Genotype And Genotype × Environment Research Articles

Multi-Environment Testing Based G × E Interactions Reveal Stable Host-Plant Resistance against Sterility Mosaic Disease in Pigeonpea

Sterility mosaic disease (SMD) is a serious biotic restraint in pigeonpea-growing regions of the Indian subcontinent. Disease control using chemicals like acaricides is not economical or sustainable, pointing towards host plant resistance as the ideal strategy for its management. In this study, from preliminary screening of 75 pigeonpea germplasm accessions and breeding lines, 21 pigeonpea genotypes showing moderate resistance to SMD were selected and again assessed at two multi-environment locations during Kharif 2021/2022 and 2022/2023. Analysis of variance partitioned the variation between the main effects of genotype and genotype × environment (GGE). The results revealed a significant variation (p ˂ 0.05) in the SMD incidence between the tested genotypes, environment, and their interactions. Genotype variance contributed the greatest effect (63.56%) to the total variation and it represents the maximum disease variation. Furthermore, a significant positive correlation was found for the levels of SMD incidence between the test environments. We observed that SMD incidence had a high negative correlation with the maximum temperature (r = −0.933), and positively correlated with the rainfall (r = 0.502). Analysis of principal components 1 and 2 of the GGE explained 95.33% of the total variation and identified 10 genotypes (G1, G3, G4, G8, G10, G12, G13, G15, G20, and G21) showing moderate resistance stability across the environments. As new sources of resistance to SMD, these genotypes should be incorporated in pigeonpea breeding trials for further release. This research broadens the area of phenotyping and identifies stable resistance sources that can be used in future SMD resistance breeding projects.

Genotype × Environment Interaction Influence Secondary Metabolite in Cowpea Infested by Flower Bud Thrips

Secondary metabolites are among the major contributors of host-plant resistance. Cowpea produces secondary metabolites that are known to enhance resistance to insect pests including flower bud thrips. However, environmental conditions tend to affect the production of secondary metabolites, thereby affecting the response of the host plants to insect pest. The objective of this study was to determine the effect of the genotype × environment interaction on the production of secondary metabolites and flower bud thrips resistance in cowpea. Six cowpea genotypes were evaluated for flower bud thrips damage and the contents of flavonoids, antioxidants, phenolics, proteins, lignin, tannins and reducing sugars in four environments with varying temperatures and rainfall patterns. The data collected were subjected to the analysis of variance and genotype and genotype × environment (GGE) analysis. Flower thrips damage, and the contents of flavonoids, antioxidants, lignin, tannins and reducing sugars varied significantly (p < 0.001) among genotypes. Genotype Sanzi produced high levels of antioxidants, while TVU-9820 led in phenolic concentrations respectively. Metabolite contents were significantly (p < 0.001) different among environments, with the long rain season of field experiments led to increased production of flavonoids, proteins, lignin and tannins. A resistant genotype, TVU-3804, produced relatively stable contents of flavonoids, antioxidants, phenolics, proteins and reducing sugars across environments. In this study, the environment influenced the concentration of the metabolites, which in turn affected the cowpea’s resistance to flower bud thrips.

Genotype × environment interaction and adaptation of cowpea genotypes across six planting seasons

Cowpea exhibits significantly inconsistent performances across different environments, and hence demands performance evaluation of genotypes prior release or cultivation in every breeding program. Hence, the goal of this study was to compare 16 cowpea genotypes over six planting seasons (2014-2019) in Akungba-Akoko, Nigeria for their stability and adaptation through Finlay and Wilkinson (FW), Additive Main Effects and Multiplicative Interaction (AMMI) and Genotype and Genotype × Environment (GGE) analyses. ANOVA revealed high significant genotype (15.33%), environment (14.71%) and GEI (64.34%) effects for seed yield among genotypes. All analyses were able to pinpoint stable high-yielding genotypes including G14 and G9. Genotypes G14, G3, G4, G5, G6 and G9 were high yielding and stable according to FW; AMMI showed G10, G9, G16, G14 and G13 stable high-yielding while GGE showed G14, G16, G9 and G13 as stable high-yielding. As analyses explored the variation in the data due to GEI, they also complemented one another, in that where one erroneously included a wrong genotype as stable; the other excluded such genotype, making recommendation possible on the basis of consistency to gain reliability.

