Genetic gains in grain yield under nitrogen stress following three decades of breeding for drought tolerance and Striga resistance in early maturing maize

2015 ◽  
Vol 154 (4) ◽  
pp. 647-661 ◽  
Author(s):  
B. BADU-APRAKU ◽  
M. A. B. FAKOREDE ◽  
M. OYEKUNLE ◽  
R. O. AKINWALE
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Central Africa ◽  
Striga Hermonthica ◽  
Maize Cultivars ◽  
Maize Populations ◽  
Striga Resistance ◽  
Early Maturing ◽  
West And Central Africa ◽  
N Rates

SUMMARYBreeding for resistance to Striga hermonthica Del. (Benth) and tolerance to drought has been a major strategy to improve maize (Zea mays L.) production and productivity in West and Central Africa during the last three decades. The three decades consisted of three breeding periods or eras based on the germplasm and methodologies used; that is, 1988–2000, 2001–06 and 2007–11. A total of 50 early maturing cultivars, combining Striga resistance with drought tolerance were developed, including 15, 16 and 19 cultivars for the three periods, respectively. Although the cultivars were not selected intentionally for low-nitrogen (N) tolerance, it was hypothesized that tolerance to low-N had been significantly improved while selecting for drought tolerance and Striga resistance. This hypothesis was tested by evaluating the 50 cultivars in 2010 and 2011 in Nigeria at Mokwa and Ile-Ife under both low-N (30 kg N/ha) and high-N (90 kg N/ha) levels. Under low-N conditions, grain yield improved from 2280 kg/ha during the first period to 2610 kg/ha during the third period, an increase of 165 kg/ha per period with r2 of 0·99. Under high-N, yield increased from 3200 to 3650 kg/ha, an increase of 225 kg/ha and r2 of 0·93. Relative gain per period was 30 kg/ha for the two N rates with r2 values of 0·99 and 0·94 respectively. Grain yield performance of the 50 cultivars under low-N conditions adequately predicted their performance under high-N. Selection for Striga resistance and drought tolerance in early maturing maize populations enhanced low-N tolerance in the maize cultivars derived from the populations. The improvement was higher in later than earlier breeding periods.

Consistency of performance of early-maturing maize cultivars in Striga-infested and Striga-free environments

2015 ◽  
Vol 95 (6) ◽  
pp. 1073-1084
Author(s):  
Baffour Badu-Apraku ◽  
Chabi Yallou ◽  
Muhyideen Oyekunle ◽  
Richard Akinwale ◽  
G. Aweke ◽  
...  
Keyword(s):  
Grain Yield ◽  
Central Africa ◽  
Farming Systems ◽  
Striga Hermonthica ◽  
Management Options ◽  
Maize Cultivars ◽  
Striga Resistance ◽  
Early Maturing ◽  
Republic Of Benin ◽  
High Consistency

Badu-Apraku, B., Yallou, C., Oyekunle, M., Akinwale, R., Aweke, G. and Kamara, A. 2015. Consistency of performance of early-maturing maize cultivars in Striga-infested and Striga-free environments. Can. J. Plant Sci. 95: 1073–1084. Despite the immense potential of maize (Zea mays L.) in savannas of West and Central Africa (WCA), production and productivity is constrained by Striga hermonthica parasitism. Sixteen early-maturing cultivars were evaluated at two locations in Nigeria and three locations in the Republic of Benin from 2007 to 2009 to assess the grain yield, stability and the consistency of the rankings of the cultivars under Striga-infested and Striga-free environments. The combined analysis of variance showed significant (P<0.01) cultivar and cultivar×environment interactions for grain yield and other traits under Striga-infested and Striga-free environments. The test of concordance was significant (P<0.001) for grain yield (W=0.68), number of emerged Striga plants (W=0.74) and Striga damage (W=0.56) under Striga infestation, indicating stability of resistance in the cultivars developed from diverse sources under artificial S. hermonthica infestation across environments. There was high consistency of the rankings of the cultivars for grain yield and other Striga-resistance traits under Striga-infested and Striga-free environments in Benin and Nigeria. The additive main effects and multiplicative interaction (AMMI) biplot analysis for grain yield revealed POOL15SR/ACR94TZECOMP5-W/ACR94TZECOMP5-W and 2004 TZE-Y Pop DT STR C4 as the most stable cultivars with above-average mean grain yield in Striga-infested environments and they can be combined with other crop management options to control the parasite in the Striga endemic environments. Cultivars TZE Comp 5-W C7F2 and TZE Comp5-Y C6 S6 (Set B) had less Striga damage and number of emerged Striga plants across test environments. These cultivars could therefore serve as unique sources of favorable alleles for improving Striga resistance in maize in different production environments and farming systems.

