scholarly journals Genetic Diversity and Heterotic Orientation of South Africa Maize Inbred Lines Towards Tropical and Temperate Testers

2021 ◽  
Author(s):  
Siphiwokuhle Funani Shandu ◽  
John Derera ◽  
Kingston Mashingaidze ◽  
Edmore Gasura
Keyword(s):  
South Africa ◽  
Genetic Diversity ◽  
Grain Yield ◽  
Combining Ability ◽  
Molecular Genetic ◽  
Inbred Lines ◽  
Genetic Distances ◽  
Specific Combining Ability ◽  
Heterotic Groups ◽  
Maize Inbred Lines

Abstract An efficient hybrid breeding program defines and utilizes few heterotic groups. The objectives of this study were to determine genetic diversity and alignment of South Africa maize inbred lines collection towards tropical and temperate testers. Forty-two maize inbred lines were genotyped with 56110 single nucleotide polymorphism (SNP) DNA markers, using the Illumina MaizeSNP50 Bead chip. The 42 lines were crossed to two tropical and two temperate inbred line testers. The testcrosses were evaluated across seven environments, in South Africa, during 2014-2016. Genotypes and specific combining ability (SCA) effects of hybrids were significantly different (P<0.05) for grain yield. There was a weak correlation between molecular genetic distances and both grain yield mean and specific combining ability effects of hybrids, indicating that productivity of maize inbred lines could not be reliably determined based on molecular genetic distances. The SCA data was capable of classifying these maize inbred lines into three heterotic groups with respect to both tropical and temperate testers. Only a few lines could not be grouped on the basis of SCA data. The study also indicated high level of diversity among the maize inbred lines, which was shown by both the dendogram and molecular genetic distances. The SNP marker data classified the inbred lines into 11 clusters that could be simplified into three major groups of normal maize endosperm and two groups of quality protein maize (QPM) endosperm types. However, the SNP data indicated that maize lines were more aligned towards tropical than temperate inbred testers. This information would be useful for simplifying heterotic classification of the lines with profound implications for breeding progress.

Relationships between heterosis, genetic distances and specific combining ability among CIMMYT and Zimbabwe developed maize inbred lines under stress and optimal conditions

Euphytica ◽  
2015 ◽  
Vol 204 (3) ◽  
pp. 635-647 ◽  
Author(s):  
Thokozile Ndhlela ◽  
Liezel Herselman ◽  
Kassa Semagn ◽  
Cosmos Magorokosho ◽  
Charles Mutimaamba ◽  
...  
Keyword(s):  
Combining Ability ◽  
Inbred Lines ◽  
Genetic Distances ◽  
Specific Combining Ability ◽  
Optimal Conditions ◽  
Maize Inbred Lines

Combining Ability, Genetic Distances, and Heterosis among Elite CIMMYT and IITA Tropical Maize Inbred Lines

Crop Science ◽  
2009 ◽  
Vol 49 (4) ◽  
pp. 1201-1210 ◽  
Author(s):  
Thanda Dhliwayo ◽  
Kevin Pixley ◽  
Abebe Menkir ◽  
Marilyn Warburton
Keyword(s):  
Combining Ability ◽  
Inbred Lines ◽  
Genetic Distances ◽  
Tropical Maize ◽  
Maize Inbred Lines

Heterosis and combining ability for grain yield and its components in selected maize inbred lines

2007 ◽  
Vol 24 (3) ◽  
pp. 133-137 ◽  
Author(s):  
D. W. Gissa ◽  
H. Zelleke ◽  
M. T. Labuschagne ◽  
T. Hussien ◽  
H. Singh
Keyword(s):  
Grain Yield ◽  
Combining Ability ◽  
Inbred Lines ◽  
Maize Inbred Lines

scholarly journals Performance of testers with different genetic structure for evaluation of maize inbred lines

2012 ◽  
Vol 42 (5) ◽  
pp. 770-776 ◽  
Author(s):  
Lauro José Moreira Guimarães ◽  
Glauco Vieira Miranda ◽  
Rodrigo Oliveira DeLima ◽  
Ciro Maia ◽  
Lucimar Rodrigues de Oliveira ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Combining Ability ◽  
Genetic Variance ◽  
Inbred Lines ◽  
General Combining Ability ◽  
Specific Combining Ability ◽  
Genetic Base ◽  
Maize Inbred Lines ◽  
Single Cross ◽  
Single Cross Hybrids

The objective of this study was to evaluate four maize testers for identification of superior inbreed lines in testcross. The four testers evaluated are cultivars with narrow or wide genetic base (single-cross hybrids and open pollinated varieties) and two kernel types (flint or dent). SynD and SynF testers are open pollinated varieties with dent and flint kernels, respectively, and FSH and DSH testers are single-cross hybrids with flint and dent kernels, respectively. SynD tester showed the biggest genetic variance among the maize inbreed lines in crosses. The effects of general combining ability (GCA) for lines and specific combining ability (SCA) for lines x testers were significant, whereas GCA effects for testers were not significant. SynD and SynF testers identified the largest number of lines with higher GCA. The DSH and FSH testers showed suitable to identify lines with high SCA. It was concluded that SynD and SynF testers are adequate to identify inbreed lines with high GCA effects, and it's possible to identify new lines with high heterotic potential in each one of the four testers.

scholarly journals Evaluation of Yield-Based Low Nitrogen Tolerance Indices for Screening Maize (Zea mays L.) Inbred Lines

Agronomy ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 240 ◽  
Author(s):  
Zhixin Zhao ◽  
Kunhui He ◽  
Zhiqian Feng ◽  
Yanan Li ◽  
Liguo Chang ◽  
...  
Keyword(s):  
Grain Yield ◽  
Geometric Mean ◽  
Inbred Lines ◽  
Shaanxi Province ◽  
High Yield ◽  
Tolerance Index ◽  
Heterotic Groups ◽  
Maize Inbred Lines ◽  
Low Nitrogen Tolerance ◽  
Low Nitrogen

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.

scholarly journals Agronomic and molecular evaluation of maize inbred lines for drought tolerance

2016 ◽  
Vol 14 (4) ◽  
pp. e0711 ◽  
Author(s):  
Sanja Mikić ◽  
Miroslav Zorić ◽  
Dušan Stanisavljević ◽  
Ankica Kondić-Špika ◽  
Ljiljana Brbaklić ◽  
...  
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Maize Yield ◽  
Field Trials ◽  
Inbred Lines ◽  
Partial Least Square ◽  
Least Square ◽  
Maize Breeding ◽  
Heterotic Groups ◽  
Maize Inbred Lines

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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