Heritability Research Articles

A multi-trait targeted genotype selection approach for screening drought tolerance in teosinte–maize hybrids

Drought tolerance is a complex characteristic and screening based on multiple traits rather than direct selection indices would result in more efficient selection. The study aims to select hybrids under optimal and water deficit conditions to achieve genetic gains in yield traits without compromising the other secondary traits viz., anthesis-silking interval, leaf chlorophyll content, delayed leaf rolling and leaf senescence, relative water content, and ROS scavenging using the multi-trait genotype ideotype distance index. The 30 teosinte-maize hybrids along with four checks were evaluated for two classes of traits: 16 morphometric and 14 physiological and biochemical traits, under well-watered (WW) and water-stress (WS) environments. Significant variations among the genotypes were observed for most traits and the presence of moderate to high heritability for most traits suggests direct selection for improvement of those traits. Significant correlation of the traits with yield and intercorrelations between traits indicate the advantage of indirect selection based on secondary traits. By assuming a selection intensity of 15% and equal weightage to all the traits, five genotypes were selected based on the MGIDI under each class of traits and in each environment. The genotypes viz. G19, G20, and G29 were commonly selected across both environments. The selection led to desired positive and negative selection gains for most of the traits studied and resulted in high positive gains for single plant yield of 35.6% under WW and 69.3% under WS. The strength and weakness plots effectively present the advantages and limitations of the selected genotypes under each environment. The multi-trait-based selection approach is an effective tool for selecting genotypes and designing breeding strategies for stress breeding.

Phenotypic Trait Analysis of Tomato (Solanum lysopersicum) Genotypes in Qatar and Indian Agro-climatic Conditions

Background: The study included four genotypes of tomato (EC620378, EC620380, EC620383, EC620534) which were cultivated to find out their similarities and differences based on phenotypic traits when they were grown under different soil zones of Doha (Qatar) and Meerut (India) to find out that which of the genotypes can be cultivated better in Qatar and India. Methods: The experiment was laid out in Randomized Complete Block Design (RBCD) with two replications. Statistical analysis for variation in quantitative characteristics among genotypes was done by collecting data in 15 qualitative and quantitative traits. Data showed great variation for almost all the traits. The principal component analysis involved plant height and days to marketable maturity as the most discriminating trait that accounted for greater variability in genotypes in both zones, and they should be considered in tomato improvement programs. The correlation analysis showed that fruit yield per plant was positively and significantly correlated with number of fruits per plant and fruit width. Present findings suggest that the identified superior genotypes may be utilized by different farms to further improve their breeding and cultivation strategies. Result: In Indian soil zone, genotype EC620534 performed extremely well in terms of maximum yield per plant. Similarly, in Qatar soil zone, EC620534 and EC620380 performed well. The phenotypic coefficient of variation (PCV) was higher than its corresponding genotypic counterpart (GCV) for all characters studied showing environmental influence. High broad-sense heritability were recorded for days to marketable maturity, fruit shape index and fruit weight in both agro-climatic zones, they were associated with low genetic advance indicating non-additive gene action and environmental influence, hence, heterosis breeding is recommended.

QTL mapping and transcriptome analysis of seed germination under PEG-induced water stress in Lactuca spp.

The impact of limited water availability on lettuce growth has been well documented. However, the mechanisms by which lettuce controls seed germination under water stress remain unknown. Germination percentage was evaluated in the cv. Salinas (Lactuca sativa) (L. sativa) × US96UC23 (Lactuca serriola) (L. serriola) recombinant inbred line (RIL) population and USDA germplasm collection using 10% polyethylene glycol (PEG). About 50% of both populations displayed less than 90% germination. The average broad-sense heritability (H2) for germination percentage was 0.81 across both populations. Two quantitative trait loci (QTL) for germination percentage were identified on chromosomes 4 and 8 in the RIL population. The RNA-Seq and network analyses of wild lettuce, US96UC23, were performed using the control (distilled water, dH2O) and treatment (10% PEG) datasets. The number of differentially expressed genes (DEGs) was 4,095. The top 20 gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were assessed by enrichment analysis. The consensus network analysis captured 44 modules. Gene networks were constructed for the top 20 hub genes in 10 significant modules from each dataset. This study comprehensively explains QTL, GO terms, KEGG pathways, and gene networks associated with lettuce seed germination under osmotic stress.

