Grain Yield In Environments Research Articles

Stability for grain yield and its contributing traits in bread wheat (Triticum aestivum)

In a study set of forty seven genotypes of common bread wheat (Triticum aestivum L. emend Fiori & Paol) were evaluated over four years during 2007-08 to 2010-11 to assess the stability of these genotypes for yield and its contributing traits over years and environments. Analysis of variance of stability with respect to 12 traits revealed highly significant variance due to environment for all traits which indicated differential effect of different seasons. The variance for genotypic effect was highly significant for all traits indicating thereby differential response of all the genotypes. Genotype×environment (linear) interaction was also significant for flag leaf length, flag leaf width, peduncle length, grains per spike and 1000-grain weight indicating substantial amount of predictable G×E interaction. Environmental indices indicated that performance of genotypes over four environments varied apparently and environment E2 showed highest favourable impact on grain yield. Varieties K 9107, UP 2382 and PBW 443 were found to be stable across the environments for grain yield and NW 1076 was the highest yielding stable variety in which superior yield was resulted from high mean values of six contributing traits, while variety LOK 1 was the only variety showed stable performance for all 12 traits. The stability of different yield contributing traits varied in compensating manner in different genotypes imparted grain yield stability. The varieties HD 2824, UP 2382, NW 1076, DBW 16, DBW 39, GW 173, HUW 234, NIAW 917, LOK 1, HD 2851 and PBW 154 have shown higher mean values, desirable regression coefficient and non-significant deviation from the regression coefficient for yield and its contributing traits. Based on stability parameters these varieties can be considered as stable performers and may be utilized for hybridization programmes to improve wheat yields.

Winter Wheat Eastern European Regional Yield Trial: Identification of Superior Genotypes and Characterization of Environments

ABSTRACTThe International Winter Wheat Improvement Program (IWWIP)—a collaboration between the government of Turkey, the International Maize and Wheat Improvement Center (CIMMYT), and the International Center for Agricultural Research in the Dry Areas (ICARDA)—develops and globally distributes improved winter wheat (Triticum aestivum L.) germplasm. The Winter Wheat Eastern European Regional Yield Trial was conducted by IWWIP during 1998–2005 using elite lines and varieties from IWWIP, Eastern Europe (EE), the United States, and Central and West Asia (CWA). This study analyzed data to identify superior genotypes and key locations that could be useful for future international collaboration on winter wheat. Grain yield and agronomic traits of 422 elite breeding lines and new varieties from 17 countries were evaluated across 39 locations. Superior genotypes and key environments for grain yield were determined using genotype and genotype × environment biplot analyses. Many superior genotypes were identified for both EE and CWA, and 11 genotypes showed high, stable grain yield across the regions. The most representative and discriminating sites for grain yield were Konya and Eskisehir, Turkey (overall); Edirne, Turkey (CWA); and Dobrich, Bulgaria (EE). These findings represent a comprehensive analysis of yield and stability of a large, globally important set of winter wheat genotypes and growing locations, which may be useful for national and international winter wheat improvement programs.

<b>Adaptability and stability of corn hybrids grown for high grain yield

The objective of the present study was to evaluate the adaptability and stability of corn hybrids for grain yield in environments with high crop management standards. Ten corn hybrids were evaluated for grain yield in 48 environments, consisting of 12 locations over a period of four years inSouth Brazil. A complete experimental, random block design with two repetitions was used. Adaptability and stability were analyzed according to the bi-segmented discontinuous model with measurement errors in the variables. The behavior of hybrids was studied as a function of the average yield in the inferior and/or superior environments, the estimates of the parameters of the equation, and the quality of the fit. The 30F36 hybrid behaved better in the superior environments and it is indicated for farmers who adopt the highest technological standards for crop management, whereas the 30F53 hybrid was classified as close to ideal; that is, it is indicated for cultivation under various environmental conditions. The 30R50 and 32R48 hybrids are appropriate only for average environments. There is a very good phenotypic stability in simple hybrids associated with high potential yield.

