High Broad Sense Heritability Research Articles

Morpho-genetic Diversity and Traits’ Relationship in Castor Germplasm

Adequate knowledge of the extent of dissimilarity among germplasm accessions and traits’ relationships are of great importance in active breeding programme. In the present study, genetic diversity and traits’ relationship were assessed among 74 castor germplasm accessions collected at the National Cereals Research Institute Badeggi, Nigeria. The accessions were evaluated on replicated plots of 7.5m2 size, arranged in a randomized complete block design. The data were taken on 20 individual plants, using standard castor descriptors. The results revealed significant variations for all the traits studied among the entries. Phenotypic and genotypic coefficients of variation estimated showed low environmental effects on the observed variations. High (≥ 70%) broad sense heritability coupled with high (≥ 20%) genetic advance as percentage of mean were observed in all the traits except days to days to first raceme maturity, number of leaf lobes and seed yield. Six cluster groups, with 4 to 38 members, were identified among the accessions. Significant positive correlations were observed between the seed yield and leaf length (0.269*), and spike length (0.972**). The partitioning of the correlations into direct and indirect yield contributors showed positive direct effects for number of internodes to first raceme, spike length and height to first raceme. The findings showed that selection for long spike early accessions could result in constituting a high yielding breeding population. The identified superior accessions could serve as good germplasm sources for castor breeding programme in Nigeria.

Studies on Genetic Variability, Heritability and Genetic Advance for Yield and Its Attributed Traits in Brinjal (Solanum melongena L.)

The genotypes of brinjal were assessed for genetic variability, heritability and genetic advance of growth and yield characters. The present investigation was carried out during rabi season of 2021 in randomized block design with three replications. The analysis of variance revealed significant variation for all the traits among the genotypes. High genotypic and phenotypic coefficient of variation was observed for the traits such as fruit weight (99.24 % and 99.27 %), number of fruits per plant (57.33 % and 57.58 %), fruit size index (54.80 % and 54.83 %), fruit length (36.54 % and 36.82 %), fruit circumference (32.16 % and 32.46 %) and fruit yield per hectare (27.26 % and 27.42 %) indicating the existence of wider variability among the genotypes for different characters. High heritability in broad sense along with high genetic advance as percent of mean was found in suggesting that these traits can be improved through direct selection due to the existence of additive gene action.

Identification of superior genotypes for leaf architecture traits in Sorghum bicolor through GGE biplot analysis

Context Well-organised leaf architecture produces compact canopies and allows for greater sunlight penetration, higher photosynthetic rates, and thus greater yields. Breeding for enhanced leaf architecture of sorghum (Sorghum bicolor L.), a key food source in semi-arid regions, benefits its overall production. Aims The study focuses on selecting useful genotypes with excellent leaf architecture for grain sorghum improvement. Methods In total, 185 sorghum genotypes were subjected to multi-environment trials. Leaf flagging-point length, leaf length, leaf width, leaf angle and leaf orientation value (LOV) were characterised under field conditions. Genotype + genotype × environment interaction (GGE) biplot analysis was used to identify the most stable genotypes with the highest LOV. Key results Statistical analysis showed significant effects of genotype × environment interaction (P < 0.001), and high broad-sense heritability for the traits. Correlation analysis demonstrated negative correlations (P < 0.001) between LOV and its components. Singular value decomposition of LOVs in the first two principal components explained 89.19% of the total variation. GGE biplot analysis identified G55 as the ideotype with the highest and most stable LOV. Conclusions Leaf architecture optimisation should be given greater attention. This study has identified a genotype with optimal and stable leaf architecture, laying the foundation for improvement in breeding to increase overall yields of sorghum. Implications Genotype G55 can be utilised as a parent with other parents that display economically important characteristics in breeding programs to produce offspring that can be planted densely to increase population yields. Genotypes identified with loose leaf architecture are useful in dissecting genes controlling leaf architecture by crossing with G55 to construct genetic mapping populations.

Morphological Characterization and Assessment of Genetic Variability, Heritability and Genetic Advance in Bread Wheat (Triticum aestivum L.)

