Moderate Heritability Estimates Research Articles

Genome-Wide Epistatic Network Analyses of Semantic Fluency in Older Adults.

Semantic fluency impairment has been attributed to a wide range of neurocognitive and psychiatric conditions, especially in the older population. Moderate heritability estimates on semantic fluency were obtained from both twin and family-based studies suggesting genetic contributions to the observed variation across individuals. Currently, effort in identifying the genetic variants underlying the heritability estimates for this complex trait remains scarce. Using the semantic fluency scale and genome-wide SNP genotype data from the Long Life Family Study (LLFS), we performed a genome-wide association study (GWAS) and epistasis network analysis on semantic fluency in 2289 individuals aged over 60 years from the American LLFS cohorts and replicated the findings in 1129 individuals aged over 50 years from the Danish LLFS cohort. In the GWAS, two SNPs with genome-wide significance (rs3749683, p = 2.52 × 10-8; rs880179, p = 4.83 × 10-8) mapped to the CMYAS gene on chromosome 5 were detected. The epistasis network analysis identified five modules as significant (4.16 × 10-5 < p < 7.35 × 10-3), of which two were replicated (p < 3.10 × 10-3). These two modules revealed significant enrichment of tissue-specific gene expression in brain tissues and high enrichment of GWAS catalog traits, e.g., obesity-related traits, blood pressure, chronotype, sleep duration, and brain structure, that have been reported to associate with verbal performance in epidemiological studies. Our results suggest high tissue specificity of genetic regulation of gene expression in brain tissues with epistatic SNP networks functioning jointly in modifying individual verbal ability and cognitive performance.

Genetic parameters for ewe lifetime productivity traits in Central Anatolian Merino sheep

Rapidly increasing population size, recent breaks in production and supply chains, due to pandemics, and those further expected because of climate change emphasize the compelling importance of animal productivity. Traits associated with the productivity of ewes have a direct impact on the overall productivity, profitability and efficiency of sheep farms. Therefore, the objective of the current study was to estimate the variance components, heritabilities as well as genetic and phenotypic correlations, for traits associated with the lifetime productivity of Central Anatolian Merino ewes. Birth and weaning records of lambs for each ewe as well as environmental factors such as sex and birth type were utilized for deriving ewe lifetime productivity traits. Genetic parameter estimations involved observations from 3101 Central Anatolian Merino ewes, encompassing mean and total lamb birth weight per ewe (MBW and TBW), mean and total lamb weaning weight per ewe (MWW and TWW), and the mean and total number of lambs weaned (MNLW and TNLW). This analysis utilized a pedigree comprising 13229 animals. Average Information Restricted Maximum Likelihood (AIREML) based Animal Linear Mixed Model estimations for the decomposition of (co)variance components were implemented based on pedigree-derived numerator relationship matrix by also accounting for the number of parities as a fixed factor. Low to moderate heritability estimates, ranging between 0.29 and 0.42, were observed for the lifetime productivity traits of the breed. A wide range of genetic and phenotypic correlations (between −0.56 and 0.99) was observed among the traits of interest. The outcomes of the study are anticipated to significantly enhance the global sheep production systems by uncovering the essential parameters for incorporating ewe’s lifetime reproductive performance and productivity into the selection indices. This will also benefit Central Anatolian Merino farmers, who form a large proportion of sheep producers in Turkey.

Evaluation of models for estimation of genetic parameters for post-weaning body measurements and their association with yearling weight in Nellore sheep.

The objective of this study was to obtain (co) variance components and genetic parameter estimates for post-weaning body measurements such as body length (BL), height at withers (HW), and chest girth (HG) recorded at six (SBL, SHW, and SHG), nine (NBL, NHW, and NHG) and twelve (YBL, YHW, and YHG) months of age along with yearling weight (YW) in Nellore sheep maintained at livestock research station, Palamaner, Andhra Pradesh, India and also the association among body measurements with YW was studied. Data on 2,076 Nellore sheep (descended from 75 sires and 522 dams) recorded between 2007 and 2016 (10 years) were utilized in the study. Lambing year, sex of lamb, season of lambing and parity of dam were included in the model as fixed effects and ewe weight was kept as a covariate. Analyses were conducted with six animal models with different combinations of direct and maternal genetic effects using restricted maximum likelihood procedure. Best model for each trait was determined based on Akaike's information criterion. Moderate estimates of direct heritability were obtained for the studied traits viz., BL (0.02 to 0.24), HW (0.31 to 0.49), and CG (0.08 to 0.35) and their corresponding maternal heritability estimates were in the range of 0.00 to 0.07 (BL), 0.13 to 0.17 (HW), and 0.07 to 0.13 (CG), respectively. Positive direct genetic and phenotypic correlations among the traits and they ranged from 0.07 (YBL-YW) to 0.99 (SBL-SHG, SHG-YW, and NBL-YBL) and 0.01 (SBL-YBL) to 0.99 (NBL-NHG), respectively. Further, the genetic correlations among all the body measurements and YW were positive and ranged from 0.07 (YW and YBL) to 0.99 (YW and SHG). There was a strong association of chest girth at six months with YW. Further, it is indicated that moderate improvement of post-weaning body measurements in Nellore sheep would be possible through selection.

