GENETIC VARIABILITY AND EXPECTED GAIN IN THREE MAIZE POPULATIONS

2018 ◽  
Vol 17 (1) ◽  
pp. 135 ◽  
Author(s):  
ALINE CARDOSO SOUZA ◽  
JOSE BRANCO MIRANDA FILHO ◽  
AURILENE SANTOS OLIVEIRA ◽  
JEFFERSON FERNANDO NAVES PINTO ◽  
CAROLINA MESSIAS SILVA ◽  
...  
Keyword(s):  
Zea Mays ◽  
Genetic Variability ◽  
Grain Yield ◽  
Plant Height ◽  
Recurrent Selection ◽  
Additive Genetic Variance ◽  
Yield Potential ◽  
Maize Populations ◽  
Expected Gain ◽  
Ear Height

ABSTRACT - The study of genetic variability in populations undergoing recurrent selection is important to quantify their real potential for breeding purposes. In the present work, three semiexotic maize populations were evaluated on their yield potential and variability for continuing the recurrent selection program. Half-sib families representing three semiexotic populations CRE-01, CRE-02, CRE-03 were evaluated for yield and agronomic traits male flowering (MF), plant height (PH), ear height (EH), ear placement (EP) - ratio = (EH/PH), tassel length (TL), tassel branches (TN), final stand (FS), ears per plot (NE), prolificacy (PR), ear length (EL), ear diameter (ED), ear yield (EY), grain yield (GY). The observed means for grain yield (GY), in percent of the hybrid check, were 93.8%, 89.4%, and 94.6%, showing a relatively good yield potential. Means (cm) for plant height (PH) and ear height (EH) were 221, 237, 241 and 117, 134, 137, respectively, with reductions in relation to the first cycle. Parameters estimates for GY were: additive genetic variance 582.28, 406.70 and 238.11 g2.plant-1; heritability 59.17%, 49.82% and 38.53%; progeny mean basis, and expected gain for progeny selection 8.16%, 6.86% and 3.88%; selection intensity of 20%.Keywords: Zea mays, recurrent selection, semiexotic population, genetic parameters.VARIABILIDADE GENÉTICA E GANHO ESPERADO EM TRÊS POPULAÇÕES DE MILHORESUMO - O estudo da variabilidade genética em uma população sob seleção é importante para quantificar seu potencial para fins de melhoramento. No presente trabalho foram avaliadas três populações semiexóticas de milho quanto ao seu potencial de produção e de variabilidade para continuar o programa de seleção recorrente em curso. Famílias de meios irmãos representando as três populações (CRE-01, CRE-02, CRE-03) foram avaliadas para caracteres agronômicos florescimento masculino (MF), altura da planta (PH), altura da espiga (EH), posição relativa da espiga (EP), comprimento do pendão (TL), ramificações do pendão (TN), estande final (FS), espigas por parcela (NE), prolificidade (PR), comprimento da espiga (EL), diâmetro da espiga (ED), peso de espiga (EY), peso de grãos (GY). As médias observadas para produção de grãos (GY) foram 93,8%, 89,4% e 94,6% da testemunha, mostrando um bom potencial de produção. As alturas médias da planta (PH) foram 221, 237 e 241 cm e da espiga (EH) foram 117, 134 e 137 cm, com reduções em relação ao primeiro ciclo. As estimativas de parâmetros para GY nas três populações foram, respectivamente: variância genética aditiva 582,28 g2 planta-1, 406,70 g2 planta-1 e 238,11 g2 planta-1; coeficiente de herdabilidade em média de progênies 59,17%, 49,82% e 38,53% e ganho com seleção para 20% de intensidade de 8,16%, 6,86% e 3,88%; ganho com seleção para 5% de intensidade de 10,81%, 10,47% e 5,32%, respectivamente para as populações CRE-01, CRE-02 e CRE-03.Palavras-chave: Zea mays L., seleção recorrente, população semiexótica, parâmetros genéticos.

