Genetic variability and genetic progress in seed traits in breeding the physic nut

Determining the chemical composition of seeds of the physic nut (Jatropha curcas L.) is of great importance for the species due to the oil content of the seeds (the principal trait of interest). Identifying promising genotypes with selectable seed traits is one of the strategies adopted in breeding the physic nut in order to increase the yield and quality of the oil. Therefore, the aim of this study was to determine the chemical composition of seed traits in ten half-sibling progeny of the physic nut, and to identify which progeny have good genetic performance for transmission to the offspring. The experimental design was completely randomised, with ten treatments and four replications. The treatments were represented by seeds from half-sibling progeny in which the carbohydrate, protein and lipid content, and the composition of the fatty acids were evaluated. The genetic parameters and the gains from their selection were predicted for the principal seed traits using mixed-model analysis, including REML (restricted maximum likelihood) and BLUP (best linear unbiased prediction). The physic-nut seeds showed an average dry matter (DM) concentration of 60 mg g-1 carbohydrates, 42 mg g-1 protein and 142 mg g-1 total lipids. Unsaturated fatty acids represented more than 85% of the total fatty acid composition, with the oil classified as oleic-linoleic. Considering the predictions of the genetic parameters, the lipid traits can be selected for the purpose of breeding, resulting in genetic progress in the yield and quality of physic-nut oil.

Genetic divergence between half-sibling progenies of kale using different multivariate approaches

ABSTRACT The aim of this study was to evaluate the genetic dissimilarity between half-sibling progenies of kale in order to determine the most divergent progenies and, also, to select potential parents. Thirty-six kale genotypes were evaluated, being thirty-three half-sibling progenies and three commercial cultivars, in a randomized block design with four replicates and six plants per plot. Twenty-eight traits were evaluated in each plant per plot, thirteen quantitative and fifteen qualitative traits. Genetic divergence was studied using MANOVA and canonical variables for quantitative observations. In addition, dendrograms were made for quantitative, qualitative and joint analyses by UPGMA method, using Mahalanobis distance. Genetic divergence was observed between genotypes. Commercial cultivars were more divergent than half-sibling progenies. Among half-sibling progenies, the most divergent ones were P1, P21, P23, P25 and P30. We concluded that half-sibling progenies P1, P23 and P30 can be used as potential parents to compose the recombinant population.

Epitheliotropic T-cell lymphoma in 2 half-sibling bontebok

We diagnosed epitheliotropic T-cell lymphoma of the forestomachs in 2 aged, half-sibling, zoo-managed bontebok ( Damaliscus pygargus pygargus). One bontebok also had mesenteric lymph node and cutaneous involvement. Both animals had a history of chronic abdominal distension and diminished body condition that resulted in euthanasia. At autopsy, both animals had marked ruminal distension with diffusely blunted ruminal papillae and reticular crests. In case 1, there was an increased amount and particle length of the ruminoreticular fibrous material with scant fluid, and a 2-cm diameter focus of cutaneous crusting adjacent to a mammary teat. In case 2, the rumen and reticulum were fluid-distended with decreased fibrous material. Histologically in case 1, the rumen, reticulum, omasum, and skin had intraepithelial nests and sheets of neoplastic small lymphocytes; in case 2, the rumen and reticulum had a similar neoplastic cell population. Immunohistochemically, neoplastic lymphocytes were immunoreactive for CD3 and negative for CD20, confirming the diagnosis of epitheliotropic T-cell lymphoma.

