Posts Tagged ‘striga’

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  

Genetic studies of extra-early provitamin-A maize inbred lines and their hybrids in multiple environments

Posted on , November 30, 2019

Vitamin A deficiency, drought, low soil nitrogen (low N) and Striga hermonthica parasitism of maize (Zea mays L.) cause malnutrition and food insecurity in sub-Saharan Africa. The objectives of this study were to determine combining abilities of extra-early provitamin A (PVA) lines, classify them into heterotic groups (HGs), identify testers, and determine yield stability of hybrids under contrasting environments in two trials. In trial 1, 20 extra-early PVA lines were inter-mated in a diallel mating scheme to obtain 190 F1 hybrids. The 190 F1 hybrids plus six checks were tested under Striga infestation, drought, and stress-free environments in Nigeria from 2015 to 2017. In trial 2, 35 extra-early yellow hybrids were evaluated under low N, Striga-infested and stress-free environments in 2018. Provitamin A concentrations of 23.98  and 22.56 µg g-1 were obtained for TZEEIOR 202 and TZEEIOR 205. TZEEIOR 197 × TZEEIOR 205 (20.1 μg g-1) and TZEEIOR 202 × TZEEIOR 205 (22.7 μg g-1) contained about double the PVA level of the commercial check, TZEEI 58 × TZEE-Y Pop STR C5 (11.4 μg  g -1). Both general (GCA) and specific (SCA) combining ability variances were statistically significant for most agronomic traits, although GCA was much larger than SCA effects,  indicating that additive genetic effects primarily controlled the inheritance of those traits. TZEEIOR 97 and TZEEIOR 197 were identified as inbred testers. TZEEIOR 197 × TZEEIOR  205 (20.1 μg g-1) was identified as a single-cross tester as well as the most stable and highest yielding hybrid across environments. TZEEIOR 202 and TZEEIOR 205 should be invaluable  resources for breeding for high PVA. PVA level was independent of hybrid yield potential, indicating that selection of superior hybrids with elevated PVA levels should be feasible.

Inheritance of Striga hermonthica adaptive traits in an early-maturing white maize inbred line containing resistance genes from Zea diploperennis

Posted on , November 30, 2019

Striga hermonthica can cause as high as 100% yield loss in maize depending on soil fertility level, type of genotype, severity of infestation and climatic conditions. Understanding the mode of inheritance of Striga resistance in maize is crucial for introgression of resistance genes into tropical germplasm and deployment of resistant varieties. This study examined the mode of inheritance of resistance to Striga in earlymaturing inbred line, TZdEI 352 containing resistance genes from Zea diploperennis. Six generations, P1, P2, F1, F2, BC1P1 and BC1P2 derived from a cross between resistant line, TZdEI 352 and susceptible line, TZdEI 425 were screened under artificial Striga infestation at Mokwa and Abuja, Nigeria, 2015. Additive‐dominance model was adequate in describing observed variations in the number of emerged Striga plants among the population; hence, digenic epistatic model was adopted for Striga damage. Dominance effects were higher than the additive effects for the number of emerged Striga plants at both locations signifying that non‐additive gene action conditioned inheritance of Striga resistance. Inbred TZdEI 352 could serve as invaluable parent for hybrid development in Striga endemic agro‐ecologies of sub‐Saharan Africa.

Studies on estimation of heterosis for striga resistance in maize test crosses in Mali

Posted on , November 30, 2019

Heterosis for yield, secondary traits and Striga resistance was estimated in maize test crosses generated from fifteen inbred lines and three testers using line by tester analysis. Hybrids, testcrosses and parents were evaluated for two years at Agricultural Research Institute, Sotuba and Sanankoroba, to identify combinations expressing high hybrid vigor in Mali under Striga- infested and Striga-free conditions. Under Striga-free condition TZISTR106 /TZISTR1230, TZISTR106/TZISTR1223 and TZISTR1033/ TZISTR1223 appeared as the best hybrids combinations with respect to grain yield, while combinations TZISTR1207/ TZISTR1226, TZISTR106 /TZISTR112, TZISTR106 / TZISTR113 and TZISTR106/ TZISTR1028 showed positive mid parent heterosis for grain yield and negative mid parent heterosis for Striga related traits under Striga infestation. These hybrids are worthy for further utilization.

Keywords: Heterosis, lattice design, genotypes, Striga related traits, maize.

Yield gains and associated changes in an early yellow bi-parental maize population following genomic selection for Striga resistance and drought tolerance

Posted on , November 30, 2019

Background: Maize yield potential is rarely maximized in sub-Saharan Africa (SSA) due to the devastating effects of drought stress and Striga hermonthica parasitism. This study was conducted to determine the gains in grain yield and associated changes in an early-maturing yellow bi-parental maize population (TZEI 17 x TZEI 11) F3 following genomic selection (GS) for improved grain yield, Striga resistance and drought tolerance. Fifty S1 lines were extracted from each of cycles C0,C 1,C 2 and C3 of the population and crossed to a tester TZEI 23 to generate 200 testcrosses. The testcrosses were evaluated under drought, artificial Striga-infested and optimal (free from Striga infestation and without limitation of water and nitrogen) environments in Nigeria, 2014-2017. Results: Gains in grain yield of 498kgha− 1 cycle− 1 (16.9% cycle− 1) and 522kgha−1 cycle− 1 (12.6% cycle− 1) were obtained under Striga-infested and optimal environments, respectively. The yield gain under Striga-infested environments was associated with increased plant and ear heights as well as improvement in root lodging resistance, husk cover, ear aspect and Striga tolerance. Under optimal environments, yield gain was accompanied by increase in plant and ear heights along with improvement of husk cover and ear rot resistance. In contrast, genomic selection did not improve grain yield under drought but resulted in delayed flowering, poor pollen-silk synchrony during flowering and increased ear height. Genetic variances and heritabilities for most measured traits were not significant for the selection cycles under the research environments. Ear aspect was a major contributor to grain yield under all research environments and could serve as an indirect selection criterion for simultaneous improvement of grain yield under drought, Striga and optimal environments. Conclusion: This study demonstrated that genomic selection was effective for yield improvement in the bi-parental maize population under Striga-infested environments and resulted in concomitant yield gains under optimal environments. However, due to low genetic variability of most traits in the population, progress from further genomic selection could only be guaranteed if new sources of genes for Striga resistance and drought tolerance are introgressed into the population.

Keywords: Genomic selection, Striga resistance, Drought tolerance, Maize, Testcrosses

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