scholarly journals YIELD POTENTIAL AND GENETIC VARIABILITY OF SEMIEXOTIC MAIZE POPULATIONS AS A BASIS FOR SELECTION

2020 ◽  
Vol 19 ◽  
pp. 19
Author(s):  
UDENYS CABRAL MENDES
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Inbreeding Depression ◽  
Recurrent Selection ◽  
Yield Potential ◽  
Improvement Program ◽  
Maize Populations ◽  
Maize Genetic ◽  
Ear Height ◽  
Improvement Programs

In order to verify the genetic and agronomic value, yield potential and inbreeding depression of synthesized composites, as well as quantifying the population variability and incorporating new sources of semiexotic germplasm in maize genetic improvement programs, four populations, identified as NAP-FA x HG-71 (P1), NAP-FL x HG-49 (P2), NAP-FB x HG-49 (P3), and NAP-DB x HG-49 (P4), with two levels of inbreeding (S0 and S1), were evaluated in three locations. From the P1 and P4 populations, 100 full-sib progenies were evaluated in only one location. Plant and ear height, lodging, breakage, ear length and diameter, resistance to diseases, ears with chalky kernels and grain yield were evaluated. The grain yield of the S0 and S1 populations varied between 5.50 and 6.65 t ha-1 and 3.8 and 4.58 t ha-1, respectively, with an average inbreeding depression between 23.9% and 38.0%. Considering all the locations, the grain yields of the non-inbreeding populations varied between 64.4% and 78.0% in relation to commercial hybrids (witnesses), indicating a good yield potential for start of improvement program. In the P1 and P4 populations, sufficient genetic variability was identified in most of the characters, which accredits them for recurrent selection. Gains of 13.7% and 17.8% for grain yield and 31.64% and 29.9% for ears with chalky kernels were estimated.

scholarly journals Selección para calidad fisiológica de la semilla y rendimiento en líneas S2 derivadas de cuatro poblaciones tropicales de maíz (Zea mays L.)

2016 ◽  
Vol 7 (1) ◽  
pp. 58
Author(s):  
Enrique Navarro ◽  
Cristina Vega ◽  
Fernando Narváez ◽  
Hugo Córdova
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Recurrent Selection ◽  
Zea Mays L ◽  
Agronomic Traits ◽  
Reciprocal Recurrent Selection ◽  
Laboratory Conditions ◽  
Flower Plant ◽  
Ear Height ◽  
Field And Laboratory Conditions

This study was carried out in 1993 to evaluate S2 lines from four maize tropical populations improved by reciprocal recurrent selection. These lines were evaluated under field and laboratory conditions, the latter one to determine physiology quality. The main goal was to measure genetic variability within and among populations for traits such as grain yield, vigor and germination and to select the best lines under field and laboratory conditions. The combined analysis of variance showed great genetic variability among the S2 lines within and among populations for grain yield, days to flower, plant and ear height, among others. The maximum genetic variability was observed on the lines from population 43 and pool 23 for most of the traits, although the latter showed a greater genetic variability for grain yield. Besides, it is important to mention that the above populations included the best genotypes for grain yield, germination and vigor. Taking into account the above mentionel agronomic traits, fifteen lines were selected; 2 belong to population 43* pool 20, 2 from pool 19* pool 23, 8 from population 43, and 3 from pool 23. These results confirm the genetic superiority of the lines from populations 43 and pool 23, so that these populations should be recommended for future genetic improvement by reciprocal recurrent procedures.

scholarly journals Selection of best lines and hybrids on the basis of genetic variability analysis in Maize (Zea mays L.)