Modelling the lactation curve in Alpine × Beetal crossbred dairy goats using random regression models fitted with Legendre polynomial and B-spline functions.

The current study sought to genetically assess the lactation curve of Alpine × Beetal crossbred goats through the application of random regression models (RRM). The objective was to estimate genetic parameters of the first lactation test-day milk yield (TDMY) for devising a practical breeding strategy within the nucleus breeding programme. In order to model variations in lactation curves, 25,998 TDMY records were used in this study. For the purpose of estimating genetic parameters, orthogonal Legendre polynomials (LEG) and B-splines (BS) were examined in order to generate suitable and parsimonious models. A single-trait RRM technique was used for the analysis. The average first lactation TDMY was 1.22 ± 0.03 kg and peak yield (1.35 ± 0.02 kg) was achieved around the 7th test day (TD). The present investigation has demonstrated the superiority of the B-spline model for the genetic evaluation of Alpine × Beetal dairy goats. The optimal random regression model was identified as a quadratic B-spline function, characterized by six knots to represent the central trend. This model effectively captured the patterns of additive genetic influences, animal-specific permanent environmental effects (c2 ) and 22 distinct classes of (heterogeneous) residual variance. Additive variances and heritability (h2 ) estimates were lower in the early lactation, however, moderate across most parts of the lactation studied, ranging from 0.09 ± 0.04 to 0.33 ± 0.06. The moderate heritability estimates indicate the potential for selection using favourable combinations of test days throughout the lactation period. It was also observed that a high proportion of total variance was attributed to the animal's permanent environment. Positive genetic correlations were observed for adjacent TDMY values, while the correlations became less pronounced for more distant TDMY values. Considering better fitting of the lactation curve, the use of B-spline functions for genetic evaluation of Alpine × Beetal goats using RRM is recommended.

Transforming Agriculture through Nanotechnology: A Comprehensive Overview

Nanotechnology has emerged as a transformative force in agriculture, offering innovative solutions to address critical challenges in food production, sustainability, and resource management. This comprehensive overview explores the multifaceted impact of nanotechnology on agriculture, providing insights into its potential to revolutionize the sector and by elucidating the fundamental principles of nanotechnology and its applicability in agriculture, emphasizing nanomaterials’ unique properties that enable precise manipulation at the molecular and nanoscale levels. It explores diverse applications, including nanoparticle-based nutrient delivery systems, nanoencapsulation for controlled release of agrochemicals, and the development of nanosensors for real-time monitoring of crop health and environmental parameters. Furthermore, this delves into the emerging field of precision farming enabled by nanotechnology, where data-driven decision-making and targeted interventions optimize resource utilization, minimize environmental impacts, and maximize crop yields. It examines the potential of nano pesticides in integrated pest management, highlighting their eco-friendly nature and reduced environmental contamination. Nanotechnology’s role in soil management and remediation is also discussed, showcasing its capacity to improve soil health, remediate contaminated lands, and enhance nutrient availability. The review sheds light on the application of nanofertilizers, which not only enhance nutrient use efficiency but also mitigate nutrient runoff, contributing to sustainable agriculture. While nanotechnology holds immense promise, it is imperative to consider safety and environmental implications. This examines the challenges and regulatory considerations surrounding the use of nanomaterials in agriculture, emphasizing the need for responsible development and rigorous risk assessment.

Genetic and environmental influences on alpha amylase stress reactivity and shared genetic covariation with cortisol

Salivary alpha amylase (sAA) is a common measure of stress reactivity, primarily reflecting sympathetic nervous system activity. Salivary cortisol is also a reliable, frequently used biomarker of stress and reflects the hypothalamic-pituitary-adrenal (HPA) axis response. This study examined heritability across varying metrics of sAA in response to a social evaluative stressor, the Trier Social Stress Test (TSST). The goal of this study was to estimate genetic and environmental influences on measurements of sAA stress reactivity. Moreover, we evaluated the shared genetic covariation between sAA and cortisol. Participants included twins aged 15–20 years (54% female). We measured alpha amylase and cortisol reactivity to the TSST via serial salivary cortisol samples collected pre- and post-TSST. Modest to moderate heritability estimates (11–64%) were observed across measures purported to capture alpha amylase stress reactivity (peak, area under the curve, baseline-to-peak change). Findings also indicate that sAA baseline and peak are primarily influenced by a shared genetic factor. There was no evidence of shared genetic influences between sAA and cortisol. These findings suggest the genetic control of the HPA and Sympathetic Adreno-Medullar axis are genetically independent of one another despite both playing a role in response to stressors.