Assessing temporal variability in durum wheat performance and stability through multi-trait mean performance selection in Mediterranean climate

Durum wheat, a staple crop in Italy, faces substantial challenges due to increasing droughts and rising temperatures. This study examines the grain yield, agronomic traits, and quality of 41 durum wheat varieties over ten growing seasons in Southern Italy, utilizing a randomized complete block design. Notably, most varieties were not repeated between trials and 45% of the data was missing. The results indicate that the interaction between genotype and environment (GEI) significantly impacted all traits. High temperatures, elevated vapor pressure deficit (VPD), and water deficits severely affected yield and quality during warm years, while cooler years with favorable water availability promoted better growth and higher yields. Broad-sense heritability (H²) was generally low, suggesting that environmental factors played a major role in the observed traits. However, some traits, such as grain yield, ears per square meter, plant height, bleached wheat, thousand-grain weight, and hectoliter weight exhibited moderate to high heritability of the mean genotype (h²mg), indicating their potential for effective selection in breeding programs. Correlation analyses revealed strong connections between certain traits, such as protein content, and gluten index as well as between grain yield, and spike per square meter. Using the Multi-Trait Mean Performance Selection (MTMPS) index, the study identified six top-performing varieties. Among these, Antalis (G4) and Core (G18) consistently demonstrated strong adaptability and stability across different environments, particularly in hotter, drier conditions. Furio Camillo (G31) also exhibited valuable traits. This study highlights the challenges and complexities of breeding durum wheat for improved yield and quality in the face of climate change.

Response to oxalic acid: an important supplement screening against stem rot resistance in groundnut (Arachis hypogaea L.)

BackgroundStem rot, caused by the soil-borne pathogen Sclerotium rolfsii, pose a serious challenge in the groundnut (Arachis hypogaea L) cultivation. Although this disease is widespread globally but had most adverse impact in groundnut growing regions of United States, India, and Australia. The pathogen primarily targets the crown region of the plant, resulting in systemic collapse and potentially leading to yield losses up to 80%. Effective genetic control measures are essential to mitigate the impact of this disease on groundnut production. Realizing the time and resource-consuming complex field-based phenotyping, the availability of easy and repeatable phenotyping methods may fasten the process of donor and gene discovery efforts.ResultsMulti-season phenotyping was performed for stem rot on 184 minicore germplasm accessions, including checks, under two conditions: sick field screening and response to oxalic acid assay. This study demonstrated medium to high heritability (52–63% broad-sense heritability) and significant environmental influence (36%). The response to the oxalic acid assay showed a high proportion of similarity (approximately 80%) with the percent mortality observed in the sick field indicating an easy way of performing precise phenotyping. Notably, seven genotypes—ICG163, ICG721, ICG10479, ICG875, ICG11457, ICG111, and ICG2857—exhibited stable resistance, with less than 30% mortality against stem rot disease. Among these, ICG163, ICG875, and ICG111 displayed low mortality and consistent stability across multiple seasons in both the sick field and controlled conditions of the oxalic acid assay.ConclusionsThe oxalic acid assay developed in this study effectively complements field phenotyping, as a reliable method for assessing stem rot resistance. Seven resistant genotypes identified through this assay can be utilized for the introgression of stem rot resistance into elite genotypes. Given the significant influence of the environment on stem rot resistance, it is essential to implement multi-season phenotyping to obtain precise results. Furthermore, the response to oxalic acid serves as a valuable supplement to traditional field phenotyping, since maintaining uniform disease pressure during field screenings is often challenging.

Genetic characterization and mapping of the shell-strength trait in peanut.