2020 ◽  
Vol 5 (01) ◽  
pp. 45-49
Author(s):  
Ankit Kumar ◽  
Amit Tomar
Keyword(s):  
Zea Mays ◽  
Genetic Variability ◽  
Grain Yield ◽  
Plant Height ◽  
Zea Mays L ◽  
Grain Weight ◽  
Variability Analysis ◽  
Selection Of

The results revealed that parents namely, TSK-10, TSK-27, New Blue-II, Kurara and TSK-109 were found highly genetic diverse for days to 50% tasseling, days to 50% silking, days to 755 dry husk. The parents namely, TSK-109, Kurara, New Blue-II and TSK-10 were found highly genetic diverse for plant height (cm), cob height, number of cobs per plant and number of grains per cob. The parents namely, Kurara, TSK-109, TSK-10, New Blue-II and TSK-27 were found highly genetic diverse for shelling percentage, grain yield per plant, grain yield per cob and 100-grain weight.

Identification of QTLs for plant height, ear height and grain yield in maize (Zea mays L.) in response to nitrogen and phosphorus supply

2012 ◽  
Vol 131 (4) ◽  
pp. 502-510 ◽  
Author(s):  
Hongguang Cai ◽  
Qun Chu ◽  
Riliang Gu ◽  
Lixing Yuan ◽  
Jianchao Liu ◽  
...  
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Plant Height ◽  
Zea Mays L ◽  
Nitrogen And Phosphorus ◽  
Ear Height

scholarly journals Genetic variability during four cycles of recurrent selection in rice

2017 ◽  
Vol 52 (11) ◽  
pp. 1033-1041
Author(s):  
Odilon Peixoto de Morais Júnior ◽  
Patrícia Guimarães Santos Melo ◽  
Orlando Peixoto de Morais ◽  
José Manoel Colombari Filho
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Plant Height ◽  
Recurrent Selection ◽  
Upland Rice ◽  
Phenotypic Variance ◽  
High Magnitude ◽  
Genetic Potential ◽  
Yield Trials ◽  
Location Interaction

Abstract: The objective of this work was to estimate genetic and phenotypic parameters among progenies of the CNA6 population of upland rice (Oryza sativa) for grain yield and plant height in four cycles of recurrent selection, in order to evaluate the genetic variability and the genotype × location interaction. The experimental data were obtained from yield trials of S0:2 progenies, which were carried out in the experimental design of Federer’s augmented blocks, without replications for progenies within each location. The effect of S0:2 progenies was significant in all cycles for grain yield and in the first three cycles for plant height, indicating the maintenance of the population’s genetic potential to generate transgressive progenies. The participation of the component of the progeny × location interaction in phenotypic variance was of high magnitude. The genetic variability of the CNA6 population of upland rice is maintained for grain yield and plant height during the four cycles of recurrent selection.

scholarly journals Agronomic Performance and Genetic Divergence in Corn (Zea mays) in the Cerrado-Amazon Ecotone

2019 ◽  
pp. 1-7
Author(s):  
Rafael Marcelino Da Silva ◽  
Weder Ferreira dos Santos ◽  
Matheus Rodrigues de Andrade ◽  
Zildiney Dantas Da Silva ◽  
Layanni Ferreira Sodré Santos ◽  
...  
Keyword(s):  
Zea Mays ◽  
Experimental Design ◽  
Grain Yield ◽  
Plant Height ◽  
Genetic Divergence ◽  
Optimization Method ◽  
Multivariate Model ◽  
Agronomic Performance ◽  
Ear Height ◽  
Generalized Distance

The objective of this work is to study the agronomic performance and genetic divergence in corn in the Cerrado-Amazon ecotone. The trials were conducted in the 2017/18 harvest at a property in the state of Pará. The experimental design was a randomized block with nine treatments and three replications, where the treatments are represented by nine cultivars of corn. The characteristics to evaluate agronomic performance and genetic divergence were: ear height (cm), plant height (cm), ear length (cm), ear diameter (mm), number of rows, number of grains per row and grain yield (kg ha−1). The cultivars were separated into a multivariate model in five groups using the Tocher optimization method. The cultivar AG 1051 showed the best agronomic performance. The results of genetic divergence were according to the generalized distance of Mahalanobis (D2), with the commences AG 8088 x CATIVERDE and AG 1051 x AL BANDEIRANTE, the most promising for future crosses.

