Genetic Variability, Correlation among Agronomic Traits, and Genetic Progress in a Sugarcane Diversity Panel

Sugarcane breeding programs require 15 years of experimentation to create more productive cultivars, and estimates of genetic progress can indicate the efficiency of breeding programs. In this study, we used a diversity panel, the Brazilian Panel of Sugarcane Genotypes (BPSG), with the following objectives: (i) to estimate, through a mixed model, the adjusted means and genetic parameters of ten traits evaluated over three harvest years; (ii) to estimate genotypic correlation among those traits; and (iii) to estimate genetic progress over six decades of breeding. The heritabilities ranged from 0.43 to 0.88, and we detected 42 significant correlations, 9 negative and 33 positive. Over six decades, the sucrose-related traits BRIX, POL%C, and POL%J showed an average increase per decade of 0.27 °Brix (0.26% and 0.31%, respectively). Stalk number, height, and weight of the plot, and cane and sucrose yields revealed average increases per decade of 3.27 stalks, 0.06 m, 9.42 kg, 11.22 t/ha, and 2.08 t/ha, respectively. The genetic progress of the main agronomic traits is discussed through a historical series of sugarcane genotypes present in the BPSG. The findings of this study could contribute to the management of new breeding strategies and allow for future studies of associative mapping.

Download Full-text

Genetic parameters and performance of sugarcane families under cold stress in the South of Brazil

Pesquisa Agropecuária Brasileira ◽

10.1590/s0100-204x2018000500007 ◽

2018 ◽

Vol 53 (5) ◽

pp. 583-592 ◽

Cited By ~ 1

Author(s):

Mario Alvaro Aloisio Verissimo ◽

Ricardo Augusto de Oliveira ◽

Sérgio Delmar dos Anjos e Silva ◽

Edelclaiton Daros ◽

Adílson Härter

Keyword(s):

Cold Stress ◽

Genetic Parameters ◽

Mixed Model ◽

Block Design ◽

Genetic Progress ◽

Incomplete Block Design ◽

Sib Families ◽

Heritability Estimates ◽

And Performance ◽

South Of Brazil

Abstract: The objective of this work was to estimate the genetic parameters for the performance prediction of sugarcane (Saccharum spp.) families under natural cold stress, in Southern Brazil, and to identify the best combinations of parents aiming at the selection for tolerance to cold. Fifty-three full-sib families were evaluated in an incomplete block design, with five replicates per family, in the municipality of Pelotas, in the state of Rio Grande do Sul, Brazil. Harvest occurred in August 2013, nine months after planting and after cold spells with negative temperatures down to -2.2ºC. Statistical analyses, performed with the mixed model methodology, detected significant differences among families. Heritability estimates among progeny means were higher than those of individual heritability. Estimates of genetic progress for the traits megagrams of stalks per hectare, megagrams of brix per hectare, and number of stalks indicated gains of 93.8, 91.0, and 53.3%, respectively. A set of eight promising families that combine high estimates for yield and cold stress tolerance was obtained.

Download Full-text

Five decades of black common bean genetic breeding in Brazil

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632016v4641371 ◽

2016 ◽

Vol 46 (3) ◽

pp. 259-266 ◽

Cited By ~ 4

Author(s):

Leiri Daiane Barili ◽

Naine Martins do Vale ◽

José Eustáquio de Souza Carneiro ◽

Fabyano Fonseca e Silva ◽

Felipe Lopes da Silva

Keyword(s):