Shell strength is an important trait in peanuts that impacts shell breakage and yield. Despite its significance, the genetic basis of shell strength in peanuts remains largely unknown, and the current methods for rating this trait are qualitative and subjective. This study aimed to investigate the genetics of shell strength using a segregating recombinant-inbred-line (RIL) population derived from the hard-shelled cultivar 'Hanoch' and the soft-shelled cultivar 'Harari'. Initially, a quantitative method was developed using a texture analyzer, focusing on the proximal part of isolated shells with a P/5 punching probe. This method revealed significant differences between Hanoch and Harari. Shell strength was then measured in 235 RILs across two distinct environments, revealing a normal distribution with some RILs exhibiting shell strength values beyond those of the parental lines, indicating transgressive segregation. Analysis of variance indicated significant effects for the RILs, with no effects of block or year, and a broad-sense heritability estimate of 0.675, indicating a substantial genetic component. Using an existing genetic map, we identified three QTLs for shell strength, with one major QTL (qSSB02) explaining 18.7% of the phenotypic variation. The allelic status of qSSB02 corresponded significantly with cultivar designation for in-shell or shelled types over four decades of Israeli peanut breeding. Physical and compositional analyses revealed that Hanoch has a higher shell density than Harari, rather than any difference in shell thickness, and is associated with increased levels of lignin, cellulose, and crude fiber. These findings provide valuable insights into the genetic and compositional factors that influence shell strength in peanut, laying a foundation for marker-assisted selection in breeding programs focused on improving pod hardness in peanuts.

Drosophila Toxicogenomics: genetic variation and sexual dimorphism in susceptibility to 4-Methylimidazole

Background4-methylimidazole is a ubiquitous and potentially carcinogenic environmental toxicant. Genetic factors that contribute to variation in susceptibility to its toxic effects are challenging to assess in human populations. We used the Drosophila melanogaster Genetic Reference Panel (DGRP), a living library of natural genetic variation, to identify genes with human orthologs associated with variation in susceptibility to 4-methylimidazole.ResultsWe screened 204 DGRP lines for survival following 24-hour exposure to 4-methylimidazole. We found extensive genetic variation for survival, with a broad sense heritability of 0.82; as well as genetic variation in sexual dimorphism, with a cross-sex genetic correlation of 0.59. Genome-wide association analyses identified a total of 241 candidate molecular polymorphisms in or near 273 unique genes associated with survival. These polymorphisms had either sex-specific or sex-antagonistic effects, and most had putative regulatory effects. We generated interaction networks using these candidate genes as inputs and computationally recruited genes with known physical or genetic interactions. The network genes were significantly over-represented for gene ontology terms involving all aspects of development (including nervous system development) and cellular and organismal functions as well as canonical signaling pathways, and most had human orthologs.ConclusionsThe genetic basis of variation in sensitivity to acute exposure to 4-methylimidazole in Drosophila is attributable to variation in genes and networks of genes known for their effects on multiple developmental and cellular processes, including possible neurotoxicity. Given evolutionary conservation of the underlying genes and pathways, these insights may be applicable to humans.

Self-injury and suicidal behaviors in high-risk adolescents: Distal predictors, proximal correlates, and interactive effects of impulsivity and emotion dysregulation.

Suicide rates are rising among U.S. youth, yet our understanding of developmental mechanisms associated with increased suicide risk is limited. One high-risk pathway involves an interaction between heritable trait impulsivity and emotion dysregulation (ED). Together, these confer increased vulnerability to nonsuicidal self-injury (NSSI), suicide ideation (SI), and suicide attempts (SAs). Previous work, however, has been limited to homogeneous samples. We extend the Impulsivity × ED hypothesis to a more diverse sample of adolescents (N = 344, ages 12-15 at Baseline, 107 males and 237 females) who were treated for major depression and assessed four times over two years. In multilevel models, the impulsivity × ED interaction was associated with higher levels and worse trajectories of NSSI, SI, and SAs. As expected, stressful life events were also associated with poorer trajectories for all outcomes, and NSSI was associated with future and concurrent SI and SAs. These findings extend one developmental pathway of risk for self-harming and suicidal behaviors to more diverse adolescents, with potential implications for prevention.

