scholarly journals Agronomic Performance Of S1 Maize Lines Derived From A Bi-Parental Cross Under Infested And Striga Free Environments

2021 ◽  
Vol 17 (25) ◽  
pp. 306
Author(s):  
Abdoul-Madjidou Yacoubou ◽  
Nouhoun Zoumarou Wallis ◽  
Hafiz Adio Salami ◽  
Alain S. Yaoitcha ◽  
Ojo Tayo ◽  
...  

Striga hermonthica, causes up to 100% yield loss in maize production in sub-Saharan Africa. Developing Striga resistant maize cultivars could be a major component of integrated Striga management strategies. This study aims at assessing the agronomic performance of S1 breeding lines in improving maize for Striga resistance. Two hundred S1 lines have been evaluated under artificial infestation Striga and Striga-free conditions in Benin for two years during 2018 and 2019 growing seasons using alpha-lattice design (51 x 4) with two replicates. Twelve agro-morphological and Striga adaptive traits have been assessed. The tested lines have displayed high genetic variability for most agronomic and Striga adaptive traits. The S1 lines exhibited high grain yield than their parents with averages of 2,552.72±593 kg ha-1 and 2,965.67±635.86 kg ha-1 under Striga artificial infestation and Striga-free conditions, respectively. Grain yield has displayed high positive and significant genetic and phenotypic correlations with ears per plant and high negative correlations with days to 50% silking, ears aspect, and Striga damage rating at 8 and 10 weeks after planting (WAP). Useful traits like ears per plant, days to 50% silking, ears aspect, number of emerged Striga plants and Striga rating at 10 WAP could assist for indirect selection under Striga conditions. Based on the selection index, a total of 15 S1 lines have been identified as top ranking and can be used as sources of resistance or tolerance genes to Striga and further improvement in maize breeding in future.

2016 ◽  
Vol 9 (2) ◽  
pp. 65
Author(s):  
María Cristina Vega ◽  
Enrique Navarro ◽  
José Espinoza ◽  
Gustavo A. Buciaga ◽  
José Luis Guerrero

This research involved ninety-six S1 maize lines with the opaque-2 gene that carne from populations 63 (26 lines), 65 (12 lines), and 68 (58 lines) from the CIMMYT maize breeding programo The S1 lines selected in the laboratory because of their high lysine content were crossed with five testers that had a different genetic base: a synthetic variety, two early lines derived from this variety, and two single intermediate crosses of normal performance. The test crosses were evaluated and compared with five control s (two commercial and three experimental hybrids) using a randomized complete block design in two sites in Mexico during 1992. The objecti ves of this research were to select SI lines in early generations according to their agronomic performance, grain lysine content, and GCA grain yield, and to compare testers' efficiency in discriminating S1 lines. On average, the SI lines of population 63 showed a greater grain yield as compared to that of populations 65 and 68 combined with all testers, except in the case of the synthetic tester YS- 201-M. A line from population 65 combined with tester B3 x B5 showed the highest grain yield (10,23 t ha-I), representing a superiority of 4% above the best commercial hybrid, AN- 447. A total ofthirty-one Sllines were selected based on their agronomic attributes and grain yield: 13, 14, and 4 from populations 63, 65 and 68 respectively]. Tester B3 x B5 tumed out to be the best line discriminator according to the following criteria: grain yield, percentage of ears damaged by Fusarium spp., and number of rotten ears.


2021 ◽  
Vol 12 ◽  
Author(s):  
Nicoleta Muchira ◽  
Kahiu Ngugi ◽  
Lydia N. Wamalwa ◽  
Millicent Avosa ◽  
Wiliter Chepkorir ◽  
...  