Optimizing selection strategy for enhancing reproduction efficiency in Indian crossbred goats using milk productivity as a selection criterion.

The present study was aimed at optimizing the selection strategy for enhancing reproductive efficiency and milk productivity of Alpine × Beetal crossbred goats. The data set included 2949 milk trait records across parities and 1389 milk records from first parity and corresponding reproductive traits. The traits included for analysis were 150-day milk yield (150DMY), days in milk (DIM), peak yield (PY) and total milk yield (TMY). The litter size (LS) and litter weight (LW) were used for specifically formulating selection plan using indirect selection. The least squares mean for lactation traits during the first parity were 150DMY: 195.32 ± 2.09 kg, DIM: 236.42 ± 3.04 days, PY: 1.82 ± 0.02 kg, TMY: 269.62 ± 4.52 kg. Notably, Alpine × Beetal goats demonstrated genetic superiority pan India for milk productivity as compared to other native goat breeds. The least squares mean for 150DMY across all parities was 236 ± 3.13 kg. An animal model employing average information restricted maximum likelihood was used for (co)variance component estimation to get the genetic parameters. The analysis revealed total heritability estimates for 150DMY, DIM, PY and TMY as 0.18 ± 0.06, 0.04 ± 0.04, 0.12 ± 0.06 and 0.08 ± 0.05, respectively. Repeatability estimates for 150DMY, DIM, and TMY were 0.28 ± 0.04, 0.21 ± 0.03 and 0.37 ± 0.03, respectively. Bivariate analysis of 150DMY with reproductive traits revealed heritability for LS and LW as 0.05 ± 0.01 and 0.10 ± 0.01, respectively using Gibbs sampling. Strong and positive genetic correlations of 150DMY with other production and reproduction traits was observed, such as DIM (0.72), PY (0.98), TMY (0.88), LS (0.57) and LW (0.33). Moderate heritability and repeatability estimate of 150DMY, along with its positive correlation with production and reproductive traits suggested it as a suitable selection criterion for early selection and overall genetic progress of lactation traits. The genetic trend analysis showed an overall improvement in all these traits, with observed gain of 98.4 g per year for 150DMY, 0.04 days per year for DIM, 0.5 g per year for PY and 220.5 g per year for TMY. We observed that selecting based on 150DMY would lead to a favourable indirect improvement for LW as 79 g and LS 0.04 units per generation. We, therefore, recommend employing 150DMY as the single trait selection criteria to enhance both milk productivity and reproductive potential of Alpine × Beetal goats.

112 Definition and Genetic Parameters Estimation for Climatic Resilience Indicators Derived from Longitudinal Vaginal Temperature Records in Lactating Sows Under Heat Stress Conditions