Genetic based knowledge of different growth traits including morphological, physiological and developmental play’s fundamental role in the improvement of wheat. Genetic divergence allows superior recombinants which are essential in any crop development project. The present investigation was involving forty-four genotypes were assessed for 13 morphological traits undertaken to study the genetic variability, heritability (bs), genetic advance, genetic advance as percent of mean analysis. Among the genotypes, almost all the traits exhibited highly significant variation. The higher extent of genotypic (GCV) as well as phenotypic coefficients of variation (PCV) were noticed for number of productive tillers per plant and grain yield per plant indicted high degree of variability in these quantitative traits and suggested the possibility of yield improvement through these traits. High heritability (in broad sense) estimates were obtained highest for biological yield per plant, spike length, grain yield per plant, protein content, 1000 grain weight, plant height, productive tillers per plant, days to maturity and spikelets per spike including that these traits are mainly controlled by the genetic factor and selection based on these factors will be rewarding. Moderate estimates of genetic advance were obtained for two traits viz., plant height and biological yield per plant. A suitable combination of these traits can be used for development of high yielding genotypes. For plant height and the number of grains per spike, there was a combination of high heritability and moderate genetic advance. As a result, these qualities are controlled by additive gene action and should be chosen for further development through the use of pedigree breeding.

Phenotyping Peanut Drought Stress with Aerial Remote-Sensing and Crop Index Data

Peanut (Arachis hypogaea L.) plants respond to drought stress through changes in morpho-physiological and agronomic characteristics that breeders can use to improve the drought tolerance of this crop. Although agronomic traits, such as plant height, lateral growth, and yield, are easily measured, they may have low heritability due to environmental dependencies, including the soil type and rainfall distribution. Morpho-physiological characteristics, which may have high heritability, allow for optimal genetic gain. However, they are challenging to measure accurately at the field scale, hindering the confident selection of drought-tolerant genotypes. To this end, aerial imagery collected from unmanned aerial vehicles (UAVs) may provide confident phenotyping of drought tolerance. We selected a subset of 28 accessions from the U.S. peanut mini-core germplasm collection for in-depth evaluation under well-watered (rainfed) and water-restricted conditions in 2018 and 2019. We measured morpho-physiological and agronomic characteristics manually and estimated them from aerially collected vegetation indices. The peanut genotype and water regime significantly (p < 0.05) affected all the plant characteristics (RCC, SLA, yield, etc.). Manual and aerial measurements correlated with r values ranging from 0.02 to 0.94 (p < 0.05), but aerially estimated traits had a higher broad sense heritability (H2) than manual measurements. In particular, CO2 assimilation, stomatal conductance, and transpiration rates were efficiently estimated (R2 ranging from 0.76 to 0.86) from the vegetation indices, indicating that UAVs can be used to phenotype drought tolerance for genetic gains in peanut plants.

Evaluation of Common Bean (<i>Phaseolus vulgaris </i>L) Cultivars for Yield and Yield-Related Traits at Sekoru District, South Western Ethiopia

The low productivity of common beans is attached to many yield constraints such as lack of improved varieties; poor management practices, biotic and abiotic factors. This study was conducted to evaluate the performance of improved common bean varieties for yield and yield related traits in the Sekoru district of the Jimma zone and identify high-yielding varieties for the study area. Eleven released and one local common bean variety were tested in two locations (Yero Sekoru and Inkure), using a randomized complete block design with three replications. Data were collected for 12 quantitative traits and subjected to analysis using SAS software. The interaction effect of genotype by location showed a highly significant variation for all traits except for plant height, dry biomass yield, and hundred seed weight. The phenotypic coefficient of variation was higher than the genotypic coefficient of variation for all traits. Higher The phenotypic coefficient of variation was recorded for 100 seed weight (52.78), pod length (28.9), pods per plant (27.63), harvest index (25.94) and seed yield (24.6) and also a high genotypic coefficient of variance (GCV) was observed for 100 seed weight (20.24) and pods per plant (20.34). Low (20) and high (93.5) heritability in broad sense were recorded in days to 50% flowering and dry biomass yield, respectively. At the phenotypic level, all traits had a positive phenotypic significant correlation with seed yield per hectare except for primary branches per plant day to 95% physiological maturity and hundred seed weight, while a negative significant correlation with seed yield per hectare was observed for days to 50% flowering. Genotypic path coefficient analysis indicates that the traits studied showed a positive direct effect on seed yield per hectare, while plant height, primary branches and secondary branches per plant, days to 50% flowering, days to 95% physiological maturity and 100 seed weight exhibited a negative direct effect. However, a positive direct phenotypic effect was observed for traits such as dry biomass yield, pod length, primary branches per plant, seeds per pod, and days to 95% physiological maturity. Among the varieties tested in both locations, the highest yield was recorded for the Ser119 variety (2865.2 kg/ha) followed by the Ser125 variety (2699.2 kg/ha). Therefore, recommending these varieties to farmers in the study area is very important to increase production and income.