Grain Yield ◽

Common Bean ◽

Seed Weight ◽

Regression Models ◽

Plant Architecture ◽

Agronomic Traits ◽

Linear Regression Models ◽

Genetic Progress ◽

Breeding Programs ◽

Genetic Breeding

ABSTRACT The increase in grain yield and other agronomic traits, in common bean cultivars, is due, in large part, to its genetic breeding. This study aimed at estimating the genetic progress for grain yield and other important agronomic traits in black common bean cultivars recommended by Brazilian breeding programs between 1960 and 2013. A randomized blocks design was used, with three replications and 40 black common bean cultivars. The following traits were evaluated: grain yield and appearance, plant architecture, number of pods per plant and seeds per pod and 1,000-seed weight. The genetic progress was estimated from the trait averages over the years, using bissegmented linear regression models that allowed the inference of the exact year in which the black common bean breeding began to present significant genetic progress. For grain yield, the genetic progress was observed from 1988, with an annual gain of 2.42 %. Improvements also occurred to grain appearance (1.85 %), plant architecture (1.35 %), number of pods per plant (2.36 %) and seeds per pod (2.24 %) and 1,000-seed weight (1.42 %), mainly after 1989.

Download Full-text

Estimates of genetic parameters of pigments and agronomic traits in green and purple lettuce

Ciência e Agrotecnologia ◽

10.1590/1413-7054201943013219 ◽

2019 ◽

Vol 43 ◽

Author(s):

Alisson Henrique Gama de Oliveira ◽

Gabriel Mascarenhas Maciel ◽

Ana Carolina Silva Siquieroli ◽

Ana Carolina Pires Jacinto ◽

Aline José da Silveira ◽

...

Keyword(s):

Genetic Parameters ◽

Agronomic Traits ◽

Characteristic Number ◽

Gene Interactions ◽

Anthocyanin Content ◽

Breeding Programs ◽

Oligogenic Inheritance ◽

Number Of Leaves ◽

Determining Factor ◽

Desirable Trait

ABSTRACT Understanding genetics and the gene interactions involved in the expression of certain characteristics becomes a determining factor for better exploration of its use. The development of breeding programs that combine one or more desirable trait into a single cultivar is directly impacted by this lack of knowledge of the genetic bases involved. The objective of the present study was to estimate the genetic parameters involved in pigment expression and agronomic characteristics in lettuce. Parental evaluations of lettuce, P1 (green) and P2 (purple) parental generations, the segregating generations F1 and F2, and the backcrosses Bc1 and Bc2 originating from the UFU-Crespa199#1#1 x UFU-Albina#2 crossing were evaluated. The chlorophyll and anthocyanin contents, number of leaves and plant diameter were evaluated. The study was conducted by testing all generations and the estimates obtained by averages and variances. Indications of polygenic or oligogenic inheritance were verified by the characteristic number of leaves, plant diameter, and anthocyanin content. The complete and additive-dominant models satisfactorily explained the performance of the variables, except the anthocyanin content.

Download Full-text

Genetic variability in maize and teosinte populations estimated by microsatellites markers

Ciência Rural ◽

10.1590/s0103-84782011005000005 ◽

2011 ◽

Vol 41 (2) ◽

pp. 205-211 ◽

Cited By ~ 4

Author(s):

Tatiana de Freitas Terra ◽

Paula Wiethölter ◽

Cícero Carlos de Souza Almeida ◽

Sérgio Delmar dos Anjos e Silva ◽

Fernanda Bered ◽

...

Keyword(s):

Zea Mays ◽

Genetic Variability ◽

Polymorphism Information Content ◽

Agronomic Traits ◽

Genetic Progress ◽

Breeding Programs ◽

Microsatellites Markers ◽

Maize Populations ◽

Genetic Source ◽

Genomic Similarity

Wild species are important sources of genetic variability and may be exploited by breeding programs. Crosses between teosinte and maize occur freely and teosinte serves as genetic source of agronomic traits for introduction in maize. The objective of this study was to estimate genetic variability among and within maize and teosinte populations (Zea mays mexicana). Two sweet maize populations (BR400 and BR402), two common maize populations (Suwan and Pampa) and one teosinte population were analyzed using microsatellites markers. Results indicated that 64,5% of the variation was detected within the populations, suggesting the possibility of obtaining genetic progress by selection within each population. The analysis with 25 microsatellites loci enabled the identification of 92 alleles with a mean of 3.7 alleles per locus. The average Polymorphism Information Content (PIC) was 0.52. The percentage of polymorphic loci varied from 64% in the BR400 and Pampa populations to 80% in the teosinte population. The estimated genetic distance confirmed the genomic similarity of maize and teosinte.