Culm Morphological Traits Contributing to Lodging Resistance in First Generation NERICA Cultivars Under Foliar Application of Orthosilicic Acid Fertilizer

Lodging resistance in upland rice requires adequate knowledge of the mechanical basis of culm morphological traits (CMTs) with potential for improved structural integrity under orthosilicic acid (OSA) fertilizer. However, assessment of lodging in NERICAs has been based solely on visual scoring which is inadequate to establish resistance to lodging. Ten upland rice cultivars, comprising NERICAs 1 to 8, Moroberekan, and Ofada were grown on loamy-sand soil under four rates (0, 250, 500 and 750 ml ha− 1) of OSA. At 20 days after heading, CMTs related to lodging were assessed among the rice cultivars. Application of 500 and 750 ml ha− 1 of OSA gave the highest CMTs with reduced lumen diameter. Lodging resistance index (LRI) varied significantly among the cultivars (0.34 in NERICA 1 to 0.70 in Ofada). Moroberekan had the highest CMTs with average LRI (0.47). Using Genotype and Genotype × Environment (GGE) comparisons bi-plot, NERICAs 4,6,7,8 and Moroberekan compared well with NERICA 1 for LRI. Bending stress had the highest but negative significant correlation (-0.74**) with LRI. Assessment of CMTs in NERICAs under OSA fertilizer can reveal variations in lodging resistance obscured by visual scoring. OSA fertilizer can improve lodging resistance through increased culm wall thickness and reduced lumen diameter in resistant cultivars such as Moroberekan and NERICA 4. NERICA cultivars with lower LRI will be more desirable to minimize lodging at moderate rate(s) of foliar OSA fertilizer. The need to characterize the CMTs of other NERICAs to establish LRI that confers susceptibility, moderate and high resistance to lodging was emphasized.

Evaluation of Yield-Based Low Nitrogen Tolerance Indices for Screening Maize (Zea mays L.) Inbred Lines

To screen the desired criterion to identify desirable genotypes and select genotypes best suited to limited nitrogen availability in order to facilitate the practice of low-nitrogen-tolerant breeding in maize, the response of 31 maize inbred lines, containing four control inbred lines (PH6WC, PH4CV, Zheng58, and Chang7-2) and others selected from the Shaan A and Shaan B heterotic groups cultivated at Northwest A&F University (Yangling, Shaanxi, China), were evaluated. The experiment was conducted following a split plot design with two replications during three growing seasons (2015, 2016, and 2017) under both high nitrogen (HN) and low nitrogen (LN) conditions at the Yulin and Yangling in Shaanxi Province, China. Seven screening indices, based on grain yield under two contrasting nitrogen (N) conditions, the stress susceptibility index (SSI), yield stability index (YSI), mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), harmonic mean (HM), and low nitrogen tolerance index (LNTI), were computed to assess the overall index that accurately screened the desirable genotypes. The results of the correlation analyses and principal component analysis showed that MP, GMP, HM and STI were correlated with grain yield significantly and positively under contrasting N conditions, and were able to accurately discriminate the desirable genotypes. Compared with the control inbred lines, many inbred lines selected from the Shaan A and Shaan B groups showed a higher LN tolerance. This shows that we can effectively improve the LN tolerance of maize inbred lines through LN screening. Based on the screening indices, the three-dimensional diagram and genotype and genotype × environment (GGE) biplots are agreed with this results, and we identified KA105, KB081, KA225, 91227, and 2013KB-47 as the desired genotypes that have the potential to be used to breed a high yield and stable hybrid.

Multi-environment analysis of grain quality traits in recombinant inbred lines of a biparental cross in bread wheat (Triticum aestivum L.)

