Browsing by Author "Pillay, Kiru"

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    Efficacy of Event MON 87460 in drought-tolerant maize hybrids under optimal and managed drought-stress in eastern and southern africa
    (Elsevier B.V, 2014-03) Obunyali, Caleb O; Pillay, Kiru; Meisel, Barbara; Ndou, Eric N; Mashingaidze, Kingstone; Sserumaga, Julius Pyton; Asea, Godfrey; Mwimali, Murenga; Tende, Regina; Beyene, Yoseph; Mugo, Stephen; Okogbenin, Emmanuel; Oikeh, Sylvester O.
    Abstract Frequent drought events due to climate change have become a major threat to maize (Zea mays L.) production and food security in Africa. Genetic engineering is one of the ways of improving drought tolerance through gene introgression to reduce the impact of drought stress in maize production. This study aimed to evaluate the efficacy of Event MON 87460 (CspB; DroughtGard®) gene in more than 120 conventional drought-tolerant maize hybrids in Kenya, South Africa, and Uganda for 3–6 years under managed drought-stress and optimal conditions and establish any additional yield contribution or yield penalties of the gene in traited hybrids relative to their non-traited isohybrids. Germplasm used in the study were either MON 87460 traited un-adapted (2008–2010), adapted traited DroughtTEGO® (2011–2013) or a mix of both under confined field trials. Results showed significant yield differences (p < 0.001) among MON 87460 traited and non-traited hybrids across well-watered and managed drought-stress treatments. The gene had positive and significant effect on yield by 36–62% in three hybrids (CML312/CML445; WMA8101/CML445; and CML312/S0125Z) relative to non-traited hybrids under drought, and without significant yield penalty under optimum-moisture conditions in Lutzville, South Africa. Five traited hybrids (WMA2003/WMB4401; CML442/WMB4401; CML489/WMB4401; CML511/CML445; and CML395/WMB4401) had 7–13% significantly higher yield than the non-traited isohybrids out of 34 adapted DroughtTEGO® hybrids with same background genetics in the three countries for ≥ 3 years. The positive effect of MON 87460 was mostly observed under high drought-stress relative to low, moderate, or severe stress levels. This study showed that MON 87460 transgenic drought tolerant maize hybrids could effectively tolerate drought and shield farmers against severe yield loss due to drought stress. The study signified that development and adoption of transgenic drought tolerant maize hybrids can cushion against farm yield losses due to drought stress as part of an integrated approach in adaptation to climate change effects.
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    Grain-yield stability among tropical maize hybrids derived from doubled-haploid inbred lines under random drought stress and optimum moisture conditions
    (Crop and Pasture Science, 2018) Sserumaga, Julius Pyton; Beyene, Yoseph; Pillay, Kiru; Kullaya, Alois; Oikeh, Sylvester O.; Mugo, Stephen; Machida, Lewis; Ngolinda, Ismail; Asea, Godfrey; Ringo, Justin; Otim, Michael; Abalo, Grace; Kiula, Barnabas
    Drought is a devastating environmental stress in agriculture and hence a common target of plant breeding. A review of breeding progress on drought tolerance shows that, to a certain extent, selection for high yield in stress-free conditions indirectly improves yield in water-limiting conditions. The objectives of this study were to (i) assess the genotype environment (GE) interaction for grain yield (GY) and other agronomic traits for maize (Zea mays L.) across East African agro-ecologies; and (ii) evaluate agronomic performance and stability in Uganda and Tanzania under optimum and random drought conditions. Data were recorded for major agronomic traits. Genotype main effect plusGE(GGE) biplot analysis was used to assess the stability of varieties within various environments and across environments. Combined analysis of variance across optimum moisture and random drought environments indicated that locations, mean-squares for genotypes and GE were significant for most measured traits. The best hybrids, CKDHH1097 and CKDHH1090, gave GY advantages of 23%and 43%, respectively, over the commercial hybrid varieties under both optimum-moisture and random drought conditions. Across environments, geno typic variance was less than the GE variance for GY. The hybrids derived from doubled-haploid inbred lines produced higher GY and possessed acceptable agronomic traits compared with the commercial hybrids. Hybrid CKDHH1098 ranked second-best under optimum-moisture and drought-stress environments and was the most stable with broad adaptation to both environments. Use of the best doubled-haploids lines in test cross hybrids make-up, well targeted to the production environments, could boost maize production among farmers in East Africa.