Evolutionary Subdivision of Domestic Chickens: Implications for Local Breeds as Assessed by Phenotype and Genotype in Comparison to Commercial and Fancy Breeds

To adjust breeding programs for local, commercial, and fancy breeds, and to implement molecular (marker-assisted) breeding, a proper comprehension of phenotypic and genotypic variation is a sine qua non for breeding progress in animal production. Here, we investigated an evolutionary subdivision of domestic chickens based on their phenotypic and genotypic variability using a wide sample of 49 different breeds/populations. These represent a significant proportion of the global chicken gene pool and all major purposes of breed use (according to their traditional classification model), with many of them being characterized by a synthetic genetic structure and notable admixture. We assessed their phenotypic variability in terms of body weight, body measurements, and egg production. From this, we proposed a phenotypic clustering model (PCM) including six evolutionary lineages of breed formation: egg-type, meat-type, dual purpose (egg-meat and meat-egg), game, fancy, and Bantam. Estimation of genotypic variability was carried out using the analysis of five SNPs, i.e., at the level of genomic variation at the NCAPG-LCORL locus. Based on these data, two generally similar genotypic clustering models (GCM1 and GCM2) were inferred that also had several overlaps with PCM. Further research for SNPs associated with economically important traits can be instrumental in marker-assisted breeding programs.

Norovirus Genotypic Variability in Brazil

Norovirus (NoV) has been recognized as the most common etiological agent of acute gastroenteritis (AGE) in various epidemiological settings worldwide. The virus displays a high genetic diversity that can be classified into genogroups, genotypes, and recombinant strains. Only genogroups I, II, and IV have been found to infect humans. Variants of genogroup II genotype 4 are the most widely circulating strains and have been responsible for all NoV outbreaks globally since the mid-1990s. Several studies from different Brazilian regions have been conducted to detect and genetically characterize NoV from sporadic AGE cases and outbreaks. In this chapter, we have summarized the data that focused on the genetic variabilities of NoVs and thus highlight the value of a surveillance system in assessing not only the true burden of the disease, but also the detection and characterization of emerging novel variants.

Expansion of the genotypic variability in watermelon by physical mutagenesis

Purpose. Studies have been conducted on 18 promising watermelon genotypes to expand the genotypic variability of watermelon by induced mutagenesis. Materials and methods. Air-dried seeds were irradiated with a closed 60Co γ-source «Doslidnyk» (Department of Molecular and Medical Biophysics, Faculty of Radiophysics, Biomedical Electronics and Computer Systems, V.N. Karazin Kharkiv National University of MES of Ukraine). Results and discussion. Each of the most informative breeding traits was statistically analyzed for their expression patterns and levels by variants of mutagenic treatment (different doses - 150 Gy, 200 Gy, and 250 Gy) in each of the 18 genotypes. The patterns of influence of the irradiation doses on plant growth and development have been determined, both in individual genotypes and for the whole sample. It has been found that γ-irradiation had a depressing effect in the majority of genotypes (late maturation, long or short stems, altered order of the 1st female flower formation, extended phases of the growing period). Genotypes and their groups (clusters), in which expression of traits is opposite (alternative), have been identified. Sources of economically valuable traits have been identified, and the following effective doses of γ-irradiation have been established for genotypes (clusters): 4 genotypes of cluster 4 γ-irradiated at 250 Gy ‑ in breeding for yield capacity; 2 genotypes of cluster 3 γ-irradiated at 150 ‑ 250 Gy – in breeding for marketability; 3 genotypes of clusters 3 γ-irradiated at 150, 200 or 250 Gy – in breeding for large fruits: 1 genotype of cluster 5 γ-irradiated at 150, 200 or 250 Gy – in breeding for late maturation; 2 genotypes of cluster 3 γ-irradiated at 200 or 250 Gy and 5 genotypes of cluster 5 γ-irradiated at 150 or 200 Gy– in breeding for early maturation; 3 genotypes of cluster 3 γ-irradiated at 200 or 250 Gy and 7 genotypes of cluster 5 γ-irradiated at 150, 200 and especially 250 Gy – in breeding for long stems; and 1 genotype of cluster 1 γ-irradiated at 150, 200 or 250 Gy – in breeding for short stems

Genetic diversity in Coffea canephora genotypes for leaf nutrient concentration

This study analyzed the genetic diversity in Coffea canephora genotypes by univariate and multivariate statistical analysis, based on concentrations of macro- and micronutrients in coffee leaves in the stages of pre-flowering and grain filling. The experiment was arranged in randomized blocks with three replications, in a 42x2 factorial design, in which factor one represented the evaluated genotypes and factor two the periods of leaf sampling, i.e., pre-flowering and grain filling. The data of leaf nutrient concentrations were subjected to analysis of variance by the F test (p <0.01), and genetic parameters were estimated. For the study of genetic diversity, the genotypes were grouped by the hierarchical unweighted pair-group method using arithmetic averages (UPGMA). The relative importance of a trait to predict genetic diversity was also studied. There is genetic divergence for leaf nutrient concentration in C. canephora genotypes. With a maximum limit of 60% of dissimilarity between genotypes, four groups were also formed by UPGMA. For the 42 evaluated genotypes, leaf S concentration was the most important trait for genetic diversity; this genotypic variability should be investigated to enhance the efficiency of nutritional diagnosis. Highlights There is genetic variability for leaf nutrient concentration in Coffea canephora The leaf concentration of nutrients in the phenological stage of pre-anthesis is different from the leaf concentration of nutrients in the coffee bean filling period. Leaf concentration of sulfur was the characteristic that contributed most to the genetic diversity among the 42 genotypes, followed by the concentration of copper, boron and magnesium. Genotypic variability for leaf nutrient concentration should be considered for better nutritional management.

Variability of fodder value of collection samples bentgrass

The peculiarities of the manifestation of variability and interrelationships of feed quality indicators in 27 genotypes belonging to three types of bentgrass were studied. A significant level of genotypic variability in the content of crude fat, crude protein, ash, phosphorus and potassium was revealed. Taking into account the low level of variability depending on the conditions of the growing year, it is recommended to pay attention to the crude fat content, crude fiber content and plant height when selecting. It is recommended to determine the genotypic divergence of genotypes when selecting parent pairs for hybridization using cluster analysis methods.