Integrating Exotic Germplasm into Corn Belt Maize Breeding Programs 1

Crop Science ◽  
1972 ◽  
Vol 12 (2) ◽  
pp. 203-206 ◽  
Author(s):  
Arnel R. Hallauer ◽  
J. H. Sears
Keyword(s):  
Corn Belt ◽  
Exotic Germplasm ◽  
Maize Breeding ◽  
Breeding Programs

Comparing Methods for Integrating Exotic Germplasm into European Forage Maize Breeding Programs 1

Crop Science ◽  
2003 ◽  
Vol 43 (6) ◽  
pp. 1952-1959 ◽  
Author(s):  
Domagoj Šimić ◽  
Thomas Presterl ◽  
Günter Seitz ◽  
Hartwig H. Geiger
Keyword(s):  
Exotic Germplasm ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Forage Maize

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 Maize gene bank collections as potentially valuable breeding material

Genetika ◽  
2010 ◽  
Vol 42 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Jelena Vancetovic ◽  
Snezana Mladenovic-Drinic ◽  
Milosav Babic ◽  
Dragana Ignjatovic-Micic ◽  
Violeta Andjelkovic
Keyword(s):  
Genetic Resources ◽  
Herbicide Tolerance ◽  
Gene Bank ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Effective Utilization ◽  
Maize Populations ◽  
Predominant Type ◽  
Superior Genotypes ◽  
Maize Gene

Characterization and evaluation of the genetic resources provide breeders with valuable information on an effective utilization of the genetic resources in breeding programs. In this paper we present the results of different research programs aimed at identification of superior genotypes among MRI gene bank accessions, regarding stress tolerance (drought and herbicides), better nutritional quality (phosphorus) and specific traits (cytoplasmic male sterility - CMS). Fifty-two genotypes were identified as a potential source for drought tolerance. Considering herbicide tolerance only genotypes with resistance to the Pivot were found. Within 100 sources of CMS in the collection S cytoplasm was identified as the predominant type. Phytate analysis of 60 maize populations identified three groups of populations - with low (8), intermediate (25) and high (27) phytate content. The results of these researches, which are a part of pre-breeding activities, will be included in MRI breeding programs, with the aim of developing new genotypes with improved traits important in commercial maize breeding and seed production.

scholarly journals Seed Quality Assurance in Maize Breeding Programs: Tests to Explain Variations in Maize Inbreds and Populations

2008 ◽  
Vol 100 (2) ◽  
pp. 337-343
Author(s):  
A. Susana Goggi ◽  
Petrutza Caragea ◽  
Linda Pollak ◽  
Gina McAndrews ◽  
Mindy DeVries ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Seed Quality ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Maize Inbreds

scholarly journals Doubled haploid technology for line development in maize: technical advances and prospects

2019 ◽  
Vol 132 (12) ◽  
pp. 3227-3243 ◽  
Author(s):  
Vijay Chaikam ◽  
Willem Molenaar ◽  
Albrecht E. Melchinger ◽  
Prasanna M. Boddupalli
Keyword(s):  
Doubled Haploid ◽  
Chromosome Doubling ◽  
Production Costs ◽  
Great Promise ◽  
Success Rates ◽  
Haploid Induction ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Line Production

Key Message Increased efficiencies achieved in different steps of DH line production offer greater benefits to maize breeding programs. Abstract Doubled haploid (DH) technology has become an integral part of many commercial maize breeding programs as DH lines offer several economic, logistic and genetic benefits over conventional inbred lines. Further, new advances in DH technology continue to improve the efficiency of DH line development and fuel its increased adoption in breeding programs worldwide. The established method for maize DH production covered in this review involves in vivo induction of maternal haploids by a male haploid inducer genotype, identification of haploids from diploids at the seed or seedling stage, chromosome doubling of haploid (D0) seedlings and finally, selfing of fertile D0 plants. Development of haploid inducers with high haploid induction rates and adaptation to different target environments have facilitated increased adoption of DH technology in the tropics. New marker systems for haploid identification, such as the red root marker and high oil marker, are being increasingly integrated into new haploid inducers and have the potential to make DH technology accessible in germplasm such as some Flint, landrace, or tropical material, where the standard R1-nj marker is inhibited. Automation holds great promise to further reduce the cost and time in haploid identification. Increasing success rates in chromosome doubling protocols and/or reducing environmental and human toxicity of chromosome doubling protocols, including research on genetic improvement in spontaneous chromosome doubling, have the potential to greatly reduce the production costs per DH line.

scholarly journals Maximizing efficiency of genomic selection in CIMMYT’s tropical maize breeding program

2020 ◽  
Author(s):  
Sikiru Adeniyi Atanda ◽  
Michael Olsen ◽  
Juan Burgueño ◽  
Jose Crossa ◽  
Daniel Dzidzienyo ◽  
...  
Keyword(s):  
Genomic Selection ◽  
Prediction Accuracy ◽  
Large Scale ◽  
Primary Objective ◽  
Breeding Program ◽  
Breeding Cycle ◽  
Training Set ◽  
Maize Breeding ◽  
Phenotypic Data ◽  
Breeding Programs

Abstract Key message Historical data from breeding programs can be efficiently used to improve genomic selection accuracy, especially when the training set is optimized to subset individuals most informative of the target testing set. Abstract The current strategy for large-scale implementation of genomic selection (GS) at the International Maize and Wheat Improvement Center (CIMMYT) global maize breeding program has been to train models using information from full-sibs in a “test-half-predict-half approach.” Although effective, this approach has limitations, as it requires large full-sib populations and limits the ability to shorten variety testing and breeding cycle times. The primary objective of this study was to identify optimal experimental and training set designs to maximize prediction accuracy of GS in CIMMYT’s maize breeding programs. Training set (TS) design strategies were evaluated to determine the most efficient use of phenotypic data collected on relatives for genomic prediction (GP) using datasets containing 849 (DS1) and 1389 (DS2) DH-lines evaluated as testcrosses in 2017 and 2018, respectively. