scholarly journals Híbridos dobles de maíz formados con líneas mejoradas por selección gamética y retrocruza.

2016 ◽  
Vol 8 (2) ◽  
pp. 61
Author(s):  
Enrique Navarro ◽  
Gustavo Burciaga ◽  
Salvador González ◽  
M. Cristina Vega ◽  
Regino Morones ◽  
...  
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Research Work ◽  
Ear Height ◽  
Female Flowering ◽  
Stalk Lodging ◽  
Gamete Selection ◽  
Yield Trials ◽  
Better Than ◽  
Double Cross

This research work includes the evaluation of 1040 double cross hybrids which were produced from single crosses improved by gamete and backcross procedures. Single hybrids were crossed with five testers. The yield trials were carried out during 1991 at Gómez Palacio, Durango, México, and the goals were as follows: 1) To evaluate the performance of double cross hybrids and 2) To determine the main agronomic traits on the observed variation. For grain yield, the double cross hybrids formed with single crosses improved by gamete selection performed better than those obtained by backross whose yields were adobe 11,6 t/ha (23% with respect to the best backcross genotype). The outstanding yields observed across the gamete procedure are probably due to the low percentage of rot ers. On the controry, the single crosses improved by backcross procedure showed early to flower, short height and had less problems ofboth root and stalk lodging. The best testers were AN258-18-19 x MLS4-1 and the AN 232 x 255- 18-19 when crossed with some single crosses yield more than 14 t/ha. It is import to mention that the outstanding grain yields were associated with values of general combining ability with the gamete selection. Finally, the multivariate analysis showed that two-thirds of the observed variation in the double cross hybrids was given by grain yield and clean grain yield, plant and ear height, male and female flowering.

scholarly journals Evaluation of Hybrid and OPV Maize Varieties for Grain Yield and Agronomic Attributes under Farmer's Field Conditions at Dukuchhap

2014 ◽  
Vol 9 ◽  
pp. 17-20 ◽  
Author(s):  
Min N. Paudel
Keyword(s):  
Grain Yield ◽  
Field Experiments ◽  
Agronomic Traits ◽  
Grain Weight ◽  
Yield Attributes ◽  
Bivariate Correlation ◽  
Maize Varieties ◽  
Ear Height ◽  
Study Support ◽  
Stalk Lodging

Field experiments were conducted during two consecutive years 2006 and 2007 in full season of maize (May-Sep) at Dukuchhap, Lalitpur to find out impact of growing hybrid and OPV maize in different rows combinations with respect to their pure stands in same environment of growing and to sort out non-lodging maize varieties. The experiments consisted of an open pollinated variety (OPV) 'Deuti' and hybrid 'Gaurab' in different row combinations (50% hybrid + 50% OPV, 75% hybrid + 25% OPV, 75% OPV + 25% hybrid plus their pure stands). The results showed that Gaurab (yellow, flint type) and Deuti (white, semi- flint type, selected from CIMMYT's material ZM 621) did not vary significantly in grain yield and yield components. There was no effect of mixed row culture between the OPV and hybrid for grain yield and yield attributes. A bivariate correlation coefficient between agronomic traits and ear traits indicated that there was a positive relation among these traits. However, a positive and highly significant (r = 0.766**) relationship between ear fill and ear length was observed while a very weak relation (r = 0.096*) between grain weight/ear and ear height was also noticed suggesting taller the ear height lower the grain yield/ear and vice versa. The findings of the study support that plant height and ear height were weakly related with other ear traits; nevertheless, these were highly related to grain weight/per plant. To cope with stalk lodging problem and to attain higher grain yield these varieties are equally potential and recommended to grow under Dukuchhap conditions.Nepal Agric. Res. J. Vol. 9, 2009, pp. 17-20  DOI: http://dx.doi.org/10.3126/narj.v9i0.11637

Yield performance with heritability measurements of half sib families obtained from maize variety Azam