Stability for Yield and its Component Traits in Durum Wheat (Triticum durumDesf.)

Fifty genotypes of durum wheat were evaluated over four diverse environments for grain yield and its component traits (tiller number, grains/spike and 100 grain weight). Genotype × environment interaction was found significant for all the traits except 100 grain weight. Further, linear component of G × E interaction was significant for 100 grain weight suggesting that the variation in performance of different genotypes could be predicted. The genotypes IDYT-CA-05-47, NI 146, PDW 215, IDYN 46 and IDYN 49 were found to desirable and stable across the environments for grain yield. Thus, these genotypes could be included in the hybridization programme to converge the stability characteristics of grain yield for the development of a stable variety adapted to wider range of environments.

Genotype by environment interaction and yield stability analysis of quality protein maize genotypes in Terai Region of Nepal

Grain yield stability for the new maize genotypes is an important target in maize breeding programs. The main objective of this study was to identify stable high yielding quality protein maize (QPM) genotypes under various locations and years in terai region of Nepal. Six quality protein maize genotypes along with Poshilo Makai-1 (Standard Check) and Farmer’s Variety (Local Check) were tested at three different locations namely Ayodhyapuri-2, Devendrapur, Madi, Chitwan; Rajahar-8, Bartandi, Rajahar, Nawalparasi; Mangalpur-2, Rampur, Chitwan during 2011 and 2012 spring and winter seasons under rainfed condition. The experiment was conducted using Randomized Complete Block Design with two replications in farmer’s fields. There was considerable variation among genotypes and environments for grain yield. The analysis of variance showed that mean squares of environments (E) was highly significant and genotypes (G) and genotype x environment interaction (GEI) were non significant. The genotypes S03TLYQ-AB02 and RampurS03FQ02 respectively produced the higher mean grain yield 5422±564 kg/ha and 5274±603 kg/ha across the locations. Joint regression analysis showed that RampurS03FQ02 and S03TLYQ-AB02 with regression coefficient 1.10 and 1.22 respectively are the most stable genotypes over the tested environments. The coefficient of determination (R2) for genotypes Rampur S03FQ02 and S03TLYQ-AB02 were as high as 0.954, confirming their high predictability to stability. Further confirmation from GGE biplot analysis showed that maize genotype S03TLYQ-AB02 followed by Rampur S03FQ02 were more stable and adaptive genotypes across the tested environments. Thus these genotypes could be recommended to farmers for general cultivation.DOI: http://dx.doi.org/10.3126/ijasbt.v1i2.8202 Int J Appl Sci Biotechnol, Vol. 1(2): 75-79

Stability of General and Specific Combining Ability Effects for Grain Yield in Elite Iranian Maize Inbred Lines

Diallel analyses provide estimates of general combining ability (GCA) and specific combining ability (SCA) effects to facilitate efficient utilization of maize (Zea mays L.) inbred lines in breeding programs. Multi-environment trials are commonly conducted to evaluate GCA, SCA, and the stability of grain yield (GY) for single-crosses across environments (E). In these studies the significant GCA × E and SCA × E interactions are usually not examined, yet they indicate that the rankings of the parental inbred lines for GCA and SCA change across environments. The major objective of this study was to quantify stability of GCA and SCA effects of nine maize inbred lines developed in Iran using a 9 × 9 diallel mating design. The 36 single- cross hybrids were evaluated for GY, kernel rows per ear (KR), and kernels per row (KN) at three locations across two years (six environments), using a randomized complete-block design with four replicates. Rank sum and rank variance were used to measure the stability of GCA and SCA for GY across environments, and the Quade's test was used to separate the rank sums. The main effect of E, hybrid, and hybrid × E was significant. Significant GCA and SCA effects were found for the traits, with GCA being more important than SCA for KR, but vice versa for GY and KN. Significant GCA × E and SCA × E were observed for the traits, indicating changes in ranking of GCA and SCA across environments. Inbred lines KE75039 and K1263/2-1 had significant positive GCA for GY. The highest SCA for GY resulted from KE75039 × K2331 cross (15.07 Mg ha−1). Ranking of GCA and SCA for GY across environments exhibited different patterns for the parental inbred lines. Inbreds KE75039 and K1263/2-1 exhibited high stability for GCA across environments for GY, and they contributed only 9% and 7% to GCA × E interaction, respectively. Cross combination KE75039 × K2331 had the highest stability for SCA across the environments, followed by K2331 × K1263/2-1 and K1263/1 × OH43/1-43 crosses. The three other notable cross combinations with relatively stable SCA each had inbred line K1263/1 in common. Combining ability and stability analyses suggest that maize breeding programs in Iran could improve GY by using inbred lines KE75039, K1263/1, and K1263/2-1. It is suggested that new adapted germplasm be introduced to broaden the genetic base of maize germplasm available in Iran.