99 Effects of feeding 60% dried corn distillers grains plus solubles or the equivalent sulfur as calcium sulfate on trace mineral concentrations in serum and seminal plasma

Thirty-six half-sibling yearling Angus bulls [256 ± 8 d; initial BW = 320 ± 2 kg] were assigned one of three diets: 1) 60% concentrate as corn (CON; n = 12); 2) 60% DDGS (60DDGS; n = 12); 3) CON diet + equivalent sulfur of 60DDGS as CaSO4 (SULF; n = 12) to evaluate effects of feeding 60% DDGS or sulfur as CaSO4 on trace mineral (TM) concentrations in serum and seminal plasma. Bulls were fed in Calan gates for 112 days and targeted to gain 1.6 kg/d. Data were analyzed as repeated measures using PROC MIXED in SAS. In serum, treatment × day interactions were observed (P ≤ 0.03) for Cu, Se, and Mo. For Cu, no differences (P > 0.15) were observed at d 0 or 56, but at d 112, 60DDGS was reduced (P < 0.01) compared with SULF and CON. At d 0, no differences (P > 0.09) were observed for Se; however, at d 56 and 112, 60DDGS was greater (P < 0.01) than CON and SULF. For Mo, at d 0, 60DDGS was greater (P = 0.03) than CON, whereas SULF was intermediate, but at d 56 and 112, CON was greater (P < 0.01) than SULF and 60DDGS. In seminal plasma, treatment × day interactions were observed (P ≤ 0.02) for Cu and Mo. For Cu, no differences (P ≥ 0.09) were observed at d 0 or 56, but at d 112, CON and 60DDGS were greater (P < 0.01) compared with SULF. For Mo, at d 0, 60DDGS was greater (P = 0.03) than SULF, whereas CON was intermediate, but on d 56 and 112, CON was greater (P < 0.01) than 60DDGS and SULF. Differences observed for TM may have influenced enzyme activity and semen kinematics which were previously reported.

Size-dependent tradeoffs in aggressive behavior towards kin

Aggression between juveniles can be unexpected, as their primary motivation is to survive until their reproductive stage. However, instances of aggression, which may escalate to cannibalism, can be vital for survival, although the factors (e.g. genetic or environmental) leading to cannibalism vary across taxa. While cannibalism can greatly accelerate individual growth, it may also reduce inclusive fitness when kin are consumed. As a solution to this problem, some cannibals demonstrate kin discrimination and preferentially attack unrelated individuals. Here, we used both experimental and modeling approaches to consider how physical traits (e.g. size in relation to opponent) and genetic relatedness mediate aggressive behavior in dyads of cannibalistic Dendrobates tinctorius tadpoles. We paired sibling, half-sibling, and non-sibling tadpoles of different sizes together in an arena and recorded their aggression and activity. We found that the interaction between size and relatedness predicts aggressive behavior: large non-siblings are significantly more aggressive than large siblings. Unexpectedly, although siblings tended to attack less overall, in size mismatched pairs they attacked faster than in non-sibling treatments. Ultimately, it appears that larval aggression reflects a balance between relatedness and size where individuals trade-off their own fitness with that of their relatives.

GENETIC DISSIMILARITY FOR RESISTANCE TO FOLIAR DISEASES ASSOCIATED WITH THE AGRONOMIC POTENTIAL IN MAIZE

ABSTRACT In the present study the objective was to evaluate the genetic diversity among families of maize siblings for resistance to foliar diseases associated with their agronomic potential, identifying groups of families that can be used as sources of resistance in maize crop. The experiments were conducted in the experimental area of the Federal University of Goiás at the Jataí Regional Unit, in Jataí, GO, Brazil, constituted by 182 half-sibling families of maize and two commercial hybrids as a control. The 182 half-sibling families were divided into three experiments with 60, 60 and 62 families, respectively. The experimental design used was randomized blocks, with three replicates. Eight quantitative characters and 4 foliar diseases were evaluated. The multivariate analysis technique was used to measure the genetic divergence for the four foliar diseases represented by the generalized Mahalanobis distance. Based on the genetic dissimilarity matrix, the dendrogram was constructed using the clustering method of the average distance between groups (Unweighted Pair Group Method with Arithmetic Mean - UPGMA). After defining the groups, univariate analysis of variance was performed in order to evaluate the effects of the groups on each character studied. Comparisons were made between the means of the groups, using the Tukey test (p <0.05). White spot (32.53%) was the disease that most contributed to the total divergence between families. Group 10 stood out among the others as a source of resistance to the disease complex associated with yield. The genetic variability of families for foliar disease complex reveals potential for future studies facing pyramiding genes.

