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 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 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 Effect of Herbicides on Yield and Yield Components of Hybrid Maize (Zea mays)

2016 ◽  
Vol 34 (4) ◽  
pp. 729-736 ◽  
Author(s):  
I.A. KHAN ◽  
G. HASSAN ◽  
N. MALIK ◽  
R. KHAN ◽  
H. KHAN ◽  
...  
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Plant Height ◽  
Maximum Yield ◽  
Weed Suppression ◽  
Maize Crop ◽  
Maize Hybrid ◽  
Maize Hybrids ◽  
Biological Yield ◽  
Hybrid Maize

ABSTRACT Maize crop (Zea mays) is facing lots of problems from different pests throughout Asia, including Pakistan. Weed infestation is one of the serious pests that remarkably decrease the grain yield in maize. In Khyber Pakhtunkhwa province of Pakistan, the trend of maize hybrid cultivation is gaining the attention of the farmers due to its higher production. Therefore, in this research we tested herbicides (Stomp 330 E, Dual gold 960 EC, 2,4-D, ester) in maize hybrids (P-3025, P-32T78, P-3203). The experiment was done in RCB design with split plots arrangement, where maize hybrids were kept in main plots, while herbicides were assigned to the subplots. Each treatment was repeated three times at the New Developmental Farm (NDF), at the Peshawar University of Agriculture, Pakistan. Results revealed that both hybrids and herbicides significantly increased plant height, biological yield and grain yield. However, the lowest weed density (142.50 m-2) was observed in Dual Gold 960 EC treated plots. Similarly, plant height (247.188 cm) and grain yield (2.253 ton ha-1) was maximum in maize hybrid P-3025 and Dual gold treated plots. From the instant experiment, it is concluded that the Dual gold 960 EC herbicide is declared as the best herbicide for weed suppression in maize, while maize hybrid P-3025 was the best hybrid giving maximum yield in the study.

scholarly journals Phenotypic characterization of wheat landraces from mid and far western districts of Nepal

2015 ◽  
Vol 4 (4) ◽  
pp. 32-44
Author(s):  
Sangharash Raj Dangi ◽  
Ramesh Raj Puri ◽  
Nutan Raj Gautam
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Phenotypic Variability ◽  
Block Design ◽  
Wheat Breeding ◽  
Phenotypic Characterization ◽  
Improvement Program ◽  
Wide Range ◽  
Wheat Landraces

The study was conducted to evaluate phenotypic variation in one hundred and sixty six wheat landraces from mid and far western districts of Nepal. They were sown in randomized complete block design with two replications at National Wheat Research Program in 2014/15. The observed traits were analyzed using descriptive statistics and multivariate analysis using MINITAB v. 14. The results showed a wide range of phenotypic variability in observed parameters. The results also showed that the highest value of the standard deviation from mean (Sd) was for grain yield (±290.10) followed by plant height (±7.21). Among the traits the lowest deviation from mean (Sd) was for thousand grain weight TGW (±2.68). Wheat landraces grouped in four clusters depending on similarity of the studied traits. The results in this cluster, showed that days to maturity ranged from 97 to111 days, TGW ranged from 16 to17 gm, plant height ranged from 76 to 85 cm, and grain yield ranged from 2800 to 3000 Kg ha-1. Wheat landraces under study are grouped depending on specific traits useful for wheat improvement program. Results of this study can be supportive to detect wheat landraces within species with similar traits. In addition it can be useful for sampling in successive studies and parental selection in wheat breeding program.International Journal of Environment Vol.4(4) 2015: 32-44

scholarly journals VARIABILITY AND CORRELATION OF AGRONOMIC CHARACTERS OF MUNGBEAN GERMPLASM AND THEIR UTILIZATION FOR VARIETY IMPROVEMENT PROGRAM Lukman Hakim

2016 ◽  
Vol 9 (1) ◽  
pp. 24 ◽  
Author(s):  
Lukman Hakim
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Seed Size ◽  
Yield Components ◽  
Block Design ◽  
Breeding Program ◽  
Path Coefficient ◽  
Individual Plant ◽  
Agronomic Characters ◽  
Improvement Program

Information on the variability and correlation between agronomic characters of mungbean accessions with their yield are important for supporting breeding program of the plant. A total of 350 mungbean accessions were evaluated at Muara Experimental Farm, Indonesian Center for Food Crops Research and Development, Bogor, during the dry season of 2005. The experiment was conducted in a completely randomized block design with three replications. Each accession was planted in two rows of 5 m long. Plant spacing was 40 cm x 20 cm, two plants per hill. Correlation and path coefficient analyses were used to quantify<br />the magnitude of the relationship between yield components and grain yield. The variability among the accessions was significant for most of the characters studied, especially for days to maturity, plant height, pods per plant, and seed size. Among the yield components, the number of pods per plant and plant height positively correlated with the grain yield, but the<br />seed size negatively correlated with grain yield. The direct effects of the number of pods per plant and plant height on seed yield as indicated by path coefficient were the highest, while other causal effects were small or negative. Yield variation (1- R2) attributable to the nine yield component variables was slightly high (61.23%), which means that mungbean accessions with high grain yield should have sufficient plant height and high number of pods per plant. Therefore, these parameters (number of pods per plant and plant height) can be used as the selection criteria in mungbean breeding program. These criteria can be visualized during bulk selection on the early generation stage of F2 to F4, and subsequently on line development of individual plant (pedigree) of F5.

