Heritability Of Growth Traits Research Articles

Genetic parameters and genomic prediction for nutritional quality-related traits of Pacific abalone (Haliotis discus hannai)

The Pacific abalone (Haliotis discus hannai) is one of the most widely cultivated shellfish species in China. Nutritional quality-related traits are a major objective in aquatics as they determine the value of products and consumer preference. Estimating genetic parameters and the potential of genomic selection is significant in designing breeding programs, which has not been performed in abalone. In the study, we developed near infrared reflectance spectroscopy (NIRS) models for collagen content (CC) and taurine content (TC) in Pacific abalone, estimated the genetic parameters for glycogen content (GLY), total protein content (TPC), CC, and TC, and assessed the prediction ability of GBLUP and three Bayesian methods for the four nutritional traits. The genetic analysis included all 274 individuals and 69,530 high quality SNPs. The prediction correlation of the NIRS models were 0.9702 and 0.9289 for CC and TC, respectively. The heritability of GLY, TPC, CC, and TC was 0.33 ± 0.13, 0.42 ± 0.14, 0.02 ± 0.10 and 0.32 ± 0.13, respectively, while the heritability of growth traits in our study ranged from 0.34 ± 0.14 to 0.47 ± 0.14. Negative correlations were observed between GLY and both TPC (−0.96 ± 0.03) and TC (−0.90 ± 0.07), whereas moderate correlations were found between GLY and growth traits. The prediction ability for GLY, TPC, and TC was 0.21 ± 0.04 to 0.22 ± 0.03, 0.27 ± 0.02 to 0.29 ± 0.03, 0.20 ± 0.03 to 0.24 ± 0.02, respectively, using four genomic selection (GS) models (GBLUP, BayesA, BayesB, and BayesCpi). The results were encouraging and showed comparable performance for the predictability of genomic estimated breeding values, demonstrating the potential for GS in selection breeding of the nutritional quality-related traits in Pacific abalone.

Genetic parameters for growth and morphological traits of the Pacific white shrimp Penaeus vannamei from a selective breeding programme in the industrial sector of Ecuador

This study aimed to estimate the genetic parameters of growth-related traits (weight and length), morphological traits (cephalothorax, abdomen, length, height, segment width and volume), and the correlated response of weight traits via the selection for morphological traits to evaluate the relative efficiency of indirect selection in P. vannamei from a selective breeding growth programme, PMG-BIOGEMAR®, under industrial production conditions in Ecuador. A total of 595 shrimps from 89 full-sibling families were reared under an extensive culturing system (estuaries) (PRODUMAR, Duran, Ecuador), and were evaluated for genetic parameters at harvest size. The heritability of growth traits was moderate-medium (0.25–0.34), whereas it was quite variable for morphological traits (0.01–0.77). Among the morphological traits, Sixth Segment Width (SW6) (0.77) and Sixth Segment Volume (SV6) (0.35) had medium-high heritability, and genetic correlations between almost all morphological and growth traits were high and positive, except those corresponding to the fourth segment. According to these genetic parameters, SW6 and SV6 as the correlated response to weight are 9.7% and 5.8%, respectively, being more efficient than direct selection for weight. Thus, the sixth segment should be considered an indirect selection criterion for growth in future breeding programmes as it is a precise, non-invasive, and low-cost morphological trait for growth improvement in the industrial sector.

Estimation of genetic parameters for female reproduction traits in the Pacific oyster, Crassostrea gigas

The Pacific oyster (Crassostrea gigas) is one of the most important aquaculture species worldwide. Female reproduction traits are considered as the major factor for production efficiency. Estimating genetic parameters for female reproduction is a common method for formulating breeding program, which has not been evaluated in the Pacific oysters. Therefore, this study aimed to estimate the genetic parameters for female reproduction traits in Pacific oysters. Genetic parameters were performed on 44 full-sib Pacific oyster families, including 646 individuals from three cultured populations (“Haida No. 1” strain, South Korean population, and Japanese population) and a wild population. The heritability of female reproduction traits including relative brood amount and egg diameter ranged from 0.32 to 0.38, while the heritability of growth traits were in the range of 0.13–0.37, suggesting that both traits may benefit from successive selection breeding. The genetic and phenotypic correlations between female reproduction and growth traits were low at −0.44 to 0.33, indicating that these traits were relatively independent traits that could be improved respectively. The four populations showed significant growth differences, whereas no significant difference was observed in female reproduction traits. This study represents the first report of genetic parameters for female reproduction in Pacific oysters, which suggests that these traits may be improved through selection breeding.

