Moderate Heritability Research Articles

Genetic Variability and Diversity in Red Onion (Allium cepa L.) Genotypes: Elucidating Morpho-Horticultural and Quality Perspectives

Onion (Allium cepa L.) is a prominent spice and vegetable crop farmed commercially worldwide. Variability is viewed as a key signal for any red onion enhancement effort. The current study was, therefore, carried out to learn about genetic variability and diversity among selected genotypes of 20 red onions at the C Block Farm, Bidhan Chandra Krishi Viswavidyalaya, India, during the winter (rabi) season of 2021–2022, in Randomized Complete Block Design (RCBD) with three replications. The characters, viz., average weight of bulbs (kg), neck thickness (cm), total soluble solids (°Brix), total sugar (%), and reducing sugar (%) demonstrated high heritability (97.38–99.97%) coupled with high genetic gain. Such traits were the least influenced by environmental effects, and additive gene action played a pivotal role in the manifestation of such characters. Traits with high heritability values (51.37–67.94%) demonstrate that the observed variability was under genetic control and provide an enormous range of possibilities for accomplishing selection depending on their phenotypic performances. For traits with moderate heritability, viz., bolting (%) and doubling (%), selection would be less effective but can still be given great importance. Based on correlation analysis, the character’s neck thickness, equatorial diameter, and polar diameter unveiled highly positive genetic correlation with the average weight of bulbs (0.120, 0.112; 0.194, 0.210 and 0.120, 0.112 for phenotypic and genotypic correlation coefficient values, respectively), which indicates that the average weight of a bulb would be increased by an increase in such components. According to path coefficient analysis, the equatorial diameter exhibited the most positive direct effect on the average weight of bulbs (0.968), followed by polar diameter (0.687) and neck thickness (0.159). A wide range of variations for qualitative traits, including foliage colour, leaf width, foliage behaviour, the degree of leaf waxiness, the shape of the bulb, and bulb skin colour were observed. Based on Mahalanobish D2 analysis, the genotypes were divided into four clusters. The highest number of genotypes was found in cluster I (eleven), followed by cluster IV (six genotypes) and cluster II (two genotypes). Cluster III had a single genotype and was monogenic. The study confirmed that a wide genetic variation prevailed in the onion genotypes taken under study, which could thereby be utilized in breeding programmes.

Genetic Analysis of F2 Populations for Quantitative Traits in Blackgram [Vigna mungo (L.) Hepper

Background: Blackgram is an important pulse crop grown in India. The creation of new variability through hybridization or mutation breeding will produce novel segregants for important yield attributing traits. The selection from the population will be effective if the traits have good genetic variability estimates. Methods: The present investigation was conducted on analysing genetic variability parameters in F2 populations of the blackgram crosses CO 5 × VBN 9 and CO 6 × VBN 11 which were evaluated during rabi, 2022. Results: Based on the coefficient of variations, it was found that sufficient amount of genetic variability and high to moderate heritability with high genetic advance were present in the populations for the traits viz., plant height, number of branches per plant, number of clusters per plant, number of pods per cluster, number of pods per plant and seed yield per plant indicates the presence of additive gene action which can be improved by simple selection in the earlier generations. The positive skewness was observed for the traits viz., number of branches per plant, number of pods per cluster, number of pods per plant, hundred seed weight and seed yield per plant in F2 population of CO 5 × VBN 9 and number of clusters per plant, number of pods per cluster, number of pods per plant and seed yield per plant in the F2 population of CO 6 × VBN 11. The above traits could be improved by intensive selection for rapid improvement. The leptokurtic nature of the distribution for the trait hundred seed weight in CO 5 × VBN 9 population and the traits viz., number of clusters per plant, number of pods per plant, pod length, number of seeds per pod and seed yield per plant in CO 6 × VBN 11 population indicates these traits are controlled by few minor genes. Hence, the good segregants could be selected from these two populations for yield improvement.

Study on Genetic Variability for Quantitative and Quality Parameters in Rice (Oryza sativa L.)