Genetic diversity and candidate genes for transient waterlogging tolerance in mungbean at the germination and seedling stages.

Mungbean [Vigna radiata var. radiata (L.) Wilczek] production in Asia is detrimentally affected by transient soil waterlogging caused by unseasonal and increasingly frequent extreme precipitation events. While mungbean exhibits sensitivity to waterlogging, there has been insufficient exploration of germplasm for waterlogging tolerance, as well as limited investigation into the genetic basis for tolerance to identify valuable loci. This research investigated the diversity of transient waterlogging tolerance in a mini-core germplasm collection of mungbean and identified candidate genes for adaptive traits of interest using genome-wide association studies (GWAS) at two critical stages of growth: germination and seedling stage (i.e., once the first trifoliate leaf had fully-expanded). In a temperature-controlled glasshouse, 292 genotypes were screened for tolerance after (i) 4 days of waterlogging followed by 7 days of recovery at the germination stage and (ii) 8 days of waterlogging followed by 7 days of recovery at the seedling stage. Tolerance was measured against drained controls. GWAS was conducted using 3,522 high-quality DArTseq-derived SNPs, revealing five significant associations with five phenotypic traits indicating improved tolerance. Waterlogging tolerance was positively correlated with the formation of adventitious roots and higher dry masses. FGGY carbohydrate kinase domain-containing protein was identified as a candidate gene for adventitious rooting and mRNA-uncharacterized LOC111241851, Caffeoyl-CoA O-methyltransferase At4g26220 and MORC family CW-type zinc finger protein 3 and zinc finger protein 2B genes for shoot, root, and total dry matter production. Moderate to high broad-sense heritability was exhibited for all phenotypic traits, including seed emergence (81%), adventitious rooting (56%), shoot dry mass (81%), root dry mass (79%) and SPAD chlorophyll content (70%). The heritability estimates, marker-trait associations, and identification of sources of waterlogging tolerant germplasm from this study demonstrate high potential for marker-assisted selection of tolerance traits to accelerate breeding of climate-resilient mungbean varieties.

Novel SNP markers for flowering and seed quality traits in faba bean (Vicia faba L.): characterization and GWAS of a diversity panel.

Faba bean (Vicia faba L.) is a legume crop grown in diverse climates worldwide. It has a high potential for increased cultivation to meet the need for more plant-based proteins in human diets, a prerequisite for a more sustainable food production system. Characterization of diversity panels of crops can identify variation in and genetic markers for target traits of interest for plant breeding. In this work, we collected a diversity panel of 220 accessions of faba bean from around the world consisting of gene bank material and commercially available cultivars. The aims of this study were to quantify the phenotypic diversity in target traits to analyze the impact of breeding on these traits, and to identify genetic markers associated with traits through a genome-wide association study (GWAS). Characterization under field conditions at Nordic latitude across two years revealed a large genotypic variation and high broad-sense heritability for eleven agronomic and seed quality traits. Pairwise correlations showed that seed yield was positively correlated to plant height, number of seeds per plant, and days to maturity. Further, susceptibility to bean weevil damage was significantly higher for early flowering accessions and accessions with larger seeds. In this study, no yield penalty was found for higher seed protein content, but protein content was negatively correlated to starch content. Our results showed that while breeding advances in faba bean germplasm have resulted in increased yields and number of seeds per plant, they have also led to a selection pressure towards delayed onset of flowering and maturity. DArTseq genotyping identified 6,606 single nucleotide polymorphisms (SNPs) by alignment to the faba bean reference genome. These SNPs were used in a GWAS, revealing 51 novel SNP markers significantly associated with ten of the assessed traits. Three markers for days to flowering were found in predicted genes encoding proteins for which homologs in other plant species regulate flowering. Altogether, this work enriches the growing pool of phenotypic and genotypic data on faba bean as a valuable resource for developing efficient breeding strategies to expand crop cultivation.