A set of 286 recombinant inbred lines (RILs) along with the parents and a popular wheat variety in India were grown for two consecutive years at three locations belonging to the two major wheat growing zones of India and evaluated for four grain quality traits. Rare recombinants with high trait value appeared for protein content (PC), thousand-kernel weight (TKW), sedimentation value (SV), and kernel hardness (KH). The magnitude of environmental effects was more pronounced than genotypic effects and genotype-environment interaction (GEI). The cumulative contribution of environment and GEI components to the total variance was highest in the expression of PC followed by TKW, SV, and KH. The top five percent (14 RILs) of genotypes with high trait value were subjected to Eberhart and Russell (1966) (ER), genotype and genotype-environment (GGE) and additive main effects and multiplicative interaction (AMMI) stability models. Five RILs were identified as stable in all the three stability models. RIL61 with 38.8%, RIL101 with 8.9%, RIL226 with 26.1% superiority over check variety were the most stable genotypes in all the three stability models for PC, TKW and KH, respectively. RIL113 was found to be stable genotype in ER and GGE models, whereas, RIL231 was the most stable genotype in AMMI and GGE models in the expression of SV. These common stable genotypes with high trait value identified through ER, AMMI and GGE models could be potential donors in active breeding programs to develop high yielding wheat varieties with improved PC, TKW, SV and KH.

Genetic Variation of Growth Traits and Genotype-by-Environment Interactions in Clones of Catalpa bungei and Catalpa fargesii f. duclouxii

Clones of Catalpa bungei and Catalpa fargesii f. duclouxii were studied over several years in central China to explore genetic variation in growth traits and to identify clones of high wood yield and high stability. The genetic parameters for height, diameter at breast height (DBH), and stem volume of clones, were estimated. The effect of clone × year on the increment of stem volume in the two species was analyzed by genotype and genotype × environment (GGE) biplot methods. Significant differences in growth traits among clones and between species were found. The growth of C. bungei exceeded that of C. fargesii f. duclouxii after 4 years. Furthermore, from the 5th year, the repeatability and genetic variation coefficient (GCV) of the C. bungei clones were higher than those of the C. fargesii f. duclouxii clones in most cases. The phenotypic variation coefficient (PCV) of the C. fargesii f. duclouxii clones was significantly lower than that of the C. bungei clones. The repeatability of stem volume was intermediate or high in the two species. ANOVA revealed significant effects of the clone by year interaction in these two species. GGE biplot analysis revealed that wood yield and stability were largely independent in C. bungei; clones 22-03, 19-27, and 20-01 were the optimal clones in this species. In contrast, the optimal clones 63 and 128 of C. fargesii f. duclouxii combined the desired characteristics of high yield and high stability. In conclusion, our results indicated that the height and stem volume of C. bungei was under strong genetic control, whereas that of C. fargesii f. duclouxii was influenced by the environment more than by genetic effects. Genetic improvement by clone selection can be expected to be effective, as the repeatability of stem volume was high. Francis and Kannenberg’s method and GGE biplot analysis were used in combination to evaluate the clones. C. bungei clone 22-03 and C. fargesii f. duclouxii clones 63 and 128 were identified as the optimal clones, which exhibited both a high increment of stem volume and high stability.

Assessment of mungbean genotypes for durable resistance to Yellow Mosaic Disease: Genotype × Environment interactions

AbstractYellow mosaic disease (YMD) is the major constraint of mungbean for realizing high productivity worldwide. Moreover, management of disease using YMD‐resistant genotypes is the simplest approach. Therefore, based on a preliminary screening of 220 genotypes during the year 2010 and 2011 at 17 locations, a set of 25 genotypes was further selected to evaluate at six locations over 2 years for identification of more stable resistant genotypes. The genotype and genotype × environment (GGE) analysis indicated that the genotypes and environment effects were significant (P < 0.001) for YMD incidence. Interestingly, the GGE biplot analysis successfully accounted for 74.71 per cent of the total variation with three genotypes (ML 818, ML 1349 and IPM 02‐14) showing high degree of resistance and stability over the locations. Notably, a strong positive association was observed between disease reaction and temperature, relative humidity and rainfall. As crop is grown in diverse growing environments, aforementioned genotypes can be used as stable/durable sources for future breeding programme to develop YMD‐resistant cultivars.

Grain yield stability of early maize genotypes

The objective of this study was to estimate grain yield stability of early maize genotypes. Five early maize genotypes namely Pool-17, Arun1EV, Arun-4, Arun-2 and Farmer’s variety were evaluated using Randomized Complete Block Design along with three replications at four different locations namely Rampur, Rajahar, Pakhribas and Kabre districts of Nepal during summer seasons of three consecutive years from 2010 to 2012 under farmer’s fields. Genotype and genotype × environment (GGE) biplot was used to identify superior genotype for grain yield and stability pattern. The genotypes Arun-1 EV and Arun-4 were better adapted for Kabre and Pakhribas where as pool-17 for Rajahar environments. The overall findings showed that Arun-1EV was more stable followed by Arun-2 therefore these two varieties can be recommended to farmers for cultivation in both environments.

