scholarly journals Gene Action, Heterotic Patterns, and Inter-Trait Relationships of Early Maturing Pro-Vitamin a Maize Inbred Lines and Performance of Testcrosses Under Contrasting Environments

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1371
Author(s):  
Baffour Badu-Apraku ◽  
Oluwafemi Obisesan ◽  
Oluwafemi B. Olumide ◽  
Johnson Toyinbo

Vitamin A deficiency is the leading cause of night blindness, total blindness, maternal and childhood mortality in developing countries. Drought, low soil nitrogen and Striga hermonthica parasitism are major constraints to maize production in sub-Saharan Africa (SSA). Thus, the development of multiple stress tolerant maize varieties with elevated levels of PVA is an economically feasible approach to simultaneously tackle malnutrition and food insecurity in SSA. The objectives of this study were to determine the gene action modulating the inheritance of grain yield and other traits, group the inbred lines, investigate inter-trait relationships among grain yield and other traits and assess the performance and stability of single-cross hybrids derived from a set of inbred lines under stress and non-stress environments. One hundred and ninety diallel crosses plus six hybrid checks were evaluated under managed drought at Ikenne during the 2016/17 and 2017/18 dry seasons, low soil N conditions at Mokwa and Ile-Ife, Striga infestation at Abuja and Mokwa, and optimal management conditions at Ikenne, Kadawa, Abuja, Bagauda and Mokwa during the 2016 and 2017 growing seasons. Both additive and non-additive gene actions were prominent in the inheritance of grain yield and other measured traits under stress and optimal management conditions. However, additive gene action was preponderant over the non-additive. The PVA inbreds were classified into three heterotic groups with TZEI 25 and TZEIOR 164 identified as inbred testers for heterotic groups 2 and 3, respectively. Plant and ear heights, ears per plant, plant and ear aspects were identified as reliable secondary traits for genetic enhancement of grain yield under both stress and non-stress conditions. Hybrids TZEIOR 4 x TZEIOR 158 and TZEIOR 119 × TZEIOR 158 were outstanding in performance and should be tested extensively for possible commercialization to combat malnutrition and food insecurity in SSA.

2019 ◽  
Vol 157 (5) ◽  
pp. 413-433 ◽  
Author(s):  
E. Obeng-Bio ◽  
B. Badu-Apraku ◽  
B. E. Ifie ◽  
A. Danquah ◽  
E. T. Blay ◽  
...  

AbstractEarly-maturing provitamin A (PVA) quality protein maize (QPM) hybrids with combined drought and low soil nitrogen (low-N) tolerance are needed to address malnutrition and food security problems in sub-Saharan Africa (SSA). The current study's objectives were to (i) examine combining ability of selected early maturing PVA-QPM inbreds for grain yield and other agronomic traits under drought, low-N, optimal environments and across environments, (ii) determine gene action conditioning PVA accumulation under optimal environments, (iii) classify inbreds into heterotic groups and identify testers and (iv) assess yield and stability of hybrids across environments. Ninety-six hybrids generated from 24 inbred lines using the North Carolina Design II together with four commercial hybrid controls were evaluated under drought, low-N and optimal environments in Nigeria in 2016 and 2017. Fifty-four selected hybrids were assayed for PVA carotenoid and tryptophan content. Additive genetic effects were greater than non-additive effects for grain yield and most agronomic traits under each and across environments. The gene action conditioning accumulation of PVA carotenoids under optimal growing conditions followed a pattern similar to that of grain yield and other yield-related traits. The inbred lines were categorized into four heterotic groups consistent with the pedigree records and with TZEIORQ 29 identified as the best male and female tester for heterotic group IV. No tester was found for the other groups. Hybrid TZEIORQ 24 × TZEIORQ 41 was the highest yielding and most stable across environments and should be further tested for consistent performance for commercialization in SSA.


