scholarly journals Combining ability and heterosis for yield, precocity and height in yellow maize genotypes

Author(s):  
Victor Mario García Mora ◽  
Julián Chura Chuquija ◽  
Julio Torres

The objective of the present study was to determine the general combinatorial aptitude (GCA), specific combinatorial aptitude (SCA) and heterosis in inbred lines of yellow maize and its crosses for, the yield of grain, height of plant and ear and days to male and female flowering. Six inbred lines from CIMMYT, their direct crosses and four controls were evaluated at UNALM during 2016-2018, under a 5 x 5 lattice design with four repetitions. The effects of GCA and SCA were calculated using method II, model I of Griffing. Heterosis was measured based on the mean and best parent. Heterosis was measured based on the mean and best parent. The combined analysis of years showed significance (p ≤ 0.01) in: genotypes by years for days to male and female flowering; GCA for years for days to male flowering and SCA for years for days to female flowering. The effects of ACG for grain yield were significant in lines CML 229 and CML 428, for plant height, precocity, ear and precocity CML 487 line highlighted. The effect of ACE was superior in the cross CML 453 x CML 486 for the grain yield character. Heterosis was higher for the grain yield in the CML 229 x CML 453 and CML 453 x CML 487 crosses. The GCA / SCA relationship evidenced effects of additive genes on plant height, days to male and female flowering, therefore, for grain yield and ear height, non-additive effects governed.

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Bhim Nath Adhikari ◽  
Jiban Shrestha ◽  
Bishal Dhakal ◽  
Bishnu Prasad Joshi ◽  
Naba Raj Bhatta

Detailed information on the genetic diversity between maize germplasm (Zea mays L.) is useful for their systematic and efficient use in breeding programs. Fourteen early maize genotypes were studied to assess their performance and genotypic diversity at Doti, Nepal in 2015. Days to tasseling, days to silking, plant height, ear height, ear length, ear diameter and grain yield were significant among genotypes. Genotype SO3TEY-PO-BM, COMPOL-NIOBP and ACROSS-99402 were found higher yielder with earlier maturity. Days to tasseling (0.85), days to silking (0.82), plant height (0.79), ear length (0.71) and ear diameter (0.66) were found highly heritable traits. Grain yield (0.39) and ear height (0.47) medium and remaining traits showed low heritability. High PCV was observed for grain yield (35.10%), number of plants/plot (34.46%), tesseling silking interval (26.85%), harvested ears/plot (24.45%) and husk cover rating (22.85%) where other traits showed medium to low PCV. Grain yield showed high GCV (21.96%), ear height and husk cover had medium and remaining traits showed low GCV (<10%). Plant height (r₌0.498), harvested plants/plot (r₌0.412), harvested ear/plot (r₌0.762), ear length (r₌0.472) and ear diameter (r₌0.470) showed significant positive correlation with grain yield. The yield can be improved if selection applied in favor of those yield components.


2021 ◽  
Vol 20 (1) ◽  
pp. 17-28
Author(s):  
M.S. Afolabi ◽  
G.O. Agbowuro ◽  
A.E Salami ◽  
M.O. Akoroda

Low-N maize variety is developed for its ability to tolerate low nitrogen soil environment. This experiment was conducted to study the genetic implication of Low-N maize variety for grain yield and related traits under low nitrogen soil conditions triple test cross analysis. Inbred lines used for the study were generated from twelve low nitrogen tolerance open pollinated maize varieties after six generations of selfing. Two inbred lines along with their F1 were used as testers for ten inbred lines in a triple test cross pattern to generate 30 crosses. The 30 crosses, their parents and the testers to State University, Ado-Ekiti during 2017 planting season. The experimental design was a Randomized Complete Block Design (RCBD). Data were collected on plant height, ear height, days to 50% anthesis, days to 50% silking, incidence of curvularia leaf spot, blight, plant aspect, ear aspect, ear rot, stay green, cob per plant, ear weight, grain moisture content and grain yield. All data were subjected to analysis of variance and complete genetic estimates. Additive and dominants were significant (P < 0.05) for all traits; however, epitasis estimates were not significant for all the traits tested. The degree of dominance component indicated partial dominance for all the traits. Correlation coefficients for days to 50% anthesis and 50% silking, plant height, ear height, number of cobs per plant and grain yield were positive and significant (P < 0.05). Since both additive and dominance gene actions were important for low-N traits, the use of reciprocal recurrent selection procedure can be adopted in incorporating the trait into elite maize varieties.