Genetic variability is the prime and fundamental requirement for any crop breeding to develop superior varieties which yields more and fulfills the demanding requirements of increasing population.The current study investigates twenty genotypes of rice, including one check variety NDR-359, that were raised in the Field Experimentation Centre of the Department of Genetics and Plant Breeding, SHUATS, Prayagraj during Kharif 2022 using a Randomized Block Design with three replications.The best genotypes for grain yield per plant were chosen based on the mean performance of genotypes RNR – 1446, followed by MTU - 1121, JGL – 24423, and Rango Komal. All of the qualities under examination had significant differences, according to the analysis of variance. The characters viz., Biological yield, Grain yield per hill, Number of spikelets per panicle exhibited high Genotypic Coefficient of Variation (GCV) and Phenotypic Coefficient of Variation (PCV). For all the features under study, there were very slight variations between GCV and PCV, indicating that the environment had little to no impact on these individuals. High heritability recorded in Biological yield (95.92%), Grain yield per hill (91.89%), Panicle length (91.80%), Plant height (91.00%) and Days to 50% flowering (87.81%), whereas moderate heritability observed in Flag leaf width (47.08%). High heritability coupled with genetic advance as percent mean is recorded in Biological yield (77.10), Grain yield per hill (59.72), Panicle length (24.65) and Plant height (34.50) indicating that simple selection could be effective for improving these characters. Correlation results shown that grain yield per hill exhibited highly and significantly correlation with biological yield and Number of spikelets per panicle. The results of the Path coefficient analysis revealed that both phenotypic and genotypic levels, had positive direct effects on grain yield while compare with parameters like Biological yield, Harvest index %, Number of panicles per hill and Days to 50% flowering. Quality characters i.e., hulling (%), cooking and eating characters i.e., kernel length and breadth before and after cooking, elongation ratio was taken for 19 genotypes. As per mean performance highest maximum grain length was observed in Kasturi, DRRH2, highest elongation ratio observed in MTU - 1121 and NLR - 40024.

Characterization of Tomato Genotypes for Important Fruit Quality Traits

Characterization of Tomato Genotypes for Important Fruit Quality Traits

The genomic architecture of high temperature tolerance in a year class of Atlantic Salmon

The yield from fisheries and aquaculture production has risen dramatically over the last few decades, with rising demands to meet the needs of a growing world population that is also consuming more seafood per capita. Aquaculture products have, in recent years, also overtaken tonnage obtained from wild fisheries. This is particularly true for finfish species such as Atlantic salmon. However, the marine lifecycle stage for Atlantic salmon aquaculture requires ocean-based net pens, which introduces environmental vulnerabilities that can negatively affect production. Of particular concern is the ability of the fish to tolerate rising seawater temperatures in the face of climate change. One way of tackling this challenge is to incorporate selective breeding for Atlantic salmon families that display greater tolerance to elevated seawater temperatures. The goal of this study was to determine the genomic heritability of seawater temperature tolerance in Atlantic salmon and to investigate the genetic architecture of this trait for more effective broodstock management. We report a moderate genomic-based heritability for seawater temperature at mortality in Atlantic salmon (0.208 ± 0.041) with a favourable correlation between growth traits (body mass and fork length) and seawater temperature at mortality. Our results also show that seawater temperature at mortality is a polygenic trait, with no significant quantitative trait loci identified. The moderate genomic heritability for seawater temperature at mortality suggests that this trait could be included in Atlantic salmon breeding programs. Importantly, the favourable correlation between growth traits and seawater temperature at mortality suggests that selection for seawater temperature tolerance would not have a negative impact on growth in this population. No single quantitative trait locus for seawater temperature at mortality was identified, suggesting that genomic selection will be required to achieve an increased tolerance to seawater temperature in this population.

Genetic architecture and polygenic risk score prediction of degenerative suspensory ligament desmitis (DSLD) in the Peruvian Horse.