Evaluation of sunflower (Helianthus annuus L.) single cross hybrids under heat stress condition

ABSTRACTSunflower is an important oilseed crop, which shows susceptibility to heat stress. In this study, 63 single cross hybrids were evaluated under heat stress condition for 2 years and compared with the two commercial hybrids. Genotype and genotype × environment (GGE) was used to differentiate single cross hybrids on the basis of multiple traits. GGE biplot showed that several single cross hybrids had higher seed yield potential than standard check. Moreover, seed yield per plant (SYP) was related to pollen viability percentage, showing that achene yield was the product of high gametophytic fertility under heat stress. Hybrids having high seed yield potential under heat stress had lower cell membrane injury. GGE biplot for SYP and its components showed that single cross hybrids were characterized into two major groups. Group I was further characterized into two sub group. Group Ia included hybrids with high 100-SW, while group Ib had the hybrids with high number of seeds per head and head diameter. Group II had the hybrids with high kernel weight and kernel to seed ratio. The hybrids could be recommended according to their potential utilization in the seed industry.

Identification of high yielding wheat genotypes through evaluation of international nurseries

High yielding, stable wheat (Triticum aestivum L.) cultivars are needed for the diverse environments in West Asia to improve rural livelihoods. This study was conducted to determine the performance of elite wheat breeding lines developed by CIMMYT, to analyze their stability for grain yield across diverse environments, and to identify superior genotypes that could be valuable for varietal release. Genetically diverse 196 advanced breeding lines were evaluated across different sites in Afghanistan. Grain yield, days to heading and plant height were analyzed. Genotypic superiority for grain yield was determined using genotype and genotype × environment (GGE) biplot analysis. The experimental genotypes showed arrays of variation for grain yield in each year, with mean values ranging from 3908 to 7209 kg/ha. A set of 20 experimental genotypes superior to the check based on their high mean yield and stability across environments as assessed by the GGE rank was identified. The most stable high yielding genotypes were HD 2687; Elvia/5/Cndo/R143//Ente/Mexi75/3/AE. sq./4/2*Oci; Quaiu; Whear/Vivitsi//Whear; Kiritati/2*Trch; Waxwing; Munal#1; Whear//Inqalab 91*2/Tukuru and Snb//Cmh79A.955/3*Cno79/3/Attila/4/Chen/A.sq.(Taus)//Bcn/3/2*Kauz. These superior genotypes also had acceptable maturity and plant height. The findings of this study provides information on adaptation of the internationally important wheat genotypes, valuable for wheat improvement program in Afghanistan and its neighbouring countries in West, Central and South Asia.

Identifying superior feed barley genotypes using GGE biplot for diverse environments in India

Barley (Hordeum vulgare L.) is an important feed purpose cereal grown under diverse production conditions and harsh environments. The present investigation was carried out to study performance of advanced breeding lines and identify superior genotypes of feed barley using multienvironment trial data from All India Coordinated Wheat and Barley Improvement Programme (AICW&BIP). Ninety three experimental genotypes and five released cultivars were tested across eleven locations during four years. Grain yield and other agronomic traits were analyzed. Stability and genotype superiority for grain yield and other traits were determined using genotype and genotype × environment (GGE) biplot analysis.The result showed that environment and genotype contributed 32.9 to 67.4% and 4.7 to 20.4% of the total variation, respectively.The genotype × environment interaction contributed 27 to 44% of total variation. The experimental genotypes showed arrays of variation for grain yield in each year, with mean values ranging from 2.12 to 5.36 t/ha. Twelve experimental genotypes were identified, which were either superior or equal performance to the best check based on their high yield and stability across environments. The locations Varanasi, Kanpur,Vijapur and Durgapura discriminated the genotypes more than other sites for grain yield and agronomic traits. The findings provided valuable information on wide adaptation of feed barley genotypes, which could be useful for barley improvement programmes.

Biplot analysis of genotype × environment interactions and identification of stable sources of resistance to Ascochyta blight in chickpea (Cicer arietinum L.)