1970 ◽  
pp. 33-36
Author(s):  
Faizan Mahmood, Hidayat- Ur-Rahman, Nazir Ahmad ◽  
Fahim-ul- Haq ◽  
Samrin Gul, Quaid Hussain ◽  
Ammara Khalid ◽  
Touheed Iqbal ◽  
...  
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Heritability Estimate ◽  
Kernel Weight ◽  
Yield Performance ◽  
Grain Moisture ◽  
Maize Variety ◽  
Ear Height ◽  
Sib Families

This study evaluated the performance of 64 half sib families (HSF) derived from “Azam” variety of maize using partially balanced lattice square design with two replications. Data were recorded on grain yield and other agronomic traits. Observations showed difference in half-sib families for studied traits. Among the 64 half-sib families, minimum days to 50% tasseling (51 days) were observed for HS-49 while maximum (57 days) for HS-63. Minimum days to 50% silking (56 days) were counted for HS-6 while maximum (63 days) for HS-23. Minimum days to 50% anthesis (55 days) were counted for HS-1 and HS-6 while maximum (62 days) for HS-23. Similarly, minimum ASI (-2 days) were observed in HS-1, HS-15, HS-16, HS-28 and HS-63 while maximum (2 days) in HS-48. Minimum (60 cm) ear height was recorded for HS-11 and maximum (93.5 cm) for HS-28. Minimum fresh ear weight (1.3 kg) was weighted for HS-17 while maximum (3.2 kg) for HS-21. Grain moisture was recorded minimum (19.35 %) for HS-19 and maximum (31.25%) for HS-2. HS-42 showed minimum (28 g) 100 kernel weight while HS-5 showed maximum (47 g). Grain yield was minimum (2323 kg ha-1) for HS-17 and maximum (5742 kg ha-1) for HS-21. Maximum heritability estimate (0.92) was recorded for fresh ear weight, while minimum (0.41) was observed for ear height.

scholarly journals Genetic characterization of the 28 maize landraces in Paraná State

2017 ◽  
Vol 38 (4) ◽  
pp. 1715 ◽  
Author(s):  
Sara Regina Silvestrin Rovaris ◽  
Pedro Mário de Araújo ◽  
Deoclécio Domingos Garbuglio ◽  
Cleber Vinicius Guiaretta de Azevedo ◽  
Cássio Egídio Cavenaghi Prete
Keyword(s):  
Recurrent Selection ◽  
Agronomic Traits ◽  
Block Design ◽  
Breeding Programs ◽  
Randomized Block Design ◽  
Fixed Model ◽  
Maize Landraces ◽  
Ear Height ◽  
Female Flowering

The characterization of maize landraces is extremely important in breeding programs for use of these genotypes as sources of genetic variability. The objective of this study was to quantitatively characterize 28 populations of maize landraces from the state of Paraná using the estimates of the effects of varieties and heterosis parents and the general combining ability, thereby assessing the main agronomic traits. In the crop of 2008/09, 56 inter-varietal hybrids, obtained through a topcross, 28 populations of maize landraces and three check varieties were evaluated for female flowering (FF), plant height (PH), ear height (EH) and grain mass (GY). The treatments were evaluated in a randomized block design, with two replications, at three Paraná State locations: the Experimental Center of the Agronomic Institute of Paraná in Londrina (IAPAR) and the experimental units of Pato Branco and Ponta Grossa. The data were submitted to an analysis of variance, considering a fixed model for genotypes and a random model for environments; the averages grouped by the Scott-Knott test, along with intersections of topcrosses, were analyzed according to a readapted model proposed by Oliveira et al. (1997). According to estimates of the parental effects, the GI 133 population showed the most promising estimates for all characteristics. The GI 088 and GI 173 populations stood out with promising estimates of the effects of heterosis. The conclusion is that the populations GI 133 and GI 173 may be indicated for recurrent selection programs or participation in obtaining composites.