scholarly journals Predicting the range of inbreeding depression of inbred lines in cross-pollinated populations

1997 ◽  
Vol 20 (1) ◽  
pp. 35-39 ◽  
Author(s):  
C.L. Souza Jr. ◽  
J.S.C. Fernandes
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Inbreeding Depression ◽  
Genetic Variance ◽  
Inbred Lines ◽  
Gene Frequencies ◽  
Mating Design ◽  
Inbreeding Coefficients ◽  
Maize Population ◽  
Two Generations

The objectives of this paper were to derive the genetic variance of inbreeding depression (<img SRC="Image482.gif" WIDTH="48" HEIGHT="33"> ) and to predict the range of inbreeding depression (RID) in cross-pollinated populations. The variance of inbreeding depression is a function of the genetic variances related to dominance effects (<img SRC="Image483.gif" WIDTH="31" HEIGHT="33">, D2, and <img SRC="Image484.gif" WIDTH="21" HEIGHT="25">), and of the inbreeding coefficients of the two generations in which inbreeding depression is measured (Ft and Fg). The results showed that the higher the level of dominance of a trait, the higher the variance of inbreeding depression. The magnitudes of <img SRC="Image485.gif" WIDTH="48" HEIGHT="33">were expected to be lower in improved (mean gene frequencies = <img SRC="Image486.gif" WIDTH="16" HEIGHT="25">> 0.6) and in unimproved (<img SRC="Image487.gif" WIDTH="16" HEIGHT="25"> < 0.4) populations, than in composite populations (<img SRC="Image487.gif" WIDTH="16" HEIGHT="25"> <FONT FACE="Symbol">»</font> 0.5). Data from a maize population used to illustrate the study showed that the range of inbreeding depression in the S<FONT FACE="Symbol">¥</font> generation of selfing was from 48.7% to 85.3% for grain yield, and from 13.9% to 24.5% for plant height. A mating design outlined to estimate the genetic variance of inbreeding depression, the range of inbreeding depression, and of the range of inbred lines is presented.

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 Agronomic performance of maize populations divergently selected for diferulate cross-linkage

2016 ◽  
Vol 154 (7) ◽  
pp. 1270-1279 ◽  
Author(s):  
R. SANTIAGO ◽  
J. BARROS-RIOS ◽  
A. ALVAREZ ◽  
R. A. MALVAR
Keyword(s):  
Cell Wall ◽  
Grain Yield ◽  
Plant Height ◽  
Agronomic Traits ◽  
Divergent Selection ◽  
Flowering Plant ◽  
Corn Borer ◽  
Corn Borers ◽  
Maize Populations ◽  
Grain Moisture

SUMMARYThe direct response of a divergent selection programme for total cell wall ester-linked diferulate concentration in maize pith stalk tissues and its indirect effect on cell wall degradability and corn borer resistance have been previously evaluated. Since increased total diferulate concentration is expected to improve crop performance in response to corn borers, the objective of the present research was to evaluate the indirect response of the divergent selection for diferulates on agronomic traits under corn borer infestation. For this purpose, five maize populations with contrasting total diferulate concentrations were evaluated four environments for performance under protected and infested conditions. Measured traits were: days to anthesis, days to silking, plant height, stalk lodging, grain moisture at harvest and grain yield. High diferulate populations showed a significant reduction in anthesis (precocity), and were 11 cm taller than the starting population, while low diferulate populations were 9 cm shorter, and showed nearly 1 t/ha lower grain yield than the original and high diferulate populations. The analysis showed that cycles of selection were positively correlated with flowering, plant height and grain yield. The infestations with borers produced >1 t/ha of reduction in grain yield; although the higher diferulate populations showed a better performance under infestation than the low diferulate populations. This positive effect on the grain yield by increasing diferulate content can be considered an extra in order to breed for resistance to corn borers.

scholarly journals Inbreeding depression in crambe1

2016 ◽  
Vol 46 (4) ◽  
pp. 401-406 ◽  
Author(s):  
Ana Carolina da Costa Lara-Fioreze ◽  
◽  
Laerte Gustavo Pivetta ◽  
Maurício Dutra Zanotto ◽  
◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Inbreeding Depression ◽  
Significant Interaction ◽  
Quantitative Traits ◽  
Grain Weight ◽  
Open Pollination ◽  
High Degree ◽  
Genetic Phenomenon

ABSTRACT Inbreeding depression in plants, caused by selfing or crossing among plants with a high degree of relatedness, is a genetic phenomenon that affects quantitative traits. This study aimed at verifying the occurrence of inbreeding depression in crambe progenies originated from selfing, in comparison with open pollination progenies. A randomized blocks design, with three replications, in a 32 x 2 factorial arrangement, with 32 crambe progenies and two reproduction systems (artificial selfing and open pollination), was used. Grain yield, 1,000-grain weight, plant height and final stand were evaluated. A significant interaction was observed between progenies and reproduction systems in all traits evaluated. A reduction in grain yield, 1,000-grain weight and plant height occurred in the majority of the selfing progenies, when compared to open pollination progenies. Inbreeding depression was observed in all traits, especially for grain yield. The heritability coefficients of selfed progenies were higher than the open pollinated ones, except for 1,000-grain weight.

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