Genetic diversity, correlation and genotype × yield × trait (GYT) analysis of grain yield and nutritional quality traits in sorghum (Sorghum bicolor [L.] Moench) genotypes in Tigray, northern Ethiopia

Selecting sorghum genotypes with higher grain yield and nutritional quality is essential to tackle food insecurity and malnutrition in arid and semi-arid areas. Therefore, this study aimed to determine the genetic diversity, trait association and genotype by yield by trait (GYT) analysis and to select superior sorghum genotypes. One hundred and ten sorghum genotypes were evaluated at three locations in Tigray during the 2018 and 2019 growing seasons using alpha lattice design. Traits such as grain yield, protein content, ash content, starch content, zinc content, iron content, calcium content and magnesium content were profiled. Results showed that wide range and highly significant (p < 0.001) genotype mean performance in each environment as well as combined environments. Several highly performing genotypes were distinguished for each trait studied that could be exploited as breeding parents or direct use. This study further detected highly significant variation (p < 0.001) among the test genotypes for all the traits studied in individual environments and across environments suggesting the presence of sufficient genetic diversity for selection. The high broad-sense heritability (H2 > 0.9) in all individual environments and moderate to high (H2 > 0.0.41 < 0.82) in pooled environments recorded in the present study assured the possibility of effective selection among the genotypes. Besides, strong positive and negative associations were detected between some of the traits in individual and across environments. The significant positive association between traits indicates that both the traits can be improved concurrently through direct selection. Using the GYT analysis, we suggest ten promising sorghum genotypes for direct use or breeding programs in arid and semi-arid areas in general and in Tigray in particular.

Evaluation of Drought Tolerance in USDA Tomato Germplasm at Seedling Stage

Drought, a crucial abiotic stressor, markedly reduces the growth and yield of tomato crops (Solanum lycopersicum L.). Consequently, adopting drought-resistant cultivars and implementing breeding programs to enhance drought tolerance have emerged as enduring solutions to alleviate the adverse effects of drought in various tomato cultivation regions. In this study, 68 United States Department of Agriculture (USDA) tomato accessions were assessed in a controlled greenhouse experiment, encompassing both water deficit treatment and a control group subjected to standard watering conditions. The experiment was arranged in a randomized complete block design with three replications. The results of this study pinpointed four accessions, PI 365956, PI 584456, PI 390510, and PI 370091, as drought-tolerant accessions. Additionally, high broad-sense heritability was revealed for leaf wilting, leaf rolling, and SPAD chlorophyll content (total leaf chlorophyll). Furthermore, positive correlations were found among parameters associated with leaf wilting, leaf rolling, and SPAD chlorophyll content. The findings offer valuable insights for tomato breeding initiatives, especially those focused on enhancing drought tolerance in elite cultivars. Future studies will expand the evaluation to include a larger pool of tomato accessions and conduct a genome-wide association study to identify single nucleotide polymorphism (SNP) markers for molecular breeding in tomatoes.

Diallel analysis of common bean (Phaseolus vulgaris L.) genotypes for seed dietary fibre, carbohydrate, calcium and phosphorus contents.

Genetic information of bean seed traits can be an immense help to the breeder in selection of suitable genotypes and the appropriate breeding strategies. Therefore, the investigation aims to assess the genetic variability and to elucidate the genetic analysis of seed dietary fibre, carbohydrate, seed calcium and phosphorus contents of Phaseolus vulgaris in the high Guinean Savannah zone conditions. 5 × 5 half-diallel crosses of these traits were conducted in randomized complete block design with three replications. Results revealed high differences between five lines beans (p < 0.05), suggesting the sufficient genetic diversity for these traits. High broad sense heritability values were recorded for seed dietary fibre, carbohydrate and seed calcium content, attesting a strong implication of the genetic factors in the control of these traits; thereby, these traits can be improved through regular selection. The ratio GCA/SCA was greater than unity only for seed phosphorus content. It indicates the prevalence of additive gene effect in the involvement of the genetic control for this trait. The combining ability analysis revealed highly significant differences between parental GCA effects and F1 cross SCA effects. The PB, BI, CT and PR lines beans will prove useful in common bean breeding programmes as donor genotypes, in the development of bean genetic resources for betterment improvement of nutritional traits.

