Assessing the representativeness and repeatability of testing sites for drought-tolerant maize in West Africa

2013 ◽  
Vol 93 (4) ◽  
pp. 699-714 ◽  
Author(s):  
B. Badu-Apraku ◽  
R. O. Akinwale ◽  
K. Obeng-antwi ◽  
A. Haruna ◽  
R. Kanton ◽  
...  

Badu-Apraku, B., Akinwale, R. O., Obeng-antwi, K., Haruna, A., Kanton, R., Usman, I., Ado, S. G., Coulibaly, N., Yallou, G. C. and Oyekunle, M. 2013. Assessing the representativeness and repeatability of testing sites for drought-tolerant maize in West Africa. Can. J. Plant Sci. 93: 699–714. The selection of suitable breeding and testing sites is crucial to the success of a maize (Zea mays L.) improvement programme. Twelve early-maturing maize cultivars were evaluated for 3 yr at 16 locations in West Africa to determine the representativeness, discriminating ability, and repeatability of the testing sites and to identify core testing sites. Genotype main effect plus genotype by environment interaction (GGE) biplot analysis revealed that Zaria (Nigeria), Nyankpala (Ghana), and Ejura (Ghana) displayed the highest discriminating ability. Two mega-environments were identified. Bagou, Nyankpala, Bagauda, Ikenne, and Mokwa constituted the first mega-environment (ME1); Ejura, Ina and Sotuba represented the second (ME2). The ME1 would be more useful for evaluating early maize genotypes for tolerance to drought than ME2 because locations in ME1 were more strongly correlated to Ikenne (managed drought stress site). Among the test locations, Bagou and Mokwa were found to be closely related to Ikenne in their ranking of the cultivars for drought tolerance; Zaria was the exact opposite, indicating that this was the least suitable location for evaluating genotypes for drought tolerance. Nyankpala and Ikenne were identified as the core testing sites for ME1 and Ejura for ME2. TZE Comp 3 C2F2 was identified as the highest yielding cultivar for ME1 and Syn DTE STR-Y for ME2, indicating that they could be used as check cultivars. Ikenne, Nyankpala, and Ejura had moderately high repeatability. They were closer to the average environment axis of each mega-environment and will be useful for culling unstable genotypes during multi-locational testing. Other sites were less representative and not repeatable and will not be useful for evaluating early maize cultivars for drought tolerance.

2017 ◽  
Vol 3 (1) ◽  
pp. 1333243 ◽  
Author(s):  
Alidu Haruna ◽  
Gloria Boakyewaa Adu ◽  
Samuel Saaka Buah ◽  
Roger A.L. Kanton ◽  
Amegbor Isaac Kudzo ◽  
...  

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1998
Author(s):  
Vinayan Madhumal Thayil ◽  
Pervez H. Zaidi ◽  
Kaliyamoorthy Seetharam ◽  
Reshmi Rani Das ◽  
Sudarsanam Viswanadh ◽  
...  

Spring maize area has emerged as a niche market in South Asia. Production of maize during this post-rainy season is often challenged due to heat stress. Therefore, incorporating heat stress resilience is an important trait for incorporation in maize hybrids selected for deployment in this season. However, due to the significant genotype × environment interaction (GEI) effects under heat stress, the major challenge lies in identifying maize genotypes with improved stable performance across locations and years. In the present study, we attempted to identify the key weather variables responsible for significant GEI effects, and identify maize hybrids with stable performance under heat stress across locations/years. The study details the evaluation of a set of prereleased advanced maize hybrids across heat stress vulnerable locations in South Asia during the spring seasons of 2015, 2016 and 2017. Using factorial regression, we identified that relative humidity (RH) and vapor pressure deficit (VPD) as the two most important environmental covariates contributing to the large GEI observed on grain yield under heat stress. The study also identified reproductive stage, starting from tassel emergence to early grain-filling stage, as the most critical crop stage highly susceptible to heat stress. Across-site/year evaluation resulted in identification of six high yielding heat stress resilient hybrids.


2013 ◽  
Vol 1 (2) ◽  
pp. 74-78 ◽  
Author(s):  
Jiban Shrestha

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


Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 62 ◽  
Author(s):  
Bui Minh ◽  
Nguyen Linh ◽  
Ha Hanh ◽  
Le Hien ◽  
Nguyen Thang ◽  
...  

Maize (Zea mays) is a major cereal crop worldwide, and there is increasing demand for maize cultivars with enhanced tolerance to desiccation. Late embryogenesis abundant (LEA) proteins group 5C is involved in plants’ responses to various osmotic stresses such as drought and salt. A putative group 5C LEA gene from Z. mays cv. Tevang 1 was isolated, named ZmLEA14tv, and cloned into a T-DNA for expression in plants. The deduced amino acid of ZmLEA14tv showed a conserved Pfam LEA_2 domain and a high proportion of hydrophobic residues, characteristic of group 5C LEA proteins. Transgenic tobacco and maize plants expressing ZmLEA14tv were generated. During drought simulation conditions, the ZmLEA14tv-expressing plants of tobacco showed improved recovery ability, while those of maize enhanced the seed germination in comparison with the non-transgenic control plants. In addition, the survival rate of ZmLEA14tv transgenic maize seedlings was twice as high as the control. These results indicated that ZmLEA14tv might be involved in the drought tolerance of plants and could be a candidate gene for developing enhanced drought-tolerant crops.