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 Heterosis in crosses among white grain maize populations with high quality protein

2006 ◽  
Vol 41 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Márcio Costa Rodrigues ◽  
Lázaro José Chaves ◽  
Cleso Antônio Patto Pacheco
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Least Square ◽  
Superior Performance ◽  
Normal Equation ◽  
High Quality ◽  
Maize Populations ◽  
High Quality Protein ◽  
Female Flowering ◽  
White Grain

The objective of this work was to investigate heterosis and its components in 16 white grain maize populations presenting high quality protein. These populations were divided according to grain type in order to establish different heterosis groups. The crosses were carried out according to a partial diallel cross design among flint and dent populations. Seven agronomic traits were evaluated in three environments while four leaf diseases and incidence of corn stunt were evaluated in one. Least square procedure was applied to the normal equation X'Xbeta = X'Y, to estimate the model effects and their respective sum of squares. Among the heterosis components, in diallel analysis, significance for average heterosis in grain yield, number of days to female flowering and to all evaluated diseases was detected. Specific heterosis was significant for days to female flowering and resistance to Puccinia polysora. Results concerned to grain yield trait indicate that populations with superior performance in dent group, no matter what flint population group is used in crosses, tend to generate superior intervarietal hybrids. In decreasing order of preference, the dent type populations CMS 476, ZQP/B 103 and ZQP/B 101 and the flint type CMS 461, CMS 460, ZQP/B 104 and ZQP/B 102 are recommended to form composites.

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 Evaluation of Drought Tolerant Maize Varieties under Drought and Rain-Fed Conditions: A Rainforest Location

2016 ◽  
Vol 8 (7) ◽  
pp. 153
Author(s):  
Abimbola Oluwaranti ◽  
Oluwatosin Temilade Ajani
Keyword(s):  
Grain Yield ◽  
Agronomic Traits ◽  
Drought Tolerant ◽  
Cropping Season ◽  
Strong Positive Relationship ◽  
Maize Varieties ◽  
Ear Height ◽  
The Relationship ◽  
Ear Number

<p>Newly developed drought tolerant maize (<em>Zea mays</em> L.) varieties have been hypothesized to be of different genetic make-ups, hence this study was conducted to evaluate drought-tolerant maize varieties under drought and rain-fed conditions, identify the highest yielding varieties and determine the relationship between agronomic traits and varieties’ yield under these conditions in a rainforest location. Nine drought tolerant varieties of maize and a local check were evaluated during the early part of the early cropping season (March) (Drought) as well as the actual early cropping season (May-June) (Rain-fed) of 2015 at the Teaching and Research Farm (T&amp;RF) of Obafemi Awolowo University, Ile-Ife (7°28'N, 4°33'E and 244 m above sea level). There were significant differences among the two environments for all the traits measured. The performance of the drought tolerant maize varieties is better under the rain-fed condition. The yield performance of all varieties are not significantly different from each other (1.36 tons/ha to 2.75 tons/ha) under drought except EVDT-W 2000 STR C<sub>0</sub> (1.10 tons/ha). All the varieties evaluated under rain-fed condition produce higher grain yield (2-44 tons/ha-3.69 tons/ha) which are not significantly different each other. All the yield components except ear height and length had a strong positive relationship with grain yield under drought while only ear number and weight had relationship with yield under rain-fed condition. In conclusion, among the drought tolerant maize varieties, EVDT-W 2000 STR C<sub>0</sub> need further improvements to drought. Furthermore, ear weight can be used to select parents for the development of drought tolerant maize varieties in this agro-ecology.</p>

scholarly journals EVALUATION OF CORN HYBRIDS PERFORMANCE IN TWO LOCATIONS OF GOIÁS

2019 ◽  
Vol 6 (1) ◽  
pp. 8-16
Author(s):  
Leandro Lopes Gomes ◽  
Wilian Henrique Diniz Buso ◽  
Janaina Batista Lima ◽  
Helber Garcez Matos ◽  
Laidson Alves Leão Junior
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Agronomic Traits ◽  
North Central Region ◽  
Stem Number ◽  
Corn Hybrids ◽  
North Central ◽  
The North ◽  
Ear Height ◽  
1000 Grain Weight