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

<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>


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

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.


2018 ◽  
Vol 17 (2) ◽  
pp. 177
Author(s):  
AURÉLIO VAZ DE MELO ◽  
VALDERE MARTINS DE SANTOS ◽  
MARCO ANTONIO FERREIRA VARANDA ◽  
DIONE PEREIRA CARDOSO ◽  
MARILENE ALVES RAMOS DIAS

 RESUMO - A cultura do milho apresenta sensibilidade à variação climática, sendo o déficit hídrico uma das causas frequentes de redução de produção na cultura. O presente trabalho teve como objetivo avaliar a performance de genótipos de milho sob estresse hídrico, no sul do Estado do Tocantins. O experimento foi implantado no município de Gurupi - TO, utilizando 64 híbridos de milho. O delineamento experimental utilizado foi Látice 6x6, com três repetições. As características avaliadas foram altura da planta, floração masculina, floração feminina, altura de inserção da espiga e produtividade de grãos. Em ambiente sem estresse foram observadas maiores médias de altura da planta em comparação ao ambiente com estresse. No ambiente com estresse o genótipo 8 apresentou a maior média de altura de plantas (129 cm). Não houve diferença estatística entre os ambientes quanto ao número de dias para o florescimento masculino. A produtividade de grãos foi significativamente maior em ambiente sem estresse. O genótipo 59 apresentou a maior média de produtividade de grãos sob estresse (7.317,6 kg ha-1) e o genótipo 9 apresentou a maior média de produtividade de grãos em ambiente sem estresse (11.551,3 kg ha-1). Os resultados demonstraram que os cultivares de milho apresentam comportamento distinto quanto à tolerância ao estresse hídrico. Os genótipos que apresentaram as menores médias de produtividade no ambiente sem estresse foram 35 e 40. Os genótipos com maiores médias de produtividade no ambiente sem estresse foram 57, 7, 15 e 61.Palavras-chave: Zea mays, condições adversas, estiagem.AGRONOMIC PERFORMANCE OF MAIZE GENOTYPES SUBJECTED TO WATER STRESS IN THE SOUTH OF TOCANTINS STATE ABSTRACT - The maize crop is sensitive to climatic variability and water deficit is one of the frequent causes of yield decrease. The objective of this work was to evaluate the performance of maize genotypes under water stress in the southern Tocantins State. The experiment was carried out in the municipality of Gurupi - TO, using 64 maize hybrids. A 6x6 lattice design was used, with three replications. The evaluated characteristics were plant height, male flowering, female flowering, height of insertion of the ear and grain yield. For plant height it was observed that the stress-free environment provided higher PA means compared to the stress environment. In the environment with stress, the cultivar 8 presented the highest average plant height (129, cm). No statistical difference between environments was observed in the number of days for male flowering. Regarding grain yield, the stress-free environment provided significantly higher values of grain yield compared to the stress environment. The cultivar 59 presented the highest grain yield (7317.6 kg ha-1) under stress and cultivar 9 had the highest grain yield (11551.3 kg ha-1) in the environment without stress. The results showed that maize cultivars presented different behavior regarding tolerance to the water stress. The cultivars with the lowest productivities in the environment without stress were 35 and 40. The cultivars with the highest productivities in the environment without stress were 57, 7, 15 and 61.Keywords: Zea mays, adverse conditions, drought.


Author(s):  
Odilon Gayosso Barragán ◽  
Griselda Chávez-Aguilar ◽  
José Angel Marroquín-Morales ◽  
Alfonso López-Benítez

Objective: To analyze the genetic diversity (agronomic attributes, forage yield, and fiber content) of 100 maize inbred lines and to identify genotypes with potential for the breeding of plants with the said traits. Design/methodology/approach: One-hundred maize inbred lines were evaluated in two environments, in a 10 x 10 complete block experimental design, with two repetitions. Days to male flowering, days to female flowering, ear height, plant height, stem diameter, green forage yield, neutral detergent fiber, and acid detergent fiber data were recorded. Results: Significant differences were observed in the environmental sources of variation and genotypes for all the traits evaluated. The first four components account for 81% of the total variation observed and the first two account for 66% of the variation. The variables which have the highest absolute value and which strongly influence the dispersion of the genotypes, as well as the formation of groups, were: plant height, forage yield, and acid detergent fiber (component one) and days to female flowering and days to male flowering (component two). Consequently, the genotypes were dispersed in four groups. Study limitations/implications: It was not possible to conduct genetic diversity studies using molecular markers. Findings/conclusions: The grouping pattern of inbred lines shows the genetic diversity present; this can be an important tool in genetic improvement programs aimed at obtaining hybrids with specific characteristics.