scholarly journals Inbreeding depression and genetic variability in agricultural traits and resistance to phytopathogens in exotic maize populations

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Aurilene Santos Oliveira ◽  
Edésio Fialho dos Reis ◽  
Ana Paula Oliveira Nogueira ◽  
Fernando Cezar Juliatti
Keyword(s):  
Genetic Variability ◽  
Inbreeding Depression ◽  
Recurrent Selection ◽  
Breeding Programs ◽  
Average Value ◽  
Maize Populations ◽  
Genetic Potential ◽  
Deleterious Alleles ◽  
Ear Height ◽  
Resistance To Phytopathogens

The effect known as depression by inbreeding refers to the reduction on the average value of quantitative traits, related to plant reproduction and physiology, due to the homozygosis of deleterious alleles.  This study evaluated the inbreeding depression and the genetic variability of agricultural traits and of the resistance to phytopathogens in inbred families of two exotic maize populations.  The experiments were done in the experimental area of the Universidade Federal de Goiás, Regional Jataí, in the second harvest 2015.  Fifty and 40 FS1 of NAP5 and NAP7 populations, respectively, were evaluated interplanting one row with a mixture of base population at every ten plots to estimate depression by inbreeding of the traits evaluated.  The experimental design was randomized blocks, with three replications.  The following traits were evaluated: AP – plant height (cm), AE – ear height (cm), FM – male flowering (days), PQ – number of broken plants, AC – number of lodged plants, PG – kernel production (kg plot-1).  The greatest estimates of depression by inbreeding in the agricultural traits were observed for kernel production, with values of 51.2 and 38.9% for the populations NAP5 and NAP7, respectively.  Among the traits of resistance to phytopathogens, the greatest estimate was observed for the stunting complex, with values of -58.9% in NAP5 and -74.2% in NAP7.  Both populations under study presented genetic potential to be used in breeding programs with recurrent selection and, after some selection cycles, lineages with good agricultural standard and resistance to phytopathogens can be obtained.

scholarly journals Combining abilities and inbreeding depression in commercial maize hybrids

2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4133
Author(s):  
Henrique José Camargo Senhorinho ◽  
Ronald José Barth Pinto ◽  
Carlos Alberto Scapim ◽  
Klayton Flávio Milani ◽  
Thiago Hideyo Nihei
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Inbreeding Depression ◽  
Combining Ability ◽  
Recurrent Selection ◽  
Inbred Lines ◽  
Square Lattice ◽  
Reciprocal Recurrent Selection ◽  
Maize Hybrids ◽  
Ear Height

<p>The objective of this study was to evaluate the combining ability and inbreeding depression of commercial maize hybrids for agricultural traits. Twenty-two commercial maize hybrids, 96 F1 crosses from a partial diallel scheme, 22 S1 populations and 4 controls were evaluated in a 12x12 simples square lattice experimental setup, totaling 144 treatments, in the municipality of Sabáudia (PR), Brazil, for harvests from 2011/2012 and 2012/2013. Three traits were evaluated: grain yield, plant height and ear height. The Griffing method (1956) was applied for the evaluation of the general combining ability (GCA) and specific combining ability (SCA). The 30B39, 30K64 and 30B30 hybrids showed increased yield, 30F53 and P1630 showed reduced plant height and AG9040 and AG7010 showed reduced ear height. These hybrids can be recommended for the extraction of inbred lines and formation of composites followed by intrapopulation selection. The combinations 30B39 x AG8088, 30B39 x AG9045 and P1630 x AG8021 showed desirable SCA effects for grain yield, plant height and ear height and are recommended for use in reciprocal recurrent selection programs. High magnitudes of inbreeding depression were verified for yield and lower values for inbreeding depression for plant and ear heights. Thus, strategies are recommended for interpopulation breeding accompanied by inbred lines extraction.</p>

scholarly journals Genetic Variability, Diversity and Association of Quantitative Traits with Grain Yield in Rice (Oryza sativa L.)