Author(s):  
Abenezer Abebe ◽  
Zelalem Tafa ◽  
Worknesh Terefe

Maize is one of the most important cereals broadly adapted worldwide. Though, a number of improved maize varieties have been released, each micro-environment has not been touched that is why the study carried out. The experiment was conducted using seven maize varieties in RCB design with three replications. The analysis of variance signifies the presence of significant difference (p<0.05) among the seven maize varieties evaluated. High value of genetic (GCV) and phenotypic coefficient of variation (PCV) for grain yield (25.1 and 37.8%) were estimated and this infers less influence of environment. Additionally, moderately high heritability (44.2%) and high genetic advance in percent mean (34.4%) were estimated for grain yield which indicate the trait governed by additive gene action and could be improved via selection based on phenotypic performance. However, traits (male and female flower) with high heritability and moderate genetic advance in percent mean inherited mostly by non-additive gene action and heterosis breeding could be useful. Regarding agronomic performance, Hora maize variety provided highest grain yield (5.0 t/ha) followed by Kuleni (4.1 t/ha), Melkasa 2 (4.0 t/ha) and check (4.0 t/ha). Hora, Melkasa 2, Melkasa 4 and check flowered earlier as compared to the other and could be used as parent for generating early flowering varieties. In summary, Hora maize variety was better performing both statistically and in eyes of farmers and need seed multiplication and distribution to farming community. Moreover, the variability observed among the maize varieties could be utilizing in future breeding activities.


2017 ◽  
Vol 9 (4) ◽  
pp. 222 ◽  
Author(s):  
Mafouasson Apala Hortense Noëlle ◽  
Kenga Richard ◽  
Gracen Vernon ◽  
Yeboah Agyei Martin ◽  
Mahamane Nasser Laouali ◽  
...  

This study was conducted to determine combining ability and gene action in elite maize inbred lines under low and high soil nitrogen conditions for hybrid breeding. Forty two tropical inbred lines (three testers and 39 lines) were crossed using line × tester mating design. The resulting 117 F1 hybrids, along with 4 hybrids used as checks, were evaluated using an 11 × 11 lattice design with two replications for grain yield and yield related traits during the 2012 and 2013 cropping seasons at two sites (Mbalmayo and Nkolbisson). Results revealed predominant additive gene effect under high soil nitrogen (N) conditions. Non-additive gene effect influenced grain yield under low soil and thus could be exploited for hybrid development. Under high N conditions inbred lines CLYN246, J16-1, CLWN201, TL-11-A-1642-5, CLQRCWQ26 and 1368 were good general combiners. Lines CML 343, ATP S6 20-Y-1, CLWN201, 1368, ATP S9 30 Y-1 and CLQRCWQ26 were good general combiners for grain yield under low N. They could be used to develop low N tolerant varieties. Different single cross hybrid combinations were identified for high grain yields under both low and high N conditions. The selected lines and single cross hybrids are a useful source of valuable genetic material for future maize hybrid breeding or direct production under low N.


Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2596
Author(s):  
Olatunde A. Bhadmus ◽  
Baffour Badu-Apraku ◽  
Oyenike A. Adeyemo ◽  
Adebayo L. Ogunkanmi

An increase in the average global temperature and drought is anticipated in sub-Saharan Africa (SSA) as a result of climate change. Therefore, early white quality protein maize (QPM) hybrids with tolerance to combined drought and heat stress (CDHS) as well as low soil nitrogen (low-nitrogen) have the potential to mitigate the adverse effects of climate change. Ninety-six early QPM hybrids and four checks were evaluated in Nigeria for two years under CDHS, low-nitrogen, and in optimal environments. The objectives of this study were to determine the gene action conditioning grain yield, assess the performance of the early QPM inbred lines and identify high yielding and stable QPM hybrids under CDHS, low-nitrogen and optimal environment conditions. There was preponderance of the non-additive gene action over the additive in the inheritance of grain yield under CDHS environment conditions, while additive gene action was more important for grain yield in a low-nitrogen environment. TZEQI 6 was confirmed as an inbred tester under low N while TZEQI 113 × TZEQI 6 was identified as a single-cross tester under low-nitrogen environments. Plant and ear aspects were the primary contributors to grain yield under CDHS and low-nitrogen environments. TZEQI 6 × TZEQI 228 and the check TZEQI 39 × TZEQI 44 were the highest yielding under each stress environment and across environments. Hybrid TZEQI 210 × TZEQI 188 was the most stable across environments and should be tested on-farm and commercialized in SSA.


Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1625
Author(s):  
Innocent Iseghohi ◽  
Ayodeji Abe ◽  
Silvestro Meseka ◽  
Wende Mengesha ◽  
Melaku Gedil ◽  
...  

Vitamin A deficiency (VAD) is a serious problem in sub-Saharan Africa (SSA) and other parts of the world. Understanding the effect of marker-based improvement (MARS) of two maize synthetics (HGA and HGB) representing different heterotic groups on their agronomic performance, carotenoid content, and combining abilities could help identify suitable sources to develop divergent inbred lines for optimizing heterosis. This study involved three selection cycles each of the two synthetics and their nine varietal-cross hybrids together with a released check variety was conducted across four diverse locations in Nigeria in 2018 and 2019. Environment and hybrid effects were significant on grain yield and other agronomic traits as well as provitamin A content and other carotenoids. Genetic improvement per cycle of MARS in the parental synthetics was 15% for provitamin A, 25% for β-carotene and 26% for lutein in HGA and 4% for grain yield, 3% for zeaxanthin and 5% for α-carotene in HGB. Grain yield and agronomic traits of the two maize synthetics were controlled by additive and non-additive gene effects, while provitamin A content and other carotenoids were mainly controlled by additive gene effects. Some selection cycles which were high in grain yield and provitamin A content were identified as potential sources of new and divergent maize inbred lines in maize breeding programs. Some varietal-cross hybrids expressed significant mid-parent heterosis for grain yield and moderate mid-parent heterosis for provitamin A, β-carotene and xanthophylls. These hybrids could be commercialized at reasonable prices to small-scale farmers in rural areas that are most affected by vitamin A deficiency.


Agronomy ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 240 ◽  
Author(s):  
Zhixin Zhao ◽  
Kunhui He ◽  
Zhiqian Feng ◽  
Yanan Li ◽  
Liguo Chang ◽  
...  

To screen the desired criterion to identify desirable genotypes and select genotypes best suited to limited nitrogen availability in order to facilitate the practice of low-nitrogen-tolerant breeding in maize, the response of 31 maize inbred lines, containing four control inbred lines (PH6WC, PH4CV, Zheng58, and Chang7-2) and others selected from the Shaan A and Shaan B heterotic groups cultivated at Northwest A&F University (Yangling, Shaanxi, China), were evaluated. The experiment was conducted following a split plot design with two replications during three growing seasons (2015, 2016, and 2017) under both high nitrogen (HN) and low nitrogen (LN) conditions at the Yulin and Yangling in Shaanxi Province, China. Seven screening indices, based on grain yield under two contrasting nitrogen (N) conditions, the stress susceptibility index (SSI), yield stability index (YSI), mean productivity (MP), geometric mean productivity (GMP), stress tolerance index (STI), harmonic mean (HM), and low nitrogen tolerance index (LNTI), were computed to assess the overall index that accurately screened the desirable genotypes. The results of the correlation analyses and principal component analysis showed that MP, GMP, HM and STI were correlated with grain yield significantly and positively under contrasting N conditions, and were able to accurately discriminate the desirable genotypes. Compared with the control inbred lines, many inbred lines selected from the Shaan A and Shaan B groups showed a higher LN tolerance. This shows that we can effectively improve the LN tolerance of maize inbred lines through LN screening. Based on the screening indices, the three-dimensional diagram and genotype and genotype × environment (GGE) biplots are agreed with this results, and we identified KA105, KB081, KA225, 91227, and 2013KB-47 as the desired genotypes that have the potential to be used to breed a high yield and stable hybrid.