2018 ◽  
Vol 17 (2) ◽  
pp. 328
Author(s):  
ANDRÉ GABRIEL ◽  
MARCOS VENTURA FARIA ◽  
MARCELO CRUZ MENDES ◽  
EMANUEL GAVA ◽  
WELTON LUIZ ZALUSKI ◽  
...  

 RESUMO – A utilização de híbridos comerciais é uma opção para gerar populações-base para obter novas linhagens superiores. Portanto, objetivou-se com a pesquisa selecionar linhagens S3 superiores para produtividade de grãos, avaliadas em dois espaçamentos, para ser avançadas no processo de endogamia. Para isso, foram avaliados 75 híbridos topcrosses juntamente com seis híbridos comerciais (DKB245 PRO2, P30F53 H, P30B39 H, AS1572, DKB315 PRO e SG6030 PRO). Foi utilizado o delineamento látice triplo 9x9 para avaliação de florescimento masculino (FM), altura de planta (AP), altura de espiga (AE), prolificidade (PR) e produtividade de grãos (PG). Houve diferença significativa entre genótipos para todas as características avaliadas, interação genótipo x espaçamento para a PG e AE. Não foi constatada diferença significativa para espaçamento entre linhas. Os híbridos topcrosses TC102-05, TC102-06, TC102-15, TC102-16, TC102-17, TC102-21 e TC102-24 se destacaram nos dois espaçamentos entre linhas, aliando características de produtividade de grãos, estatura e ciclo precoce, cujas respectivas linhagens deverão ser avançadas no processo de endogamia.Palavras-chave: Zea mays L., testador, linhagens parcialmente endogâmicas. EVALUATION OF S3 MAIZE LINES TOPCROSSED IN TWO ROW SPACINGS ABSTRACT – The use of commercial hybrids is an option to generate base populations for obtaining new superior lines. The objective of this study was to select S3 lines superior for grain yield, evaluated in two row spacings, to be advanced in the process of inbreeding. For this, 75 topcross hybrids were evaluated along with six commercial hybrids (DKB245 PRO2, P30F53 H, P30B39 H, AS1572, DKB315 PRO and SG6030 PRO). The 9x9 triple lattice design was used.to evaluate the agronomic traits of male flowering (MF), plant height (PH), ear heigth (EH), prolificacy (PR) and grain yield (GY). There was a significant difference between genotype for all traits evaluated, interaction genotype x spacing for EH and GY. No significant difference was observed for line spacing. The topcross hybrids TC102- 05, TC102-06, TC102-15, TC102-16, TC102-17, TC102-21 and TC102-24 were superior in the two row spacings, combining the characters of grain yield, stature and early cycle, whose lines should be advanced in the process of endogamy.Keywords: Zea mays L., tester, partially inbred lines.


2015 ◽  
Vol 3 (3) ◽  
pp. 387-391
Author(s):  
Hari Kumar Prasai ◽  
Subarna Sharma ◽  
Ujjawal Kumar Singh Kushwaha ◽  
Jiban Shrestha