Download Full-text

Genetic Parameters and Inbreeding Effect of Morphological Traits in Sardinian Anglo Arab Horse

Animals ◽

10.3390/ani10050791 ◽

2020 ◽

Vol 10 (5) ◽

pp. 791

Author(s):

Andrea Giontella ◽

Francesca Maria Sarti ◽

Giovanni Paolo Biggio ◽

Samira Giovannini ◽

Raffaele Cherchi ◽

...

Keyword(s):

Genetic Parameters ◽

Agricultural Research ◽

Genetic Correlations ◽

Mean Value ◽

Genetic Progress ◽

Breeding Programs ◽

Chest Girth ◽

Inbreeding Rate ◽

Biometric Measurements ◽

The Mean

The purpose of this study was to estimate the heritability and genetic correlations of four biometric measurements and an overall score (OS) in the Sardinian Anglo-Arab horse (SAA); moreover, the effect of inbreeding on these traits was investigated. A dataset with 43,624 horses (27,052 females and 16,572 males) was provided by the Agricultural Research Agency of Sardinia (AGRIS). Cannon bone circumference (BC), chest girth (CG), shoulder length (SL), and withers height (WH) were measured on 6033 SAA horses born in Sardinia between 1967 and 2005; beside the measurements, an overall score (OS) was taken comparing the morphology of each horse to an “ideal type” that is scored out of 100. The mean value is 20.5 cm for BC, 185.9 cm for CG, 67.6 cm for SL, 160.8 cm for WH, and 73.2 for the OS. The heritability estimates ranged from 0.78 to 0.23. The results allow to foresee high genetic progress through the breeding programs. The most affected trait by the inbreeding rate seems to only be the withers height.

Download Full-text

Genetic parameters estimation in King palm through a mixed mating system model

Horticultura Brasileira ◽

10.1590/s0102-05362003000100020 ◽

2003 ◽

Vol 21 (1) ◽

pp. 93-98 ◽

Cited By ~ 7

Author(s):

Marilene L. A. Bovi ◽

Marcos Deon V. de Resende ◽

Sandra H. Spiering

Keyword(s):

Mating System ◽

Genetic Parameters ◽

Mixed Model ◽

Block Design ◽

Leaf Sheath ◽

Parameters Estimation ◽

System Model ◽

Mixed Mating ◽

Genetic Progress ◽

Mixed Mating System

Overestimation of the genetic parameters is common in palms due to the occurrence of geitonogamy and the absence of self-incompatibility mechanisms. Data from nursery grown Archontophoenix palms were utilized, assuming a mixed mating system including random cross-pollination and selfing at different rates. The objective was to show the importance of knowing the mating system predominant and define breeding strategies for that genus. Twenty-four King palm half sib families were evaluated at nursery conditions using a randomised complete block design, with nine replications and eleven plants per plot. Ten months after sowing, traits such as diameter, height, number of green leaves and length of the leaf sheath of the second leaf, were individually measured. Traits related to biomass were also estimated through regression procedure. It was concluded that King palm cannot be considered allogamous and the mixed mating system model should be used when estimating genetic parameters. At least 50% of selfing occurred at the time of pollination in the mother plants. The multi-effects index, using all random effects of the linear model, provided the highest selection accuracy for all traits, whatever the individual heritability level, and should be used in King palm heart-of-palm breeding programs. Under the allogamous model, the effective size of the studied population was equivalent to 93 unrelated individuals. This size was reduced to 32 palms under the mixed model; even so this population has enough variability to allow genetic progress by selection.

