scholarly journals Combining ability of twelve maize populations

2002 ◽  
Vol 37 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Elton Vacaro ◽  
José Fernandes Barbosa Neto ◽  
Diego Girardi Pegoraro ◽  
Claudio Natalino Nuss ◽  
Leo Duc Haa Conceição
Keyword(s):  
Combining Ability ◽  
Environmental Influence ◽  
Genetic Progress ◽  
Breeding Programs ◽  
Maize Populations ◽  
Population Improvement ◽  
Source Populations ◽  
Stalk Lodging ◽  
Genetic Phenomenon ◽  
Ear Number

Genetic progress depends on germplasm quality and breeding methods. Twelve maize populations and their crosses were evaluated to estimate combining ability and potential to be included as source populations in breeding programs. Plant height, point of insertion of the first ear, number of ears per plant, number of grains per ear, root and stalk lodging and grain yield were studied in two locations in Brazil, during the 1997/98 season. Genotype sum of squares was divided into general (GCA) and specific (SCA) combining ability. Results indicated the existence of genetic divergence for all traits analyzed, where additive effects were predominant. The high heterosis levels observed, mainly in Xanxerê, suggested the environmental influence on the manifestation of this genetic phenomenon. Populations revealed potential to be used in breeding programs; however, those more intensively submitted to selection could provide larger genetic progress, showing the importance of population improvement for the increment of the heterosis in maize.

scholarly journals Genetic variability in maize and teosinte populations estimated by microsatellites markers

2011 ◽  
Vol 41 (2) ◽  
pp. 205-211 ◽  
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.

scholarly journals Combining Ability for Kernel Starch Content in Maize Synthetic Populations Obtained from Local Populations

2013 ◽  
Vol 70 (1) ◽  
pp. 192-200
Author(s):  
Leon MUNTEAN ◽  
Nicolae TRITEAN ◽  
Ioan HAS ◽  
Voichita HAS ◽  
Alin GULEA
Keyword(s):  
Combining Ability ◽  
Starch Content ◽  
Low Cost ◽  
Local Population ◽  
Inbred Lines ◽  
Additive Effects ◽  
Experimental Conditions ◽  
Maize Populations ◽  
Synthetic Populations ◽  
Source Populations

Synthetic populations of maize (Zea mays L) are low-cost and stable varieties, obtained by cross pollination of a group of inbred lines, local population or hybrids. The main advantage of these populations is that the heterosis does not diminish significantly in F2. In order to complete the research on the combining ability of maize synthetic populations, the objective of this work was to study seven maize synthetic populations, determining their general combining ability (GCA) and specific combining ability (SCA) for kernel starch content, as well as their potential as source populations in breeding programmes.To achieve the proposed objectives, we studied top cross hybrids of the type “inbred line x synthetic population” resulted from the crossing between seven synthetic maize populations and four early inbred lines used as tester. For all experimental conditions, the differences between genotypes were statistically assured for kernel starch content. The experimental years and testing locations have provided conditions for differentiation of genotypes for starch content and interactions between the environment and genotypes were statistically significant, indicating dependence of starch content on environmental conditions. The additive effects for starch content provided by GCA were high for Tu SRR 5DR(6I)(5) and Tu SRR 5D (2I)(2). Non additive effects, corresponding to SCA were high for the following hybrid combinations: TC 233 x TuSyn 1 (3), CO 255 x Tu SRR 5D (2I)(2) and TC 209 x Tu SRR 5DR(6I)(5). In the case of synthetic maize populations, the determinism of starch is influenced equally by GCA and SCA.

scholarly journals POTENCIAL DE LINHAGENS ORIUNDAS DE POPULAÇÕES DE MILHO BRAQUÍTICO PARA OBTENÇÃO DE HÍBRIDOS

2017 ◽  
Vol 16 (1) ◽  
pp. 120
Author(s):  
BELISA CRISTINA SAITO ◽  
JOÃO ANTÔNIO DA COSTA ANDRADE
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Maize Populations ◽  
Single Cross ◽  
Ear Height ◽  
Stalk Lodging ◽  
Partial Diallel ◽  
Single Cross Hybrids

