Genetic Heritability Research Articles

Assessment of Genetic Divergence and Character Association Studies on Germplasm Accessions of Rice (Oryza sativa L.)

In this study, fifty-five rice germplasm accessions were used along with five checks, namely IR64, Swarna, Jaya, DRR Dhan 42 and MTU1010, for evaluating genetic variability, heritability and genetic advance during kharif 2023. The analysis of variance revealed extremely large genotype differences for each of the 16 traits under investigation. The highest heritability measures were found in number of filled grains per panicle followed by paddy breadth, paddy length:breadth ratio, brown rice length:breadth ratio, 100 seed weight, paddy length, plant height, brown rice breadth, number of effective tillers per plant, brown rice length, number of unfilled grains per panicle, grain yield per plant, panicle length, and harvest index. High heritability with high genetic advance shown by characters such as plant height, number of filled grains per panicle, paddy length and brown rice length this indicates that the heritability is due to additive gene action and is found least influenced by environment. Hence, the desirable characters with high heritability coupled with genetic advance can be used for selection. Grain yield per plant exhibits a positive and highly significant correlation with the days to 50% flowering (0.383), number of effective tillers per plant (0.315), number of filled grain per panicle (0.219) and paddy length (0.219). In terms of direct effect, paddy length (4.735) shows the highest impact, followed by brown rice length (1.183), number of filled grain per panicle (0.578), days to 50% flowering (0.347), panicle length (0.135), harvest index (0.082).

Unveiling the Rice Hybrid Parental Lines - A Study of Genetic Variability for Yield Attributing Traits (Oryza sativa. L)

Fifty-five rice hybrid parental lines along with five checks were evaluated in augmented block design (ABD) at ICAR-IIRR Hyderabad, to determine the genetic variability, heritability and genetic advance for ten traits during Rabi,2023-24. Analysis of variance showed that significant variation was present in the hybrid parental lines studied. The phenotypic coefficient of variation was found to be higher than the genotypic coefficient of variation for all the traits. High GCV (Genotypic Coefficient of Variation) and PCV (Phenotypic Coefficient of Variation) levels were recorded for number of productive tillers (20.12% and 22.28%) and grain yield per plant (21.82% and 23.88%) respectively. Heritability was high for all the traits studied. High heritability coupled with high genetic advance as percent of mean was recorded for majority of the traits suggesting importance should be given to these characters during selection.

Genetic potential of papaya genotypes: insights from agronomic descriptors and parameter estimation

Carica papaya L., a fruit crop of high nutritional and economic importance, faces significant challenges regarding yield stability, fruit quality and environmental stress tolerance. This study explored genetic variation, heritability and trait correlations to support targeted papaya breeding programs. Through a Line × Tester mating design, 40 F1 hybrids were developed from 14 parental genotypes, revealing considerable genetic diversity. High heritability values (87.25% – 99.65%) for key traits confirmed the strong genetic influence on fruit yield, size and number of fruits per plant. Notable anticipated genetic advances, particularly for fruit yield (93.16%), emphasize the prospects for substantial improvement through selective breeding. Traits such as fruit yield per plant (45.30%), fruit weight (39.06%) and number of fruits per plant (31.46%) showed the highest genotypic and phenotypic variability. The study also highlighted the impact of environmental factors, as phenotypic coefficients of variation exceeded genotypic coefficients across traits, underlining the need for integrating ecological adaptability in breeding strategies. These results emphasize the importance of utilizing genetic diversity to enhance papaya yield and quality, meeting both domestic and global market demands. By leveraging the observed genetic potential, breeders can develop improved genotypes that align with sustainability goals, ensuring higher productivity, better market returns and enhanced food security in papaya-producing regions.

Exome sequencing identifies protein-coding variants associated with loneliness and social isolation.

Loneliness and social isolation are serious yet underappreciated public health problems, with their genetic underpinnings remaining largely unknown. We aimed to explore the role of protein-coding variants in the manifestation of loneliness and social isolation. We conducted the first exome-wide association analysis on loneliness and social isolation, utilizing 336,115 participants of white-British ancestry for loneliness and 346,115 for social isolation. Sensitivity analyses were performed to validate the genetic findings. We estimated the genetic burden heritability of loneliness and social isolation and provided biological insights into them. We identified six novel risk genes (ANKRD12, RIPOR2, PTEN, ARL8B, NF1, and PIMREG) associated with loneliness and two (EDARADD and GIGYF1) with social isolation through analysis of rare coding variants. Brain-wide association analysis uncovered 47 associations between identified genes and brain structure phenotypes, many of which are critical for social processing and interaction. Phenome-wide association analysis established significant links between these genes and phenotypes across five categories, mostly blood biomarkers and cognitive measures. The measurements of loneliness and social isolation in UK Biobank are brief for these multi-layer social factors, some relevant aspects may be missed. Our study revealed 13 risk genes associated with loneliness and 6 with social isolation, with the majority being novel discoveries. These findings advance our understanding of the genetic basis of these two traits. The study provides a foundation for future studies aimed at exploring the functional mechanisms of these genes and their potential implications for public health interventions targeting loneliness and social isolation.