1970 ◽  
Vol 17 ◽  
pp. 77-82 ◽  
Author(s):  
Praveen Pandey ◽  
P John Anurag ◽  
DK Tiwari ◽  
SK Yadav ◽  
Binod Kumar
Keyword(s):  
Genetic Diversity ◽  
Oryza Sativa ◽  
Genetic Variability ◽  
Grain Yield ◽  
Plant Height ◽  
Harvest Index ◽  
Test Weight ◽  
Yield Potential ◽  
Early Maturity ◽  
Biological Yield

Context: Genetic diversity is pre-requisite for any crop improvement programme as it helps in the development of superior recombinants. Objectives: Recognizing the importance of genetic diversity in plant breeding experiments, the present research work was taken up to estimate genetic diversity in different accessions of rice for various agro-economically important characters. Materials and Methods: Experiments were carried out with 40 Rice (Oryza sativa L.) genotypes which were evaluated for yield and yield contributing traits in Kharif-2007-08. The data were recorded on 10 randomly selected plants from each replication for 12 quantitative characters studied. However days to 50% flowering was recorded on per plot basis. Mean values were subjected to analysis of variance to test the significance for each character. The genetic divergence was estimated and the grouping of the genotypes into cluster was done.Results: Sufficient amount of variability was found in the entire gene pool for all traits studied. The higher magnitude of genotypic and phenotypic coefficients of variation was recorded for plant height, grain yield per hill, harvest index and biological yield per hill. High heritability along with high genetic advance as percent of mean was registered for harvest index, grain yield, plant height, biological yield, test weight, number of tillers per hill and number of spikelets per panicle suggesting preponderance of additive gene action in the expression of these characters. On the basis of Mahalanobis D2 statistics the genotypes were grouped into seven clusters. Plant height, biological yield and test weight contributed considerably, accounting for 86.16 % of total divergence. The genotypes superior in some clusters may be involve in a multiple crossing programme to recover transgressive segregants with high genetic yield potential and early maturity. Conclusion: The promising genotypes selected from diverse clusters should be involved in the hybridization programme in order to transfer some of the desirable yield contributing characters consisted by them.  Key words: Rice (Oryza sativa); genetic variability; diversity; clustering pattern DOI: 10.3329/jbs.v17i0.7110J. bio-sci. 17: 77-82, 2009

scholarly journals Inheritance of Plant and Ear Height in Maize (Zea Mays L.)

2002 ◽  
pp. 34-38 ◽  
Author(s):  
Zsuzsanna Zsubori ◽  
Zsuzsanna Gyenes-Hegyi ◽  
Ottó Illés ◽  
István Pók ◽  
Ferenc Rácz ◽  
...  
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Plant Height ◽  
Dry Matter ◽  
Zea Mays L ◽  
Plant Density ◽  
Pests And Diseases ◽  
Stover Yield ◽  
Ear Height ◽  
Positive Correlations

Plant and ear height are very important characters not only for describing new varieties of maize (Zea mays L.), but for green and dry matter production, and even for grain yield. Significant positive correlations have been reported by various authors between plant height and stover yield, plant height and dry matter yield, and plant height and grain yield. The height of the main ear is also correlated to plant height. It depends on the variety or the environment, but is likely to be the same height within a population. Many environmental and agronomical factors (e.g. plant density, fertilization, pests and diseases) influence the expression of these characters, which are not quality traits. Their expression is controlled by many genes and by the interactions between these genes. The heritability of these traits is high and they show significant genotypic variability and positive heterosis, as reported in many research publications.

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