scholarly journals Gains in Genetic Enhancement of Early Maturing Maize Hybrids Developed during Three Breeding Periods under Striga-Infested and Striga-Free Environments

Agronomy ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1188
Author(s):  
Baffour Badu-Apraku ◽  
Gloria B. Adu ◽  
Abdoul-Madjidou Yacoubou ◽  
Johnson Toyinbo ◽  
Samuel Adewale
Keyword(s):  
Grain Yield ◽  
Central Africa ◽  
Striga Hermonthica ◽  
Genetic Enhancement ◽  
Maize Production ◽  
Maize Hybrids ◽  
Early Maturing ◽  
Yield Gain ◽  
West And Central Africa ◽  
Damage Number

Striga hermonthica is a major maize production constraint in West and Central Africa (WCA). Fifty-four early maturing maize hybrids of three breeding periods: 2008–2011, 2012–2013, 2014–2015, were evaluated under Striga-infested and non-infested environments in WCA. The study aimed at assessing genetic improvement in grain yield of the hybrids, identifying traits associated with yield gain during the breeding periods, and grain yield and stability of the hybrids in Striga infested and non-infested environments. Annual increase in grain yield of 101 kg ha−1 (4.82 %) and 61 kg ha−1 (1.24%) were recorded in Striga-infested and non-infested environments, respectively. The gains in grain yield from period 1 to period 3 under Striga-infested environments were associated with reduced anthesis-silking interval, reduced Striga damage, number of emerged Striga plants, improved ear aspect, and increased ears per plant. Ear aspect, ears per plant, and Striga damage at 8 and 10 weeks after planting (WAP) were significantly correlated with yield in Striga-infested environments, whereas ears per plant and plant and ear aspects had significant correlations with yield in non-infested environments. Hybrids TZdEI 352 × TZEI 355, TZdEI 378 × TZdEI 173, and TZdEI 173 × TZdEI 352 were outstanding in grain yield and stability in Striga-infested environments, whereas TZEI 326 × TZdEI 352, TZEI 495 × ENT 13, and TZdEI 268 × TZdEI 131 were superior in non-stress environments. These hybrids should be further tested extensively and commercialized. Significant genetic gains have been made in breeding for resistance to Striga hermonthica in early maturing maize hybrids.

scholarly journals Testcross performance and combining ability of early maturing maize inbreds under multiple-stress environments

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Benjamin Annor ◽  
Baffour Badu-Apraku ◽  
Daniel Nyadanu ◽  
Richard Akromah ◽  
Morakinyo A. B. Fakorede
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Central Africa ◽  
Optimal Conditions ◽  
Gene Effects ◽  
Maize Production ◽  
Multiple Stress ◽  
Early Maturing ◽  
Additive Gene ◽  
West And Central Africa

Abstract Availability of multiple-stress tolerant maize is critical for improvement in maize production in West and Central Africa (WCA). A study was carried out to (i) assess a set of inbred lines for combining ability under stressed and optimal conditions, (ii) determine the performance of the testcrosses under different conditions, and (iii) identify outstanding hybrids across the conditions. Two hundred and five testcrosses were planted with five hybrid checks under Striga-infested, low soil nitrogen, drought and optimal conditions between 2015 and 2016 in Nigeria. The grain yield inheritance under optimal condition was largely regulated by additive gene effect whereas non-additive gene effects largely regulated grain yield under the three stresses. Four of the inbreds had significant positive general combining ability effects each under low N and drought, and three under Striga infestation for grain yield. The inbreds could be vital sources of beneficial alleles for development and improvement of tropical yellow maize hybrids and populations. Hybrids TZEI 443 x ENT 13 and TZEI 462 x TZEI 10 were high yielding and stable; they out-performed the three early maturing released hybrids in WCA. The new hybrids should be extensively assessed and released in the sub-region to improve food security.

Genetic diversity assessment of extra-early maturing yellow maize inbreds and hybrid performance inStriga-infested andStriga-free environments

2012 ◽  
Vol 151 (4) ◽  
pp. 519-537 ◽  
Author(s):  
I. C. AKAOGU ◽  
B. BADU-APRAKU ◽  
V. O. ADETIMIRIN ◽  
I. VROH-BI ◽  
M. OYEKUNLE ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Grain Yield ◽  
Central Africa ◽  
Striga Hermonthica ◽  
Environment Interaction ◽  
Maize Production ◽  
Growing Seasons ◽  
Diversity Assessment ◽  
Early Maturing ◽  
Growing Conditions