Download Full-text

Assessment of Piglet Vitality by Farmers—Validation of A Scoring Scheme and Estimation of Associated Genetic Parameters

Animals ◽

10.3390/ani9060317 ◽

2019 ◽

Vol 9 (6) ◽

pp. 317 ◽

Cited By ~ 1

Author(s):

Katharina Schodl ◽

Regine Revermann ◽

Christoph Winckler ◽

Birgit Fuerst-Waltl ◽

Christine Leeb ◽

...

Keyword(s):

Mortality Rate ◽

Genetic Analysis ◽

Litter Size ◽

Genetic Parameters ◽

Mixed Model ◽

Linear Mixed Model ◽

Large White ◽

Breeding Programs ◽

Piglet Mortality ◽

On Farm

Maternal breeds for sows have been bred for high prolificacy during recent decades. Although large litters may be beneficial for economic efficiency, pre-weaning mortality is increased. Thus, focus should instead be put on new traits such as piglet vitality (PV). Until now, no validated scoring scheme for piglet vitality exists, which is feasible to be applied for routine on-farm trait recording. The objective of this study was to validate a four-point vitality scoring scheme (1 = low vitality to 4 = high vitality) applied by farmers based on pre-weaning mortality and to estimate genetic parameters. A linear mixed model was fitted for piglet vitality for 3172 litters from Large White and Landrace sows on 23 farms and correlations were calculated for vitality score and piglet mortality. A subsample of 2900 records was used for genetic analysis. Pre-weaning mortality differed significantly between all vitality score categories except for 1 and 2, ranging between 7.98% (category 4) and 29.1% (category 1). PV was genetically negatively correlated to litter size (−0.68) and mortality rate (−0.65), whereas litter size was positively correlated with mortality rate (0.59). Including PV into breeding programs may, thus, improve animal welfare.

Download Full-text

Genetic progress in popcorn recurrent selection by a multivariate mixed-model approach

Ciência e Agrotecnologia ◽

10.1590/1413-70542018422016817 ◽

2018 ◽

Vol 42 (2) ◽

pp. 159-167

Author(s):

Hugo Junqueira Ematné ◽

José Airton Rodrigues Nunes ◽

João Cândido de Souza ◽

Patrício Ricardo Muñoz

Keyword(s):

Genetic Parameters ◽

Recurrent Selection ◽

Mixed Model ◽

Genetic Relationships ◽

Multivariate Approach ◽

Genetic Progress ◽

Mixed Model Approach ◽

Contrast Gain ◽

Univariate Approach ◽

Model Approach

ABSTRACT Recurrent selection is a viable alternative for popcorn breeding. However, frequent verification of progress attained is required. The aim of this study was to estimate the genetic progress attained for popping expansion (PE) and grain yield (GY) after four cycles of recurrent selection and to compare this progress with the expected progress estimated at the end of each cycle while considering the genetic relationships between the progenies via univariate and multivariate mixed-model approaches. To estimate the genetic parameters and gains from indirect selection, cycles 1, 2, 3, and 4 of a UFLA population were used. To estimate the genetic gains achieved, the following cycles were used: UFLA (original) and cycles 0, 1, 2, 3, and 4, evaluated in three environments. The multivariate approach provided more accurate estimates than did the univariate approach. There was genetic gain for PE in the recurrent selection program. In contrast, gain was not observed for GY using the different estimation strategies.

Download Full-text

Identification of the Optimum Environments for the High Yield and Quality Traits of Lentil Genotypes Evaluated in Multi-Location Trials

Sustainability ◽

10.3390/su13158247 ◽

2021 ◽

Vol 13 (15) ◽

pp. 8247

Author(s):

Dimitrios N. Vlachostergios ◽

Christos Noulas ◽

Anastasia Kargiotidou ◽

Dimitrios Baxevanos ◽

Evangelia Tigka ◽

...