Introduction: Spontaneous rupture of tendons and ligaments is common in several species including humans. In horses, degenerative suspensory ligament desmitis (DSLD) is an important acquired idiopathic disease of a major energy-storing tendon-like structure. DSLD risk is increased in several breeds, including the Peruvian Horse. Affected horses have often been used for breeding before the disease is apparent. Breed predisposition suggests a substantial genetic contribution, but heritability and genetic architecture of DSLD have not been determined. Methods: To identify genomic regions associated with DSLD, we recruited a reference population of 183 Peruvian Horses, phenotyped as DSLD cases or controls, and undertook a genome-wide association study (GWAS), a regional window variance analysis using local genomic partitioning, a signatures of selection (SOS) analysis, and polygenic risk score (PRS) prediction of DSLD risk. We also estimated trait heritability from pedigrees. Results: Heritability was estimated in a population of 1,927 Peruvian horses at 0.22 ± 0.08. After establishing a permutation-based threshold for genome-wide significance, 151 DSLD risk single nucleotide polymorphisms (SNPs) were identified by GWAS. Multiple regions of enriched local heritability were identified across the genome, with strong enrichment signals on chromosomes 1, 2, 6, 10, 13, 16, 18, 22, and the X chromosome. With SOS analysis, there were 66 genes with a selection signature in DSLD cases that was not present in the control group that included the TGFB3 gene. Pathways enriched in DSLD cases included proteoglycan metabolism, extracellular matrix homeostasis, and signal transduction pathways that included the hedgehog signaling pathway. The best PRS predictive performance was obtained when we fitted 1% of top SNPs using a Bayesian Ridge Regression model which achieved the highest mean of R2 on both the probit and logit liability scales, indicating a strong predictive performance. Discussion: We conclude that within-breed GWAS of DSLD in the Peruvian Horse has further confirmed that moderate heritability and a polygenic architecture underlies the trait and identified multiple DSLD SNP associations in novel tendinopathy candidate genes influencing disease risk. Pathways enriched with DSLD risk variants include ones that influence glycosaminoglycan metabolism, extracellular matrix homeostasis, signal transduction pathways.

Milk coagulation properties are moderately heritable in dairy cows: a meta-analysis using the random-effects model.

This study aimed to conduct a meta-analysis using the random-effects model to merge published genetic parameter estimates for milk coagulation properties (MCP: comprising rennet coagulation time (RCT), curd-firming time (k20), curd firmness 30 min after rennet addition (a30), titrable acidity (TA) and milk acidity or pH) in dairy cows. Overall, 80 heritability estimates and 157 genetic correlations from 23 papers published between 1999 and 2020 were used. The heritability estimates for RCT, a30, k20, TA, and pH were 0.273, 0.303, 0.278, 0.189 and 0.276, respectively. The genetic correlation estimates between RCT-a30, RCT-pH, and RCT-TA were 0.842, 0.549 and -0.565, respectively. Genetic correlation estimates between RCT and production traits were generally low and ranged from -0.142 (between RCT and casein content) to 0.094 (between RCT and somatic cell score). Moderate and significant genetic correlations were observed between a30-pH (-0.396) and a30-TA (0.662). Also, the genetic correlation estimates between a30 and production traits were low to moderate and varied from -0.165 (between a30 and milk yield) to 0.481 (between a30 and casein content). Genetic correlation estimates between pH and production traits were low and varied from -0.190 (between pH and milk protein percentage) to 0.254 (between pH and somatic cell score). The results of this meta-analysis indicated the existence of additive genetic variation for MCP that could be used in genetic selection programs for dairy cows. Because of the moderate heritability of MCP and small genetic correlations with production traits, it could be possible to improve MCP with negligible correlated effects on production traits.

Assessment of body shape variation using Elliptic Fourier descriptors and ellipse fitting estimators and their genetic estimates in the flatfish Senegalese sole

Body shape is an important morphological trait in aquaculture. This study investigates the use of Elliptic Fourier descriptors (EFDs) analysis and ellipse fitting estimators to assess shape variation in Senegalese sole and their genetic variance components. A total of 2271 fish were individually photographed and body contours reconstructed using 20 Elliptic Fourier harmonics. Principal component analysis identified four symmetric components that explained the 68.6% of the total variation. They were mainly related to the adjustment of the body to an ellipse (PC1s and PC3s) and caudal fin morphological features (PC2s, PC3s, PC4s). Moreover, four asymmetric components related to caudal fin (PC1a, PC2a, PC3a) and head orientation (PC4a) that explained 24.5% of the total variation were also found. In addition to EFDs, body perimeter and five ellipse fitting estimators including the maximum body height to caudal peduncle height ratio (MBH/CPH), body aspect ratio (AR), ellipticity (ELL), AR from theoretical ellipse (ARe) and solidity (SOL) were calculated. PC1s was strongly correlated with ARe, AR and ELL (≥0.75), PC2s with SOL (−0.79) and PC3s with AR and ELL (0.48–0.49). Males appeared more elliptic than females as revealed by all ellipse descriptors with a tendency to caudal fins with obtuse angles (PC3a) and heads orientated toward the abdominal cavity (PC4a). Overall, heritabilities for symmetric components were higher than for asymmetric. Heritabilities for body ellipse fitting estimators including PC1s were high or very high with the highest values for AR (0.80) and ARe (0.78) for body and whole-body, respectively. Heritability for MBH/CPH was high (0.51) with low genetic correlation with other morphological traits. Heritabilities for symmetrical and asymmetrical features of caudal fin were moderate or low and indirect selection using other highly correlated traits such as PC2s through SOL and PC3a through PC4a or PC1s would facilitate progress in the selection. Perimeter showed a moderate heritability and it was more genetically correlated with growth than shape-related traits. The data provided represent a valuable tool to assess body shape in sole and in the design of genetic breeding programs in Senegalese sole.