Phenotypic plasticity of leaf shape in selected and semi-domesticated genotypes as new tool of Argania spinosa L. Skeels breeding

Leaves are part of the plant organs that are important to sustain its life. These organs are sensitive to climate changes and may present phenotypic plasticity in response to environmental conditions. However, affirmation of the leaves morphological plasticity and their regulation in different environments is still little studied up to date. In the present research, we evaluated performance of 20 different groups of Argania spinosa (L.) Skeels genotypes (half-sibling). Each group contains 3 half-sibs. Genotype × environment interactions (GxE) were evaluated as well, for shape and size leaves. To perform this, geometric morphometric principles were applied to analyze genotypes morphology in three locations (Central, North-Western and South-Western of Morocco). Univariate and multivariate analysis was used for data analysis. Results showed significant variation of symmetric and asymmetric components for genotypes, half-sibling and location with relatively high variation coefficient (ca 60%). Shape and size differences among genotypes, suggest that they were the main source in leaf morphology variation. Canonical Variate Analysis of leaf shapes reveals that the regions are clearly distinct from each other. For symmetric component analysis, Mahalanobis distances values among locations reached 35.53 between South-Western and North-Western locations, 21.88 North-Western and Central locations and 18.29 for South-Western and Central location. The differentiation between the groups using the Canonical Variations value showed a significant effect of the environment on the studied argan tree genotypes. Small leaves and narrow blades were observed in Central location compared to others. However, leaves originated from South-Western location had mainly an ovate shape. The same genotypes presented a high spectrum of shape variation varying from obovate to ovate in the other regions. This study highlights the strong correspondence between leaf morphology and genotype within different environments, and demonstrates that GxE interaction shave an impact to take into consideration in breeding programs.

Progeny selection of "Myrocarpus frondosus" for improved growth vigor of seedlings

In this study, we aimed to evaluate half-sibling progenies of Myrocarpus frondosus based on morphological characteristics and to select seedlings with high growth vigor and quality. Seedlings were evaluated for shoot height and diameter, shoot height/diameter ratio, and number of leaves. The shoot height showed the highest estimations of linear correlation with the other characteristics. The linear correlation of shoot height between two consecutive evaluations was high from 60 days of cultivation, indicating that selection should be applied after this period. Selection of 101 seedlings within the best progenies resulted in a genetic gain of 15.13% for shoot height. The greatest indirect gain from selection was for the shoot height/diameter ratio, whereas the lowest indirect gain was for the stem diameter. Myrocarpus frondosus progenies can be selected for shoot height at 60 days of nursery cultivation, resulting in high direct gain for growth and indirect gain for stem height/diameter ratio.

Simultaneous selection of cupuassu tree and Brazilian mahogany genotypes in an agroforestry system in Pará state, Brazil

ABSTRACT This study aimed to evaluate and select progenies and matrices of cupuassu-tree siblings, and to select Brazilian mahogany matrices with superior characteristics to be used in agroforestry systems (AFS). Twenty-five full cupuassu tree sibling progenies and one Brazilian mahogany half-sibling progeny were evaluated. The study was conducted for 14 years in a commercial property in Tomé Açu, Pará State, Brazil. The number of fruits and fruit yield per plant, as well as the rate of plants with symptoms of witches’ broom disease, were used as response variables for cupuassu. For mahogany, the following response variables were used: total height, commercial height, crown height, diameter at breast height and commercial wood volume. There were five cupuassu tree progenies with interesting characteristics to be used in AFS. Based on the high values observed in the selection accuracy and heritabilities, a good potential for the selection of promising individuals in the cupuassu tree population is inferred. Based on the ranking of genotypic values and their agronomic performance, 10 matrices of cupuassu tree were selected. For Brazilian mahogany, three matrices showed excellent silvicultural performance. The matrices of these two species should be propagated vegetatively in order to evaluate clonal tests.