Abstract Climatic resilience (CR) can be defined as the ability of an animal to maintain euthermia under thermally stressful conditions. However, CR based on longitudinal physiological variables has not been included in current swine genetic selection schemes. This is the first study deriving novel CR indicators using automatically recorded vaginal temperatures (TV) and estimating genetic parameters for them. Therefore, the study objectives were to: 1) derive novel indicators of CR based on automatically recorded vaginal temperature (TV); and 2) estimate (co)variance components and genetic parameters for these indicators. TV of 1,381 lactating sows (parities 2 to 7; Landrace × Large White) were measured automatically every 10 minutes from June 5th, 2021 to July 30th, 2021 using a vaginally implanted thermochron data recorder. A total of 1,639 F1 (Landrace x Large White) sows within the studied population were genotyped using the PorcineSNP50K Bead Chip. A total of 18 HS indicators derived from Tv, their definitions, heritability estimates, and mean genomic estimated breeding value (GEBV) accuracies are shown in Table 1. Multi-trait animal models were fitted for estimating the (co)variance components, considering the effects of week of data collection, parity, and location (barn and room within barn) as fixed. Heritability estimates for these resilience traits ranged from 0.0004 ± 7.16E-6 (SlopeDe) to 0.291 ± 0.047 (HSAB). Most traits derived directly from vaginal temperature (e.g., Duration: 0.201 ± 0.033, MaxTv: 0.203 ± 0.032) are moderately heritable with substantial additive genetic variance. Besides, LnVar(Med) that is derived from the deviation between the real and predicted value had moderate heritability (0.196 ± 0.041) and high mean GEBV accuracy (0.616 ± 0.042). The indicators defined based on the slope of Tv and time had low heritability estimates, which are close to zero, and low mean GEBV accuracy (0.106 ± 0.050 – 0.337 ± 0.065). Among all the CR indicators, Duration, MaxTv, Nor_medvar, Nor_avevar, HSAA, and HSAB outperformed the other indicators with moderate heritability estimates and high average GEBV accuracies. Genetic correlations were estimated among the six indicators with moderate heritability and high mean GEBV accuracy. Moderate to high positive genetic correlations (0.508 ± 0.034 to 0.992 ± 0.025) were estimated among Duration, MaxTv, Nor_medvar, HSAB, and HSAA. LnVar(Med) showed low negative genetic correlations (-0.218 ± 0.028 to -0.039 ± 0.018) with the traits Duration, MaxTv, HSAA, and HSAB, except with Nor_medvar, which was positive (0.156 ± 0.022). Thus, Duration, LnVar(Med), MaxTv, Nor_medvar, HSAB, and HSAA might be promising CR indicator and contribute toward improving lactating sows’ resilience to thermal stress through genetic selection. New studies about the relationship between these new indicators and other economic important traits in pigs are required before including them in selection indexes.

124 Disease Resilience Indicators Based on Phagocytosis Assays on Blood from Young Healthy Pigs

Abstract Infectious diseases impact the swine industry through increased morbidity and mortality, leading to large economic losses and reduced animal welfare. Disease resilience is the ability of an animal to maintain production performance under pathogen exposure and has gained traction as an approach to help reduce the impact of infectious disease. For this purpose, a wean-to-finish polymicrobial natural disease challenge model was set up, in which, using a continuous flow system, batches of 60 or 75 young healthy Landrace × Yorkshire barrows from one of seven breeding companies of PigGen Canada were entered into a quarantine nursery before their entry in a nursery/finisher that was seeded with multiple pathogens. The objective of this study was to evaluate phagocytosis assays that can be conducted on blood from young healthy pigs as potential indicator traits to select for disease resilience in high-health nucleus breeding herds. Immune cell proportions and their phagocytic activity were evaluated in blood collected at ~26 days of age in the quarantine nursery on 985 pigs. Genetic parameters, including heritabilities and genetic correlations with disease resilience phenotypes collected on these pigs and an additional 2,220 pigs from the same companies in the polymicrobial challenge were estimated using GBLUP in ASReml 4.2, with the fixed effect of batch, the covariate of entry age, and random effects of pen by batch, litter, and additive genetics, using a genomic relationship matrix derived from genotypes of 650K single nucleotide polymorphisms. Results showed moderate heritability estimates for immune cell proportions (average = 0.36; range = 0.22-0.42) and the % of phagocytizing cells for each cell type (0.32; 0.19-0.48), but low estimates for mean fluorescence intensity (MFI) of the phagocytizing cells of each type (0.2; 0.05-0.3). Estimates of genetic correlations with disease resilience traits ranged from -0.93 to 0.72, but had substantial standard errors. Granulocyte % had a high positive genetic correlation with number of health treatments across the challenge nursery and finisher (0.72 ± 0.5), while a greater % phagocytizing eosinophils was genetically correlated with decreased growth rate in the challenge nursery (-0.26 ± 0.2) but greater growth rate (0.33 ± 0.2) and reduced mortality in the finisher (-0.78 ± 0.6) and across the challenge nursery and finisher (-0.50 ± 0.4). Greater MFI of phagocytizing eosinophils was also genetically correlated with reduced mortality across the challenge nursery and finisher (-0.93 ± 0.5). These results provide insights into potential indicator traits that can be used to select for disease resilience without the need to subject animals to disease, with the overall aim to improve animal welfare and increase production performance in herds that are subject to hard-to-manage infectious pathogens. This project was supported by Genome Canada, Genome Alberta, PigGen Canada, and USDA-NIFA grant #2017-67007-26144.