HERITABILITY OF BODY WEIGHT AND LINEAR BODY MEASUREMENTS OF ISA BROWN x LOCAL CHICKEN GENOTYPES

Heritability of growth traits was studied at 2, 10 and 20 weeks using 531 day-old unsexed crossbred chickens belonging to six genotypes. Heritability estimates were obtained from variance components of sire ( ), dam ( ) and sire plus dam ( ) by analysis of variance in a nested design. The heritability of body weight was high (0.43-0.66) in frizzle feathered x Isa Brown (FxIB), Isa Brown x frizzle feathered (IBxF), Isa Brown x normal feathered (IBxN) and normal feathered x Isa Brown (NxIB) at 10 and 20 weeks, but low to moderate (0.02-0.38) in Isa Brown x naked neck (IBxNa) and naked neck x Isa Brown (NaxIB) at all ages from different variance components. The heritability of shank length was high at weeks 2 (0.45) in NaxIB, 10 (0.53-0.90) in IBxF, IBxN and NaxIB and 20 (0.40 - 0.53) in IBxNa and IBxN from . The heritability of drumstick length (0.40 - 0.46), body girth (0.54 - 0.62), body width (0.50 - 0.81) and keel length (0.72 - 1.50) was also high from different variance components and ages. Body length was highly heritable only in IBxN (0.50) from at 20 weeks. Wing length was lowly to moderately heritable (0.01 - 0.36) at all ages of the genotypes. There was large additive genetic variance for most of the traits in different genotypes and ages. Rapid genetic improvement of growth can be made in these chickens by individual selection, especially using shank length of IBxN from sire lines between 10 and 20 weeks of age.

Estimation of nonadditive and additive genetic effects on growth traits of Horro cattle.

The estimation of nonadditive genetic effects plays a significant role in the accuracy of estimated breeding values for growth traits. Data for estimation of individual and maternal heterosis of crossbreed cattle in Ethiopia are limited to research institutions and universities. This paper aimed to estimate the crossbreeding effects for growth traits of Holstein Friesian × Horro and Jersey × Horro crossbreds in Ethiopia. The data included pedigree and weight data of animals born between 1980 and 2008. Heritability of growth traits was estimated using restricted maximum likelihood (ASREML). However, the additive genetic, maternal, and heterosis effects for growth traits of crossbred animals were estimated using the crossbreeding effects (CBE3) package by fitting Kinghorn's Model one. The direct and maternal heritability estimates for 1-year weight with the model that included the direct maternal covariance were 0.77 ± 0.12 and 0.26 ± 0.09, respectively. Individual heteroses estimated for Holstein Friesian × Horro and Jersey × Horro were significantly high and positive for 1-year weight (21.6 ± 6.7 and 26.0 ± 3.9kg), preweaning average daily gain (27.4 ± 26 and 28.9 ± 15g), and postweaning average daily gain (68.8 ± 16.6 and 61.8 ± 9.9g), respectively. The maternal additive genetic effect for growth traits was mostly positive; therefore, it may be preferable to use crossbred cows from purebred dams instead of crossbred cows from crossbred dams. The significantly higher heterosis and additive genetic parameters in Holstein Friesian × Horro crossbreds indicated that these crossbreds may be preferable to Jersey × Horro crossbreds in areas occupied by Horro cattle.

Performance and Genetic Parameters of Poplar Hybrids and Clones in a Field Trial Are Modified by Contrasting Environmental Conditions during the Vegetative Propagation Phase.