Rare functional variants in the CRP and G6PC genes modify the relationship between obesity and serum C-reactive protein in white British population.

C-reactive protein (CRP) is a sensitive biomarker of inflammation with moderate heritability. The role of rare functional genetic variants in relation to serum CRP is understudied. We aimed to examine gene mutation burden of protein-altering (PA) and loss-of-function (LOF) variants in association with serum CRP, and to further explore the clinical relevance. We included 161,430 unrelated participants of European ancestry from the UK Biobank. Of the rare (minor allele frequency <0.1%) and functional variants, 1,776,249 PA and 266,226 LOF variants were identified. Gene-based burden tests, linear regressions, and logistic regressions were performed to identify the candidate mutations at the gene and variant levels, to estimate the potential interaction effect between the identified PA mutation and obesity, and to evaluate the relative risk of 16 CRP-associated diseases. At the gene level, PA mutation burdens of the CRP (β = -0.685, p = 2.87e-28) and G6PC genes (β = 0.203, p = 1.50e-06) were associated with reduced and increased serum CRP concentration, respectively. At the variant level, seven PA alleles in the CRP gene decreased serum CRP, of which the per-allele effects were approximately three to seven times greater than that of a common variant in the same locus. The effects of obesity and central obesity on serum CRP concentration were smaller among the PA mutation carriers in the CRP (pinteraction = 0.008) and G6PC gene (pinteraction = 0.034) compared to the corresponding non-carriers. PA mutation burdens in the CRP and G6PC genes are strongly associated with decreased serum CRP concentrations. As serum CRP and obesity are important predictors of cardiovascular risks in clinics, our observations suggest taking rare genetic factors into consideration might improve the delivery of precision medicine.

Genetic Diversity and Population Structure Analysis of Potato Somaclones

Cultivated potato varieties are tetraploid and vegetatively propagated. Therefore genetic improvement for new traits is less effective through hybridization. The mutation is considered an alternative method for crop improvement of those varieties. This study aimed to evaluate the effects of gamma-ray irradiation on increasing genetic diversity among the somaclones and the changes in population structure. Forty-four somaclones were used as observed materials. The population was grown in a screen house using a completely randomized design with genotype (somaclone) as a single factor. Thirteen qualitatively and quantitatively morphological characters were observed. Six SSR markers were used for analyzing the population structure. The selection process was based on a weighting method divided into quartiles. Selected numbers were taken from quartile 3. Morphological analysis of stems and leaves resulted in five different somaclones, with significant differences in anthocyanin appearance and intensity of the green color of the leaflets. Diversity criteria based on quantitative characteristics showed a high level of diversity with a high heritability for tuber weight, length, and diameter and a moderate heritability for tuber number. Analyzing the population structure has offered insight into how gamma irradiation affected the somaclones. As a result of the selection, 12 somaclones met the requirements to serve as seed sources for field testing. It is expected that the results of this study will provide information about the diversity caused by gamma-ray irradiation treatment on potato somaclones and a method for improving the efficiency of the initial selection of potato populations.