Genetic parameter estimates for daily predicted gross feed efficiency and its association with energy-corrected milk in South African Holstein cattle

Genetic parameters for daily predicted gross feed efficiency (pGFE) and energy corrected milk (ECM) in the first three parities of South African Holstein cattle were estimated by repeatability animal models. Data comprised of 11,068 test-day milk production records of 1,575 Holstein cows that calved between 2009 and 2019. Heritability estimates for pGFE were 0.12 ± 0.06, 0.09 ± 0.04 and 0.18 ± 0.05 in early, mid and late lactation, respectively. Estimates were moderate for primiparous (0.21 ± 0.05) and low for multiparous (0.10 ± 0.04) cows. Heritability and repeatability across all lactations were 0.14 ± 0.03 and 0.37 ± 0.03, respectively. Genetic correlations between pGFE in different stages of lactation ranged from 0.87 ± 0.24 (early and mid) to 0.97 ± 0.28 (early and late), while a strong genetic correlation (0.90 ± 0.03) was found between pGFE and ECM, across all lactations. The low to moderate heritability estimates for pGFE suggest potential for genetic improvement of the trait through selection, albeit with a modest accuracy of selection. The high genetic correlation of pGFE with ECM may, however, assist to improve accuracy of selection for feed efficiency by including both traits in multi-trait analyses. These genetic parameters may be used to estimate breeding values for pGFE, which will enable the trait to be incorporated in the breeding objective for South African Holstein cattle.

Genetic parameters for automatically-measured vaginal temperature, respiration efficiency, and other thermotolerance indicators measured on lactating sows under heat stress conditions

BackgroundGenetic selection based on direct indicators of heat stress could capture additional mechanisms that are involved in heat stress response and enable more accurate selection for more heat-tolerant individuals. Therefore, the main objectives of this study were to estimate genetic parameters for various heat stress indicators in a commercial population of Landrace × Large White lactating sows measured under heat stress conditions. The main indicators evaluated were: skin surface temperatures (SST), automatically-recorded vaginal temperature (TV), respiration rate (RR), panting score (PS), body condition score (BCS), hair density (HD), body size (BS), ear size, and respiration efficiency (Reff).ResultsTraits based on TV presented moderate heritability estimates, ranging from 0.15 ± 0.02 to 0.29 ± 0.05. Low heritability estimates were found for SST traits (from 0.04 ± 0.01 to 0.06 ± 0.01), RR (0.06 ± 0.01), PS (0.05 0.01), and Reff (0.03 ± 0.01). Moderate to high heritability values were estimated for BCS (0.29 ± 0.04 for caliper measurements and 0.25 ± 0.04 for visual assessments), HD (0.25 ± 0.05), BS (0.33 ± 0.05), ear area (EA; 0.40 ± 0.09), and ear length (EL; 0.32 ± 0.07). High genetic correlations were estimated among SST traits (> 0.78) and among TV traits (> 0.75). Similarly, high genetic correlations were also estimated for RR with PS (0.87 ± 0.02), with BCS measures (0.92 ± 0.04), and with ear measures (0.95 ± 0.03). Low to moderate positive genetic correlations were estimated between SST and TV (from 0.25 ± 0.04 to 0.76 ± 0.07). Low genetic correlations were estimated between TV and BCS (from − 0.01 ± 0.08 to 0.06 ± 0.07). Respiration efficiency was estimated to be positively and moderately correlated with RR (0.36 ± 0.04), PS (0.56 ± 0.03), and BCS (0.56 ± 0.05 for caliper measurements and 0.50 ± 0.05 for the visual assessments). All other trait combinations were lowly genetically correlated.ConclusionsA comprehensive landscape of heritabilities and genetic correlations for various thermotolerance indicators in lactating sows were estimated. All traits evaluated are under genetic control and heritable, with different magnitudes, indicating that genetic progress is possible for all of them. The genetic correlation estimates provide evidence for the complex relationships between these traits and confirm the importance of a sub-index of thermotolerance traits to improve heat tolerance in pigs.

Genetic evaluation of growth and reproductive traits for Dawuro sheep in Ethiopia

This study aimed to estimate genetic parameters and genetic trends for growth, reproductive traits, and inbreeding levels in Dawuro sheep. Data on the studied traits were collected between 2017 and 2022.The genetic parameters were estimated by fitting different univariate models, considering/ignoring maternal effects, using WOMBAT software. The estimated direct heritability obtained from the best-fit models were 0.07±0.03, 0.16 ± 0.04, 0.45 ± 0.27, 0.21 ± 0.07, and 0.48 ± 0.04 for birth weight (BWT), weaning weight (3WT), 6-month weight (6WT), average daily gain from birth to weaning (ADG1), and average daily gain from weaning to 6 months of age (ADG2), respectively. The estimated direct heritability for litter size (LS), lambing interval (LI), and annual reproductive rate (ARR) were 0.10 ± 0.10, 0.001 ± 0.10, and 0.09 ± 0.49, respectively. The trait selected for improvement was 6WT, which exhibited a positive genetic trend and moderate heritability estimates. Positive genetic trend suggests the potential for further enhancement of post-weaning lamb growth traits.

