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.

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 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 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 Genetic variability, heritability and genetic advance for growth, yield and yield related traits in maize genotypes

2021 ◽  
Vol 2 (2) ◽  
pp. 96-104
Author(s):  
Roshesh Rai ◽  
Prakash Khanal ◽  
Prabin Chaudhary ◽  
Rabin Dhital
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Agronomic Traits ◽  
Block Design ◽  
Genetic Advance ◽  
Improvement Program ◽  
Positive Correlation ◽  
Maize Genotypes ◽  
High Heritability ◽  
Ear Height

Evaluation of the genetic variability, heritability and genetic advance of traits is an essential task in any plant improvement program. Twenty maize genotypes were replicated twice in a randomized complete block design on a research plot of Prithu Technical College, Deukhuri Dang of Nepal from June 2017 to September 2017 to determine genetic variability, heritability, and genetic advance for different agronomic traits. Analysis of variance showed significant differences in the traits tassel length, ear height, days to fifty percent tasseling, days to fifty percent silking, kernels’ rows ear-1, kernels row-1 and grain yield. The highest GCV (31.53%) and PCV (39.20%) were recorded on grain yield. Grain yield and ear height recorded high heritability along with high genetic advance as a percent of mean (GAM). Tassel length and kernels row-1 showed high heritability integrated with moderate GAM and moderate heritability integrated with moderate GAM respectively. Further, grain yield showed a significant and positive correlation with plant height, tassel length, ear height, cob length, cob diameter, kernels’ rows ear-1, and kernels row-1. Thus the selection of ear height, tassel length and kernels row-1 is suggested as they performed better in terms of both heritability and GAM than other traits and they also recorded a significant and positive correlation with yield.

scholarly journals Mean components for choosing maize populations to extract inbred lines

2020 ◽  
Vol 44 ◽  
Author(s):  
Ewerton Lélys Resende ◽  
Renzo Garcia Von Pinho ◽  
Eric Vinicius Vieira Silva ◽  
João Júlio Massitela ◽  
Vander Fillipe de Souza ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Inbreeding Depression ◽  
Development Stage ◽  
Additive Effects ◽  
Improvement Program ◽  
Initial Development ◽  
Maize Hybrids ◽  
Maize Populations ◽  
Yield Trait

ABSTRACT The choice of germplasm is one of the most important phases of a genetic improvement program to the fact that it is the initial development stage of superior hybrids. Hence, the objectives of this study were to obtain the estimates of m+a and d, and inbreeding depression for grain yield and plant height traits, for cultivars lacking this information, and thus to predict the potential of maize hybrids for the extraction of lines. The F1 and F2 generations of 12 maize hybrids were tested at two sites, during the crop years of 2017-18 and 2018-19, accounting for four environments. Both the generations were evaluated in contiguous experiments in randomized blocks design with three and two repetitions during the years 2017-18 and 2018-19, respectively. The data on plant height and grain yield were collected, per plot, from both the generations, utilizing which, the m+a and d mean components were estimated. The effects of dominance had greater importance for the character grain yield. The most promising hybrids for extraction of lines were AG1051, AG8025, BG7046, DKB455, and OMEGA due to their greater estimates of m+a. The hybrids AG8025 and BG7046 were associated with high values of m+a and grain yield. For the plant height trait, there was a greater contribution of additive effects. Therefore, greater inbreeding depression was observed for the grain yield trait when compared to the height of the plant.

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 Use of recurrent selection in middle late synthetic maize populations. results of the first cycle in synthetic “1/2017”

2021 ◽  
Vol 13 (30) ◽  
pp. 79-83
Author(s):  
Natalyia Petrovska ◽  
◽  
Valentina Valkova ◽  
Keyword(s):  
Genetic Variability ◽  
Grain Yield ◽  
Experimental Work ◽  
Recurrent Selection ◽  
Inbred Lines ◽  
Maturity Group ◽  
Maize Populations ◽  
X 43 ◽  
Foreign Standard ◽  
Direct Outcome

The present study shows the results of a completed first cycle of recurrent selection in a middle late synthetic population “1/2017” and the inbred lines PAU 1617 and B 113 are used as a recurrent parents. The aim of the improving selection is to obtain from the synthetic inbred lines which are later to be used as parental forms for receiving hybrids of this maturity group. The experimental work was carried out in the period 2017 – 2019 when two hundred and ten testcrosses were tested. After the data was analyzed, eighty even inbred progeny variants displaying the best results have been included for crosspollination and a new cycle of breeding. The genetic variability in the synthetic has been preserved as the selected progeny represent 41,4 % of the initially chosen ones. The index of variability after recurrent selection is 12,2 % which allows for efficient testing in the subsequent stages of the improving selection. As a direct outcome of the research, thirteen crosses have been pointed out – B 113 x 37/1, B 113 x 25/5, PAU 1617 x 71/3, B 113 x 29/1, B 113 x 33/1, PAU 1617 x 97/3, PAU 1617 x 85/3, B 113 x 71/5, B 113 x 71/6, B 113 x 53/1, B 113 x 55/1, B 113 x 77/3 and B 113 x 43/1. They exceed in grain yield the foreign standard in the maturity group respectively with 25.2, 20.0, 16.9, 16.6, 15.1, 15.0, 13.1, 12.5, 10.5, 9.0, 8.8, 8.8 and 8.2%. They are still tested in varietal and ecological trials.

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

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.

scholarly journals Assessment of Genetic Diversity for Drought, Heat and Combined Drought and Heat Stress Tolerance in Early Maturing Maize Landraces

Plants ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Nelimor ◽  
Badu-Apraku ◽  
Tetteh ◽  
N’guetta
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Drought Stress ◽  
Grain Yield ◽  
Yield Potential ◽  
Yield Reduction ◽  
International Institute ◽  
Improvement Program ◽  
Maize Varieties ◽  
Drought And Heat Stress

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.

Sign in / Sign up

Export Citation Format

Share Document