This study investigates epigenetics-like phenomena: how performance phenotypic plasticity, genotypic variation, and the heritability of growth traits and total phenolic compounds of Populus hybrids and clones in field trials may be modified by contrasting temperature conditions at their vegetation propagation phase. The significant effect of rooting–growing conditions on further tree performance in field trials was found for height increment in 2020, although the interaction hybrid by rooting–growing conditions was highly significant for phenolic compounds, tree height, and diameter, meaning that the performance of some hybrids was affected by rooting–growing conditions, thus demonstrating epigenetic-like effects. For phenolic compounds, interactions were also significant at the clonal level. High estimates of ecovalency indicate that some hybrids are ecologically sensitive, and epigenetic-like phenomena might occur. Hybrid P. balsamifera × P. trichocarpa is characterized by high ecovalency and specific adaptations according to mean tree height when vegetatively propagated under different rooting–growing conditions. Low estimates of P. deltoides × P. trichocarpa ecovalency demonstrate a general adaptation according to mean tree height in a field trial. Vegetative propagation conditions have also altered the genetic variation of traits in trees being planted in field trials.

Genetic parameters and genotype by environment interaction for growth traits of razor clam Sinonovacula constricta, from outdoor pond and semi-natural environment

The razor clam, Sinonovacula constricta, is a commercially important bivalve. To date, there have been very limited quantitative genetic studies of this species, especially in different aquaculture environments. This study is the first report of genotype by environment (G × E) interactions for growth traits of razor clams from outdoor pond (OP) and semi-natural environments (SNE). Over a 2-month period, the data for shell length (SL), shell height (SH), shell width (SW), and body weight (BW) of razor clams were recorded for 1 month, and marked as Data 1 and Data 2. Phenotypic data of 1627 individual clams from 17 full-sib families were used for the analysis. The overall heritabilities (h2) for all growth traits were from low to moderate, ranging from 0.127 to 0.230. The h2 of SNE was higher than that of OP (0.243–0.423 vs. 0.101–0.285). Heritabilities for growth traits indicated that these traits could be effectively selected in both aquaculture environments. Overall, both phenotypic (rp) and genetic (rg) characteristics showed high positive correlations among the growth traits. However, the rg and rp were highly variable in OP, ranging from 0.435 to 0.973 and from 0.597 to 0.874, respectively. The rg of SL, SH, SW, and BW between the two aquaculture environments for Data 1 were 0.867, 0.682, 0.651, and 0.844, respectively. The rg ranged from 0.274 to 0.619 for Date 2. These results indicated significant G × E interactions among families at different sites. This study therefore provided optimal guidelines to select breeding programs for razor clams reared in different aquaculture environments.

Genetic parameter estimations of new traits of morphological quality on gilthead seabream (Sparus aurata) by using IMAFISH_ML software

In this study, a total of 18 novel productive traits, three related to carcass [cNiT] and fifteen related to morphometric [mNiT]), were measured in gilthead seabream (Sparus aurata) using Non-invasive Technologies (NiT) as implemented in IMAFISH_ML (MatLab script). Their potential to be used in industrial breeding programs were evaluated in 2348 offspring reared under different production systems (estuarine ponds, oceanic cage, inland tank) at harvest. All animals were photographed, and digitally measured and main genetic parameters were estimated. Heritability for growth traits was medium (0.25–0.37) whereas for NiT traits medium-high (0.24–0.61). In general, genetic correlations between mNiT, cNiT and growth and traits were high and positive. Image analysis artifacts such as fin unfold or shades, that may interfere in the precision of some digital measurements, were discarded as a major bias factor since heritability of NiT traits after correcting them were no significantly different from original ones. Indirect selection of growth traits through NiT traits produced a better predicted response than directly measuring Body Weight (13–23%), demonstrating that this methodological approach is highly cost-effective in terms of accuracy and data processing time.

Genetic Analysis of the Fatty Acid Profile in Gilthead Seabream (Sparus aurata L.).