Genetic Variability, Heritability, and Genetic Advance of Garlic (Allium sativum L.) Genotypes among Bulb Yield and Related Traits at Kulumsa, Southeastern Ethiopia

Genetic Variability, Heritability, and Genetic Advance of Garlic (Allium sativum L.) Genotypes among Bulb Yield and Related Traits at Kulumsa, Southeastern Ethiopia

Assessment of Genetic Variability, Heritability and Correlation in Crossandra (Crossandra infundibuliformis (L.) (Nees) Genotypes

Assessment of Genetic Variability, Heritability and Correlation in Crossandra (Crossandra infundibuliformis (L.) (Nees) Genotypes

Genomic prediction for yield and malting traits in barley using metabolomic and near-infrared spectra

Key messageGenetic variation for malting quality as well as metabolomic and near-infrared features was identified. However, metabolomic and near-infrared features as additional omics-information did not improve accuracy of predicted breeding values.Significant attention has recently been given to the potential benefits of metabolomics and near-infrared spectroscopy technologies for enhancing genetic evaluation in breeding programs. In this article, we used a commercial barley breeding population phenotyped for grain yield, grain protein content, and five malting quality traits: extract yield, wort viscosity, wort color, filtering speed, and β-glucan, and aimed to: (i) investigate genetic variation and heritability of metabolomic intensities and near-infrared wavelengths originating from leaf tissue and malted grain, respectively; (ii) investigate variance components and heritabilities for genomic models including metabolomics (GOBLUP-MI) or near-infrared wavelengths (GOBLUP-NIR); and (iii) evaluate the developed models for prediction of breeding values for traits of interest. In total, 639 barley lines were genotyped using an iSelect9K-Illumina barley chip and recorded with 30,468 metabolomic intensities and 141 near-infrared wavelengths. First, we found that a significant proportion of metabolomic intensities and near-infrared wavelengths had medium to high additive genetic variances and heritabilities. Second, we observed that both GOBLUP-MI and GOBLUP-NIR, increased the proportion of estimated genetic variance for grain yield, protein, malt extract, and β-glucan compared to a genomic model (GBLUP). Finally, we assessed these models to predict accurate breeding values in fivefold and leave-one-breeding-cycle-out cross-validations, and we generally observed a similar accuracy between GBLUP and GOBLUP-MI, and a worse accuracy for GOBLUP-NIR. Despite this trend, GOBLUP-MI and GOBLUP-NIR enhanced predictive ability compared to GBLUP by 4.6 and 2.4% for grain protein in leave-one-breeding-cycle-out and grain yield in fivefold cross-validations, respectively, but differences were not significant (P-value > 0.01).

Assessment of genetic variability, heritability and genetic advance in bread wheat (Triticum aestivum L.)

Assessment of genetic variability, heritability and genetic advance in bread wheat (Triticum aestivum L.)

Estimation of genetic variability, heritability, and genetic advance for drought-tolerant traits in an F2 mapping population of rice

Estimation of genetic variability, heritability, and genetic advance for drought-tolerant traits in an F2 mapping population of rice

Genetic Variability, Heritability and Genetic Advance for Yield and Yield Related Traits in Rice (Oryza Sativa L.)