Striga hermonthica is the most important parasitic weed in sub-Saharan Africa and remains one of the most devastating biotic factors affecting sorghum production in the western regions of Kenya. Farmers have traditionally managed Striga using cultural methods, but the most effective and practical solution to poor smallholder farmers is to develop Striga-resistant varieties. This study was undertaken with the aim of identifying new sources of resistance to Striga in comparison with the conventional sources as standard checks. We evaluated 64 sorghum genotypes consisting of wild relatives, landraces, improved varieties, and fourth filial generation (F4) progenies in both a field trial and a pot trial. Data were collected for days to 50% flowering (DTF), dry panicle weight (DPW, g), plant height (PH, cm), yield (YLD, t ha−1), 100-grain weight (HGW, g), overall disease score (ODS), overall pest score (OPS), area under Striga number progress curve (ASNPC), maximum above-ground Striga (NSmax), and number of Striga-forming capsules (NSFC) at relevant stages. Genetic diversity and hybridity confirmation was determined using Diversity Arrays Technology sequencing (DArT-seq). Residual heterosis for HGW and NSmax was calculated as the percent increase or decrease in performance of F4 crossover midparent (MP). The top 10 best yielding genotypes were predominantly F4 crosses in both experiments, all of which yielded better than resistant checks, except FRAMIDA in the field trial and HAKIKA in the pot trial. Five F4 progenies (ICSVIII IN × E36-1, LANDIWHITE × B35, B35 × E36-1, F6YQ212 × B35, and ICSVIII IN × LODOKA) recorded some of the highest HGW in both trials revealing their stability in good performance. Three genotypes (F6YQ212, GBK045827, and F6YQ212xB35) and one check (SRN39) were among the most resistant to Striga in both trials. SNPs generated from DArT-seq grouped the genotypes into three major clusters, with all resistant checks grouping in the same cluster except N13. We identified more resistant and high-yielding genotypes than the conventional checks, especially among the F4 crosses, which should be promoted for adoption by farmers. Future studies will need to look for more diverse sources of Striga resistance and pyramid different mechanisms of resistance into farmer-preferred varieties to enhance the durability of Striga resistance in the fields of farmers.


2017 ◽  
Vol 8 (2) ◽  
pp. 259-263 ◽  
Author(s):  
F. A. Rodrigues ◽  
P. Defourny ◽  
B. Gérard ◽  
F. San Vicente ◽  
A. Loladze

Assessment of Tar Spot Complex (TSC) severity in maize breeding experiments is conducted visually and may sometimes result in inconsistencies due to human interpretation. Disease scoring using remote sensing technologies may help bring more precision to the phenotyping process. An experiment for assessment of grain yield losses due to TSC was conducted at the Aguafria Experimental Station of the International Center for Wheat and Maize Improvement – CIMMYT in Mexico. Twenty-five maize genotypes were planted in spring of 2016 under a fungicide treatment to control TSC development and no fungicide treatment in a square lattice design with three replications. Four flights were carried out using an Unmanned Aerial Vehicle (UAV) equipped with a multispectral (550, 660, 735, 790 nm) and a thermal camera, simultaneously with the visual disease scorings and the yield was measured after harvesting. The preliminary results of the study indicated that the use of remote sensing in disease resistance phenotyping may be as effective as visual disease scoring since both correlate highly with the grain yield. Structural and chlorophyll vegetation indices (VIs) proved to be a good alternative for the estimation of yield losses caused by TSC in experimental field conditions, which may be potentially used for screening for resistance to this disease in maize genotypes, hypothetically reducing the need for visual disease scoring in the field.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. E. Stanley ◽  
A. Menkir ◽  
B. Ifie ◽  
A. A. Paterne ◽  
N. N. Unachukwu ◽  
...  

AbstractStriga hermonthica is a widespread, destructive parasitic plant that causes substantial yield loss to maize productivity in sub-Saharan Africa. Under severe Striga infestation, yield losses can range from 60 to 100% resulting in abandonment of farmers’ lands. Diverse methods have been proposed for Striga management; however, host plant resistance is considered the most effective and affordable to small-scale famers. Thus, conducting a genome-wide association study to identify quantitative trait nucleotides controlling S. hermonthica resistance and mining of relevant candidate genes will expedite the improvement of Striga resistance breeding through marker-assisted breeding. For this study, 150 diverse maize inbred lines were evaluated under Striga infested and non-infested conditions for two years and genotyped using the genotyping-by-sequencing platform. Heritability estimates of Striga damage ratings, emerged Striga plants and grain yield, hereafter referred to as Striga resistance-related traits, were high under Striga infested condition. The mixed linear model (MLM) identified thirty SNPs associated with the three Striga resistance-related traits based on the multi-locus approaches (mrMLM, FASTmrMLM, FASTmrEMMA and pLARmEB). These SNPs explained up to 14% of the total phenotypic variation. Under non-infested condition, four SNPs were associated with grain yield, and these SNPs explained up to 17% of the total phenotypic variation. Gene annotation of significant SNPs identified candidate genes (Leucine-rich repeats, putative disease resistance protein and VQ proteins) with functions related to plant growth, development, and defense mechanisms. The marker-effect prediction was able to identify alleles responsible for predicting high yield and low Striga damage rating in the breeding panel. This study provides valuable insight for marker validation and deployment for Striga resistance breeding in maize.