Genetic gain in grain yield and drought tolerance of durum wheat breeding lines under rainfed conditions in Iran

The main objective of this study was to evaluate the genetic gain for grain yield, yield attributes and drought tolerance of 11 durum breeding lines and also to compare it with one modern cultivar and two durum and bread wheat landraces in contrasting environment groups in a period of four cropping seasons (2005–09) within the Iran/ICARDA joint project for moderately cold rainfed areas of Iran. The significant genotype × year interaction indicated that the average yield performance of genotypes across environments was not consistent over the years. Genetic gain (%) for grain yield was distinguishable between the stressed and non-stressed environments. A positive genetic gain (27.7 to 23.9%) was observed in the non-stressed environment and a negative genetic gain (−11.5 to −24.1%) in the stressed environment for the breeding lines, compared to the landraces, suggesting that the evaluation of breeding materials under non-stressed conditions should be continued. Unlike the modern cultivar, the landraces were low yielding, and less responsive to non-stressed environments for grain yield and yield attributes. The drought resistance indices, i.e. tolerance index (TOL) and stress susceptibility index (SSI), were better in landraces than breeding lines, while the drought tolerance indices, i.e. stress tolerance index (STI) and drought response index (DRI), were better in breeding lines. In contrast with landraces, the modern cultivar and the breeding lines showed significant changes for both grain yield and drought tolerance.

Choice of shrinkage parameter and prediction of genomic breeding values in elite maize breeding populations

AbstractGenomic selection (GS) is a promising alternative to marker‐assisted selection particularly for quantitative traits. In this study, we examined the prediction accuracy of genomic breeding values by using ridge regression best linear unbiased prediction in combination with fivefold cross‐validation based on empirical data of a commercial maize breeding programme. The empirical data is composed of 930 testcross progenies derived from 11 segregating families evaluated at six environments for grain yield and grain moisture. Accuracy to predict genomic breeding values was affected by the choice of the shrinkage parameter λ2, by unbalanced family size, by size of the training population and to a lower extent by the number of markers. Accuracy of genomic breeding values was high suggesting that the selection gain can be improved implementing GS in elite maize breeding programmes.

Genomic prediction of sunflower hybrid performance

AbstractPredicting single‐cross performance is of high importance to improve the efficiency of sunflower (Helianthus annuus L.) hybrid breeding programmes. We used experimental data from inter‐ and intragroup sunflower hybrids and their parental lines adapted to Central Europe to (i) study the genetic diversity and combining ability and (ii) examine the accuracy to predict hybrid performance based on phenotypic and genomic data. We evaluated 133 intragroup and 104 intergroup hybrids with their parental lines in replicated trials at four environments for grain yield, oil yield and oil content. Furthermore, the parental lines were fingerprinted with 572 AFLP markers. Variance due to specific combining ability was comparable for intergroup and intragroup crosses. This suggested a lack of clearly defined heterotic groups for the sample of studied sunflower lines. Prediction accuracy of hybrid performance based on general combining ability effects was high and could not be increased using genomic selection approaches. For situations where no information on GCA effects of parental lines was available, hybrid prediction based on genomic selection methods was accurate for groups of related lines. For groups of unrelated lines, however, we observed a strong decrease in the prediction accuracy. This suggests that prediction of hybrid performance for crosses based on genetically distant parents remains challenging.

