Impacts of genetic selection on Sequoia sempervirens mini-cutting rooting and initial growth in the field

Background: Vegetative propagation from superior individuals allows multiple copies of plants that are genetically identical to the parent plant to be obtained. However, vegetative propagation success varies among individual genotypes, with some clones having more difficulty forming roots than others. The aim of this study was to evaluate the genetic gain in Sequoia sempervirens (D.Don) Endl. clones using parameters describing vegetative propagation success and initial growth in field. Methods: Vegetative propagation success was quantified for 16 clones in a completely randomised design consisting of 10 replications, each containing 10 mini-cuttings. At 90 days, rooting (RT), survival (SV) and the number of new shoots (NS) were evaluated. Performance after planting in the field was assessed using 13 clones from the previous experiment, arranged in linear parcels of 10 plants with 8 replicates. After 18 months, survival (SV), stem diameter (SD), height (H) and dominance breakdown (DB) were assessed. Estimates of variance components, heritability and genetic correlations were obtained using the Selegen-REML/BLUP software. Results: The mini cuttings of the 16 clones had a coefficient of genetic variation (CVgi%) of 32.32% for RT, 5.44% for SV and 5.35% for NS. The heritability of the total genetic effects (H2 g) for RT was 0.68. The clones with the best predicted genotypic classifications for the characteristics evaluated in the field were A116, A140 and A138 for SV, A126, A140 and A138 for SD, A138, A140 and A117 for H and A138, A228 and A116 for DB. Conclusions: In general, it was possible to obtain high genetic gain for rooting and medium gain for dendrometric variables in the field.

Genetic and Phenotypic Assessment of Garden Peas (Pisum sativum L.) Genotypes

The field trial was conducted during the growing season 2017-2019 in the experimental fields of the Maritsa Vegetable Crop Institute, Plovdiv, Bulgaria. The study used 10 samples of garden peas (Pisum sativum L). for measurement. Plant tall (?m), height to first fertile node (?m), length of internode (cm), number of tillers, number of branches, number of ineffective nodes, total number of nodes, total number of pods per plant, one pod per fruiting handle, two pods per fruiting handle, pod length (?m), pod width (?m), pod weight per plant, weight of green grains per plant (g), % filled grains, % unfilled grains, average number of grains per pod were assessed. Analysis variance showed significant differences between the genotypes of garden peas in all the traits studied. A lower level of the genetic variance was found compared to the phenotypic one by the number of branches, total number of nodes and one pod per fruiting handle. The coefficient of genetic variation is higher than the phenotypic one for most of the traits and ranged from 5.51-5.82% for pod width and total number of nodes to 56.98-59.09% for number of branches and % unfilled grains. For signs of plant tall (98.32% and 129.31%), height to first fertile node (91.22% and 29.32%), weight of pods per plant (86.83%, 29.32), weight of green grains per plant (83.7%, 11.89%) and % filled grains (77.81% and 24.96%). It was found high inheritance combined with high genetic progress. This is a prerequisite for increasing the biological potential on these traits and a real opportunity to create new forms of garden peas possessing such qualities. The best genotypes were found GEN 1 (22/16-n.), GEN 6 (Marsy-n.), GEN 4 (Plovdiv-n.) and GEN 9 (1/17-n.). They may be used in new breeding programs and hybrid lines may be entered in competitive variety lists.

Potential exists to change, through breeding, the yield of individual primal carcass cuts in cattle without increasing overall carcass weight1