Simple SummaryHumans require essential fatty acids in their diet and marine fish are a source of them, especially omega3 fatty acids that present high benefits on diverse vascular diseases and the immune system. Breeding programs in gilthead seabream usually include growth as the first criterion in the selection process of the fish. However, that could lead to fish with a higher fillet fat content and a fatty acid profile with a lower polyunsaturated fatty acids percentage. Fillet fat content and its fatty acids profile have been revealed as heritable traits. Therefore, further studies to go deeper in the selection process are advisable.The gilthead seabream is one of the most valuable species in the Mediterranean basin both for fisheries and aquaculture. Marine fish, such as gilthead seabream, are a source of n3 polyunsaturated fatty acids, highly appreciated for human food owing to their benefits on the cardiovascular and immune systems. The aim of the present study was to estimate heritability for fatty acid (FA) profile in fillet gilthead seabream to be considered as a strategy of a selective breeding program. Total of 399 fish, from a broodstock Mediterranean Sea, were analysed for growth, flesh composition and FA profile. Heritabilities for growth traits, and flesh composition (fat, protein, and moisture content) were medium. Heritability was moderate for 14:0, 16:0 and 18:1n9 and for sum of monounsaturated FA and n6/n3 ratio, and it was low for 20:1n11 and 22:6n3 and the ratio unsaturated/saturated FA. Breeding programs in gilthead seabream usually include growth as the first criterion in the selection process of the fish. However, other quality traits, such as fillet fat content and its fatty acids profile should be considered, since they are very important traits for the consumer, from a nutritional point of view and the benefits for the health.

Aggregation distributions across stand age in provenances of Cunninghamia lanceolata (Lamb.) Hook

It is particularly important to select the provenance with better adaptability in the context of the counteracting potential adverse effects of climate change. However, the growth environment of trees and the length of breeding cycle determine the uncertainty of early selection. Thereby, it is advisable to provide information for provenance selection by analyzing the relationship between young, middle and mature forests. Chinese fir(Cunninghamia lanceolata (Lamb.) Hook.) is an evergreen coniferous tree species with rapid growth and high-quality timber, and it is an important reforestation and commercial tree species in South China. The provenance experimental forests of Chinese fir in Jiangxi and Guangxi were taken as the test object, the growth survey went by three stages of growth: young, middle and mature ages. The linear mixed model was used to evaluate the differentiation of different forest stage provenances in terms of growth. K-medoids clustering algorithm was used to group provenances, the geographical distribution characteristics of Chinese fir were evaluated based on the major groups, and the risk of early selection and the genetic gain of excellent provenances were calculated. The highest total variability was explained by the genotype effect (G) in the young, middle-aged and mature forest stage, the influence of genotype increased through time, while the influence of site was reduced and the G×E interaction changed in a small range. The differences in heritability were similar between young and middle-aged forests, but the heritability of growth traits was higher at Jiangxi than Guangxi in the mature forest stage. The provenances with excellent productivity Chinese fir showed aggregation distribution at the mature forest stage, and the provenances with worst growth were mainly distributed in the northern marginal production area.

Genetic parameters of growth and survival in the Pacific oyster Crassostrea gigas

The Pacific oyster Crassostrea gigas is a representative bivalve mollusc that is widely cultured in the world and is the largest molluscan group cultured in China. In order to assess the feasibility of improving survival of C. gigas through genetic selection, the heritability and genetic correlations for growth and survival traits between different life stages were examined. Genetic parameters were estimated based on intraclass correlations of 49 full-sib families (29 half-sib families) in larvae (4 and 20 days after fertilization) and spat (140 days after fertilization) stages. The heritability for growth traits in larvae and spat was 0.30–0.86 and 0.53–0.59, respectively, and varied with ages. The heritability of survival was low in larvae (0.13 ± 0.05 and 0.17 ± 0.04, respectively for 4 and 20 days after fertilization) but medium (0.39 ± 0.07) in spat, suggesting that selection for increasing spat survival was feasible. The genetic correlation between growth traits within age was medium to high and positive (ranging from 0.47 to 0.96, respectively, between shell length (SL) and shell height (SH) at 20 days and between SL and SH at 140 days after fertilization), suggesting that selection to improve single growth trait will cause positive response in another growth traits in C. gigas. The genetic correlations between survival and growth traits at 140 days were low but positive (ranging from 0.23 to 0.27, respectively, between survival and SH and between survival and SL at 140 days after fertilization), suggesting that selection for survival may not have a negative response in growth. Overall, this study suggests that survival traits should be taken as improving target of next selection breeding programme in C. gigas.