The coordinated varietal trial of quality protein maize was carried out in research station of regional agricultural research station, Doti during 2011/12 and 2012/13. A total of fourteen entries including standard and local checks were included in the experiment of both years. Out of tested entries of the year 2011/12, S99TLYQ-A produced the highest grain yield (2814 kg/ha) followed by SO3TLYQ-AB-01 (2765 kg/ha) and SO3TLYQ-AB-02 (2293 kg/ha). MSTATC software was used in data analysis. Flowering days, plant height and grain yield due to genotypes was found significant at 1-5% level. Amongst the tested entries include in the experiment of the year 2012/13, S99TLYQ-AB recorded the highest grain yield (6006 kg/ha) followed by SO3TLYQ-AB-01 (5409 kg/ha) and S99TLYQ-A (5330 kg/ha). There was significant difference in flowering days, plant height, ear height and grain yield due to genotypes at 1-5 % level. Combined analysis over year was also carried out. Genotypes SO3TLYQ-AB-01 (4087 kg/ha), S99TLYQ-A (4072 kg/ha) and S99TLYQ-AB (3750 kg/ha) identified as promising genotypes for lower hills and river basin agro-environment of far western hills. Similarly, experiment on selection of drought tolerance maize genotypes was also carried out at this research station during 2011/12 and 2012/13. Total 105 genotypes of maize were planted for selection of drought tolerance maize genotypes during 2011/12 and it was replicated twice. Quantitative and qualitative traits were recorded for screening against drought. Out of the genotypes included in the experiment, Manakamana-4 was found super variety in terms of grain yield (4561 kg/ha), leaf senescence (1) and leaf roll (1). Statistically, plant height, ear height, flowering days and leaf senescence due to genotypes were found significantly different. Total eight genotypes were selected for second year's drought tolerance genotypes selection experiment and were planted in three replications. Out of the eight genotypes included in the experiment, Upahar (6897 kg/ha), TLBRSO7F16 (6216 kg/ha) and BLSBSO7F12 (6215 kg/ha) were found superior in terms of grain yield.Int J Appl Sci Biotechnol, Vol 3(3): 387-391


2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Syed Farman Ullah ◽  
Fawad Ali ◽  
Abdus Salam ◽  
Muhammad Siddique Afridi ◽  
Hidayat Ur Rahman

Thirty yellow maize inbred lines were selected from different source populations and planted in isolation with common male testers (YD-2 and YD-4) in 1:4:1 ratio at Cereal Crop Research Institute (CCRI) Pirsabak, Nowshera during spring-2014 (season–I). On the bases of best seed setting and other important traits, eighteen test-crosses were selected using line × tester approach. The developed 18 test-crosses, nine parental lines and two testers along with two check cultivars (Sarhad Yellow and CS2Y10) were grown in summer season-2014 (July – November) using two replications.Data were collected on various maturities and yield related traits via; days to pollen shedding, silking, ear height, plant height, 100-kernel weight, kernel row ear-1 and grain yield. Significant differences were observed among test-crosses for yield related traits mainly 100-kernel weight and grain yield. L-9 using YD-4 as a tester revealed minimum days to pollen shedding (50.5 days) and days to silking (52.5 days). L-3 using YD-2 as a tester recorded maximum plant height while, L-9 using YD-4 as a tester obtained maximum ear height and length. L-9 using YD-4 as a tester revealed high 100-kernel weight, grain yield and high GCA effect, while L-8 using YD-4 as a tester recorded high SCA effect for 100-kernel weight. L-9 exhibited high GCA effect for grain yield while, high SCA effect was obtained for L-2 using tester (YD-2). L-9 using tester YD-4 revealed maximum mid-parent and best-parent heterosis for ear length and grain yield. For maximum traits, L-9 was the best combiner followed by L-3 and L-6 using the same tester (YD-4) under conducted study.


2018 ◽  
Vol 6 (1) ◽  
pp. 15-22
Author(s):  
Afolabi M. Segun ◽  
Salami A. Ekundayo

Low-N maize is bred for its ability to tolerate low soil nitrogen (N) by growing and producing grain that compares appreciably to conventional varieties. This experiment was conducted to study the genetic effects of grain yield and other agronomic traits in Low-N maize using triple test cross analysis. Twelve low-N open pollinated maize varieties were converted to the inbred line after six generations of selfing and used for the experiment. Two inbred lines along with their F1 were used as testers for ten inbred lines in a triple test cross pattern to generate 30 crosses and along with their parents and testers to make a total of 43 entries which were evaluated at the Teaching and Research Farms of Ekiti State University, Ado-Ekiti during in 2017. The design was a Randomized Complete Block Design (RCBD). Data was collected on plant height, ear height, days to 50% anthesis, days to 50% silking, the incidence of Curvularia leaf spot, blight, plant aspect, ear aspect, ear rot, stay green, cob per plant, ear weight, grain moisture content and grain yield. All data was subjected to analysis of variance and complete genetic estimates made. Additive and dominants were significant (P0.05) for all traits, however, epitasis estimates were not significant for all the traits. The degree of dominance component indicated partial dominance for all the traits. Correlation coefficients for days to 50% anthesis and 50% silking, plant height, ear height, number of cob per plant and grain yield were positive and significant (P0.05). Since both additive and dominance gene actions were important for low-N traits, the use of reciprocal recurrent selection procedure can be adopted in incorporating the trait into elite maize varieties.


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