Aims: To evaluate genetic variability, heritability, and genetic advance for key agronomic traits in rice to identify traits with high potential for selection and improvement in breeding programs. Experimental Design: The experiment was conducted in a randomized block design (RBD) with three replications. Place and Duration of Study: Regional Sugarcane and Rice Research Station (RS&RRS), Rudrur, Nizamabad, during the kharif 2022 season. Methodology: Eighteen Advanced Varietal Trial (AVT) entries were evaluated with a spacing of 20 cm × 15 cm. Data were recorded from five randomly selected plants per entry in each replication for agronomic and yield-related traits: days to 50% flowering (DFF), plant height (PH), panicle length, number of panicles per square meter, filled grains per panicle, 1000-grain weight, and grain yield per hectare (GY/ha). Analysis of variance (ANOVA) and genetic parameters, including environmental coefficient of variation (ECV), genotypic and phenotypic coefficients of variation (GCV and PCV), heritability (h²), and genetic advance as a percentage of the mean (GAM), were calculated using Windostat Version 9.1. Results: The ECV was low across all traits, indicating minimal environmental influence. GCV was low for DFF (4.957%) and PH (4.789%) but moderate for filled grains per panicle (15.874%) and 1000-grain weight (16.33%). PCV was slightly higher than GCV for most traits, confirming limited environmental effects. Heritability ranged from medium (37.4% for GY/ha) to very high (99.7% for 1000-grain weight). GAM was high for filled grains per panicle (31.96%) and 1000-grain weight (33.586%), indicating strong potential for genetic improvement. Conclusion: Traits with high heritability and genetic advance, such as filled grains per panicle and 1000-grain weight, are ideal for selection. These findings will aid in enhancing rice breeding programs through targeted genetic improvement.

Genetic Parameters in Germplasm Lines for Yield and Its Contributing Traits in Grain Amaranth (Amaranthus hypochondriacus L.)

The present investigation was conducted to estimate the genetic variability, heritability and genetic advance of genotypes of grain amaranth during kharif, 2022 at Agricultural Research Station, Tornala. Fifty nine genotypes of grain amaranth along with 4 checks (Suvarna, BGA-2, GA-5 and RMA 7) were evaluated in an augmented block design for access their performances. High phenotypic and genotypic coefficient of variation were observed for grain yield/plant (82.73/82.70), no. of spikelets/ plant (62.41/62.36), inflorescence length (49.72/49.66), plant height (41.54/41.47) and days to 50% flowering (21.78/21.66) indicating the presence of high variability in germplasm for selection. The characters viz., days to 50% flowering, plant height, inflorescence length, no. of spikelets/ plant and yield/plant expressed high heritability coupled with high genetic advance as percent of mean, which indicates preponderance of additive gene action in controlling the traits. Hence, the characters having high GCA & PCA can be relied upon and simple selection can be practiced for further improvement. Based on the performance, genotypes SKGPA183, EC322998, IC 551493, IC 551496 and IC 551499 have been found superior among the genotypes which can be used in breeding programmes for crop improvement.

Genetic variability, heritability and genetic advance in chrysanthemum (Dendranthema grandiflora) genotypes evaluated for loose flower production

Genetic variability, heritability and genetic advance in chrysanthemum (Dendranthema grandiflora) genotypes evaluated for loose flower production

Submergence tolerance in rice: A comprehensive screening of 250 Indian landraces for resilience under water stress

As erratic rainfall and flooding pose serious threats to rice yields, submergence tolerance is critical for sustainable cultivation. This study screened 250 Indian rice landraces at the seedling stage to identify genotypes capable of surviving submergence stress. Advanced statistical analyses, including trait association, variability, principal component analysis and cluster analysis, revealed the genetic and phenotypic factors influencing submergence stress tolerance. Significant variability was observed among the genotypes for key traits, such as shoot elongation, leaf regeneration and survival percentage. Diversity analysis through cluster analysis indicated that cluster III, particularly IRGC93, IRGC535 and IRGC706, exhibited survival rates exceeding 85%, highlighting their potential as donor lines for submergence tolerance. Further biochemical analysis of selected lines with survival percentages greater than 50% revealed that tolerance is associated with greater chlorophyll and non-structural carbohydrate retention percentages. The findings emphasize the importance of genetic variability and heritability in breeding resilient rice varieties for flash flooding conditions. This research contributes to advancing rice breeding strategies to produce submergence-tolerant varieties, thereby promoting the sustainability and productivity of paddy production systems.

Studies on Genetic Variability, Heritability and Genetic Advance in Fennel (Foeniculum vulgare Mill.)

The present investigation was carried out with a view to study the extent of variability, heritability in broad sense, genetic advance in per cent of mean in fennel during Rabi season 2018-19 in Augmented Block Design. Plant spacing of 60cm x 40cm and each genotypes were grown in the plot size of 2.0 m x 1.2 m. The observations were recorded on ten characters. In Analysis of variance, the variances due to checks and genotypes were highly significant for all the characters, while, the variance due to blocks were significant for days to 50%flowering, number of umbels per plant and number of umbellets per umbel. Based on mean performance NDF-1, NDF-2, NDF-58, NDF-59, NDF-55, NDF-60 and NDF-76 were observed as significant and most promising genotypes for seed yield per plant and its component traits. The estimates of phenotypic coefficients of variation (PCV) were higher than genotypic coefficient of variation (GCV) for all traits. High magnitudes of variability PCV and GCV were observed in case of seed yield per plant (37.12, 36.95) followed by number of umbels per plant (30.89, 29.78), number of branches per plant (28.25, 22.92), weight of grains per umbel (26.02, 24.01) and number of umbellets per umbel (21.29,19.80). High heritability was observed for all the characters except number of branches per plant (65.83%) having moderate heritability. While, high genetic advance in per cent of mean was estimated for seed yield per plant (75.76) followed by number of umbels per plant (59.13). The high heritability coupled with high genetic advance in per cent of mean was estimated for maximum characters which indicated opportunity for selection response.

