulatory factors. To further characterize the dynamic biosynthetic pathways, protein-protein interaction (PPI) networks were constructed using significant KEGG proteins and putative TFs. In PPIs, enzymes from the CYP450, TaABA8OH2, PAL, and GST families play important roles in water-deficit tolerance in connection with MYB13-1, MADS-box, and NAC transcription factors

Relationship between Pigments and Seed Fall Rate of Iranian Castor Genotypes and Genetic Diversity

This study aimed to examine the relationship between pigments and seed fall rate of Iranian castor genotypes and genetic diversity, specifically 28 castor genotypes (27 native and 1 modified), a randomized complete block design with three replications was conducted in 2014 and 2015 at the Research Farm of Islamic Azad University in Damghan, northern Iran. During the growth period, the following traits were sampled: seed length; seed width; weight of 1,000 seeds; color of seed coat; number of leaves in the bush; leaf, nervure, and stem color; seed fall rate; growth type; seed performance; oil percentage; and chlorophyll fluorescence rate. After data collection, variance analysis was conducted through SAS and mean comparison was performed through Duncan test at 5% probability level. Correlation coefficients were calculated to find correlations, and cluster analysis was used to group the genotypes. Finally, graphs were drawn with Excel. The results indicated diversity in the investigated traits. Differences were observed among the native castor genotypes so that they were divided into five groups in terms of grain fall rate. A significant negative correlation at 1% probability level between the grain fall rate and the leaf color (r= –0.71**), nervure color (r= –0.56**), and stem color (r= –0.57**) indicated that in all of these three traits, when the color changed to dark red, the rate of grain loss decreased. Thus, the color trait can be used as a reference in breeding programs so that grain fall in the castor plant can be prevented in the future

Gene action for some agronomic traits in maize (Zea mays L.)

Results indicated over-dominance gene effects for days from silking to physiological maturity, days from anthesis to physiological maturity, plant height, kernel depth, number of rows per ear and grain yield. The most appropriate strategy for the exploitation of these effects is to obtain hybrid cultivars and evaluate these characteristics in hybrid combinations. The gene effect for days from emergence to physiological maturity and number of kernels per row was complete dominance, suggesting that reciprocal recurrent selection would be effective. Ear leaf area and ear length were controlled by partial dominance, indicating that additive gene effects were more important than non-additive gene effects for controlling the inheritance of these traits. Therefore, improvement of these traits through selection of breeding materials is highly feasible. Broad-sense heritability ranged between 47.4% and 89.4% for days to physiological maturity and number of rows per ear; however, narrow-sense heritability varied between 7.3% and 50.6% for days from anthesis to physiological maturity and ear leaf area, respectively. Non-additive gene effects were predominant for controlling the majority of traits

Investigation of presence, distribution and flight period of oak leaf roller moth, Tortrix viridana (Lep.: Tortricidae) using pheromone traps in Kurdistan province

Forests cover about 5,200,000 hectares of the west of Iran, from which 500,000 hectares are located in Kurdistan province. One of the most important pests in the oak forests of this province is oak leaf roller moth, Tortrix viridana L. (Lep.: Tortricidae). This pest significantly damages the oak forest each year. Using pheromone trap is one of the suitable methods for monitoring of this pest. In this work, distribution and flight period of the pest were studied by pheromone traps during two years. Fifteen regions were trapped at the equal distances (40 km) from Kamyaran (south west of Kurdistan province) to Baneh (north west of Kurdistan province) to investigate the presence and distribution of this moth. Also, a region located between Sanandaj and Marivan was selected to study the flight period. Some traps were established in this region and checked every two days. Investigation of pest distribution showed that oak leaf roller moth was present all over the sites from Kamyaran to Baneh. Different populations of moth were trapped in all over the sites. The highest population was trapped in Colit region (mid-west of Kurdistan province). The study of flight period showed that first moths were trapped on May, 16th and the peak of the flight took place on May, 21st and finally the last moths were trapped on June, 24th. Therefore, adults activated during 40 days; mating and oviposition occurred during this period. Incubation period lasted 9 months and activation of larvae was coincident with flashing of foliar buds

Marker-Assisted Selection for Recognizing Wheat Mutant Genotypes Carrying HMW Glutenin Alleles Related to Baking Quality

Allelic diversity of HMW glutenin loci in several studies revealed that allelic combinations affect dough quality. Dx5 + Dy10 subunits are related to good baking quality and Dx2 + Dy12 are related to undesirable baking quality. One of the most regular methods to evaluate the baking quality is SDS-PAGE which is used to improve baking quality labs. Marker-assisted selection is the method which can recognize the alleles related to baking quality and this method is based on polymerase chain reaction. 10 pairs of specific primers related to Dx2, Dx2.1, Dx5, Dy10, and Dy12 subunits were used for recognizing baking quality of some wheat varieties and some mutant genotypes. Only 5 pairs of them could show the specific bands. All subunits were recognized by the primers except Dx2.1. Some of the primers were extracted from previous studies and the others were designed based on D genome subunits of wheat. SDS-PAGE method accomplished having confidence in these marker’s results. To realize the effect of mutation, seed storage proteins were measured. It showed that mutation had effect on the amount of seed storage protein on the mutant seeds (which showed polymorphism)