SUMMARYMaize (Zea maysL.), a major staple food crop in West and Central Africa (WCA), is adapted to all agro-ecologies in the sub-region. Its production in the sub-region is greatly constrained by infestation ofStriga hermonthica(Del.) Benth. The performance and stability of the extra-early maturing hybrids, which are particularly adapted to areas with short growing seasons, were assessed underStriga-infested andStriga-free conditions. A total of 120 extra-early hybrids and an open-pollinated variety (OPV) 2008 Syn EE-Y DT STR used as a control were evaluated at two locations each underStriga-infested (Mokwa and Abuja) andStriga-free (Ikenne and Mokwa) conditions in 2010/11. TheStriga-resistant hybrids were characterized by higher grain yield, shorter anthesis–silking interval (ASI), better ear aspect, higher numbers of ears per plant (EPP), lowerStrigadamage rating, and lower number of emergedStrigaplants at 8 and 10 weeks after planting (WAP) compared with the susceptible inbreds. UnderStrigainfestation, mean grain yield ranged from 0·71 to 3·18 t/ha and 1·19 to 3·94 t/ha underStriga-free conditions. The highest yielding hybrid, TZEEI 83×TZEEI 79, out-yielded the OPV control by 157% underStrigainfestation. The hybrids TZEEI 83×TZEEI 79 and TZEEI 67×TZEEI 63 were the highest yielding under bothStriga-infested andStriga-free conditions. The genotype main effect plus genotype×environment interaction (GGE) biplot analysis identified TZEEI 88×TZEEI 79 and TZEEI 81×TZEEI 95 as the ideal hybrids across research environments. Twenty-three pairs of simple sequence repeat (SSR) markers were used to assess the genetic diversity among the inbred lines. The correlations between the SSR-based genetic distance (GD) estimates of parental lines and the means observed in F1hybrid underStrigainfestation and optimum growing conditions were not significant for grain yield and other traits except ASI under optimum conditions. Grain yield of inbreds was not significantly correlated with that of F1hybrids. However, a significant correlation existed between F1hybrid grain yield and heterosis underStrigainfestation (r=0·72,P<0·01). These hybrids have the potential for increasing maize production inStrigaendemic areas in WCA.

scholarly journals Performance of provitamin A- quality protein maize inbred lines and derived hybrids in contrasting environments

2019 ◽  
Author(s):  
Ebenezer Obeng-Bio ◽  
Baffour Badu-Apraku ◽  
Beatrice Elohor Ifie ◽  
Agyemang Danquah ◽  
Essie Blay ◽  
...  
Keyword(s):  
Grain Yield ◽  
Central Africa ◽  
Inbred Lines ◽  
Provitamin A ◽  
Quality Protein Maize ◽  
Whole Grain ◽  
Maize Inbred Lines ◽  
Early Maturing ◽  
West And Central Africa ◽  
The Relationship

Abstract Background Early maturing provitamin A (PVA) quality protein maize (QPM) inbred lines with tolerance to drought and low-N are needed to develop superior hybrids in West and Central Africa (WCA). This study aimed to (i) identify inbred lines that combined drought and low-N tolerance with increased levels of PVA and tryptophan and (ii) assess the relationship among PVA carotenoids, tryptophan and grain yield. Sixty-four inbred lines plus six inbred checks were evaluated under induced drought, low-N and optimal conditions in 2016 and 2017 in Nigeria. The inbred lines were assayed for PVA and tryptophan contents. Results Thirty-three of the lines were found to be tolerant to drought and low-N. Ninety percent of the inbred lines had tryptophan contents > 0.075 % per sample in whole grain substantiating the presence of the QPM trait in the inbred lines. Inbred lines TZEIORQ 55 and TZEIORQ 29 combined high PVA contents (15.38 and 12.10μg g-1, respectively) with low-N tolerance while nine inbred lines combined moderate PVA levels (5.06 – 8.34μg g-1) with drought and low-N tolerance. Conclusions These maize inbred lines could be utilized to develop superior drought and low-N tolerant hybrids and synthetics with elevated levels of PVA and tryptophan for WCA. The correlations observed among grain yield, PVA and tryptophan of the lines were not significant suggesting that these traits could be improved independently.