RESUMO - O objetivo do trabalho foi a identificar linhagens com alta capacidade de combinação visando o desenvolvimento de híbridos simples adaptados à condição de elevada densidade populacional de plantas. Treze linhagens originadas de duas populações de milho braquítico foram cruzadas seguindo o esquema de dialelo parcial (6x7). Os híbridos simples foram avaliados em duas safras (primeira e segunda safras). Os efeitos da interação entre as capacidades gerais de combinação (CGC) e safras foram diferentes para rendimento de grãos apenas para linhagens Isanão-VD1, enquanto que para a altura de plantas, altura de espigas e acamamento mais quebramento os efeitos da interação CGCs x safras foram diferentes para ambos os grupos de linhagens. Levando em consideração apenas o rendimento de grãos, os melhores híbridos são esperados entre as linhagens IVF1-5 e IVF1-10 da população Isanão VF1 e IVD1-1 e IVD1-2 da população Isanão-VD1. Considerando-se todos os caracteres, as linhagens promissoras para a primeira safra são IVF1-6, IVD1-1 e IVD1-5, e para a segunda safra as linhagens são IVF1-10, IVD1-8 e IVD1-9. Os híbridos mais adequados são IVF1-10 x IVD1-5 para primeira safra e IVF1-10 x IVD1-8 e IVF1-10 xIVD1-9 para a segunda.Palavras-chave: dialelo parcial, capacidade geral de combinação, capacidade específica de combinação.POTENTIAL OF INBRED LINES DERIVED FROM BRACHYTIC MAIZE POPULATIONS FOR OBTAINING HYBRIDSABSTRACT - The objective of this study was to identify parents with high combining ability aiming at the development of outstanding hybrids. Thirteen inbred lines originated of two brachytic maize populations were crossed following the partial diallel (6x7) scheme. The single-cross hybrids were evaluated in two crop seasons (regular crop and second crop). The effects of interaction general combining abilities (GCAs) x seasons were different for yield only for lines of Isanão-VD-1, while for plant height, ear height and stalk lodging and breaking, the effects of interaction GCAs x seasons were different for both groups of lines. Taking into account only the grain yield, the best hybrids are expected between the inbred lines IVF1-5, and IVF1-10, of the population Isanão-VF1 and IVD1-1 and IVD1-2 and IVD1-5 of the population Isanão-VD1. Considering all the traits, the inbred lines promising for the first crop are IVF1-6, IVD1-1 and IVD1-5 and for the second crop are the inbred lines IVF1-10, IVD1-8 and IVD1-9. The most suitable hybrids are IVF1-10 x IVD1-5 for the first crop and IVF1-10 x IVD1-8, and IVF1-10 xIVD1-9 for second crop.Keywords: partial diallel, general combining ability, specific combining ability.

scholarly journals Adaptation assessment of drought tolerance in maize populations from the Sahara in both shores of the Mediterranean Sea

Euphytica ◽  
2021 ◽  
Vol 217 (8) ◽  
Author(s):  
Oula Maafi ◽  
Pedro Revilla ◽  
Lorena Álvarez-Iglesias ◽  
Rosa Ana Malvar ◽  
Abderahmane Djemel
Keyword(s):  
Drought Tolerance ◽  
Biomass Production ◽  
Genetic Regulation ◽  
Breeding Programs ◽  
Favorable Alleles ◽  
Maize Germplasm ◽  
Maize Populations ◽  
Potential Source ◽  
Main Stress ◽  
And Control

AbstractDrought is the main stress for agriculture, and maize (Zea mays L.) germplasm from the Sahara has been identified as potential source of drought tolerance; however, information about adaptation of semitropical maize germplasm from the Sahara to temperate areas has not been reported. Our objective was assessing the adaptation of maize germplasm from Saharan oases as sources of drought tolerance for improving yield and biomass production under drought conditions in temperate environments. A collection of maize populations from Saharan oases was evaluated under drought and control conditions in Spain and Algeria. Algerian populations were significantly different under drought for most traits, and the significant genotype × environment interactions indicated that drought tolerance is genotype-dependent, but tolerance differences among genotypes change across environments. Based on yield, the Algerian maize populations PI527474, PI527478, PI527472, PI527467, PI527470, and PI527473 would be appropriate sources of drought tolerance for temperate environments. Concerning biomass production, the most interesting populations were PI527467, PI542685, PI527478, and PI527472. These Saharan populations could provide favorable alleles for drought tolerance for temperate breeding programs, and could also be used for studying mechanisms and genetic regulation of drought tolerance.

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

Animals ◽  
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.

scholarly journals GENERAL AND SPECIFIC COMBINING ABILITY IN SUNFLOWER (Helianthus annuus L.) / APTITUD COMBINATORIA GENERAL Y ESPECÍFICA EN EL GIRASOL (Helianthus annuus L.) / APTITUDE À LA COMBINATION GENERAL ET SPECIFIQUE CHEZ LE TOURNESOL (Helianthus annuus L.)