Ascochyta blight (AB) caused by Ascochyta rabei (Pass.) Labr. is one of the most important constraints that limits the productivity of chickpea (Cicer arietinum L.). The absence of high levels of stable resistant sources to the pathogen has necessitated the continued search and identification of new sources of resistance. The main aim of this work was to identify new sources of resistance to AB and validate their stability across multi-environments. A collection of 424 elite chickpea genotypes were evaluated for AB resistance under controlled environmental conditions in 2005–2006 at the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India. Fifty-one genotypes with AB severity ≤3.0 (based on the 1–9 scale) were selected for a second round of evaluation in 2006–2007 at ICRISAT. Based on the results obtained during both years, an Ascochyta Blight Nursery (ABN) was established to evaluate the selected 29 chickpea genotypes, including 4 germplasm lines, 24 breeding lines and a highly susceptible line. The nursery was evaluated at 3 locations (Almora, Dhaulakuan and Ludhiana) in India over three crop seasons (2007–2008, 2008–2009 and 2009–2010) and under controlled environment conditions at ICRISAT to further confirm the stable performance of these genotypes. Analysis of variance revealed highly significant effects of year, location (year), genotype and genotype × location (year) interaction. The genotype and genotype × environment (GGE) biplot analyses of multi-environment data showed that resistance of five genotypes (EC 516934, ICCV 04537, ICCV 98818, EC 516850 and EC 516971) had mean disease severity ≤3.0 on the 1–9 scale and the reactions were consistent across the environments. Genotype EC 516934 was found resistant to AB at the seedling stage in the controlled environment at ICRISAT. The remaining genotypes showed moderately resistant reaction (3.0–5.0) to AB under controlled environment conditions. A significant positive correlation was found between the performance of the genotypes under controlled environment and field screening conditions (r = 0.70; P < 0.01). The resistant genotypes identified in the present study would be useful in breeding programs as stable resistant donors to evolve agronomically desirable AB resistant varieties.

Identification and multi-environment validation of resistance to Fusarium oxysporum f. sp. ciceris in chickpea

Chickpea wilt incited by Fusarium oxysporum f. sp. ciceris is one of the most important constraints to chickpea production worldwide and best managed through host plant resistance. The aim of this work was to find new sources of resistance to wilt disease and validate their stability across different environments. One-hundred and twenty three lines with wilt incidence <10% were selected from preliminary evaluation of 948 lines including germplasm and breeding lines from the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) for wilt resistance in the sick plot during 2003/2004 crop season at ICRISAT, Patancheru, India. Sixty lines were selected for second round of evaluation (2005/2006) and from those 57 lines were selected for third round of evaluation (2006/2007). In order to validate resistance stability, a Chickpea Wilt Nursery was constituted with 27 lines (7 germplasm accessions, 19 breeding lines and a highly susceptible check) and further tested in multi-location experiment for wilt resistance at 9 locations in India for three years (2007/2008–2009/2010). Variability in wilt incidence due to genetic differences among the genotypes, among the environments, and that due to genotype×environment interaction was highly significant (P<0.001). Although complete resistance across the locations was not found, the genotype and genotype×environment (GGE) biplot analyses allowed the selection of three breeding lines (ICCV 05527, ICCV 05528 and ICCV 96818) and one germplasm accession (ICC 11322) with moderate level of disease resistance and stable performance across the environments. Genotype×environment (G×E) interaction contributed 36.7% of total variation of the multi-environment evaluation, revealing instability of the phenotypic expression across environments. The identified resistant sources should be useful to chickpea disease resistance breeding programs.

Multiple-disease resistance in Vicia faba: Multi-environment field testing for identification of combined resistance to rust and chocolate spot

The aim of this work was to identify Vicia faba germplasm resistant both to rust and chocolate spot. A collection of 43 accessions of V. faba previously identified as chocolate-spot resistant was evaluated for rust and chocolate spot resistance in Egypt and in Spain. The genotype and genotype × environment (GGE) biplot analyses allowed the selection of 11 accessions resistant to both diseases in those locations. These 11 accessions were evaluated for rust in an additional field trial in Spain, all performing better than the susceptible check. The joint analysis of the 11 accessions in the four field trials where they had been evaluated revealed no significant effects either for genotype, environment or the genotype × environment interaction. They are hence promising sources of resistance, both for their low severities and their stable responses across the studied environments. This collection was also tested under controlled conditions against the Egyptian and the Spanish isolates of rust present in the field trials further underlining the stable performance of these genotypes. Finally, the effect of previous infection with chocolate spot on rust resistance was assessed under controlled conditions and no influence of it was found.