Keyword(s):

Crude Protein ◽

Agronomic Traits ◽

High Yield ◽

Breeding Programs ◽

Growing Seasons ◽

Yield And Quality ◽

Food And Feed ◽

Superior Genotypes ◽

Selection Of ◽

The Ideal

Lentil is a versatile and profitable pulse crop with high nutritional food and feed values. The objectives of the study were to determine suitable locations for high yield and quality in terms of production and/or breeding, and to identify promising genotypes. For this reason, five lentil genotypes were evaluated in a multi-location network consisting of ten diverse sites for two consecutive growing seasons, for seed yield (SY), other agronomic traits, crude protein (CP), cooking time (CT) and crude protein yield (CPY). A significant diversification and specialization of the locations was identified with regards to SY, CP, CT and CPY. Different locations showed optimal values for each trait. Locations E4 and E3, followed by E10, were “ideal” for SY; locations E1, E3 and E7 were ideal for high CP; and the “ideal” locations for CT were E3 and E5, followed by E2. Therefore, the scope of the cultivation determined the optimum locations for lentil cultivation. The GGE-biplot analysis revealed different discriminating abilities and representativeness among the locations for the identification of the most productive and stable genotypes. Location E3 (Orestiada, Region of Thrace) was recognized as being optimal for lentil breeding, as it was the “ideal” or close to “ideal” for the selection of superior genotypes for SY, CP, CT and CPY. Adaptable genotypes (cv. Dimitra, Samos) showed a high SY along with excellent values for CP, CT and CPY, and are suggested either for cultivation in many regions or to be exploited in breeding programs.

Download Full-text

Genomic Analysis, Progress and Future Perspectives in Dairy Cattle Selection: A Review

Animals ◽

10.3390/ani11030599 ◽

2021 ◽

Vol 11 (3) ◽

pp. 599

Author(s):

Miguel A. Gutierrez-Reinoso ◽

Pedro M. Aponte ◽

Manuel Garcia-Herreros

Keyword(s):

Dairy Cattle ◽

Production Efficiency ◽

Association Studies ◽

Phenotypic Traits ◽

Progeny Testing ◽

Genome Wide Association Studies ◽

Genetic Progress ◽

Breeding Programs ◽

Increased Risk ◽

Selection Of

Genomics comprises a set of current and valuable technologies implemented as selection tools in dairy cattle commercial breeding programs. The intensive progeny testing for production and reproductive traits based on genomic breeding values (GEBVs) has been crucial to increasing dairy cattle productivity. The knowledge of key genes and haplotypes, including their regulation mechanisms, as markers for productivity traits, may improve the strategies on the present and future for dairy cattle selection. Genome-wide association studies (GWAS) such as quantitative trait loci (QTL), single nucleotide polymorphisms (SNPs), or single-step genomic best linear unbiased prediction (ssGBLUP) methods have already been included in global dairy programs for the estimation of marker-assisted selection-derived effects. The increase in genetic progress based on genomic predicting accuracy has also contributed to the understanding of genetic effects in dairy cattle offspring. However, the crossing within inbred-lines critically increased homozygosis with accumulated negative effects of inbreeding like a decline in reproductive performance. Thus, inaccurate-biased estimations based on empirical-conventional models of dairy production systems face an increased risk of providing suboptimal results derived from errors in the selection of candidates of high genetic merit-based just on low-heritability phenotypic traits. This extends the generation intervals and increases costs due to the significant reduction of genetic gains. The remarkable progress of genomic prediction increases the accurate selection of superior candidates. The scope of the present review is to summarize and discuss the advances and challenges of genomic tools for dairy cattle selection for optimizing breeding programs and controlling negative inbreeding depression effects on productivity and consequently, achieving economic-effective advances in food production efficiency. Particular attention is given to the potential genomic selection-derived results to facilitate precision management on modern dairy farms, including an overview of novel genome editing methodologies as perspectives toward the future.

Download Full-text