Helia ◽  
2001 ◽  
Vol 24 (34) ◽  
pp. 1-16 ◽  
Author(s):  
Domenico Laureti ◽  
Andrea Del Gatto
Keyword(s):  
Helianthus Annuus ◽  
Combining Ability ◽  
Central Italy ◽  
Specific Combining Ability ◽  
First Year ◽  
Male Sterile ◽  
Breeding Programs ◽  
East Central ◽  
Helianthus Annuus L ◽  
Selection For

SUMMARYA total of 245 test cross progenies obtained by crossing cytoplasmic male sterile (CMS) lines and restorer (RHA) lines were evaluated in replicated trials in 1995 and 1997. Experiments were carried out in two locations (Osimo, East Central Italy and Budrio, Northern Italy) in 1995, whereas in 1997 trials were conducted only in Osimo. General combining ability (GCA) and specific combining ability (SCA) of the parents was evaluated to identify genotypes suitable to be used as testers for breeding programs and to verify the performance of hybrids. The results obtained in 1995 were used to make test crosses in 1996 to be evaluated in 1997. The GCA and SCA of RHA and CMS lines were nearly always significant for all the studied traits when lines were randomly taken in 1995. When selected testers were used on the basis of the results of the first year, the SCA of new RHA lines and GCA of new CMS lines were not significant for achene yield, but they were for the other traits.The best GCA estimates for RHA were often higher than those of CMS, indicating that selection for RHA could be more useful than for CMS. As expected, GCA was always lower than SCA. CMS and RHA, with high variance among their test crosses for yield and many other traits, could be used as testers. The lack of a tester with high variance in all traits requires more than one tester in evaluating lines. The GCA of a line can change in function of the germplasm with which it is combined.

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

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 533
Author(s):  
Fernanda Zatti Barreto ◽  
Thiago Willian Almeida Balsalobre ◽  
Roberto Giacomini Chapola ◽  
Antonio Augusto Franco Garcia ◽  
Anete Pereira Souza ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Mixed Model ◽  
Agronomic Traits ◽  
Average Increase ◽  
Genetic Progress ◽  
Breeding Programs ◽  
Future Studies ◽  
Diversity Panel ◽  
Adjusted Means ◽  
Historical Series

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.

Breeding Programs and Genetic Progress

2017 ◽  
pp. 165-190 ◽  
Author(s):  
Aik Chin Soh ◽  
Sean Mayes ◽  
Jeremy Roberts ◽  
Nicolas Philippe Daniel Turnbull ◽  
Tristan Durand-Gasselin ◽  
...  
Keyword(s):  
Genetic Progress ◽  
Breeding Programs

scholarly journals Inheritance of plant height, spike length and number of spikelets per spike in Durum wheat

2007 ◽  
pp. 27-33 ◽  
Author(s):  
Biljana Gorjanovic ◽  
Marija Kraljevic-Balalic
Keyword(s):  
Durum Wheat ◽  
Plant Height ◽  
Combining Ability ◽  
Wheat Breeding ◽  
Specific Combining Ability ◽  
Spike Length ◽  
First Year ◽  
Gene Effects ◽  
Breeding Programs ◽  
Additive Genes

Using the line x tester analysis we studied the combining ability and gene effects of plant height, spike length and number of spikelets per spike in durum wheat. The results of the study show that non-additive genes play more important role than additive genes in the inheritance of plant height, number of spikelets per spike in both years and in inheritance of spike length only in the first year of research. Variety Belfugito, the best general combiner for plant height and number of spikelets per spike, combined well in two best hybrids: Belfugito x Alifen and Belfugito x Yavaros 79, and these hybrids may be used in wheat breeding programs. In the majority of the cases, good specific combining ability (SCA) effects were associated with crosses of two genetically divergent parents having at least one parent as a good general combiner.

scholarly journals Maize gene bank collections as potentially valuable breeding material

Genetika ◽  
2010 ◽  
Vol 42 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Jelena Vancetovic ◽  
Snezana Mladenovic-Drinic ◽  
Milosav Babic ◽  
Dragana Ignjatovic-Micic ◽  
Violeta Andjelkovic
Keyword(s):  
Genetic Resources ◽  
Herbicide Tolerance ◽  
Gene Bank ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Effective Utilization ◽  
Maize Populations ◽  
Predominant Type ◽  
Superior Genotypes ◽  
Maize Gene

Characterization and evaluation of the genetic resources provide breeders with valuable information on an effective utilization of the genetic resources in breeding programs. In this paper we present the results of different research programs aimed at identification of superior genotypes among MRI gene bank accessions, regarding stress tolerance (drought and herbicides), better nutritional quality (phosphorus) and specific traits (cytoplasmic male sterility - CMS). Fifty-two genotypes were identified as a potential source for drought tolerance. Considering herbicide tolerance only genotypes with resistance to the Pivot were found. Within 100 sources of CMS in the collection S cytoplasm was identified as the predominant type. Phytate analysis of 60 maize populations identified three groups of populations - with low (8), intermediate (25) and high (27) phytate content. The results of these researches, which are a part of pre-breeding activities, will be included in MRI breeding programs, with the aim of developing new genotypes with improved traits important in commercial maize breeding and seed production.

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