GENETIC PARAMETERS OF BODY WEIGHT AND MEASUREMENTS TRAITS IN BALADI BLACK RABBITS

ABSTRACT: A total of 250 progeny of 17 sires and 58 dams from Baladi Black breed population were used to estimate variance components and heritability of growth traits. Traits studied were individual body weight (BW12), body length (BL12), head length (HL12) and thigh circumference (TC12) all at 12 weeks of age. Single-trait Animal Model (DFREML) was used to estimate genetic variance components, as well as permanent environmental variation. Estimates of variance components were 0.52, 0.96, 0.91 and 0.81 for BW12, BL12, TC12 and HL12, respectively. Heritability estimates were 0.24, 0.36, 0.36 and 0.33 for BW12, BL12, TC12 and HL12 respectively. The proportions of variance due to permanent environmental effect of dams were 0.08, 0.05, 0.10 and 0.12 for BW12, BL12, TC12 and HL12, respectively. Results showed that out of the principal components (PC) calculated, the one represent 68.98 % of the total variance. The PC1 was 68.98 of the generalized variance. Principal component factor scores expound 77 % of the variation in the body weight of rabbits. Conclusively, the use of orthogonal body shape characters (PC1) derived from the principal component factor solution could be more reliable in predicting body weight compared to the use of the original autocorrelated body measurements. This is because multicollinearity of interdependent explanatory variables could lead to false inferences when original body measurements are used as predictors. Key words: Body measurements, multicollinearity, Rabbits, Principal Component Analysis.

Effect of Breeding on Income at First Commercial Thinning in Silver Birch Plantations

The economic importance of fast-growing tree species like silver birch (Betula pendula Roth.) is increasing due to growing demand for timber. Tree breeding provides the opportunity to increase the timber supply and thus ensure the most efficient use of forest land. Application of the results of a breeding program—the planting of young stands—is costly, and information on (potential) early income for the landowner from this investment is scarce. Therefore, the aim of this study was to characterize the gain from the use of improved silver birch material at the first commercial thinning. Material was collected from an open-pollinated progeny trial of 524 silver birch plus-trees at the age of 14 years in the central part of Latvia. Incomes from the first thinning were calculated at low and high timber prices. Heritability of growth traits (assessed as diameter at breast height) and timber value at first thinning were similar. Both timber market fluctuations and genetics had a notable impact on economic outcome: the internal rate of return for the selected best-performing families was 9.4% and 8.3% in the case of high and low timber prices, respectively; on average, for all families in the trial the figures were 8.1% and 6.7%, respectively. Results indicate profitability for investments in planting of improved regeneration material, even at a young age, in hemiboreal forests.

Heritability of growth traits in a natural population of the facultative apomictic tree Aspidosperma polyneuron

Heritability of growth traits in a natural population of the facultative apomictic tree Aspidosperma polyneuron

Heritability of energy intake and allocation and their correlated responses to selection on growth traits in cultured juvenile and adult red abalone Haliotis rufescens

Increasing abalone growth rates and their physiological efficiency in the use of energy through selective breeding could improve abalone production. High potential responses to selection for growth traits have been estimated in several abalone species; however, the genetic bases underlying individual differences in physiological performance are unknown. The aims of this study were to estimate the heritable variation of physiological traits associated with energy intake and allocation for the red abalone Haliotis rufescens; and the potential correlated responses to selection between growth and physiological traits at three developmental stages. Growth traits (shell length and width, and total mass) and physiological traits [energy intake, standard metabolic rate (SMR), and energy losses by ammonia excretion and feces] were measured in individuals belonging to 60 full-sib families in 2-years old juveniles, 3-y old young adults, and 4-y old near-harvest adult (n = 500–380 individuals/age; total n = 1300). Food intake showed significant h2 in juveniles and young adults (0.37 and 0.14, respectively); but near zero h2 in near-harvest adults. Variation in energy required for SMR showed low but significant h2 (0.13) in young and near-harvest adults. Variation in energy lost through ammonia excretion showed significant h2 in juveniles (0.33) and in near-harvest adults (0.14). Heritability for variation in the energy losses through feces was not significant. Heritabilities for growth traits were all moderate to high and significant for young and pre-harvest adults, but were not significant for juveniles. At the young adult stage, food intake was negatively and highly genetically correlated with each of the growth traits (−0.70 to −0.85); and at the near-harvest adult stage both SMR and ammonia excretion showed high-negative genetic correlations with each growth trait (−0.88 to −1.00). Thus, estimated correlated response to selection indicated that if selection was exerted for higher growth (choosing 5% best individuals), we would be indirectly selecting for abalones with lower food intake (correlated responses of −11 to −15%); or lower metabolic demands of (−14 to −24%), if the selection was applied to young or near-harvest adults, respectively. In turn, shell length could be enhanced up to 18% per generation. These results suggest that higher growth in red abalone is genetically associated with a more efficient use of food and a lower metabolic demand. The possibility to reduce food intake or metabolic demands by selecting for faster growing abalones would be a very positive development for the sustainability of this culture.