The ability to alter the morphology of cattle towards greater yields of higher value primal cuts has the potential to increase the value of animals at slaughter. Using weight records of 14 primal cuts from 31,827 cattle, the objective of the present study was to quantify the extent of genetic variability in these primal cuts; also of interest was the degree of genetic variability in the primal cuts adjusted to a common carcass weight. Variance components were estimated for each primal cut using animal linear mixed models. The coefficient of genetic variation in the different primal cuts ranged from 0.05 (bavette) to 0.10 (eye of round) with a mean coefficient of genetic variation of 0.07. When phenotypically adjusted to a common carcass weight, the coefficient of genetic variation of the primal cuts was lesser ranging from 0.02 to 0.07 with a mean of 0.04. The heritability of the 14 primal cuts ranged from 0.14 (bavette) to 0.75 (topside) with a mean heritability across all cuts of 0.48; the heritability estimates reduced, and ranged from 0.12 (bavette) to 0.56 (topside), when differences in carcass weight were accounted for in the statistical model. Genetic correlations between each primal cut and carcass weight were all ≥0.77; genetic correlations between each primal cut and carcass conformation score were, on average, 0.59 but when adjusted to a common carcass weight, the correlations weakened to, on average, 0.27. The genetic correlations among all 14 primal cut weights was, on average, strong (mean correlation of 0.72 with all correlations being ≥0.37); when adjusted to a common carcass weight, the mean of the genetic correlations among all primal cuts was 0.10. The ability of estimated breeding values for a selection of primal cuts to stratify animals phenotypically on the respective cut weight was demonstrated; the weight of the rump, striploin, and fillet of animals estimated to be in the top 25% genetically for the respective cut, were 10 to 24%, 12 to 24%, and 7 to 17% heavier than the weight of cuts from animals predicted to be in the worst 25% genetically for that cut. Significant exploitable genetic variability in primal carcass cuts was clearly evident even when adjusted to a common carcass weight. The high heritability of many of the primal cuts infers that large datasets are not actually required to achieve high accuracy of selection once the structure of the data and the number of progeny per sire is adequate.

GENETIC VARIABILITY IN PROGENIES OF Eucalyptus grandis AND Eucalyptus urophylla FOR TOLERANCE TO HYDRIC DEFICIT

Genetic variability in progenies of Eucalyptus grandis and Eucalyptus urophylla for tolerance to hydric deficit. Information on the adaptation and genetic potential of Eucalyptus under water deficit conditions is necessary owing to the increasing cultivation of the genus in regions considered as "forest frontiers". Therefore, the present study aimed to estimate genetic variability, genotypic and phenotypic correlations, and estimated genetic gains in progenies of E. grandis and E. urophylla. Two progeny tests (TP1 and TP2) were performed in the municipality of Vila Nova dos Martirios (state of Maranhão, Brazil), in 30-month-old plants. The experiment was carried out using a randomized block design, with five replicates, nine plants/square plot, and 144 treatments in TP1 and 264 in TP2. Statistical analysis was performed and genetic parameters were estimated. Individual and within-progeny heritabilities were corrected using the kinship coefficient for eachspecies. Genetic gains were low, ranging from 0.96 to 6.39% for E. grandis and 1.62 to 5.48% for E. urophylla. The diameter at breast height (DBH) showed a higher coefficient of genetic variation compared with the other measured characteristics, suggesting a higher potential for selection. High, positive, and significant correlations were observed between DBH and height (H), indicating the possibility of obtaining gains based on a single characteristic. Heritability was considered low, thus directly influencing the selection gains, which were lower than those commonly reported in other studies. These findings provide important information for breeding programs in areas of forest expansion.

Variasi Pertumbuhan dan Estimasi Parameter Genetik Semai Nyawai (Ficus variegata Blume)

Growth variation and genetic parameter estimation of Ficus variegata Blume seedlings were done at The Centre for Forest Biotechnology and Tree Improvement, Yogyakarta at 8 months of age. Genetic materials from Banyuwangi population which comprised of 15 families and Cilacap-Pangandaran population comprised of 19 families. The trial was designed as a Randomized Completely Block Design (RCBD) with family as treatment, 3 replications and each replication comprises 10 seedlings. The purpose of this study was to observe growth variation and genetic parameter of these populations at seedlings level. Analysis of variance was performed to find out family effect on height and diameter traits. Analysis of variance component was used to estimate coefficient of genetic variation, heritability and genetic correlation. This study showed that family effect on height and diameter variation was very significant at both populations. The estimation of coefficient of genetic variation for height and diameter trait ranged from 10.80% (categorized as intermediate) to 18.04% (categorized as high). Family heritability estimation for height trait ranged from 0.96 to 0.99 and diameter trait ranged from 0.89 to 0.96, both categorized as high. Strong genetic correlation for height and diameter trait ranged from 0.87 to 0.89.Keywords: Nyawai, Ficus variegata, growth, genetic parameter, seedling.