2018 ◽  
Vol 43 (4) ◽  
pp. 599-609
Author(s):  
ANMS Karim ◽  
S Ahmed ◽  
AH Akhi ◽  
MZA Talukder ◽  
A Karim

Combining ability effects were estimated for grain yield and some other important agronomic traits of maize in a 7×7 diallel analysis excluding reciprocals. The variances for general combining ability (GCA) were found significant for yield, days to pollen shedding, days to silking and ear height while it was found non-significant for plant height and number of kernels/ear. Non-significant general combining ability (GCA) variance for plant height and number of kernels/ear indicates that these two traits were predominantly controlled by non- additive type of gene action. Specific combining ability (SCA) was significant for all the characters except yield and days to silking. Non-significant specific combining ability (SCA) variance for yield and days to silking suggests that these two traits were predominantly controlled by additive type of gene action. Both GCA and SCA variances were found significant only in days to pollen shedding and ear height indicated the presence of additive as well as non additive gene effects for controlling the traits. However, relative magnitude of these variances indicated that additive gene effects were more prominent for all the characters studied except days to silking. Parent BIL95 was the best general combiner for both high yield and number of kernels/ear and parent BML4 for dwarf plant type. Two crosses (BML4× BML36 and BIL114× BIL31) exhibited significant and positive SCA effects for grain yield involved low × average and average × average general combining parents. The range of heterosis expressed by different crosses for grain yield and days to silking was from -65.83 to 21.26 percent and -17.85 to 8.22 percent, respectively.. The better performing three crosses (BIL114×BIL31, BIL138×BIL95 and BIL31×BIL95) can be utilized for developing high yielding hybrid varieties as well as for exploiting hybrid vigour.Bangladesh J. Agril. Res. 43(4): 599-609, December 2018


2015 ◽  
Vol 39 (4) ◽  
pp. 675-683
Author(s):  
MN Amin ◽  
M Amiruzzaman ◽  
A Ahmed ◽  
MR Ali

Maize inbred lines were evaluated by using line × tester method involving 11 lines and 3 testers for grain yield and its components through estimation of general combining ability (gca) and specific combining ability (sca) effects. Highly significant genotypic differences were observed indicated wide range of variability present among the genotypes. The crosses with high sca effect for grain yield were evolved from high × low general combiner parents which reveled additive × dominance type of gene action. The cross combinations 9MS4-1 × L22, 9MS4-1 × L486, 9MS4-2 × L431, 9MS4-11 × L486 and 9MS4- 15 × L431 with high positive sca effect having high mean values might be used for obtaining high yielding hybrids. The information on the nature of gene action with respective variety and characters might be used depending on the breeding objectives. DOI: http://dx.doi.org/10.3329/bjar.v39i4.22547 Bangladesh J. Agril. Res. 39(4): 675-683, December 2014


2016 ◽  
Vol 14 (4) ◽  
pp. e0711 ◽  
Author(s):  
Sanja Mikić ◽  
Miroslav Zorić ◽  
Dušan Stanisavljević ◽  
Ankica Kondić-Špika ◽  
Ljiljana Brbaklić ◽  
...  

Drought is a severe threat to maize yield stability in Serbia and other temperate Southeast European countries occurring occasionally but with significant yield losses. The development of resilient genotypes that perform well under drought is one of the main focuses of maize breeding programmes. To test the tolerance of newly developed elite maize inbred lines to drought stress, field trials for grain yield performance and anthesis silk interval (ASI) were set in drought stressed environments in 2011 and 2012. Inbred lines performing well under drought, clustered into a group with short ASI and a smaller group with long ASI, were considered as a potential source for tolerance. The former contained inbreds from different heterotic groups and with a proportion of local germplasm. The latter consisted of genotypes with mixed exotic and Lancaster germplasm, which performed better in more drought-affected environments. Three inbreds were selected for their potential drought tolerance, showing an above-average yield and small ASI in all environments. Association analysis indicated significant correlations between ASI and grain yield and three microsatellites (bnlg1525, bnlg238 and umc1025). Eight alleles were selected for their favourable concurrent effect on yield increase and ASI decrease. The proportion of phenotypic variation explained by the markers varied across environments from 5.7% to 22.4% and from 4.6% to 8.1% for ASI and yield, respectively. The alleles with strongest effect on performance of particular genotypes and their interactions in specific environments were identified by the mean of partial least square interactions analysis indicating potential suitability of the makers for tolerant genotype selection.


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