Genetic Variant Analyses Identify Novel Candidate Autism Risk Genes from a Highly Consanguineous Cohort of 104 Families from Oman.

Deficits in social communication, restricted interests, and repetitive behaviours are hallmarks of autism spectrum disorder (ASD). Despite high genetic heritability, the majority of clinically diagnosed ASD cases have unknown genetic origins. We performed genome sequencing on mothers, fathers, and affected individuals from 104 families with ASD in Oman, a Middle Eastern country underrepresented in international genetic studies. This approach identified 48 novel candidate genes significantly associated with ASD in Oman. In particular, 35 of these genes have been previously implicated in neurodevelopmental disorders (NDDs) in other populations, underscoring the conserved genetic basis of ASD across ethnicities. Genetic variants within these candidate genes that would impact the encoded protein included 1 insertion, 4 frameshift, 6 splicing, 12 nonsense, and 67 missense changes. Notably, 61% of the SNVs were homozygous, suggesting a prominent recessive genetic architecture for ASD in this unique population. The scarcity of genetic studies on ASD in the Arabian Peninsula has impeded the understanding of the unique genetic landscape of ASD in this region. These findings help bridge this knowledge gap and provide valuable insights into the complex genetic basis of ASD in Oman.

Exploring Genetic Variability in Rice for Yield Improvement under Low Phosphorus Soil Conditions

Phosphorus (P) is an essential macronutrient for all living organisms. P deficiency in soils is a major limiting factor for crop growth in rice and reduces yield. Understanding genetic variability for low P tolerance is crucial for improvement of rice genotypes for this stress. This study was conducted under low soil P and normal conditions to evaluate genetic variability in yield and its associated traits among rice genotypes. The experimental material consists of 91 F2:3 mapping population along with two checks, planted in a low P and normal plot at ICAR-IIRR, Hyderabad. Traits assessed included days to 50% flowering, plant height, total number of tillers, number of productive tillers per plant, flag leaf length, flag leaf width, panicle length, total number of grains per panicle, spikelet fertility, single plant yield, shoot length, root length, root volume, dry root weight, dry shoot weight and root to shoot ratio. ANOVA analysis suggested, mean sum of squares due to test genotypes were significant (p<0.01) for most of the traits under study. Plant height, number of tillers per plant, number of productive tillers per plant, flag leaf length, number of grains per panicle, spikelet fertility, single plant yield, shoot length, root volume, shoot dry weight, root dry weight and root to shoot ratio possessed high GCV and PCV values under low P condition. Genetic advance as per cent of mean for all traits possessed high genetic advance as per cent mean except for days to 50% flowering which showed medium GAM under low P condition. The genotypes showed varied response to genetic variability, heritability and genetic advance as per cent mean for days to 50% flowering (low), plant height (high), number of productive tillers per plant (high), panicle length (medium to high), flag leaf length (high), flag leaf width (medium to high), number of grains per panicle (high), spikelet fertility (high), single plant yield (high), root volume (high), shoot dry weight (high), root dry weight (high) and root to shoot ratio (high) under low P condition. This study identified these traits with high genetic variability and heritability, which are useful for developing P efficient rice cultivars and selection based on these traits would improve the rice for low soil P tolerance.

Advancing crop improvement through GWAS and beyond in mung bean.

Accessing the underlying genetics of complex traits, especially in small grain pulses is an important breeding objective for crop improvement. Genome-wide association studies (GWAS) analyze thousands of genetic variants across several genomes to identify links with specific traits. This approach has discovered many strong associations between genes and traits, and the number of associated variants is expected to continue to increase as GWAS sample sizes increase. GWAS has a range of applications like understanding the genetic architecture associated with phenotype, estimating genetic correlation and heritability, developing genetic maps based on novel identified quantitative trait loci (QTLs)/genes, and developing hypotheses related to specific traits in the next generation. So far, several causative alleles have been identified using GWAS which had not been previously detected using QTL mapping. GWAS has already been successfully applied in mung bean (Vigna radiata) to identify SNPs/alleles that are used in breeding programs for enhancing yield and improvement against biotic and abiotic factors. In this review, we summarize the recently used advanced genetic tools, the concept of GWAS and its improvement in combination with structural variants, the significance of combining high-throughput phenotyping and genome editing with GWAS, and also highlights the genetic discoveries made with GWAS. Overall, this review explains the significance of GWAS with other advanced tools in the future, concluding with an overview of the current and future applications of GWAS with some recommendations.

