Incorporation of tropical maize germplasm into inbred lines derived from temperate × temperate-adapted tropical line crosses: agronomic and molecular assessment

2003 ◽  
Vol 107 (5) ◽  
pp. 798-805 ◽  
Author(s):  
R. S. Lewis ◽  
M. M. Goodman
Keyword(s):  
Inbred Lines ◽  
Tropical Maize ◽  
Maize Germplasm ◽  
Molecular Assessment

Dissection of mechanisms of resistance to Aspergillus flavus and aflatoxin using tropical maize germplasm

2018 ◽  
Vol 11 (2) ◽  
pp. 215-224 ◽  
Author(s):  
V. Garrido-Bazan ◽  
G. Mahuku ◽  
M. Bibbins-Martinez ◽  
A. Arroyo-Bacerra ◽  
M. Ángel Villalobos-López
Keyword(s):  
Aspergillus Flavus ◽  
Fungal Biomass ◽  
Safety Issue ◽  
Inbred Lines ◽  
Aflatoxin Contamination ◽  
Tropical Maize ◽  
Mechanisms Of Resistance ◽  
Maize Germplasm ◽  
Maize Inbred Lines ◽  
Maize Varieties

Aspergillus flavus induced ear rots and subsequent contamination of maize (Zea mays L.) by aflatoxin is a serious food safety issue, especially in developing countries where the crop is mostly cultivated by smallholder famers for own consumption and income generation. A better understanding of the mechanisms of resistance could help breeders to develop resistant maize varieties. In this study, a set of six tropical maize inbred lines previously identified as resistant or susceptible under natural field conditions were evaluated for response to A. flavus colonisation and aflatoxin contamination. Fungal biomass was significantly higher (P<0.05) in susceptible than resistant maize inbred lines, and this was highly correlated (P=0.001) to aflatoxin levels. Maize inbred lines MRI, MR2 and MR3 had low fungal biomass and low aflatoxin levels, suggesting that resistance in these lines was mediated through restricted fungal colonisation and establishment. Among the three putatively resistant inbred lines mentioned above, MR2 had a relatively high colonisation compared to the other two lines, revealing that A. flavus could establish and colonise kernels that were injured during inoculation, but did not contain high levels of aflatoxin. This could signify the presence of host genes that interfere with the aflatoxin biosynthetic pathway.

scholarly journals Enhancing Drought Tolerance and Striga hermonthica Resistance in Maize Using Newly Derived Inbred Lines from the Wild Maize Relative, Zea diploperennis

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 177
Author(s):  
Abdulwahab S. Shaibu ◽  
Baffour Badu-Apraku ◽  
Monininuola A. Ayo-Vaughan
Keyword(s):  
Drought Tolerance ◽  
Grain Yield ◽  
Combining Ability ◽  
Inbred Lines ◽  
Wild Relatives ◽  
Striga Hermonthica ◽  
Tropical Maize ◽  
Heterotic Groups ◽  
Maize Germplasm ◽  
Zea Diploperennis

Recurrent drought and Striga hermonthica (Del.) Benth parasitism constrains maize production in sub-Saharan Africa (SSA). Transfer of resistance genes from wild relatives can improve resistance to drought and Striga in tropical maize. The objectives of this study were to (i) determine the combining ability of 12 extra-early yellow maize inbreds derived from Zea diploperennis and tropical maize germplasm; (ii) classify the inbreds into heterotic groups using heterotic grouping based on the general combining ability (GCA) of multiple traits (HGCAMT) method; (iii) examine hybrid performance under contrasting environments; and (iv) examine the stability of hybrid combinations involving the inbreds. Sixty-six diallel crosses involving the inbreds plus four checks were evaluated for two years under drought, Striga-infested and rainfed environments in Nigeria. Significant differences (p < 0.05) were observed for the effects of genotype, environment, genotype × environment, GCA and specific combining ability (SCA) on grain yield and other measured traits. Inbred lines such as TZdEEI 7 × TZEEI 63 derived from Z. diploperennis and tropical germplasm exceeded the checks by a range of 28 to 41%. Across environments, the hybrid TZdEEI 1 × TZdEEI 7, which was derived from Z. diploperennis, was the highest-yielding with a grain yield of 4302 kg ha−1. The results revealed the predominance of GCA over SCA effects for most measured traits, suggesting that additive gene action governed the inheritance of Striga resistance and drought tolerance related traits in the inbreds. The 12 inbreds were classified into three heterotic groups, while TZEEI 79 and TZdEEI 7 were identified as inbred testers and TZdEEI 7 × TZEEI 12 as a single-cross tester across environments. Hybrid TZdEEI 9 × TZEEI 79 was the highest-yielding and most stable. Other promising hybrids were TZdEEI 7 × TZEEI 79, TZdEEI 1 × TZdEEI 7 and TZdEEI 12 × TZEEI 95. These hybrids should be extensively tested on-farm for potential commercialization in SSA. Overall, our results highlighted the importance of harnessing beneficial alleles from wild relatives of maize for improvement of resistance to Striga and tolerance to drought in adapted maize germplasm.