Genotype × Environment Effects on Single‐Plant Selection at Low Density for Yield and Stability in Climbing Dry Bean Populations

Breeders ought to consider the confounding effects of the environment and genotype × environment (G × E) interaction on response to early generation selection. To meet this requirement, honeycomb breeding was performed at a low density within two dry bean populations (Phaseolus vulgaris L.) under typical open‐field conditions and in an adjacent greenhouse. Nineteen progeny lines were formed through selection of nine and ten of the highest‐yielding plants in the greenhouse and the field, respectively. Honeycomb progeny testing at the low density in the two distinct environments showed up to 75% improvement in plant‐yield potential. Under farming‐density conditions in five environments, six of the lines outyielded the respective original population by 12 to 38% and exhibited the greatest stability according to the genotype and genotype × environment (GGE) biplot model. At low density, the greenhouse evaluation demonstrated less acquired variance than the field evaluation and was especially useful for selection and progeny evaluation. Three of the six outstanding lines originated from the greenhouse. Honeycomb progeny estimation on a single‐plant yield basis in the greenhouse, rather than in the field, gave a better prediction of yield potential on an area basis. The results showed that honeycomb breeding performed in two environments to address the G × E interaction may be successful for developing varieties that exhibit both high and stable productivity.

Determination of Mega‐Environments for Peanut Breeding Using the CSM‐CROPGRO‐Peanut Model

Breeding for locally adapted cultivars requires a subdivision of the target region into mega‐environments. Crop models could assist in generating the required data for mega‐environment determination. The objective of this study was to determine whether subdividing the peanut (Arachis hypogaea L.) production areas in Thailand into mega‐environments using a crop simulation model would be justified. The Cropping System Model (CSM) CROPGRO‐Peanut was used to simulate pod yield of 17 diverse peanut lines for 130 locations covering all peanut production areas in Thailand. The data were statistically analyzed, and the genotype and genotype × environment (GGE) biplot method was used to subdivide the peanut production areas into subregions. The results reveal that the genotype × location interaction accounted for only a small proportion of total yield variation for all years. The analyses of yearly data by the GGE biplot shows inconsistent results across years for location grouping as well as for the winning genotypes of the individual location‐groups. The GGE biplot analysis of the mean data over 30 yr also indicates a similarity in genotype discrimination for all the locations. The results from this study show that the subdivision of peanut production areas into mega‐environments is not justified for Thailand. Therefore, for peanut breeding, Thailand should be considered as one mega‐environment.

Performance stability of maize genotypes across diverse hill environments in Nepal

The national maize improvement program in Nepal regularly receives elite maize (Zea mays L.) genotypes from CIMMYT and other countries and tests them for their performance stability in highly diverse environments. Studies were conducted on research stations and farmers’ fields at five sites in three years to determine performance stability of exotic maize genotypes. Replicated on-station and on-farm studies were conducted using 25 and 10 genotypes, respectively, including a local check and an improved check (Manakamana-3), in 2004–2006. We analyzed grain yield, days to flowering, plant and ear height, plant population, husk cover, and plant and ear aspect. Stability and genotype superiority for grain yield was determined using genotype and genotype × environment (GGE) biplot analysis that compares among a set of genotypes with a reference ‘ideal’ genotype, which has the highest average value of all genotypes and is absolutely stable. Several genotypes produced significantly higher grain yield than the local check. Four genotypes (‘Across9942 × Across9944’, ‘Open Ended White Hill Population’, ‘Population 44C10’ and ‘ZM621’), that produced significantly higher grain yield than the improved check, also had other agronomic traits (days to flowering, plant and ear height, number of ears, resistance to leaf blight, plant and ear aspect and husk cover tightness) equal to or better than the improved check. GGE-biplot analysis showed that Across9942 × Across9944 and ZM621 were the most superior genotypes in the on-station and on-farm trials, respectively. The findings from this study provide new information on the stability of the maize genotypes that are also adapted to other regions of the world. Such information could be useful for maize improvement program for the highlands in Nepal and other similar environments.