Genetic Variability, Heritability and Genetic Advance in Oleaginous Gourd Lagenaria siceraria (Molina) Standl

The present investigation was carried out to estimate phenotypic and genotypic coefficients of variation, heritability and genetic advance as percent of mean in F2 generation for seeds yield of Lagenaria siceraria and its components in three crosses NI283 x NI215, NI354 x NI215 and NI106 x NI215. For each family, involving six diverses parents on two locations, Abidjan and Manfla. The experimental layout was a randomized completed block design with three replications. The phenotypic coefficients of variation are higher than those of genotypic coefficients of variation in Abidjan and Manfla. That indicated the influence of environment in the expression of all characters. For fruit weight and number of seeds, average values recorded for genotypic and phenotypic coefficients of variation are all high in crosses made in two localities. High heritability with high genetic advance as percent of mean observed in majority of crosses indicates high degree of additive genes effect implies less control by environment on these traits. For 100-seed weigh high to moderate range of heritability in conjunction with high genetic advance as percent of mean was observed for this trait which indicates the preponderance of additive gene action governing the inheritance of this character and offers the best possibility of improvement through simple selection procedure. For seeds yield or seed weight, the values of the phenotypic and genotypic coefficients of variation are moderate and low respectively in the two localities. Moderate heritability estimate coupled with moderate genetic advance as percentage mean indicated the role of non additive genetic variance in their expression. A significant difference was recorded for all traits, indicating the presence of high degree of variability in the genotypes studied that suggesting the possibility of improving yield through selection for these traits.

Assessment of Genetic Variability, Heritability and Genetic Advance of Rice Genotypes (Oryza sativa L.)

The present investigation was carriedout with 25 rice genotypes. The evaluation was taken under three different environmental locations based on 11 quantitative traits. The trials were laid out in RBD with three replications at Students Instructional Farm, MES (Main Experimental Station) and Agronomy Farm of A.N.D.U.A.T., Kumarganj, Ayodhya. The environment-wise analysis of variance and pooled analysis of variance for three environments covering one crop seasons, revealed high significant mean squares for all the eleven characters under evaluation. Considering the mean performance of genotypes for different environmental conditions, the genotypes viz. T-3, Kavery Sampoorna, NDRK-11-27, Moti Gold and NDRK-11-29 were exhibiting high mean performance for grain yield per plant and some of its important components under irrigated condition. Three genotypes, T-3, Kavery Sampoorna, NDRK-11-27 possessed highest grain yield per plant among 25 genotypes across three environments. A wide range of phenotypic and genotypic coefficient of variability was observed. The high magnitude (&gt;20%) of PCV along with GCV observed for productive biological yield per plant (34.88), grain yield per plant (33.41%), L/B ratio (24.76) while high GCV recorded in biological yield per plant (31.00%), grain yield per plant (25.14%), no. of spikelet per panicle (21.15%). Moderate estimates of PCV along with GCV were recorded for harvest index (17.75%), panicle length (15.21%), plant height (13.6%) and days to 50% flowering (12.41%) and GCV were recorded productive tiller per plant (17.92%), harvest index (15.28%), leaf area index (13.81%), L/B ratio (13.55%), plant height (12.37%), days to 50% flowering (11.98%) and panicle length (10.75%). The magnitude of heritability in broad sense varied between 93.28% in case of days to 50% flowering to 27.37% in case of L/B ratio. The high estimation of heritability recorded into days to 50% flowering (93.28%) followed by plant height (82.72%), biological yield per plant (78.99%), spikelet fertility (75.70%). moderate estimates of heritability were reported for harvest index (74.08%), productive tiller per plant (69.72%), number of fertile spikelet per panicle (66.78%). while low estimates of heritability were reported in case of L/B ratio (27.37), leaf area index (31.14%). High heritability along with high genetics advance in percent of mean was recorded for days to 50% flowering indicating the preponderance of additive gene action.