Evaluation of Sugarcane Families and Identification of Promising Families for Cane Yield and Juice Quality Traits in Early Selection Stages

The utilization of superior parental lines and identification of promising families enhance the genetic gain in sugarcane. To identify the promising families, 1620 progenies derived from twenty two crosses involving genetically diverse historical parents were evaluated for cane yield and juice quality attributing traits. The mean number of millable canes per clump (9.00), cane girth (2.32 cm), millable cane height (217.00 cm) and Brix% in juice (20.79%) were recorded. The significant variance, high broad-sense heritability and genetic advance over mean suggested that number of millable canes per clump, single cane weight, millable cane height, Pol% in juice and Brix% in juice are suitable for family evaluation. Based on progeny performance, families of Co 86032 × CoVC 14061 and Co 0312 GC, were found significantly superior compared to most popular clonal check, Co 86032 for number of millable canes per clump, similarly, CoVC 14062 × Co 89003 and Co 86002 × ISH 69 for cane girth, and CoVC 14062 × Co 89003, Co 11015 and Co 87015 for CCS% in juice content at early selection stages. Among 22 families studied, the four families viz., Co 86032 × CoVC 14061, CoVC 14062 × Co 89003, CoVC 14062 GC, Co 87015 GC and Co 11015 GC, produced higher percentage of population selection with acceptable range for commercially important traits (Brix% in juice, cane yield components). These identified promising families can be further exploited in sugarcane varietal improvement.

Genetic Estimations of Available Quality Traits for Improved Growth Yield of Pumpkin (Cucurbita moschata Duch) in Kumarganj, India

Pumpkin is one of the most economically important and nutritious member of the family Cucurbitaceae. The present investigation was conducted to evaluate genetic variability, heritability and genetic advance in per cent of mean among the 30 genotypes including one check variety (Narendra Agrim) for 21 qualitative and quantitative traits. The experiment was conducted in randomized block design with three replication ,the observations were recorded on the traits like days to 50% staminate flower anthesis , days to 50% pistillate flower anthesis, node no. to first staminate flower anthesis, node no. to first pistillate flower anthesis, vine length, no. of nodes, no. of primary branches, inter-nodal length, days to first fruit harvest, polar circumference, equatorial circumference, flesh thickness, cavity, average fruit weight, no. of fruits per plant, total soluble solids, reducing sugars, non reducing sugars, total sugars, fruit yield per plant. The analysis of variance for the design of experiments indicated highly significant difference among the genotypes for all 21 characters. The four genotypesviz.NDPK-17-12-1,NDPK-23,NDPK-P-6 and NDPK-32-1-2 were found significantly superior for fruit yield per plant over the check variety (NarendraAgrim).The PCV was higher than the GCV and was found highest for the trait fruit yield per plant, the presence of high heritability in broad sense along with high genetic advance in per cent of mean were observed for fruit yield per plant.Therefore,from the above obtained results it can be concluded that the characters will result in effective crop improvement for higher yield and yield contributing traits.

Scald resistance in hybrid rye (Secale cereale): genomic prediction and GWAS.

Rye (Secale cereale L.) is an important cereal crop used for food, beverages, and feed, especially in North-Eastern Europe. While rye is generally more tolerant to biotic and abiotic stresses than other cereals, it still can be infected by several diseases, including scald caused by Rhynchosporium secalis. The aims of this study were to investigate the genetic architecture of scald resistance, to identify genetic markers associated with scald resistance, which could be used in breeding of hybrid rye and to develop a model for genomic prediction for scald resistance. Four datasets with records of scald resistance on a population of 251 hybrid winter rye lines grown in 2 years and at 3 locations were used for this study. Four genomic models were used to obtain variance components and heritabilities of scald resistance. All genomic models included additive genetic effects of the parental components of the hybrids and three of the models included additive-by-additive epistasis and/or dominance effects. All models showed moderate to high broad sense heritabilities in the range of 0.31 (SE 0.05) to 0.76 (0.02). The model without non-additive genetic effects and the model with dominance effects had moderate narrow sense heritabilities ranging from 0.24 (0.06) to 0.55 (0.08). None of the models detected significant non-additive genomic variances, likely due to a limited data size. A genome wide association study was conducted to identify markers associated with scald resistance in hybrid winter rye. In three datasets, the study identified a total of twelve markers as being significantly associated with scald resistance. Only one marker was associated with a major quantitative trait locus (QTL) influencing scald resistance. This marker explained 11-12% of the phenotypic variance in two locations. Evidence of genotype-by-environment interactions was found for scald resistance between one location and the other two locations, which suggested that scald resistance was influenced by different QTLs in different environments. Based on the results of the genomic prediction models and GWAS, scald resistance seems to be a quantitative trait controlled by many minor QTL and one major QTL, and to be influenced by genotype-by-environment interactions.