The objective of this study was to evaluate the agronomic traits and grain yield of corn hybrids in two locations of the North Central region of Goiás. The experimental design was a randomized block, in the 17x2 factorial scheme (17 hybrids and two locations) with four replications. The locations were Itapaci and Ceres. Each plot consisted of two rows of five meters, spaced 0.50 m and rows were sown on the sides, which served as a border. The evaluations occurred in the two central rows, excluding 0.50 m at the extremities. The variables analyzed were: first ear height, plant height, stem, number of ears per plant, number of grain rows, number of grains per row, 1000 grain weight and grain yield (kg ha-1). The hybrids that showed the best conditions for plant height were DKB 290 PRO 3, DKB 290 PRO 2, DKB 310 PRO 2, DAS 2B810 PW, DKB 390 PRO 2 and AS 1633 PRO 2, with emphasis on DKB 310 PRO 2, which also showed satisfactory first ear height and stem and ear diameter. About grain yield, the hybrids MG 652 PW, AGN 30A37 PW, STATUS, DKB 310 PRO 2, AG 7098 PRO 2, MG 600 PW and IMPACTO presented highest grain yield performance in both municipalities.

scholarly journals Grain yield and population densities of new corn hybrids released by the INIFAP and UNAM for the High Valleys of Mexico†

2020 ◽  
Vol 38 (3) ◽  
pp. 507-515
Author(s):  
Margarita Tadeo-Robledo ◽  
Alejandro Espinosa-Calderón ◽  
Enrique Canales-Islas ◽  
Consuelo López-López ◽  
Benjamín Zamudio-González ◽  
...  
Keyword(s):  
Grain Yield ◽  
Plant Density ◽  
Block Design ◽  
Research Work ◽  
Corn Hybrids ◽  
Randomized Block Design ◽  
Plant Densities ◽  
Ear Height ◽  
Area Unit ◽  
H 51

In Mexico, corn (Zea mays L.) is one of the most important cereals from the alimentary, industrial, social, political, and cultural points of view. It is grown in different agroecological niches, water regimes, and management systems. The objective of the present research work was to study the optimum plant density per area unit and its effect on grain yield and agronomical characteristics of different corn hybrids. Six corn hybrids (H-51 AE, H 53 AE, H 47 AE, H 49 AE, Tsíri PUMA, and H-48) and three plant densities (50 000, 65 000, and 80 000 plants ha-1) were evaluated. Sowing was done during the spring-summer season, 2015, in field owned by the FESC-UNAM and CEVAMEX-INIFAP. A completely randomized block design was used with four replicates. Significant differences (P ≤ 0.05) were detected for genotypes (G) in the variables of grain yield, plant height, ear height, days to male and female flowering, volumetric weight, grain weight, ear length, and grains per ear. Moreover, the effect of the environment (E) was significant (P ≤ 0.05) for the same variables, with the exception of ear length. No significant differences (P ≥ 0.05) were registered for the densities factor (D). Only the G×E interaction had significant differences (P ≤ 0.05) in the grain yield trait. The better environment was CEVAMEX, with a mean yield of 5497 kg ha-1. The Tsíri PUMA hybrid had the best grain yield with 5856 kg ha-1. Although there were no differences for the studied interactions, the 65 000 plants ha-1 population density was the most appropriate. The densities factor did not affect the performance of the evaluated hybrids. Therefore, we recommend using 65 000 plants ha-1 to avoid investing in large amounts of seeds.

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

2020 ◽  
Vol 37 (4) ◽  
pp. 410-429
Author(s):  
Victor Mario García Mora ◽  
Julián Chura Chuquija ◽  
Julio Torres
Keyword(s):  
Grain Yield ◽  
Plant Height ◽  
Inbred Lines ◽  
Male And Female ◽  
Lattice Design ◽  
Maize Genotypes ◽  
Ear Height ◽  
Female Flowering ◽  
The Mean ◽  
Additive Genes

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.

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