Bayesian mapping of multiple traits in maize: the importance of pleiotropic effects in studying the inheritance of quantitative traits

Pleiotropy has played an important role in understanding quantitative traits. However, the extensiveness of this effect in the genome and its consequences for plant improvement have not been fully elucidated. The aim of this study was to identify pleiotropic quantitative trait loci (QTLs) in maize using Bayesian multiple interval mapping. Additionally, we sought to obtain a better understanding of the inheritance, extent and distribution of pleiotropic effects of several components in maize production. The design III procedure was used from a population derived from the cross of the inbred lines L-14-04B and L-08-05F. Two hundred and fifty plants were genotyped with 177 microsatellite markers and backcrossed to both parents giving rise to 500 backcrossed progenies, which were evaluated in six environments for grain yield and its components. The results of this study suggest that mapping isolated traits limits our understanding of the genetic architecture of quantitative traits. This architecture can be better understood by using pleiotropic networks that facilitate the visualization of the complexity of quantitative inheritance, and this characterization will help to develop new selection strategies. It was also possible to confront the idea that it is feasible to identify QTLs for complex traits such as grain yield, as pleiotropy acts prominently on its subtraits and as this "trait" can be broken down and predicted almost completely by the QTLs of its components. Additionally, pleiotropic QTLs do not necessarily signify pleiotropy of allelic interactions, and this indicates that the pervasive pleiotropy does not limit the genetic adaptability of plants.

Combining ability of early-maturing quality protein maize inbred lines adapted to Eastern Africa

Adapted early-maturing quality protein maize (QPM) hybrids with high grain yield potential in Eastern Africa would benefit maize farmers through increased grain production and subsequently higher income but they are not widely available. Fourteen early-maturing QPM inbred lines developed from POOL15QPM-SR, were crossed using the diallel mating design. The resulting single-cross hybrids were evaluated under six well-watered, drought stress and low nitrogen conditions at six locations in Eastern Africa. The objectives were to assess the grain yield potential of early-maturing F 1 QPM hybrids, estimate the general combining ability (GCA) and specific combining ability (SCA) for grain yield and other agronomic traits and determine the relationship between grain yield and other agronomic traits of the QPM hybrids. Days to anthesis, days to silking, anthesis–silking interval, ears per plant, root and stalk lodging, ear aspect, and grain yield were measured. Variation among hybrids was significant for all traits except root lodging. The best single-cross hybrid across environments was POOL15QPMFS538-B-3-B-B × POOL15QPMFS462-B-4-B-B (5.30 t ha −1). Mean squares due to GCA were significant, whereas mean squares due to SCA were not for measured traits indicating that additive genetic effects were much more important in this set of genotypes. Inbred line POOL15QPMFS538-B-3-B-B exhibited very good GCA effects for grain yield in well-watered environments and across environments for grain yield (0.74 t ha −1). Inbred line Pool15QPMFS478-B-3-B-B had the best GCA effect for grain yield under managed drought stress (0.26 t ha −1), while inbred line POOL15QPMFS319-B-2-B-B had the best GCA effect (−1.11 days) for reduced days to anthesis across environments. The new QPM inbred lines with desirable traits could be used to improve grain yield and protein quality of maize breeding programs in Eastern Africa.