Multi-Trait Selection Index for Simultaneous Selection of Water Yam (Dioscorea alata L.) Genotypes

Water yam (Dioscorea alata L.) is the most widely cultivated yam species with good agronomic attributes. However, several biotic and abiotic constraints and its lower food quality such as poor pound ability limit its production and use. Therefore, the identification of superior genotypes with suitable characteristics is needed for water yam improvement. This study aims to assess a panel of half-sib (progenies with one parent in common) and full-sib (progenies with the same male and female parents) progenies as well as their parents for selection of desirable ideotypes based on their agronomic and quality characteristics. A total of 280 progenies from bi-parental populations as well as five parents were evaluated, and a significant variation was observed (p &lt; 0.01) in their performances for the eight traits used in the study. A moderate to high broad-sense heritability (30% &lt; H2–H2 ≥ 60%) was observed for all traits except for tuber pound ability (H2 &lt; 30%). Positive correlations were displayed between the traits, while the hierarchical clustering grouped genotypes into three clusters indicating the potential for selection of diverse genotypes for multiple traits from the four families under study. Plant vigor and number of tubers per plant contributed (p &lt; 0.01) positively to the yield per plant in the path coefficient analysis. Using the multi-trait genotype–ideotype distance index (MGIDI), a total of 39 most promising genotypes were identified. These promising genotypes could be further used as progenitors in D. alata improvement programs targeting good agronomic and quality traits targeted for farmers and end users.

Phenotypic and genetic characterization of an Avena sativa L. germplasm collection of diverse origin: implications for food-oat breeding in Chile.

Oats are known for their nutritional value and also for their beneficial properties on human health, such as the reduction of cholesterol levels and risk of coronary heart disease; they are an important export product for Chile. During the last decade (2010-2022) over 90% of the oat cultivated area in Chile has been covered with Avena sativa L. cv. Supernova INIA. This lack of genetic diversity in a context of climate change could limit the long-term possibility of growing oats in Chile. The present study is a phenotypic and genetic analysis of 132 oat cultivars and pure lines of diverse origin that can be considered as potential breeding material. The germplasm was evaluated for 28 traits and analyzed with 14 SSR markers. The effects of genotypes on phenotype were significant over all traits (P ≤ 0.05). Most traits exhibited moderate to high broad-sense heritability with exceptions such as yield (H2 = 0.27) and hulls staining (H2 = 0.32). Significant undesirable correlations between traits were generally of small biological importance, which is auspicious for achieving breeding objectives. Some of the heritability data and correlations provided here have not been previously reported. The overall phenotypic diversity was high (H' = 0.68 ± 0.18). The germplasm was grouped into three phenotypic clusters, differing in their qualities for breeding. Twenty-six genotypes outperforming Supernova INIA were identified for breeding of conventional food-oats. The genetic diversity of the germplasm was moderate on average (He = 0.58 ± 0.03), varying between 0.32 (AM22) and 0.77 (AME178). Two genetic subpopulations supported by the Structure algorithm exhibited a genetic distance of 0.24, showing low divergence of the germplasm. The diversity and phenotypic values found in this collection of oat genotypes are promising with respect to obtaining genetic gain in the short term in breeding programs. However, the similar genetic diversity, higher phenotypic diversity, and better phenotypic performance of the germplasm created in Chile compared to foreign germplasm suggest that germplasm harboring new genetic diversity will be key to favor yield and quality in new oat cultivars in the long term.