2020 ◽  
Vol 98 (6) ◽  
Author(s):  
Bjarke G Poulsen ◽  
Bjarne Nielsen ◽  
Tage Ostersen ◽  
Ole F Christensen

Abstract Longevity in commercial sows is often selected for through stayability traits measured in purebred animals. However, this may not be justifiable because longevity and stayability may be subject to both genotype by environment interaction (G × E) and genotype by genotype interaction (G × G). This study tested the hypothesis that stayability to service after first parity is more strongly genetically correlated with longevity in commercial herds when stayability is measured in commercial herds rather than multiplier herds. The analysis was based on farrowing- and service-records from 470,824 sows (189,263 multiplier; 281,561 commercial) and 300 herds (156 multiplier; 144 commercial sows). Multiplier sows were either purebred Landrace or Yorkshire and commercial sows were mainly rotationally crossbreds between the two breeds. Commercial longevity was defined as age in days when culled (LongC), and stayability to service after first parity was defined for both commercial sows (StayC) and multiplier sows (StayM). The genetic correlations between LongC, StayC, and StayM were estimated by restricted maximum likelihood using linear mixed models. Genetic parameters were estimated separately for Landrace and Yorkshire. In Landrace, the genetic correlations between LongC and StayC, LongC and StayM, and StayC and StayM were 0.86 ± 0.02, 0.24 ± 0.05, and 0.34 ± 0.06, respectively. In Yorkshire, the genetic correlations between LongC and StayC, LongC and StayM, and StayC and StayM were 0.81 ± 0.03, 0.17 ± 0.05, and 0.18 ± 0.7, respectively. Conclusively, longevity in commercial herds is more strongly correlated with stayability when stayability is measured in commercial herds rather than multiplier herds.


2014 ◽  
Vol 41 (11) ◽  
pp. v ◽  
Author(s):  
Vincent Vadez ◽  
Jairo Palta ◽  
Jens Berger

Under increasing water scarcity, food production for an increasing population is a global challenge. Maintaining crop production under limiting water supply is a common problem in agriculture, which is best addressed by the coordinated efforts of geneticists, physiologists and agronomists. This special issue is a selection of oral and poster presentations at the InterDrought IV conference, held in Perth (2–6 September 2013). These papers provide a broad, multidisciplinary view on the way to develop improved cultivars in the face of water deficit, providing the conference highlight: an integration of views from different disciplinary angles, generating constructive debate that was not buried in disciplinary silos. More specifically, the topics covered deal with the challenge of adaptation implicit in genotype-by-environment interaction, bring new perspectives on root systems and water productivity, and review the challenges and opportunities provided by crop management, genomic and transgenic approaches to cultivar improvement.


2021 ◽  
Author(s):  
Gemechu Getachew ◽  
Beyene Abebe ◽  
Deselegn Chelchisa ◽  
Sara Oli ◽  
Temesgen Chebsa ◽  
...  

Abstract The current research examined the magnitude of genotype by environment interaction (G x E) and evaluated the adaptability and stability of maize genotypes for grain yield in Ethiopia's transitional highland agroecology using an additive main effects and multiplicative interaction (AMMI) model. The study's goals were to first assess the yield output and stability of maize genotypes in Ethiopia's transitional highlands, and then to investigate the effect of genotype- environment interaction on genotype yield. During the main season of 2017/2018, thirteen advanced maize genotypes which was selected from different observation trials with two commercial check hybrids were evaluated at five representative locations for agroecology. The experiment was set up using an alpha lattice (3*5) with three replications and two rows per plot. AMMI showed highly significant(P < 0.001) variation of grain yield was observed due to the effect of genotype (G), Environment(E) and their interaction (G x E). In fact, all genotypes evaluated in representative locations for this agroecology had higher grain yield advantages than the best commercial check except one genotype. Overall, this study discovered the possibility of fast releasing and overtake of new maize hybrids for transitional high land agroecology of Ethiopia to exploits availability maize germplasm to maximize production. The best candidate genotype, MABK181261 is a stable and high-yielding product. It is recommended for release as a commercial hybrid alternative after national variety verification trial in a high land transitional agroecology of Ethiopia. In addition, the parental lines of this genotypes can be used to enhance germplasm of opposite heterotic group in maize breeding for East Africa.


2021 ◽  
Author(s):  
Tesfaye Walle Mekonnen ◽  
Firew Mekbib ◽  
Berhanu Amsalu ◽  
Melaku Gedil ◽  
Maryke Labuschagne

Abstract Cowpea is one of the most important indigenous food and forage legumes in Africa. It serves as a primary source of protein for poor farmers in drought-prone areas of Ethiopia. The crop is used as a source of food, and insurance crop during the dry season. Cowpea is adaptable to a wide range of climatic conditions. Despite this, the productivity of the crop is generally low due to lack of stable and drought tolerant varieties. In this study, 25 cowpea genotypes were evaluated in five environments using a triple lattice design during the 2017 and 2018 main cropping seasons. The objectives of this study were to estimate the magnitude of genotype by environment interaction (GEI) and grain yield stability of selected drought tolerant cowpea genotypes across different environments. The additive main effect and multiplicative interaction (AMMI) model indicated the contribution of environment, genotype and GEI as 63.98 6%, 2.66% and 16.30% of the total variation for grain yield, respectively. The magnitudes of the GEI sum of squares were 6.12 times that of the genotypes for grain yield. The IPCA1, IPCA2 and IPCA3 were all significant and explained 45.47%, 28.05% and 16.59% of the GEI variation, respectively. The results from AMMI, cultivar superior measure (Pi), genotype plus genotype-by-environment (GGE) biplot yield stability index (YSI), and AMMI stability value (ASV) analyses identified NLLP-CPC-07-145-21, NLLP-CPC-103-B and NLLP_CPC-07-54 as stable and high yielding genotypes across environments. Thus, these genotypes should be recommended for release for production for drought prone areas. NLLP-CPC-07-143, Kanketi and CP-EXTERETIS were the least stable. The AMMI1 biplot showed that Jinka was a high potential and favorable environment while Babile was an unfavorable environment for cowpea production.


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