Genetic diversity in Ethiopian sorghum germplasm for root system architecture and trait association

Sorghum productivity in arid and semi-arid regions of Africa is very low, mainly due to limited water availability. Roots are the primary conduit for plants to access moisture and nutrients. Root growth angle determines the direction of root elongation in the soil profile and is an important trait for adaptation to water-limited environments. Information on the extent of genetic variation in root system architecture (RSA) and its relationship with drought response is critical for improving the performance of the crop under drought stress. The objective of this study was to examine the degree of genetic variability for root and shoot traits in sorghum germplasm during the seedling stage. Two hundred and ninety-one sorghum germplasm adapted to different agroecologies of Ethiopia were phenotyped for root and shoot traits using a purpose-built root chamber in the greenhouse at Jimma University. The experiment was set up in a row-column design with three replicates. Significant genetic variation (P < 0.01) was observed for all traits examined except root hair number and shoot dry weight. Root angle varied from 9° to 21.3° with an average of 14.9° and showed moderate heritability of 44.38%. Root dry weight also exhibited moderate heritability (49.3%). Correlation and path coefficient analysis revealed that root angle (RA) was uncorrelated with other RSA traits. Cluster analysis using the RSA traits grouped the 291 genotypes into four different clusters. The first three principal components accounted for about 50% of the total variation. The results demonstrate that the Ethiopian sorghum germplasm exhibits large variation in RSA traits that can be harnessed in breeding programs to enhance sorghum productivity under drought stress.

GENETIC DIVERSITY OF DIFFERENT RADISH (RAPHANUS SATIVUS L.) CULTIVARS UNDER THE BASTAR PLATEAU OF CHHATTISGARH, INDIA

The presented study, held at the Research cum Instructional Farm of the College of Horticulture and Research Station, Jagdalpur, Chhattisgarh, India, ran during the Rabi season of 2021, to investigate superior radish cultivars for selection having high yield potential and better quality root for Bastar plateau. The experiment, laid out in randomized block design (RBD), had 15 treatments and three replications. Observing high genotypic and phenotypic coefficient of variation was for the following traits: dry and fresh weights of roots, plants, and leaves; root and leaf yields; days to 50% germination; the diameter and length of the root, North-South and East-West spread of the plant; plant height, and the number of leaf plant-1, having recorded significant heritability and high genetic advance. Similarly, high heritability showed for root yield and fresh and dry weights of roots. Moderate heritability levels appeared for the traits, viz., the plant’s dry weight and the root diameter. The genetic gain resulted high for characters, viz., root yield and fresh and dry weights of roots. High heritability followed by high genetic advance indicates that selection may be effective for improving such characteristics. Root yield (t ha-1) exhibited a highly significant positive correlation with the fresh weight of the plant at the phenotypic and genotypic levels, followed by dry weight of roots, dry weight of the plant, East-West spread of the plant, the diameter of the root, and leaf yield plot-1 . The fresh weight of roots had the maximum positive direct effect on root yield in the genotypic path, followed by the dry weight of roots and the plant, the East-West spread of the plant, the diameter of the root, and leaf yield in radish. The selection of these characters can benefit in improving the yield of radishes.

Estimation of the Heritabilities for Body Shape and Body Weight in Yellow River Carp (Cyprinus carpio haematopterus) Based on a Molecular Pedigree

Estimation of the heritability for a given phenotype would provide basic information for potential breeding programs. As one of the most precious common carp strains, Yellow River carp was subject to selection for fast growth and a slender body to meet market demands. In the present study, heritabilities for body shape (body length, BL and body height, BH) and body weight (BW) were estimated based on a molecular parentage assignment for 750 progenies from 58 half-sib and full-sib Yellow River carp families. Eight highly polymorphic microsatellites were used for the construction of the molecular pedigree, and the average observed heterozygosity (Ho), expected heterozygosity (He), and the polymorphism information content (PIC) were 0.841, 0.792, and 0.763, respectively. All 750 progenies were successfully assigned to single parental pairs with 100% accuracy. Using the linear mixed model, the heritabilities were estimated to be 0.268, 0.338, and 0.340 for BL, BH, and BW, respectively. High phenotypic (0.831–0.927) and genetic (0.952–0.987) correlations among these three traits suggested that selection for BW could also largely affect the body shape and vice versa. Moderate heritabilities and high genetic corrections revealed by this study strongly indicate substantial potentials for genetic improvement of both growth rate and body formation in Yellow River carp breeding programs.

Layer myocardial strain is the most heritable echocardiographic trait.