Heritability of growth traits and correlation with hepatic gene expression among hybrid striped bass exhibiting extremes in performance

Hybrid striped bass is a major aquaculture species in the United States. Artificial breeding of this species can introduce large variation in growth during production to market size. To assess the ...

Effects of marker density and population structure on the genomic prediction accuracy for growth trait in Pacific white shrimp Litopenaeus vannamei

BackgroundDue to the great advantages in selection accuracy and efficiency, genomic selection (GS) has been widely studied in livestock, crop and aquatic animals. Our previous study based on one full-sib family of Litopenaeus vannamei (L. vannamei) showed that GS was feasible in penaeid shrimp. However, the applicability of GS might be influenced by many factors including heritability, marker density and population structure etc. Therefore it is necessary to evaluate the major factors affecting the prediction ability of GS in shrimp. The aim of this study was to evaluate the factors influencing the GS accuracy for growth traits in L. vannamei. Genotype and phenotype data of 200 individuals from 13 full-sib families were used for this analysis.ResultsIn the present study, the heritability of growth traits in L. vannamei was estimated firstly based on the full set of markers (23 K). It was 0.321 for body weight and 0.452 for body length. The estimated heritability increased rapidly with the increase of the marker density from 0.05 K to 3.2 K, and then it tended to be stable for both traits. For genomic prediction on the growth traits in L. vannamei, three statistic models (RR-BLUP, BayesA and Bayesian LASSO) showed similar performance for the prediction accuracy of genomic estimated breeding value (GEBV). The prediction accuracy was improved with the increasing of marker density. However, the marker density would bring a weak effect on the prediction accuracy after the marker number reached 3.2 K. In addition, the genetic relationship between reference and validation population could influence the GS accuracy significantly. A distant genetic relationship between reference and validation population resulted in a poor performance of genomic prediction for growth traits in L. vannamei.ConclusionsFor the growth traits with moderate or high heritability, such as body weight and body length, the number of about 3.2 K SNPs distributed evenly along the genome was able to satisfy the need for accurate GS prediction in the investigated L.vannamei population. The genetic relationship between the reference population and the validation population showed significant effects on the accuracy for genomic prediction. Therefore it is very important to optimize the design of the reference population when applying GS to shrimp breeding.

Heritability of growth traits in the Asian seabass (Lates calcarifer)

Growth is an economically important trait in aquaculture. To improve growth trait of the Asian seabass (Lates calcarifer) we have been carrying out, since 2004, a selective breeding program. This study focuses on growth traits in the F2 fish generation, comprised of offspring from 23 mass crosses from 383 F1 brooders. Using genotyping analysis for 10 microsatellites from both brood stock and progeny we have reconstructed the pedigree of each mass-cross. For F2 generation at 90 days post hatch (dph), we have recorded body weight (BW) for 12,117 individuals and total length (TL), standard length (SL) and condition factor (Ktl and Ksl) for 3530 individuals; and all five traits for 2136 individuals at 270 dph. At 90 dph the average BW was 46.88 ± 20.95 g. Combining pedigree information, recorded growth traits and Restricted Maximum Likelihood method, we have estimated that the narrow sense heritability (h2) in F1 fish for BW, TL, SL, Ktl and Ksl was at, 90 dph, 0.12 ± 0.03, 0.11 ± 0.03, 0.10 ± 0.03, 0.20 ± 0.04 and 0.11 ± 0.03, respectively and, at 270 dph, 0.34 ± 0.07, 0.32 ± 0.07, 0.30 ± 0.06, 0.13 ± 0.04 and 0.11 ± 0.04, respectively. At 90 dph the realised heritability for BW was 0.13. Comparing with F1 generation, the growth performance of F2 fish was increased by 14.4%. Heritability of growth traits will be useful for future genetic improvement programmes of the Asian seabass.