2018 ◽  
Vol 31 (1) ◽  
pp. 72-79 ◽  
Author(s):  
JÉSSICA DANIELE LUSTOSA DA SILVA ◽  
KAESEL JACKSON DAMASCENO-SILVA ◽  
MAURISRAEL DE MOURA ROCHA ◽  
JOSÉ ÂNGELO NOGUEIRA DE MENEZES JÚNIOR ◽  
VALDENIR QUEIROZ RIBEIRO

ABSTRACT Cowpea bean is a socioeconomically important legume that contribute to generate employment and income. This species presents great grain variability, and the commercial subclass black eye stands out as a very appreciated grain in Brazil and abroad, thus requiring the development of new cultivars. The objective of this work was to evaluate and select lineages of commercial black eye cowpea, based on simultaneous, and direct selection. First, 105 progenies and four controls were evaluated using the Federer's augmented block design. Seventy-seven progenies, selected from this evaluation-first selection cycle-and four controls were evaluated in three environments, using a simple 9×9 lattice design. Based on this evaluation, the second selection cycle was possible, resulting in 24 progenies. The gain by direct selection was lower than the predicted gain for grain yield in the first cycle, indicating that the selection was not effective. This result was probably due to the reduced genetic variability caused by the selection pressure. In the second cycle, the predicted and observed gains were similar, indicating that much of the expected gain was observed. The predicted and observed gains, with simultaneous selection based on the rank sum selection index, were similar in the first and second cycle. The simultaneous and direct selections resulted in genetic gains for grain yield in the two selection cycles, making it possible the selection of high grain yield lineages.


Weed Science ◽  
2018 ◽  
Vol 66 (4) ◽  
pp. 516-524 ◽  
Author(s):  
Fred Kanampiu ◽  
Dan Makumbi ◽  
Edna Mageto ◽  
Gospel Omanya ◽  
Sammy Waruingi ◽  
...  

AbstractThe parasitic purple witchweed [Striga hermonthica(Del.) Benth.] is a serious constraint to maize production in sub-Saharan Africa, especially in poor soils. VariousStrigaspp. control measures have been developed, but these have not been assessed in an integrated system. This study was conducted to evaluate a set of promising technologies forS. hermonthicamanagement in western Kenya. We evaluated three maize genotypes either intercropped with peanut (Arachis hypogaeaL.), soybean [Glycine max(L.) Merr.], or silverleaf desmodium [Desmodium uncinatum(Jacq.) DC] or as a sole crop at two locations under artificialS. hermonthicainfestation and at three locations under naturalS. hermonthicainfestation between 2011 and 2013. Combined ANOVA showed significant (P<0.05) cropping system and cropping system by environment interactions for most traits measured. Grain yield was highest for maize grown in soybean rotation (3,672 kg ha−1) under artificial infestation and inD. uncinatumand peanut cropping systems (3,203 kg ha−1and 3,193 kg ha−1) under natural infestation. Grain yield was highest for theStrigaspp.-resistant hybrid under both methods of infestation. A lower number of emergedS. hermonthicaplants per square meter were recorded at 10 and 12 wk after planting on maize grown underD. uncinatumin the artificialS. hermonthicainfestation. A combination of herbicide-resistant maize varieties intercropped with legumes was a more effective method forS. hermonthicacontrol than individual-component technologies. Herbicide-resistant andStrigaspp.-resistant maize integrated with legumes would help reduce theStrigaspp. seedbank in the soil. Farmers should be encouraged to adopt an integrated approach to controlStrigaspp. for better maize yields.


