Posts Tagged ‘heat’

The list of STMA-supported research publications from West Africa for the year 2019 is out

Posted on News, Press room, Published Journals, Research News, Seed System Publication, West Africa News, West Africa Publications, November 30, 2019

Melaku Gedil and Abebe Menkir. 2019. An Integrated Molecular and Conventional Breeding Scheme for Enhancing Genetic Gain in Maize in Africa. Published in Frontiers. Plant Sciences and accessible here

Adu, G. B., Badu-Apraku, B., Akromah, R., Garcia-Oliveira, A. L., Gedil, M., Awuku, F. J. 2019. Genetic diversity and population structure of early-maturing tropical maize inbred lines using SNP markers, published  in PloS ONE, volume 14, number 4 and accessible here  

Badu-Apraku, B., Talabi, A. O., Fakorede, M., Fasanmade, Y., Gedil, M., Magorokosho, C., Asiedu, R. 2019. Yield gains and associated changes in an early yellow bi-parental maize population following genomic selection for Striga resistance and drought tolerance, published in BMC Plant Biology, volume 19, number 129, and accessible here.

Bankole, F., Menkir, A., Olaoye , G.*, Olakojo, O.*, Gedil, M. 2019. Association studies between grain yield and agronomic traits of a MARS maize (Zea mays L.) population under drought and non-stress condition, published in Acta Agriculturae Slovenica, volume 114, and accessible here.

Kammo, E. Q., Suh, C., Mbong, G. A., Djomo, S. H., Chimi, N. L. L., Mbeungang, D. L., Mafouasson, H. A., Meseka, S. K. and Menkir, A. 2019. Biological versus chemical control of fall armyworm and Lepidoptera stem borers of maize (Zea mays), published in Agronomie Africaine, volume 31, number 2, and accessible here.

Kolawole, A. O., Menkir, A., Blay, E., Ofori, K. and Kling, J. G., 2019. Changes in heterosis of maize (Zea mays L.) varietal cross hybrids after four cycles of reciprocal recurrent selection, published in Cereal Research Communications, volume 47, number 1, and accessible here .

Sangare, A., Menkir, A., Ofori, K. and Gracen, V., 2019. Studies on estimation of heterosis for striga resistance in maize test crosses in Mali, published in Journal of Genetics, Genomics & Plant Breeding, volume 3, number 3, and accessible here

Akaogu, I. C., Badu-Apraku, B., Tongoona, P., Ceballos, H., Gracen, V. E., Offei, S. and Dzidzienyo, D. 2019. Inheritance of Striga hermonthica adaptive traits in an early-maturing white maize inbred line containing resistance genes from Zea diploperennis. published in Plant Breeding, and accessible here  

Annor, B., Badu-Apraku, B., Nyadanu, D., Akromah, R. and Fakorede, M. 2019. Testcross performance and combining ability of early maturing maize inbreds under multiple-stress environments, published in NATURE Scientific Reports, volume 9, and accessible here .

Nelimor, C., Badu-Apraku, B., Nguetta, S. P., Tetteh, A. Y. and Garcia-Oliveira, A. L. 2019. Phenotypic characterization of maize landraces from Sahel and Coastal west Africa reveals marked diversity and potential for genetic improvement, published in Journal of Crop Improvement, and accessible here .

Obeng-Bio, E., Badu-Apraku, B., Ifie, B. E., Danquah, A., Blay, E. and Annor, B. 2019. Genetic analysis of grain yield and agronomic traits of early provitamin A quality protein maize inbred lines in contrasting environments,  published in The Journal of Agricultural Science, and accessible here.

Nelimor, C., Badu-Apraku, B., Tetteh, A. Y.* and Nguetta, A. S. 2019. Assessment of genetic diversity for drought, heat and combined drought and heat stress tolerance in early maturing maize landraces, published in Plants, volume 8, and accessible here.

Badu-Apraku, B., Fakorede, M., Talabi, A. O., Oyekunle, M., Aderounmu, M., Lum, A. F., Ribeiro, P. F., Adu, G. B. and Toyinbo, J. O. 2019. Genetic studies of extra-early provitamin-A maize inbred lines and their hybrids in multiple environments, published in Crop Science, and accessible here.  

Badu-Apraku, B. and Akinwale, R. O. 2019. Biplot analysis of line X tester data of maize (Zea mays L.) inbred lines under stress and nonstress environments. Published in Cereal Research Communications, volume 47, number 3, and accessible here.

Oyinbo, O., Mbavai, J. J., Shitu, M. B., Kamara, A., Abdoulaye, T. and Ugbabe, O. O. 2019. Sustaining the beneficial effects of maize production in Nigeria: does adoption of short season maize varieties matter?  Published in Experimental Agriculture, and accessible here  

Kadjo, D., Ricker-Gilbert, J., Shively, G. and Abdoulaye, T. 2019. Food safety and adverse selection in rural maize markets. Published in Journal of Agricultural Economics, and accessible here .

Assfaw Wossen, T., Alene, A., Abdoulaye, T., Feleke, S. and Manyong, V. 2019. Agricultural technology adoption and household welfare: measurement and evidence, published in Food Policy, and accessible here  

Assessment of genetic diversity for drought, heat and combined drought and heat stress tolerance in early maturing maize landraces

Posted on , November 30, 2019

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasmwithgoodlevelsoftolerancetotheabioticstresses. Theprimaryobjectiveofthisstudywas toidentifylandraceswithcombinedhighyieldpotentialanddesirablesecondarytraitsunderdrought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.

Genome-Wide Association Mapping and Genomic Prediction Analyses Reveal the Genetic Architecture of Grain Yield and Flowering Time Under Drought and Heat Stress Conditions in Maize

Posted on , November 17, 2019

Drought stress (DS) is a major constraint to maize yield production. Heat stress (HS)
alone and in combination with DS are likely to become the increasing constraints.
Association mapping and genomic prediction (GP) analyses were conducted in a
collection of 300 tropical and subtropical maize inbred lines to reveal the genetic
architecture of grain yield and flowering time under well-watered (WW), DS, HS, and
combined DS and HS conditions.

Out of the 381,165 genotyping-by-sequencing SNPs, 1549 SNPs were significantly associated with all the 12 trait-environment combinations, the average PVE (phenotypic variation explained) by these SNPs was 4.33%, and 541 of them had a PVE value greater than 5%. These significant associations were clustered into 446 genomic regions with a window size of 20 Mb per region, and 673 candidate genes containing the significantly associated SNPs were identified.

In addition, 33 hotspots were identified for 12 trait-environment combinations and most were located on chromosomes 1 and 8.

Compared with single SNP-based association mapping, the haplotype-based associated mapping detected fewer number of significant associations and candidate genes with higher PVE values. All the 688 candidate genes were enriched into 15 gene ontology terms, and 46 candidate genes showed significant differential expression under the WW and DS conditions. Association mapping results identified few overlapped significant markers and candidate genes for the same traits
evaluated under different managements, indicating the genetic divergence between the individual stress tolerance and the combined drought and HS tolerance. The GP accuracies obtained from the marker-trait associated SNPs were relatively higher than those obtained from the genome-wide SNPs for most of the target traits.

The genetic architecture information of the grain yield and flowering time revealed in this study, and the genomic regions identified for the different trait-environment combinations are useful in accelerating the efforts on rapid development of the stress-tolerant maize germplasm through marker-assisted selection and/or genomic selection.

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