English

Coffee breeding programs aim at developing superior genotypes, which entail exploring the genetic variability existing in conilon/robusta coffee. This study aimed at examining the variability and estimate genetic param of physical and physiological nature in Coffea canephora seeds in order to provide bases for the selection of genotypes for superior seeds quality. Forty-three C. canephora genotypes were evaluated for 11 physical and physiological seed traits. Estimates of genetic param, environmental variance, phenotypic variance, genotypic variance, broad-sense heritability, variation index and Pearson's correlation were obtained. The Dissimilarity between genotypes was obtained by generalized Mahalanobis distance. The dendrogram was constructed using unweighted pair group method with arithmetic mean (UPGMA). C. canephora genotypes presented high germination potential and exhibited genetic diversity for all seed traits, with estimates of genetic variance greater than environmental variance. Heritability reached values above 96.0% and all genetic variation indices found were higher than unity. The UPGMA hierarchical method grouped the genotypes in three groups. The physical traits (circumference, area and roundness) were those that contributed the most to explaining the dissimilarity between genotypes. Genotypes Alecrim, AP, Bamburral, Z39 and Tardio C were the most divergent. The results revealed the presence of genetic variability between C. canephora genotypes and greater genetic than environmental influence on the characters of seeds, indicating that selection for the studied traits showed favorable conditions in terms of immediate gain.

Genetic analysis of maize crude fat content by multi-locus genome-wide association study

Crude fat is an important nutritional component of maize kernels. However, the genetic mechanisms underlying crude fat content in maize kernels remain elusive. Previous studies used single-model genome-wide association studies (GWAS) with limited population sizes, which can result in false positives of loci and hinder the identification of functional genes. Therefore, this study used a population consisting of 495 maize inbred lines, combined with 1.25 million single nucleotide polymorphisms (SNPs), and implemented GWAS using six models to identify quantitative trait nucleotides (QTNs) controlling crude fat content and to mine key genes. The results revealed a wide variation in crude fat content (0.62–16.03%) and broad-sense heritability (96.23%). In total, 744 significant QTNs were detected, with 147 co-located across different models, environments, and methods. Based on the 147 co-located QTNs, candidate genes were searched at 50 kb up- and downstream intervals of each QTN. We finally screened eight candidate genes (GRMZM2G169089, GRMZM2G117935, GRMZM2G002075, GRMZM2G368838, GRMZM2G058496, GRMZM2G090669, GRMZM2G001241, and GRMZM2G333454) related to crude fat content that exhibited high expression levels during kernel development in maize inbred line B73. Notably, GRMZM2G169089, GRMZM2G117935, GRMZM2G002075, and GRMZM2G368838 are involved in the linoleic acid metabolic pathway, oil metabolism, kernel growth, and development in maize. Furthermore, co-expression network analysis revealed that the eight candidate genes exhibited strong correlations with 30 known genes. Proteins encoded by candidate genes interact with various other proteins and play an important role in oil content and oleic acid metabolism in maize kernels. The best haplotypes of candidate genes might increase crude fat content without decreasing maize yield. These results broaden the understanding of the genetic mechanism of crude fat content and facilitate marker-assisted selection for high-crude fat breeding programs for maize.