Enumeration of Genetic Parameters and Genetic Diversity of Morpho-Physiological Traits in CIMMYT Bread Wheat Accessions [Triticum aestivum (L.) em. Thell

Fifty genotypes of CIMMYT bread wheat were evaluated at Agricultural Research Farm, BHU, Varanasi during 2019-2020.The analysis of variance revealed significant differences among genotypes for all traits. High Phenotypic coefficient of variation was recorded compared to the genotypic coefficient of variation. However, high genotypic coefficients of variation were found particularly for: grain yield per plot (8.71), harvest index (9.22), test weight (8.9), normalized difference vegetative index (9.59) and chlorophyll content (9.79), suggesting that these traits are having ample genetic potential for selection amongst genotypes, in breeding programs. The highest broad sense heritability manifested for harvest index (91.61%); remaining traits showed moderate estimates of heritability. Low to moderate genetic advance as percent mean was estimated for all the traits studied. This suggests the existence of variability for agronomic traits in the studied wheat genotypes which, should be exploited during future breeding programmes. Fifty genotypes were divided into six non-overlapping distinct clusters using tocher's method based on Euclidean distances. Thirty-one genotypes were classified in the first cluster accounting 62% of total genotypes followed by 15 genotypes categorized in the second cluster. The remaining four clusters have one genotype each. Divergence and cluster mean show that, crossings between genotypes of clusters (II, III), and VI could lead to recovery of good transgressive segregants for maximum heterosis in wheat varietal improvement.

Assessment of Genetic Variability, Cause and Effect Inter-relationship among Yield Component Characters in Maize (Zea mays L.)

The present investigation was carried out to assess genetic variability parameters, correlation coefficient analysis, path analysis in 21 maize genotypes for 15 quantitative traits viz Days to 50% tasseling, Days to 50% silking, Days to 50% tasseling, anthesis – silking interval, Days to 75% maturity, Plant height (cm), Ear height (cm), Cob length (cm), Cob girth (cm), Cob weight (g), Number of grain rows per cob, Number of grains per row, 100 grains weight (g), Biological yield per plant (g), Harvest index (%), Grain yield per plant (g) in Randomized Block Design with three replications in Kharif season of 2022 in experimentation field, Department of Genetics and Plant Breeding, Naini Agricultural Institute, Sam Higginbottom University Of Agriculture, Technology and Sciences, Prayagraj. Analysis of Variance revealed that high significant differences among the genotypes of all traits. Genotypes VL 19458, VL 19457, VL 183879, VL 19453 had depicted higher grain yield per plant. All the characters had expressed high to moderate estimates of heritability. GCV and PCV investigations revealed a high level of variation and the impact of environment in exhibiting of these traits. Grain yield per plant was positively and significantly associated at both genotypic and phenotypic levels, according to the correlation coefficient analysis between yield and yield attributing traits. In Phenotypic and Genotypic Path analysis a detailed analysis of diagonal values show positive direct effect on Grain yield per plant.

Prevalence and heritability of alcohol use disorders in 18-year old Swedish twins.

Background: Heritability of alcohol use disorders (AUDs) varies widely, with reported estimates of 30-78% in twin studies. This variation might be due to methodological differences (e.g., using different thresholds for AUDs, age differences between samples). Aim: To investigate the heritability of AUDs in a nation-wide sample of male and female twins in late adolescence (18 years). Participants: The study is based on data from 8,330 18-year-old Swedish monozygotic (MZ) and dizygotic (DZ) twins from the Child and Adolescent Twin Study (Sweden). Method: Univariate sex-limitation twin analyses were performed using (a) total AUDIT score, (b) different AUDIT cut-offs (AUDIT-10: potentially harmful alcohol use and most likely alcohol dependent ; AUDIT-C: potential hazardous alcohol consumption/active alcohol use disorders), and (c) a risk-group classification for alcohol dependence based on AUDIT total score. Results: Prevalence of potential hazardous alcohol consumption/active alcohol use was 57.1%, and for potentially harmful alcohol use prevalence was 26.5%. Prevalence was higher among females (59.0% and 31.1% respectively) than males (54.4% and 20.0% respectively). Overall, the results of the univariate model fitting indicated that there were qualitative sex differences in the genetic and environmental influences on AUDs, with generally moderate heritability estimates ranging between 0.37 and 0.50. Discussion: At odds with previous research, a harmful/hazardous drinking pattern was more common in this age group among females than a low-risk drinking pattern (where males were overrepresented). Heritability estimates were moderate throughout all measures and cut-offs, with equally high contributions from shared and non-shared environment. Sex-limitation models revealed qualitative sex differences for AUDs, suggesting that different genetic and/or environmental factors influence variation in AUDs in males and females.

Genetic association between feed efficiency, growth, scrotal circumference, and carcass traits in Guzerat cattle.