Genetic Variability and Heritability in Bitter Gourd for better Yield and Quality under Sodic Soil

Bitter Gourd (Momordica charantia) is a tropical and subtropical vine widely grown in Asian and African countries. This study evaluates thirty genotypes of bitter gourd for about eight quantitative characters under sodic soil during 2022-23. The evaluation was carried out using Randomized Block Design with three replications. All the parameters exhibited significant differences among the genotypes. The genotype MCPKM-04 recorded for the highest number of fruits and fruit yield while MCPKM-19 recorded superiority in terms of earliness. The quality parameters viz., ascorbic acid and phenol content observed highest in the genotype MCPKM-05. Yield parameters viz., number of fruits, fruit weight and fruit yield exhibited higher GCV, while close association of GCV and PCV were observed in all the studied parameters suggesting that the variations are only due to genetic differences and not due to environment.

Endometriosis-Related Genetic Factors and Their Role in Preterm Birth: A Two-Sample Mendelian Randomisation Study.

Endometriosis affects 10% of women worldwide and is linked to adverse pregnancy outcomes, including preterm birth. Recent epidemiological and genetic studies indicate that endometriosis may influence gestational duration and the likelihood of preterm birth. This study aimed to estimate the direct genetic causal effects of endometriosis on gestational duration and preterm birth using Mendelian randomisation (MR) analysis, leveraging genetic data from recent genome-wide association studies (GWASs). A two-sample MR study. Summary statistics from published GWASs on European ancestry populations for endometriosis and gestational duration. Instrumental variables for endometriosis were derived from a meta-analysis comprising 60 674 endometriosis cases and 701 926 controls. Genetic correlations and heritability estimates were calculated using linkage disequilibrium score regression. Two-sample MR with multiplicative random-effects inverse variance weighting assessed the primary objectives, supplemented by sensitivity analyses to validate MR assumptions. Primary outcomes were gestational duration and preterm birth, sourced from the latest GWAS data. LD score regression revealed no genetic correlation between endometriosis and either gestational duration or preterm birth. MR analysis showed no causal association between endometriosis and maternal effects on offspring gestational duration (β = 0.40, 95% CI: -0.39 to 1.19, p = 0.32) or preterm birth (OR = 0.94, 95% CI: 0.82-1.06, p = 0.36). Sensitivity analyses indicated pleiotropy but no violations of MR assumptions. Of the four loci overlapping between the gestational duration and endometriosis GWASs, three (EBF1, WNT4, and GDAP1) were identified as outliers using MR-Presso. Contrary to observational studies, MR analyses found no direct causal link between endometriosis and gestational duration or preterm birth. Overlaps in genomic regions suggest that the relationship may be mediated through different biological pathways.

Assessment of Genetic Variability and Heritability of Morpho-physiological Traits in Indian Mustard (Brassica juncea) Genotypes under Heat Stress

To assess genetic variability, broad-sense heritability and genetic advance among Indian mustard genotypes, a study was conducted using 18 genotypes (including one check) under heat stress conditions. The experiment followed a Complete Randomized Block Design (CRBD) with three replications, carried out at the ICAR-Directorate of Rapeseed-Mustard Research, Bharatpur, Rajasthan, during the rabi season of 2020-2021. In terms of mean performance, genotype DRMRHT-18-134 took the least number of days (33.5 days) to reach 50% flowering, while genotype DRMRHT-18-142 had the highest seed yield per plant (30.00 g). The phenotypic coefficient of variation (PCV) was greatest for the membrane stability index (44.42%), as was the genotypic coefficient of variation (GCV) (44.25%). Heritability estimates in the broad sense were notably high for the membrane stability index (99.48%). Additionally, high heritability combined with a significant genetic advance was observed for the membrane stability index, secondary branches per plant and seed yield per plant. For traits like days to 50% flowering and chlorophyll b content (mg/g FW), high heritability was associated with moderate genetic advance, while chlorophyll a content (mg/g FW) showed low heritability with moderate genetic advance.