Myocardial deformation assessed by strain analysis represents a significant advancement in our assessment of cardiac mechanics. However, whether this variable is genetically heritable or whether all/most of its variability is related to environmental factors is currently unknown.We sought to determine the heritability of echocardiographically determined cardiac mechanics indices in a population setting. A total of 1357 initially healthy subjects (women 51.6%; 48.2 ± 14.1 years) were included in this study from 20 years follow-up after the 4th visit of the longitudinal familial STANISLAS cohort (Lorraine, France). Data were acquired using state-of-the-art cardiac ultrasound equipment, using acquisition and measurement protocols recommended by the EACVI/ASE/Industry Task Force. Layer-specific global longitudinal strain (GLS) and global circumferential strain (GCS) (full-wall, subendocardial and subepicardial) and conventional structural and functional cardiac parameters and their potential heritability were assessed using restricted maximum likelihood analysis, with genetic relatedness matrix calculated from genome-wide association data. Indices of longitudinal/circumferential myocardial function and left ventricular (LV) ejection fraction had low heritability (ranging from 10 to 20%). Diastolic and standard LV function parameters had moderate heritability (ranging from 20 to 30%) except for end-systolic and end-diastolic volumes (respectively 30 and 45%). In contrast, GLSEndo/GLSEpi ratio had a high level of heritability (65%). Except for GLSendo/GLSepi ratio, a large percentage of variance remained unexplained (greater than 50%). In our population cohort, GLSendo/GLSepi ratio had a high level of heritability whereas other classical and mechanical LV function parameters did not. Given the increasing recognition of GLSendo/GLSepi ratio as an early/sensitive imaging biomarker of systolic dysfunction, our results suggest the possible existence of individual genetic predispositions to myocardial decline.

Genetic Parameter Estimates of Growth Curve and Feed Efficiency Traits in Japanese Quail.

This study aimed to estimate heritabilities for weekly body weight traits, the Gompertz growth curve parameters, and feed efficiency characteristics, as well as genetic correlations among characteristics. A total of 700 Japanese quails with pedigree records were used in this study. Body weight and feed consumption were measured individually on a weekly basis. Using weekly body weight data, the growth model parameters were estimated for each bird using the Gompertz nonlinear regression model. Multi-trait variance-covariance matrices were obtained with Bayesian inference using the Gibbs sampler. While estimates of high heritability (0.59 to 0.61) were found for weekly body weight traits, estimates of moderate heritability (0.23 to 0.37) were determined for feed intake and feed conversion efficiency traits. The estimated heritabilities for the parameters of the Gompertz model and inflection point coordinates were moderate (0.37 to 0.47). While genetic correlations between feed intake and body weight characteristics were positive and moderate (0.28 to 0.49), the genetic correlations between feed conversion efficiency and body weight traits were positive and strong (0.52 to 0.83). It has been concluded that the moderate negative genetic relationship between feed conversion efficiency and body weight may constrain selection studies. Due to the weak genetic correlation between the asymptotic body weight parameter of the Gompertz model and the feed conversion efficiency, it is thought that the total genetic gain will be greater if the mature weight parameter is also used as a selection criterion in genetic improvement studies.

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.

Smaller cornu ammonis (CA3) as a potential risk factor for suicidal behavior in mood disorders

Mood disorders and suicidal behavior have moderate heritability and familial transmission, and are associated with smaller hippocampal volumes. However, it is unclear whether hippocampal alterations reflect heritable risk or epigenetic effects of childhood adversity, compensatory mechanisms, illness-related changes, or treatment effects. We sought to separate the relationships of hippocampal substructure volumes to mood disorder, suicidal behavior, and risk and resilience to both by examining high familial risk individuals (HR) who have passed the age of greatest risk for psychopathology onset. Structural brain imaging and hippocampal substructure segmentation quantified Cornu Ammonis (CA1-4), dentate gyrus, and subiculum gray matter volumes in healthy volunteers (HV, N = 25) and three groups with one or more relatives reporting early-onset mood disorder and suicide attempt: 1. Unaffected HR (N = 20); 2. HR with lifetime mood disorder and no suicide attempt (HR-MOOD, N = 25); and 3. HR with lifetime mood disorder and a previous suicide attempt (HR-MOOD + SA, N = 18). Findings were tested in an independent cohort not selected for family history (HV, N = 47; MOOD, N = 44; and MOOD + SA, N = 21). Lower CA3 volume was found in HR (vs. HV), consistent with the direction of previously published findings in MOOD+SA (vs. HV and MOOD), suggesting the finding reflects a familial biological risk marker, not illness or treatment-related sequelae, of suicidal behavior and mood disorder. Familial suicide risk may be mediated in part by smaller CA3 volume. The structure may serve as a risk indicator and therapeutic target for suicide prevention strategies in high-risk families.