Prediction of genotypic values of maize hybrids in unbalanced experiments

The objective of this study was to evaluate whether the REML/BLUP can be useful for predicting the genotypic values of maize hybrids in a group of unbalanced experiments. A set of 256 single-crosses were evaluated in 13 environments for grain yield, plant height and plant lodging. Sets of hybrids within environments and sets of environments were withdrawn from the experiments to simulate unbalanced data, and the hybrid predictions of the unbalanced data were computed by the REML/BLUP, simulated using the bootstrap resampling procedure. The coefficients of determination and percentage of selection coincidence were computed for the predicted genotypic values of unbalanced data and their means from the balanced data. The REML/BLUP method accurately predicted the genotypic values of missing hybrids under losses of up to 20% of hybrids within environments or a reduction of 23% of the environments, even in the presence of significant and complex hybrid x environment interaction.

Combining ability in medium-maturity maize genotypes adapted to mid-altitude and lowland tropical environments

Maize (Zea mays L.) is grown in different agro-ecological zones in the semi-arid tropical regions. Breeding for high production requires information on the combining ability and the magnitude of useful genetic variances among adapted genotypes. This study was conducted to determine the combining ability among tropical lowland and mid-altitude medium-maturity maize genotypes, provide information to clarify the relationship among them and identify suitable lines for distribution to growers. Six mid-altitude adapted maize inbred lines and six lowland adapted maize inbred lines were crossed in a full diallel mating system. The resulting 132 crosses, excluding the parental lines were evaluatedin four environments for grain yield, days to silking, plant height, ear height, ear weight and grain moisture at harvest. The subdivision of treatment effects in the general (GCA) and specific (SCA) combining ability were performed according to Griffing’s diallel analysis method 3, model 2. Both GCA and SCA were significant for all traits. The reciprocal meansquares were significant for ear height, ear weight, grain moisture and grain yield. Both additive and nonadditive gene effects were involved in combining ability between maize germplasm from different ecologies. Additive genetic effects were more important than nonadditive effects in controlling expression of the various traits evaluated. Positive GCAeffects for yield were observed with the lines EXP124, NCREGP1103, NCREGP28, and TZUT57 among the lowland and the lines TZMI308, 87036 among the mid-altitude lines. Crosses involving parents of different adaptation ecologies yielded hybrids with good agronomic performances and high estimates of SCA for all assessed traits. Crosses with atleast one mid-altitude female parent were better than lowland x lowland and mid-altitude x mid-altitude crosses in all environments. Mid-altitude maize germplasm may hold potential for use as source populations for both mid-altitude and lowland ecologies. These results emphasize the need to exploit the full potential of interpopulation crosses ofmaize genotypes.

Number of recombinations and genetic properties of a maize population undergoing recurrent selection

In maize recurrent selection programs, selected genotypes were recombined once to generate genetic variability for the next selection cycle. Selection generates negative gametic phase disequilibrium which reduces genetic variances, and this disequilibrium is not significantly reduced with only one generation of recombination. The objective of this research was to assess the effects of one additional generation of recombination on phenotypic and genotypic parameters in a maize population undergoing recurrent selection. Selected progenies of the EPB-4 population were subjected to one and two generations of recombination, and from each generation half- and full-sib progenies were developed and evaluated at three environments for grain yield, plant and ear heights, prolificacy, and ear placement. There were no significant changes between each progeny type with one and two generations of recombination for the means, ranges, phenotypic distribution of the traits, genetic variances, heritability coefficients, and genetic correlations for the traits assessed. The results suggest that an additional generation of recombination will not increase the effectiveness of maize recurrent selection programs.

Genotype-Environment Interaction and Stability Analysis for Grain Yield of Maize (Zea mays L.) in Ethiopia

Fifteen maize genotypes were tested at nine different locations in 2005 under rainfed condition to determine stable maize genotypes for grain yield and determine genotypes with high yield and form homogenous grouping of environments and genotypes. The experiment was conducted using Randomized Complete Block Design with three replications. There was considerable variation among genotypes and environments for grain yield. Stability was estimated using the Additive Main Effects and Multiplicative Interactions (AMMI). Based on the stability analysis, genotypes 30H83, BH-540, Ambo Synth-1, AMH-800 and BHQP-543 were found to be stable for grain yield. The first two Interaction Principal Component axis (IPCA1 and IPCA2) were significant (p<0.01) and cumulatively contributed 70.27% of the total genotype by environment interaction. The coefficient of determination (R) for genotypes 30H83 was as high as 0.92, confirming its high predictability to stability. Among the genotypes, the highest grain yield was obtained from genotype 30H83 and BH-541 (8.98 and 8.051 ha) across environments. Clustering of AMMI-estimate values grouped genotypes in to four clusters and the environment in to three clusters. Environment Goffa was unique as it is grouped differently from all other environments.