Estimation of genetic parameters of various economic traits in a synthetic broiler dam line

A study to estimate heritability, genetic and phenotypic correlations for growth and egg production traits was carried out with the data pertaining to1624 broiler dam line maintained at Poultry Breeding Farm of Department of Animal Genetics and Breeding, LUVAS, Hisar. Traits recorded during the study were body weights at 6, 20 and 40 weeks, age at first egg, egg weight, egg number, egg mass, clutch, pause size up to 40 weeks of age, percent fertility of selected pullets, percent hatchability on total egg set basis and percent hatchability on fertile egg set basis. As per results, the pooled least squares means of BW6, BW20 BW40 AFE, EN40 EW40, EM40 CS, PS, PF, TES and FES 832.81±4.80 g, 2314.24±23.33 g, 2912.49±30.31 g, 147.89±0.77 days, 79.37±0.64, 53.18±0.21’g, 4220.67±35.74 g, 2.74±0.05 eggs, 1.97±0.08 days, 81.04±0.60 %, 59.65±0.76 % and 72.86±0.64 % respectively. Results pointed out that the effect of hatch within generation was significant (P<0.01) on the BW20, BW40, AFE, EW40, EN40, EM40, CS, PS, PF, TES and FES. The heritability of growth traits, production traits and reproduction traits ranged from 0.14±0.06 to 0.23±0.08, 0.22±0.08 to 0.32±0.11 and 0.15±0.29±0.07 respectively. Low to moderate estimates of heritability for growth and production traits and moderate estimates of heritability for reproduction traits indicated that these traits can be improved through family selection.

Genetic Assessment of &lt;i&gt;Amaranthus&lt;/i&gt; Linn. Genotypes in Treatment Combinations of &lt;i&gt;Glomus clarum&lt;/i&gt; and &lt;i&gt;Leucaena leucocephala&lt;/i&gt; Lam. Using Simple Sequence Repeat (SSR) Marker

The molecular and genetic assessments of the seeds of five Amaranthus genotypes in four treatment combinations of Arbuscular mycorrhiza Fungus ( Glomus clarum ) and Green manure ( Leucaena leucocephala ) were evaluated using SSR maker with four primers. The experiment was laid out in a complete randomized design with four replicates. Heritability of growth traits were higher than yield traits for treated Amaranthus genotypes. The plant height had strong positive correlation with stem length (r=0.8919), inflorescent length (r=0.6150) and inflorescent width (r=0.6004). Prin 1 accounted for the highest variation with proportion of 0.4197 and eigenvalue of 5.8765. The study detected the polymorphism, gene and allelic diversity and established phylogenetic relationships among the Amaranthus population. NGBO1271 treated with G. clarum + L . leucocephala had the highest concentration of extracted DNA (4039.2ul), while NGBO1234 treated with G. clarum and NGBO1234 treated with L . leucocephala had highest genomic DNA nanodrop of 2.14 gl. A total of 15 alleles were detected and number of allele per primer ranged from 3 to 5 with mean value of 3.75. The highest allelic frequency of 0.75 was recorded for ASAAC005 and ASAAC006. However, ASAAC001 primer was polymorphic (66.86%), with highest allele number and allele diversity of 5.0000 and 0.7200 respectively. The result from Nei’s coefficient also confirmed genetic variation based on the total gene diversity and gene diversity per locus. The dendogram among the treated Amaranthus genotypes showed their phylogenetic relationship which can be useful in selection of closely related genotypes for desirable traits. Therefore, NGBO1234 and NGBO1271, G. clarum and L . leucocephala could be suitable genotypes and further explored in genetic improvement of crops. Also, ASAAC001 primer could be considered in molecular breeding of Amaranthus and other vegetables.