Chronic Overlapping Pain Conditions and Nociplastic Pain

Chronic Overlapping Pain Conditions (COPCs) are a subset of chronic pain conditions commonly comorbid with one another and more prevalent in women and assigned female at birth (AFAB) individuals. Pain experience in these conditions may better fit with a new mechanistic pain descriptor, nociplastic pain, and nociplastic pain may represent a shared underlying factor among COPCs. We applied GenomicSEM common-factor genome wide association study (GWAS) and multivariate transcriptome-wide association (TWAS) analyses to existing GWAS output for six COPCs in order to find genetic variation associated with nociplastic pain, followed by genetic correlation (linkage-disequilibrium score regression), gene-set and tissue enrichment analyses. We found 24 independent single nucleotide polymorphisms (SNPs), and 127 unique genes significantly associated with nociplastic pain, and showed nociplastic pain to be a polygenic trait with significant SNP-heritability. We found significant genetic overlap between multisite chronic pain and nociplastic pain, and to a smaller extent with rheumatoid arthritis and a neuropathic pain phenotype. Tissue enrichment analyses highlighted cardiac and thyroid tissue, and gene set enrichment analyses emphasized potential shared mechanisms in cognitive, personality, and metabolic traits and nociplastic pain along with distinct pathology in migraine and headache. We use a well-powered network approach to investigate nociplastic pain using existing COPC GWAS output, and show nociplastic pain to be a complex, heritable trait, in addition to contributing to understanding of potential mechanisms in development of nociplastic pain.

A finite mixture distribution to model genetic architecture of image‐based oat grain morphology

AbstractThe multi‐floral oat (Avena sativa L.) inflorescence influences grain size and shape distributions, affecting the physical attributes of grain quality such as plumpness, size, and uniformity. While the grain size and shape distribution has been characterized as multi‐modal, very little is known about the genetic determinants of those distributions and their properties. The goal of this study was to model grain size and shape distribution using a finite mixture distribution approach and propose new distributional traits (i.e., emerging distributional traits) to characterize genotypes. We evaluated 47 oat genotypes in four highly replicated field experiments. Grains of three panicles per plot were individually threshed and scanned. Grain area, length, width, and roundness were obtained from each grain‐based image, while emerging distributional traits were evaluated using a finite mixture distribution approach. Finally, grain size distributions from hand‐threshed panicles (representing the full biological distribution) were compared with the grain size distributions of grains harvested with a combine harvester representing commercial harvest where small grains may be blown out. The heritability of all grain traits was high (0.89–0.94), and trait distributions differed among genotypes. Grain area and length show bi‐ and trimodal distributions, while grain width and roundness are uni‐ and bimodal. Although the full biological distribution of grains differed from the combine‐harvested grains, their genetic correlations were high, suggesting the combine‐harvested distributions can be used as a proxy for full biological distributions. This study proposes a straightforward methodological approach to model grain attributes that can aid in quality evaluations for genetic studies, breeding decisions, and industry characterization.

Heritability and Variability of Productivity Traits in Spring Soft Wheat Hybrids of the First to Fourth Generations

Abstract Under the conditions of the Absheron region, the effects of interaction between genotype and environment were determined in nine varieties of spring soft wheat and seven hybrid populations F1…F4 formed with their participation. A reliable effect of environmental conditions on all the studied traits was established. The contribution of the “year” factor to the number of grains per ear in varieties and hybrids was 10.9 and 13.9%, respectively; to the weight of 1000 grains – 5.8 and 19.5%; to the yield – 47.3 and 41.1%. The genetic component made a significant contribution to the weight of 1000 grains in varieties and hybrids (81.5 and 58.8%), as well as to the number of grains in varieties (38.4%). A higher varietal specificity in the manifestation of traits in parental varieties was noted compared to hybrids. Two component traits of ear productivity in a series of generations against the background of various lim-factors were analyzed, shifts of their average values and their influence on the yield were predicted and determined. The phenotypic dominance index (hp) was determined in the first generation by the number of grains per ear and 1000-grain weight, combinations with a high level were identified. The selection differential and efficiency of selections carried out under contrasting environmental conditions in the second and third hybrid generations were calculated. The yield in the initial populations varied within 219.0…789.6 g/m2, in the selected progeny – 317.0…647.6 g/m2. The average yield increase in the progeny selected in a dry year, in relation to the initial populations, was 56.8 g/m2; in the progeny selected under conditions of excess moisture – 10.8 g/m2. Correlation analysis revealed an average positive relationship between the hp indicator in the first generation and the selection differential in subsequent generations for the traits “weight of 1000 grains” and “number of grains per ear”.