Genetic improvement trends in agronomic performances and end-use quality characteristics among hard red winter wheat cultivars in Nebraska

Evaluation of wheat cultivars from different eras allows breeders to determine changes in agronomic and end-use quality characteristics associated with grain yield and end-use quality improvement over time. The objective of this research was to examine the trends in agronomic and end-use quality characteristics of hard red winter wheat cultivars grown in Nebraska. Thirty historically important and popular hard red winter wheat cultivars introduced or released between 1874 and 2000 were evaluated at Lincoln, Mead and North Platte, Nebraska in 2002 and 2003. An alpha lattice design with 15 incomplete blocks of two plots and three replications was used at all locations. Agronomic (days to flowering, plant height, spike length, culm length, grain yield and yield components, and grain volume weight) and end-use quality (flour yield, SDS-sedimentation value, flour protein content, and mixograph time and tolerance) traits were measured in each environment. Highly significant differences were observed among environments, genotypes and their interactions for most agronomic and end-use quality characteristics. Unlike modern cultivars, older cultivars were low yielding, and less responsive to favorable environments for grain yield and yield components. Semidwarf cultivars were more stable for plant height than traditional medium to tall cultivars. All cultivars had high grain volume weight since it is part of the grading system and highly selected for in cultivar release. Modern cultivars were less stable than older cultivars for SDS-sedimentation and mixing tolerance. However, the stability of older cultivars was attributed to their having weak mixing tolerance and reduced SDS-sedimentation values. The reduced protein content of modern cultivars was offset by increased functionality, as measured by mixograph and SDS sedimentation. In conclusion, breeders have tailored agronomic and end-use quality traits essential for hard red winter wheat production and marketing in Nebraska.

Some Useful Characters Implicated in Tolerance to Low Phosphorus and Water Stresses in Hexaploid Triticale x Bread Wheat Derivatives

The response of elite, true breeding triticale x wheat derivatives was studied in the non stress, P stress, irrigated and rainfed environments for grain yield and 15 other morpho-physiological traits. Sufficient genetic variability was present for almost all the characters in all the environments. Yield potential and stress tolerance were found to be independent attributes. P efficiency and water stress tolerance were also found to be unlinked traits. Some characters are described which could be useful while breeding towards P efficient and water stress tolerant genotypes.

Agronomic performance of lines derived from anther culture, maize pollination and single-seed descent in a spring wheat cross

Anther culture and maize hybridization are two frequently used techniques for doubled haploid production in wheat (Triticum aestivum L.). Information on the field performance of lines derived from these techniques is limited. This study was conducted to compare the performance of F(4:6) lines obtained by single-seed descent with lines obtained by anther culture and maize (Zea mays L.) pollination from the same cross of spring wheat, 'Chris'/MN 7529. Thirty-three lines derived from each of those techniques were evaluated in six environments for grain yield, protein content, test weight, heading date, kernel weight and plant height. Mean performance of the single-seed descent lines exceeded performance of the anther culture lines for grain yield, kernel weight and plant height with no apparent differences for grain protein content, test weight and heading date. No differences between trait means for the single-seed descent and maize pollination lines were found except for plant height. The best 5 lines from each method for grain yield, protein content and test weight were similar in performance except that the protein content was higher for the maize pollination lines than for the single-seed descent lines. Acceptable levels of agronomic performance could be found among lines from each method. Wide acceptance of the doubled haploid technique for pure line production in breeding programs may, however, be limited by the often poor efficiency of doubled haploid line production, resulting in smaller population sizes for selection of desirable traits in comparison to the single-seed descent method.