Breeding Dual-Purpose Maize: Grain Production and Biofuel Conversion of the Stover

The improvement of maize double cropping has become increasingly important in recent years. In order to establish breeding programs for sustainable maize production, the goals of the research were (i) to understand the correlations between grain and stover yield and saccharification efficiency, and (ii) to identify QTL and metabolic pathways to design of breeding programs in a double exploitation approach. We carried out a genome-wide association study (GWAS) and a metabolic pathway analysis using a panel of highly diverse maize inbreds. As results, we have obtained that the regulation of energetic and developmental pathways have been pointed out as key pathways related to stover quantity and utilization, while no specific pathways could be identified in relation to grain yield. However, due to the moderate high heritability of yields and their positive correlation a phenotypic selection approach would be adequate for the improvement of both yields, while for saccharification efficiency improvement upcoming genomic selection models are more advisable. Overall, breeding strategies that manage the dual use of maize are viable and will contribute to a more sustainable maize crop in the near future.

Strategies to improve genomic predictions for 35 duck carcass traits in an F2 population

BackgroundCarcass traits are crucial for broiler ducks, but carcass traits can only be measured postmortem. Genomic selection (GS) is an effective approach in animal breeding to improve selection and reduce costs. However, the performance of genomic prediction in duck carcass traits remains largely unknown.ResultsIn this study, we estimated the genetic parameters, performed GS using different models and marker densities, and compared the estimation performance between GS and conventional BLUP on 35 carcass traits in an F2 population of ducks. Most of the cut weight traits and intestine length traits were estimated to be high and moderate heritabilities, respectively, while the heritabilities of percentage slaughter traits were dynamic. The reliability of genome prediction using GBLUP increased by an average of 0.06 compared to the conventional BLUP method. The Permutation studies revealed that 50K markers had achieved ideal prediction reliability, while 3K markers still achieved 90.7% predictive capability would further reduce the cost for duck carcass traits. The genomic relationship matrix normalized by our true variance method instead of the widely used sum {2p}_{i}(1-{p}_{i}) could achieve an increase in prediction reliability in most traits. We detected most of the bayesian models had a better performance, especially for BayesN. Compared to GBLUP, BayesN can further improve the predictive reliability with an average of 0.06 for duck carcass traits.ConclusionThis study demonstrates genomic selection for duck carcass traits is promising. The genomic prediction can be further improved by modifying the genomic relationship matrix using our proposed true variance method and several Bayesian models. Permutation study provides a theoretical basis for the fact that low-density arrays can be used to reduce genotype costs in duck genome selection.

Heritability and Selection Using GGE Biplots and the Sustainability Index (SI) of Maize Mutants under Different Cropping Systems in Upland

A good maize plant breeding program must consider the effect of genotype-by-environment interactions (GEIs) and the correlation of important traits. The purpose of this study was to evaluate genetic variation, identify and investigate the implications of GEIs on breeding maize mutants in order to determine the ideal genotypes (stable and high yield), identify the best intercropping system for maize mutants, and identify the heritability and relationships of the traits tested that are important in cultivation. This research was carried out in five different intercropping systems in Upland West Java, Indonesia. A randomized block design with two replications was used in the field experiment. The measurement results revealed that the genetic diversity of maize mutants is broad, with six axes having eigenvalues ranging from 8.76 to 1.07 and a cumulative value of 76.64%. The neighbor-joining tree also showed a wide range of variation, yielding five distinct groups. The GEIs had a significant effect on the 14 traits tested, particularly yield. The environment had a significant impact on the variation of all the traits tested. The ideal cropping system for selecting the ideal maize mutant was Environment 4 (maize + rice). Superior maize mutants were successfully selected based on the GGE biplot. Thus, the sustainability index (SI) was used to successfully select maize mutants that were superior by 20.00%. These two methods selected only 15.00% of the maize mutants. One trait has a low heritability value, five traits have a moderate heritability value, and 17 traits have a high heritability value. The yields correlated positively and significantly with nine yield traits. Future maize-breeding programs can be based on data on genetic diversity, heritability, and the relationship of the traits tested. The best intercropping system can be used as an alternative for increasing maize cultivation income. Selected maize mutants can be proposed as new superior genotype candidates.