Genome-Wide Association-Based Identification of Alleles, Genes and Haplotypes Influencing Yield in Rice (Oryza sativa L.) Under Low-Phosphorus Acidic Lowland Soils

Rice provides poor yields in acidic soils due to several nutrient deficiencies and metal toxicities. The low availability of phosphorus (P) in acidic soils offers a natural condition for screening genotypes for grain yield and phosphorus utilization efficiency (PUE). The objective of this study was to phenotype a subset of indica rice accessions from 3000 Rice Genome Project (3K-RGP) under acidic soils and find associated genes and alleles. A panel of 234 genotypes, along with checks, were grown under low-input acidic soils for two consecutive seasons, followed by a low-P-based hydroponic screening experiment. The heritability of the agro-morphological traits was high across seasons, and Ward’s clustering method identified 46 genotypes that can be used as low-P-tolerant donors in acidic soil conditions. Genotypes ARC10145, RPA5929, and K1559-4, with a higher grain yield than checks, were identified. Over 29 million SNPs were retrieved from the Rice SNP-Seek database, and after quality control, they were utilized for a genome-wide association study (GWAS) with seventeen traits. Ten quantitative trait nucleotides (QTNs) for three yield traits and five QTNs for PUE were identified. A set of 34 candidate genes for yield-related traits was also identified. An association study using this indica panel for an already reported 1.84 Mbp region on chromosome 2 identified genes Os02g09840 and Os02g08420 for yield and PUE, respectively. A haplotype analysis for the candidate genes identified favorable allelic combinations. Donors carrying the superior haplotypic combinations for the identified genes could be exploited in future breeding programs.

Comparison of blood parameters in two genetically different groups of horses for functional longevity in show jumping

IntroductionIn order to find early selection criteria to improve the longevity of show jumping horses, a specific protocol was designed.MethodsBefore entering competition, young horses selected from extreme stallions for longevity were measured for many traits, including blood parameters. Blood samples were taken from 952 horses aged 2–4 years old, sired by two groups of stallions: one with unfavorable (U) and the other with favorable (F) extreme estimated breeding values for functional longevity. These breeding values were previously calculated from data on 202,320 horses that participated in show jumping competitions between 1985 and 2022. Functional longevity was defined as time spent in competition, adjusted for the level of performance. The 59 measured parameters included hematology, proteins, cytokines, liver and kidney function, bone and joint health, oxidative stress and endocrinology. Heritability was estimated using a mixed model that accounted for the effect of age, sex, estimated weight, visit (place and date of collection), and animal random additive value with 10,280 horses in pedigree. A Partial Least Square logistic regression was performed to predict the sire group.ResultsAge, sex and estimated weight significantly affected 36, 19 and 16 variables, respectively. The visit had a significant effect on all variables. Heritability estimates were high, with 75% higher than 0.20% and 30% higher than 0.50. The most heritable traits included mean corpuscular volume (0.92, se 0.11), mean corpuscular hemoglobin (0.90, se 0.11), white blood cells (0.55, se 0.13), total alkaline phosphatase (0.68, se 0.12) and percentage of γ-globulin (0.57, se 0.12). The logistic regression that predicted the group of sires favorable for longevity identified 16 significant variables. Key findings included: lower mean corpuscular hemoglobin (p-value < 0.001), lower mean corpuscular volume (p-value < 0.001), lower number of white blood cells (p-value < 0.01), higher percentage of intestinal and bone alkaline phosphatase (p-value < 0.01) for a lower total alkaline phosphatase (p-value < 0.01), higher percentage of α2-globulin (p-value < 0.001) and lower percentage of β1-globulin (p-value < 0.01).DiscussionBlood parameters measured at rest in young horses may be predictive of their genetic value for functional longevity in show jumping.