Genetic Variation in Growth Traits of Two Years Old Ficus variegata Blume

A progeny trial of nyawai (Ficus variegata Blume) with subline system was established in Mangunan, Bantul, Yogyakarta and designed as a Randomized Completely Block Design. Lombok subline comprised of 17 families and Cilacap-Pangandaran subline comprised of 19 families. This study was aimed to observe growth variation and genetic parameter of these sublines at two years after planting. Varians analysis was performed to find out family effect on survival, height, and diameter traits. Component varians analysis was used to estimate coefficient of genetic variation and heritability. This study showed that survival rate of the trial ranged from 89.01% to 91.42%. Family effect on height and diameter variation was very significant at both sublines. Estimation coefficient of genetic variation for height and diameter traits ranged from 4.41% to 9.04% or categorized as intermediate. Individual heritabilities for height traits ranged from 0.15 to 0.22; diameter ranged from 0.18 to 0.09, while family heritabilities for height and diameter traits ranged from 0.49 to 0.60 and 0.29 to 0.66 respectively.

Genetic variation among and within provenances and progenies of Corymbia maculata (Hook.) K. D. Hill and L. A. S. Johnson, in Pederneiras, SP

This study aimed to estimate genetic parameters and variation in a provenance-progeny test of C. maculata (ex Eucalyptus maculata Hook.), conducted at Pederneiras Experimental Station, in São Paulo Forest Institute. The test was based on 21 open-pollination progenies from provenance Woondum St. Forest and 17 from provenance Wondai St. Forest, both in Australia. A compact family block design was adopted consisting of ten blocks, six plants per straight-line plot and two outer border rows, with spacing 3 x 2 m. Traits assessed included diameter at breast height (DBH), height, volume, form and survival rate at age 4 and 21 years. Significant differences were detected only at age 4 between provenances for DBH and height and among progenies for DBH, height and volume. The coefficient of genetic variation was higher for all traits at age 21. The heritability coefficient at the progeny level (h m²) was also higher at age 21 and ranged from 0.21 for volume to 0.40 for height, indicating that genetic progress can be achieved through selection of the best progenies. Genetic correlations were high between traits within and between age categories, showing that potential genetic gains can be achieved through indirect, early selection. Results indicate that considerable gains can be made if high selection intensity is applied among and within progenies, with values ranging from 12.48% for height to 21.77% for volume.

The genetic relationship between interval to commencement of luteal activity postpartum and UK national fertility proofs for dairy cattle

The coefficient of genetic variation of fertility traits is of a similar magnitude to that present in production traits, however traditional measurements of fertility have low heritability (h2 < 0.05), and recording is often poor, hindering the identification of genetically superior animals. The effect of sire on daughter fertility has been examined as part of a DEFRA LINK project to produce an UK fertility index. The project is investigating the use of six currently recorded traits to calculate sire genetic merit for fertility: calving interval (CI), interval to first service (DIMFIR), nonreturn rate 56 (NR56), number of services per conception (CINSOBS), milk yield and condition score (Wall et al., 2002). An alternative way to measure fertility is to use endocrine measurements such as interval to commencement of luteal activity postpartum (CLA). This parameter is less influenced by management decisions and has a moderate heritability (0.16; Royal et al., 2002a.) and is measurable early in lactation. Although information on the genetic relationships between CLA and other traits of economic importance have been reported previously (Royal et al., 2002a.; Royal et al, 2002b.) further information would be useful in order to assess the usefulness of incorporating CLA into a future UK breeding programme. The objective of these analyses was therefore to obtain information on the genetic correlation (rA) between lnCLA and the emerging UK national fertility proofs.