The objective of this study was to estimate the genetic parameters for feed efficiency-related traits and their genetic correlations with growth, male fertility, and carcass traits using multi-trait analysis in Guzerat cattle. Further, it aimed to predict the direct and correlated responses for feed efficiency traits when selection was applied for growth, male fertility, and carcass traits. The evaluated traits were adjusted weight at 120 (W120), 210 (W210), 365 (W365), and 450days of age (W450), adjusted scrotal circumference at 365days of age (SC365) and at 450days of age (SC450), scrotal circumference, ribeye area (REA), backfat thickness (BFT), rump fat thickness (RFT), residual feed intake (RFI), and dry matter intake (DMI). The genetic parameters were obtained by the restricted maximum likelihood method (REML), using an animal model in multi-trait analyses. The heritability estimates for W120, W210, W365, W450, SC365, and SC450 varied from low to high (0.17 to 0.39). The carcass traits, REA, BFT, and RFT, displayed low to moderate heritability estimates, 0.27, 0.10, and 0.31, respectively. The heritability estimates for RFI (0.15) and DMI (0.23) were low and moderate, respectively. The RFI showed low genetic correlations with growth traits, ranging from - 0.07 to 0.22, from 0.03 to 0.05 for scrotal circumference, and from - 0.35 to 0.16 for carcass, except for DMI, which ranged from 0.42 to 0.46. The RFI and DMI presented enough additive genetic variability to be used as selection criteria in Guzerat breed genetic improvement program. Additionally, the response to selection for RFI would be higher when selection is performed directly for this trait. The selection for residual feed intake would not promote unfavorable correlated responses for scrotal circumference, carcass (yield and finish), and growth traits. Therefore, the selection for more efficient animals would not compromise the productive, reproductive, and carcass performance, contributing to reduce the production costs, increasing the profitability and sustainability of beef cattle production in tropical areas.

Relationship between milk urea content and important milk traits in Holstein cattle

Breeding cattle with low nitrogen emissions has been proposed as a countermeasure against eutrophication due to dairy production. Milk urea content (MU) could potentially serve as a new readily measured indicator trait for nitrogen emissions by cows. Therefore, we estimated genetic parameters related to MU and its relationship with other milk traits. We analysed 4 178 735 milk samples collected between January 2008 and June 2019 from 261 866 German Holstein dairy cows during their first, second, and third lactations. Restricted maximum likelihood estimation was conducted using univariate and bivariate random regression sire models in WOMBAT. We obtained moderate average daily heritability estimates for the daily MU of 0.24 in first lactation cows, 0.23 in second lactation cows, and 0.21 in third lactation cows with average daily genetic SDs of 25.16 mg/kg, 24.93 mg/kg, and 23.75 mg/kg, respectively. Averaged over days in milk, the repeatability estimates were low at 0.41 in first, second, and third lactation cows. A strong positive genetic correlation was found between MU and milk urea yield (MUY; 0.72 on average). In addition, 305-day heritabilities were estimated as 0.50, 0.52, and 0.50 in first, second, and third lactation cows, respectively, with genetic correlations of 0.94 or higher for MU in different lactations. By contrast, the averaged estimates of the genetic correlations between MU and other milk traits were low (−0.07 to 0.15). Moderate heritability estimates clearly allow the possible selection for MU, and the near-zero estimates of genetic correlations indicate no risk of undesired correlated selection responses in other milk traits. However, a relationship still needs to be established between MU as an indicator trait and the target trait, defined as total individual nitrogen emissions.

Variance Components, Correlation and Path Coefficient Analysis of Morpho-Physiological and Yield Related Traits in Spider Plant (Gynandropsis gynandra (L.) Briq.) under Water-Stress Conditions

Drought is the most complex abiotic stress for crop production at the global level. Therefore, developing new African spider plant genotypes tolerant to drought stress is one of the best approaches to achieving and optimizing high yield potential with water use efficiency. Advances in the selection of this crop can be determined by an understanding of genetic variability, heritability, and the associations that exist among different traits. The aim of this study was to gather information that will aid in the breeding of African spider plant cultivars with improved drought tolerance. A randomized complete block design (RCBD) experiment with eighteen genotypes and four replications was carried out across three water regimes: severe drought (30% field capacity), intermediate drought (50% field capacity), and well-watered (100% field capacity), in two seasons. Data on twelve morpho-physiological traits were recorded. The analysis of variance showed significant differences among genotypes (p &lt; 0.05) in leaf yield and yield-related traits. The phenotypic coefficient of variation (PCV) was greater than the genotypic coefficient of variation (GCV) for all 12 traits evaluated. High to moderate heritability estimates combined with a high to moderate genetic advance were observed for number of leaves, leaf width, plant height and stem diameter under drought stress conditions, indicating that these traits are controlled by additive gene action. Because of their predominant additive gene effects, correlation with leaf yield and favorable direct and indirect effects via the other yield-attributing traits, number of leaves per plant, plant height, days to 50% flowering, relative water content, net photosynthesis and leaf length could be used as target traits to improve spider plant leaf yield under drought-stressed conditions.