Variability of Agronomic Traits of Wheat (Triticum aestivum L.) Lines in Two Agroecosystems in Indonesia

Wheat is an important agricultural commodity in Indonesia, yet the country remains heavily reliant on imports to meet domestic demand. The diverse agroclimatic conditions in the highlands and lowlands pose significant challenges for national wheat production. This study aimed to evaluate the performance of wheat lines in two distinct altitude environments: Cipanas (1120 m above sea level) and Cisarua (600 m above sea level). An augmented randomized complete block design (RCBD) assessed 50 F6 wheat lines derived from the HP1744/”Selayar” cross. The results revealed significant variability in agronomic traits attributable to altitude differences. However, genotype-by-environment (GxE) interactions were found to be non-significant for all evaluated characters. Broad-sense heritability was classified as medium for the grain-filling period in Cipanas and seed weight of the main panicle in Cisarua, while all other traits exhibited low heritability. Based on the stress sensitivity index (SSI), 14 lines (28%) were identified as tolerant to higher temperatures in the medium-altitude environment, particularly in terms of seed weight of the main panicle. These findings are of utmost importance as they underscore the need to consider genetic and environmental factors in developing wheat cultivars suitable for Indonesia’s diverse agro-climatic conditions.

Heritable heart failure traits in mice undergoing early life stress

Abstract Introduction Adverse childhood experiences, known as early life stress (ELS), are associated with increased cardiovascular disease risk in later life, yet the underlying mechanisms remain elusive. Recent evidence indicates that parental life experiences can be transmitted to the offspring. Whether ELS exerts transgenerational effects on the heart is unknown. Purpose To investigate the effects of ELS on cardiac structure and function in exposed parents and in their offspring, across 3 generations. Methods We used a mouse model of ELS (MSUS) that mimics the exposure to traumatic experiences during childhood in humans. Mouse pups (F1) were separated from their mother (F0) unpredictably each day for 3 hours from postnatal day 1 (PND1) to PND14. During separation, dams were exposed to an additional unpredictable stressor by being subjected to either, a forced swim (18°C water for 5 minutes) or a 20-minute physical tube restraint, anytime (unpredictably) during the 3 hours. From PND15, mice are left undisturbed with their mother until PND21, are then raised normally until adulthood. Control litters were raised normally. A high-resolution Micro-Ultrasound System (Vevo 3100, Visualsonics) was used for the echocardiographic assessment at 6, 12 and 18 months both in the exposed animals (F0) as well as in their offspring (F1) and grandoffspring (F2). Both male and female mice were studied. Heart weight/tibia length and left ventricle weight/tibia length were used to assess cardiac mass while myocardial fibrosis was assessed by Masson's Trichrome and Picriosirius Red stainings. Lung congestion was assessed as lung wet/dry weight ratio. Single cell RNA sequencing (scRNAseq) was used in LV specimens from MSUS mice to unveil cell-specific transcriptional changes. Finally, MSUS mice underwent environmental enrichment (cages containing running wheels, maze) to investigate any rescuing effect on cardiac function. Results F1 mice displayed increased LV mass, impaired diastolic function, myocardial fibrosis and lung congestion. A time-dependent worsening of cardiac performance was observed from 6 to 18 months, both in males and females. ScRNAseq unveiled dysregulation of transcriptional programs underlying inflammation and lipotoxicity in the cardiomyocyte and endothelial cell clusters. The MSUS offspring did not show changes of cardiac function at 6 months, however diastolic dysfunction and lung congestion were observed at 12 and 18 months. A similar impairment of cardiac function was observed in the MSUS grandoffspring (F3). Of interest, 6-week exposure to an environmental enrichment protocol was able to improve LV mass, diastolic function and lung congestion in 12 months-old MSUS mice. Conclusions ELS induces a transgenerational transmission of cardiac phenotypic alterations which can be rescued by EE. Our results shed light on the potential role of ELS on heart failure development and potential mitigation strategies.