Agronomic Performance and End‐Use Quality of 1B vs. 1BL/1RS Genotypes Derived from Winter Wheat ‘Rawhide’

The winter wheat (Triticum aestivum L.) cultivar Rawhide is heterogenous for the 1BL/1RS translocation. The 1BL/1RS translocation has been proven to increase grain yield and decrease end‐use quality in bread wheat. The objective of this research was to investigate if the excellent yield performance of Rawhide was due to higher yielding 1BL/1RS lines compensating for lower yielding 1B lines and if the acceptable quality of Rawhide was produced by higher end‐use quality 1B lines compensating for lower end‐use quality 1BL/1RS lines. To do so, 19 homogeneous 1B genotypes and 18 homogeneous 1BL/1RS genotypes were selected from Rawhide. These genotypes, three composites (Composite 1B, Composite 1BL/1RS, and Composite Total), Raw‐hide, and three check cultivars, were evaluated in four Nebraska environments for grain yield, yield components, and end‐use quality traits. No significant differences were found between chromosome classes for grain yield. The 1BL/1RS genotypes had a higher kernel weight (4%) than IB genotypes; however, the 1B genotypes had a greater number of spikes per square meter (5%). Composites were no different from Rawhide and from each other for grain yield and yield components. For end‐use quality traits, the 1BL/1RS genotypes had a higher protein content (137 mg g−1)&gt; similar mixing time (4.8 min), and lower mixing tolerance (3.5) than 1B genotypes (132 mg g−1, 5.0 min, and 4.9, respectively). However, a mixing tolerance value of 3.5 is acceptable. In general, no differences were found among the composites and between the composites and Rawhide for quality traits. Hence, the 1BL/1RS translocation was not beneficial for yield nor was it detrimental for end‐use quality in this genetic background.

Analysis of Diallel Crosses among Colombian Landraces and Improved Populations of Maize

Few of the world's maize (Zea mays L.) germplasm collections have been systematically evaluated in spite of the recognized necessity of broadening the germplasm base of this crop. Knowledge of new heterotic patterns and the breeding potential of maize collections stored in gene banks can contribute to a widening of the genetic base. The objectives of this study were to (i) evaluate the breeding potential eight tropical maize germplasms, and (ii) provide further information to clarify the relationships among them. Five Colombian landraces (‘Andaqui’, ‘Común’, ‘Costeñio’, ‘Puya’, and ‘Yucatán’) and three improved maize populations (‘Tuxpeñio‐1’, ‘Suwan‐1’, and ‘ETO’) were crossed in a diallel mating system. The parents and the 28 hybrids were evaluated in six environments for grain yield, days to 50% silking, prolificacy, and ear height. Cuitivar (additive) and heterotic effects were highly significant (P ≤ 0.01) for all traits except ear height. Significant (P ≤ 0.05) cultivar heterosis and specific heterotic effects were found for grain yield, with an average 10% high‐parent heterosis. Cultivar effects were positive for Suwan‐1 (0.86**) and Tuxpeño‐1 (0.62**) and negative for Andaqui (−0.42*) and Puya (−0.78**). The same materials showed significant cultivar heterotic effects (0.29**, 0.12*, −0.23″*, and −0.22**, respectively). Specific heterosis was found in crosses between Tuxpeñio‐1 and Común (0.44″*), Yucatán (0.35*), and Suwan‐1 (−0.67**). The best materials were improved populations, Suwan‐1, and Tuxpeñio‐1. The ETO population did not perform well per se or in hybrid combinations. Yucatán outyielded ETO and was a parent in two of the three highest yielding crosses. The hybrid Tuxpeñio‐1 × Yucatán showed the highest high‐parent heterosis value (25%**). Results generally agreed with the reported relationships among the parents and pointed to Yucatán as a potentially useful genetic resource for tropical maize breeding programs.