The influence of drought stress on growth, yield and yield components of selected maize genotypes

2003 ◽  
Vol 141 (1) ◽  
pp. 43-50 ◽  
Author(s):  
A. Y. KAMARA ◽  
A. MENKIR ◽  
B. BADU-APRAKU ◽  
O. IBIKUNLE
Keyword(s):  
Grain Yield ◽  
Water Deficit ◽  
Yield Components ◽  
Central Africa ◽  
Growth Yield ◽  
Drought Tolerant ◽  
Maize Genotypes ◽  
Yield And Yield Components ◽  
West And Central Africa ◽  
Savannah Zone

The risk of drought is high in the Sudan savannah zone of West and Central Africa because rainfall in this area is unpredictable in quantity and distribution. Thus, improved maize genotypes tolerant to drought could stabilize maize grain yield in this zone, where recurrent drought threatens grain production. Six maize genotypes, two each of hybrids, open-pollinated varieties (OPVs) and landraces, were evaluated for tolerance to terminal water deficit before flowering. Water deficit significantly reduced growth, grain yield and yield components of the maize genotypes. Significant differences were observed among genotypes for all the traits measured. One hybrid, 9011-30, and two improved OPVs, STR-EV-IWD and IYFD-C0, that showed tolerance to water stress recorded higher grain yield, and accumulated and partitioned more assimilates to the grain than the drought-susceptible genotypes. Also the drought-tolerant genotypes, 9011-30, STR-EV-IWD and IYFD-C0 had more ears/plant and greater numbers of kernels/ear. These genotypes could serve as sources of drought tolerance for the development and improvement of new drought-tolerant maize genotypes.

Performance of tropical early-maturing maize cultivars in multiple stress environments

2010 ◽  
Vol 90 (6) ◽  
pp. 831-852 ◽  
Author(s):  
B. Badu-Apraku ◽  
A. Menkir ◽  
S. Ajala ◽  
R. Akinwale ◽  
M. Oyekunle ◽  
...  
Keyword(s):  
Drought Stress ◽  
Striga Hermonthica ◽  
Environment Interaction ◽  
Maize Productivity ◽  
Maize Cultivars ◽  
Genotype Environment Interaction ◽  
Maize Varieties ◽  
Early Maturing ◽  
Use Efficiency ◽  
Growing Conditions

Maize (Zea mays L.) production in west Africa (WA) is constrained by drought, Striga hermonthica infestation and low soil nitrogen (N). Maize varieties resistant to Striga, drought, and low N are ideal for WA, but genotype × environment interaction on these traits are usually significant due to differential responses of cultivars to growing conditions. Three studies were conducted from 2007 to 2009 at five locations in Nigeria to evaluate the performance of selected early-maturing cultivars under drought stress versus well-watered, Striga-infested versus Striga-free, and in low- versus high-N environments. Drought stress reduced grain yield by 44%, Striga infestation by 65%, and low N by 40%. GGE biplot analysis showed that the genotypes TZE-W DT STR C4, Tillering Early DT, TZE-W DT STR QPM C0 and TZE-Y DT STR C4 performed relatively well in all study environments. TZE-W DT STR C4 and TZE Comp3 C1F2 were outstanding under drought, TZE-W DT STR C4, EVDT-W 99 STR QPM C0 and TZE-W DT STR QPMC0 under Striga infestation and Tillering Early DT, EVDT 97 STRC1, TZE-W DT STR C4, and TZE Comp3 C3 under N deficiency. Maize productivity in WA can be significantly improved by promoting cultivation of genotypes that combine high resistance/tolerance to Striga and drought with improved N-use efficiency.

scholarly journals Assessment of genetic variability among accessions of okra (Abelmoschus esculentus L. Moench)

2021 ◽  
Vol 24 (2) ◽  
pp. 141-147
Author(s):  
Richard Olayiwola ◽  
Rukayat Ayomikun Yusuf ◽  
Oyeboade Adebiyi Oyetunde ◽  
Olufemi Sunday Sosanya ◽  
Omolayo Johnson Ariyo
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Central Africa ◽  
Principal Component ◽  
Breeding Program ◽  
Genetic Base ◽  
Cropping Season ◽  
Principal Component Analyses ◽  
Early Maturing ◽  
West And Central Africa

Abstract Okra yields are low in West and Central Africa and factors including narrow genetic base of available germplasm have been implicated. An assessment of genetic variability among germplasm from various sources and knowledge of trait contributions to these variations is crucial to the success of okra breeding program. Eighteen okra accessions were evaluated during the 2020 cropping season in Nigeria to assess the genotypes for genetic diversity, group the accessions into clusters and identify traits that chiefly accounted for the variations among the genotypes. Data obtained were subjected to analysis of variance (ANOVA), metroglyph and principal component analyses (PCA). ANOVA revealed significant accession mean squares for majority of the measured traits. Metroglyph analysis grouped the accessions into four clusters with members of Cluster IV generally high-yielding, early-maturing and short genotypes. NGB00353 and NGB00356 that were among genotypes with high total index scores were members of Cluster IV. The first four principal components (PCs) accounted for 80% of the total observed variation. PC1 with the highest discriminatory power was loaded with days to budding, internode length, pod yield.plot−1 and the number of pods.plant−1. The variation within and between clusters could be explored in okra breeding program.

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