THE INHERITANCE OF SOME QUANTITATIVE CHARACTERS OF F2 GENERATION FOR COMMON WHEAT IN SULAIMANI-IRAQ

This study was aimed to testing 25 genotypes (5 parents + 10 diallel + 10 reciprocal crosses) using full Diallel mating design in winter season 2021-2022 for F2 generation of common wheat, in two locations. The first was in Qlyasan Agricultural Research Station, College of Agricultural Engineering Sciences; University of Sulaimani located (Lat 35° 34′; N, Long 45° 21′; E, 765 MASL), the second was in Koya Agricultural Station-Ministry of Agricultural (Lat 36° 04′; N, Long 44° 37′; E, 582 MASL). The results of the study confirmed that the mean squares of genotypes was highly significant for all characters in both locations, the same for the mean squares for gca with the exception of grain weight plant-1 in Qlyasan location which was only significant. The mean square for sca was highly significant for most characters at Qlyasan location, while at Koya location it was significant only for grain weight plant-1. The mean square for rca was significant for spike weight plant-1 at Qlyasan location and 1000-grain weight at Koya location and not significant for the other characters. The Diallel cross 1×4 at Qlyasan location and the reciprocal cross 2×1 at Koya location showed the best performance for grain weight plant-1 recording 58.083 and 40.941g plant-1 respectively. The magnitude of σ2sca was more than σ2gca for all characters in both locations indicating the importance of non-additive gene effects in controlling these characters. Heritability in broad sense for Diallel crosses due to grain weight plant-1 was found to be high in both locations, while for reciprocal crosses was low, and it was low for narrow sense for all crosses.

HETEROSIS AND GENETIC PARAMETERS FOR YIELD AND YIELD COMPONENTS IN MAIZE USING HALF DIALLEL CROSS

The study was aimed to determine heterosis, GCA, SCA and some genetic parameters in maize (Zea mays L.). Seeds for half diallel crosses among eight inbred lines Planted in spring season 2021 during fall season 2021, the eight parents and 28 hybrids were sowing (10/7/2021) using Randomize Complete Block Design with three replications at the field of College of Agricultural Engineering Sciences, University of Duhok. The results revealed that the mean square for all genotypes was highly significant effects in all studied traits except number of ears per plant. The (Un44052) line was superior in number of rows per ear and grain yield per plant, while the cross (Zp-505 x Un44052) was superior in number ear per plant and number of rows per ear. Six crosses exhibited significant positive heterosis, the crosses Dkc-f-59 x Dk-17, Dkc-f-59 x Un44052, Dkc-f-59 x Zp-430, Zp-505 x Un44052, Zp-607 x Zp-505 and Zp-179 x Un44052. The heritability in broad sense was higher than the heritability narrow sense in studied traits, between 0.33 and 0.97 for number of ear per plant and grain yield per plant. The average degree of dominance was higher than one in studied traits.

Analysis of Genetic Variability, Heritability and Genetic Advance for Yield and Yield-related Traits of Linseed (Linum usitatissimum L.)

Linseed is recognized as an excellent source of essential minerals, nutrients, and is particularly rich in omega-3 fatty acids and alpha-linolenic acid (ALA), making it highly recommended for cardiovascular health. It is cultivated mainly for both linen and oil production, which is used for the production of paints, varnishes, and linoleum paste. The objective of the present investigation was to analyze genetic variability, heritability, and genetic advance for yield and yield traits among 75 linseed genotypes including ten checks using Randomized Block Design with three replications at Oilseeds Research Farm, Kalyanpur, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur, Uttar Pradesh, (India) during Rabi season 2019-20. Analysis of variance revealed significant variation across all studied traits. The genotypic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) ranged from low to high, with the lowest GCV and PCV observed for days to maturity, number of seeds per capsule, and days to 50% flowering. Conversely, the highest GCV and PCV values were recorded for seed yield per plant (g), number of capsules per plant, number of secondary branches per plant, and plant height. All traits recorded the highest heritability. High heritability and genetic advance were recorded for seed yield per plant, number of capsules per plant, number of secondary branches per plant, plant height, thousand seed weight, number of primary branches and oil content, indicating the presence of additive gene action for these characters. In conclusion, the genotypes studied show significant genetic variation for yield and its attributes, which should be leveraged in future breeding programs.