Genotypic variation and relationships among traits for root morphology in a panel of tropical maize inbred lines under contrasting nitrogen levels

Euphytica ◽  
2019 ◽  
Vol 215 (3) ◽  
Author(s):  
Lívia Gomes Torres ◽  
Diego Gonçalves Caixeta ◽  
Wemerson Mendonça Rezende ◽  
Andreia Schuster ◽  
Camila Ferreira Azevedo ◽  
...  
Keyword(s):  
Root Morphology ◽  
Genotypic Variation ◽  
Inbred Lines ◽  
Tropical Maize ◽  
Nitrogen Levels ◽  
Maize Inbred Lines

scholarly journals Phenotypic and molecular characterization of a set of tropical maize inbred lines from a public breeding program in Brazil

BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Sirlene Viana de Faria ◽  
Leandro Tonello Zuffo ◽  
Wemerson Mendonça Rezende ◽  
Diego Gonçalves Caixeta ◽  
Hélcio Duarte Pereira ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Inbred Lines ◽  
Breeding Program ◽  
Tropical Maize ◽  
Maize Breeding ◽  
Breeding Programs ◽  
The Public ◽  
Maize Inbred Lines

Abstract Background The characterization of genetic diversity and population differentiation for maize inbred lines from breeding programs is of great value in assisting breeders in maintaining and potentially increasing the rate of genetic gain. In our study, we characterized a set of 187 tropical maize inbred lines from the public breeding program of the Universidade Federal de Viçosa (UFV) in Brazil based on 18 agronomic traits and 3,083 single nucleotide polymorphisms (SNP) markers to evaluate whether this set of inbred lines represents a panel of tropical maize inbred lines for association mapping analysis and investigate the population structure and patterns of relationships among the inbred lines from UFV for better exploitation in our maize breeding program. Results Our results showed that there was large phenotypic and genotypic variation in the set of tropical maize inbred lines from the UFV maize breeding program. We also found high genetic diversity (GD = 0.34) and low pairwise kinship coefficients among the maize inbred lines (only approximately 4.00 % of the pairwise relative kinship was above 0.50) in the set of inbred lines. The LD decay distance over all ten chromosomes in the entire set of maize lines with r2 = 0.1 was 276,237 kb. Concerning the population structure, our results from the model-based STRUCTURE and principal component analysis methods distinguished the inbred lines into three subpopulations, with high consistency maintained between both results. Additionally, the clustering analysis based on phenotypic and molecular data grouped the inbred lines into 14 and 22 genetic divergence clusters, respectively. Conclusions Our results indicate that the set of tropical maize inbred lines from UFV maize breeding programs can comprise a panel of tropical maize inbred lines suitable for a genome-wide association study to dissect the variation of complex quantitative traits in maize, mainly in tropical environments. In addition, our results will be very useful for assisting us in the assignment of heterotic groups and the selection of the best parental combinations for new breeding crosses, mapping populations, mapping synthetic populations, guiding crosses that target highly heterotic and yielding hybrids, and predicting untested hybrids in the public breeding program UFV.

scholarly journals Phenotypical Variability of “TURDA” Maize Germplasm for Grain Chemical Composition