Agronomy ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1585
Author(s):  
Laouali M. Nasser ◽  
Baffour Badu-Apraku ◽  
Vernon E. Gracen ◽  
Hortense N. A. Mafouasson

Grain-yield potential of maize (Zea mays L.) is limited by the harsh climatic conditions during dry seasons in the savanna of sub-Saharan Africa (SSA). One hundred and five hybrids derived from diallel crosses involving 15 early-maturing yellow maize inbreds were screened under combined drought and heat stress (CDHS) and well-watered (WW) conditions at four locations representative of the dry savannas of Niger, 2012–2014. The objective of the study was to examine the general combining ability (GCA) effects of the inbred lines and specific combining ability (SCA) of the crosses under CDHS and WW environments, assess yield and stability of the derived hybrids under contrasting environments and investigate inter-relationships among traits of the hybrids under contrasting environments. GCA and SCA effects for grain yield and other measured traits were significant, with preponderance of GCA effects over SCA effects under both the CDHS and WW environments. Inbred ENT 13 possessed positive and significant GCA effects for grain yield under both CDHS and WW environments indicating that the inbred could be used for developing outstanding hybrids with good levels of tolerance to CDHS. This also implied that the inbred line could serve as invaluable genetic resource for introgression of favorable alleles into tropical early-maturing maize populations for accelerated genetic gains from selection for improved grain yield. Hybrids ENT 13 × TZEI 167 and TZEI 157 × ENT 13 were the most stable and among the highest yielding hybrids across research environments. These outstanding hybrids could be tested extensively for commercialization in SSA to improve food security. Plant and ear aspects and days to 50% silking could be combined with grain yield in a selection index for improvement of yield under CDHS without yield penalties under WW environments.


2021 ◽  
Vol 911 (1) ◽  
pp. 012002
Author(s):  
Muhammad Iqbal ◽  
Willy Bayuardi Suwarno ◽  
Muhammad Azrai

Abstract Climate change alters crop production in tropical and subtropical regions, and drought is a big challenge in maize production nowadays and near future. Breeding drought-tolerant varieties is important to keep production stability and food security. This research was undertaken to evaluate agronomic performance and yield potential of several maize genotypes in a drought stress environment, and to identify potential genotypes for further utilization in a maize breeding program. The experiment was conducted using an augmented design with 370 test genotypes and 6 checks at Sukoharjo Village, Kediri, East Java, from September 2014 to January 2015. The plants suffered from drought stress in the pre-anthesis period. Results of the analysis of variance showed that the effect of genotype is significant on grain yield, ear yield, plant height, and ear height. Linear correlation analysis showed that grain yield is negatively correlated with leaf senescence. Selection for tolerant genotypes was conducted using selection index and cluster analysis. Line 249 and 252 are considered potential for subsequent breeding processes because they have similar traits with a formerly known drought-tolerant variety, namely Bima 19URI.


2018 ◽  
Vol 10 (2) ◽  
pp. 217 ◽  
Author(s):  
Amadou T. Sall ◽  
Madiama Cisse ◽  
Habibou Gueye ◽  
Hafssa Kabbaj ◽  
Ibrahima Ndoye ◽  
...  

The Senegal River basin (Guinea, Mali, Mauritania, and Senegal) is a key agricultural production area in sub-Saharan Africa. Here, rice fields are left fallow during the cooler winter season, when the night temperatures reach 16 °C but the maximum daily temperatures remain above 30 °C. This season was used for the first time to conduct multi-environmental trials of durum wheat. Twenty-four elite breeding lines and cultivars were tested for adaptation during seasons 2014-15 and 2015-16 at two stations: Kaedi, Mauritania and Fanaye, Senegal. Phenological traits, grain yield and its components were recorded. Top grain yield was recorded at 5,330 kg ha-1 and the average yield at 2,484 kg ha-1. The season lasted just 90 days from sowing to harvest. Dissection of the yield in its components revealed that biomass and spike fertility (i.e. number of seeds produced per spike) were the most critical traits for adaptation to these warm conditions. This second trait was confirmed in a validation experiment conducted in 2016-17 at the same two sites. Genotype × environment interaction was dissected by AMMI model, and the derived IPC values used to derive an ‘AMMI wide adaptation index’ (AWAI) to asses yield stability. The use of a selection index that combined adjusted means of yield and AWAI identified three genotypes as the most stable and high yielding: ‘Bani Suef 5’, ‘DAWRyT118’, and ‘DAWRyT123’. The last two genotypes were also confirmed among the best in a validation trial conducted in season 2016-17. The data presented here are meant to introduce to the breeding community the use of these two research stations along the Senegal River for assessing heat tolerance of wheat or other winter cereals, as well as presenting two new ideal germplasm sources for heat tolerance, and the identification of spike fertility as the key trait controlling adaptation to heat stress.


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