Analysis of Genetic Variability and Correlation in Rice (Oryza sativa L.) Recombinant Inbred Lines (F6) for Yield and Its Component Traits

grain yield and its component traits in 150 rice recombinant inbred lines, their parents and six checks at ICAR-IIRR, Hyderabad and AHRS, Kathalagere in wet 2022. The experiments were laid out in an augmented block design with five blocks. Phenotypic coefficients of variance were higher than genotypic coefficients of variance for all the traits across the locations. A joint consideration of high heritability in broad sense (h2) and genetic advance as per cent mean estimates were obtained for plant height, number of tillers, number of productive tillers, panicle length, number of grains per panicle, test weight, grain yield per plant suggesting that the traits were primarily under genetic control. Furthermore, high heritability (h2) and GAM recorded in these characters could be explained by additive gene action. However, high estimates (h2) combined with moderate GAM recorded for days to 50% flowering could be due to non-additive gene effect. Grain yield per plant recorded positive and significant correlation with the total number of grains per panicle (0.32***, 0.30***) and number of productive tillers per plant (0.21***, 0.26***) at both the locations. This result indicates that selection based on these two traits will be highly effective for yield improvement in rice.

Genetic Studies for Selected Agronomic Traits in 19 Maintainer Genotypes of Rice (Oryza sativa L.)

The current study was performed at MARDI Seberang Perai, Penang, Malaysia, during the Off Season 2020. This study aims to analyze genetic parameters, correlation, and path coefficient for 11 agronomic traits in 19 maintainer rice genotypes. All experimental units were arranged in a randomized complete block design with three replications. Observations were recorded for days to 50% flowering, plant height, culm height, panicle length, total panicle per plant, total spikelet per panicle, spikelet fertility, thousand-grain weight, grain length, grain width, and grain yield per plant. Analysis of variance revealed significant differences in the genotype factor for all assessed traits. The total spikelet per panicle trait exhibited the highest phenotypic and genotypic variance. Moreover, this trait had high broad-sense heritability and high genetic advance as percent of mean. Total panicle per plant recorded the highest value of phenotypic and genotypic coefficient of variation among traits under study and were classified as high and moderate, respectively. The traits association study revealed a significant positive correlation between grain yield per plant and two traits: total panicle per plant and spikelet fertility. Path analysis revealed a very high direct effect of plant height, culm height, and panicle length on grain yield per plant. This study contributes essential knowledge for the strategic design of effective breeding programs.

Niger germplasm evaluation for major morphological and agronomical traits

A panel of niger (Guizotia abyssinica (L.f) Cass) accessions were augmented and evaluated to characterize for various morphological and agronomical traits. The analysis of variance has shown that there was a significant variation observed among the genotypes. Variability analysis revealed that the oil content had high GCV with high broad sense heritability. High PCV was observed among the other yield related traits which indicates that these traitsare highly influenced by the environmental factors.

Genetic Variability and Heritability of Medium Maturity Group’s Soybean (Glycine max (L.)) Genotypes at Oromia, Ethiopia

Field experiment was conducted to assess the extent of genetic variability and heritability in soybean genotypes for yield and its related traits. A total of thirty six soybean genotypes were evaluated using simple lattice design at Fedis eastern Ethiopia. Data were recorded for major quantitative traits and analyzed using appropriate statistical R-software. Analysis of variance revealed that the genotypes were highly significant for all the traits studied, indicating the existence of considerable magnitude of variability. High broad sense heritability estimate coupled with relatively high genetic advance as percentage of mean were computed for pods/plant, plant height, grain yield and primary branches/plant. Moderate to high genetic advance as percent of mean was estimated from the present result days to maturity, primary branches/plant, plant height, pods/plant, seeds/pod, hundred seeds weight and grain yield were recording high genetic advance as percent of mean, while days to flowering and secondary branches/plant estimated moderate genetic advance as percent of mean. High values of phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), broad sense heritability (H2), and genetic advance as percent of mean (GAM) were estimated for plant height, primary branches per plant, pod per plant, seeds per pod, and grain yield indicating the ease of direct selection for the improvement of these traits. Hence, selection for these traits is likely to be effective as high heritability values were associated with high genetic advance as percent of means in the improvement of the performance of the soybean genotypes. As a result breeder can improve the tested soybean genotypes through plant height, number of pods/plant, number of primary branches/plant and grain yield.