1970 ◽  
Vol 66 (1) ◽  
Author(s):  
Voichita HAS ◽  
Ioan HAS ◽  
Doru PAMFIL ◽  
Ana COPANDEAN ◽  
Sorin CAMPEAN
Keyword(s):  
Grain Quality ◽  
Selection Criterion ◽  
Quality Attributes ◽  
Inbred Lines ◽  
Phenotypic Correlation ◽  
Starch Concentration ◽  
Maize Germplasm ◽  
Grain Starch ◽  
Food And Feed ◽  
Phenotypical Variability

Maize grain has many and diverse uses in the food and feed industry. The diversity of applications requires characteristics of quality in accordance to that. To examine phenotypical diversity in the grain content, it was evaluated a total of 754 maize samples: 265 local populations (landraces); 59 synthetics/composites; 430 “TURDA” inbred lines for their grain quality attributes. Comparison of the inbred lines diversity is on average the most divergent in grain starch concentration (range value 19.9) from landraces (range value 11.8) and synthetics (range value 12.5). The grain oil and ash content showed high variability among the genotypes. The quality attributes in most of the cases showed positive phenotypic correlation except grain starch contents which was negatively correlated at phenotypic levels. The objective of this study was to evaluate the potential of maize “TURDA” germplasm in according to its grain quality content, such as: protein, oil, fiber, ash and starch concentration; to estimate the extent of phenotypical variability and correlation for various quality components to formulate a selection criterion in a breeding program.

Estimates of Heterosis among Temperate, Subtropical and Tropical Maize Germplasm

2003 ◽  
Vol 3 (1) ◽  
pp. 6-10 ◽  
Author(s):  
H.N. Malik . ◽  
S.I. Malik . ◽  
S.R. Chughtai . ◽  
H.I. Javed .
Keyword(s):  
Tropical Maize ◽  
Maize Germplasm

scholarly journals Morpho-physiological traits associated with heat stress tolerance in tropical maize (Zea mays L.) at reproductive stage

2019 ◽  
Vol 13 ((04) 2019) ◽  
pp. 536-545 ◽  
Author(s):  
Jewel Jameeta Noor ◽  
M.T. Vinayan ◽  
Shahid Umar ◽  
Pooja Devi ◽  
Muhammad Iqbal ◽  
...  
Keyword(s):  
Heat Stress ◽  
Grain Yield ◽  
Stress Tolerance ◽  
Inbred Lines ◽  
Physiological Traits ◽  
Optimal Temperature ◽  
Tropical Maize ◽  
Important Trait ◽  
Heat Stress Tolerance ◽  
Secondary Traits

Heat stress resilience has emerged as an important trait in maize hybrids targeted for post–monsoon spring cultivation in large parts of South Asia and many other parts of the tropics. Selection based on grain yield alone under heat stress is often misleading, and therefore an approach involving stress-adaptive secondary traits along with grain yield could help in the development of improved, stable heat stress tolerant cultivars. We attempted to identify reliable and effective secondary traits associated with heat stress tolerance in tropical maize and sources of heat stress tolerant germplasm. A panel of 99 elite maize inbred lines representing the wider genetic diversity of tropical maize and a set of 58 elite hybrids were phenotyped under natural heat stress and optimal temperature for grain yield and 15 secondary traits including 10 morpho-physiological traits and 5 yield attributes. Evaluation under natural heat stress was done during the spring season by adjusting the planting date so that the complete reproductive stage (from tassel emergence to late grain filling) was exposed to heat stress. The optimal temperature trial was planted during the monsoon season with no exposure to heat stress at any crop stage. Heat stress significantly affected most of the observed traits. Among the traits studied two yield attributing traits, i.e.- ears per plant (EPP) and kernel per row (KPR), and three morpho-physiological traits, i.e.- chlorophyll content (CC), leaf firing (LF) and tassel blast (TB) were found to be the key secondary traits associated with grain yield under heat stress. In addition, low anthesis-silking internal (ASI) is an important trait that needs to be added in the index selection for heat stress tolerance. The study identified nine promising heat stress tolerant maize inbred lines with desirable secondary traits and grain yield under severe heat stress, which could be used as source germplasm in heat stress tolerance maize breeding program.

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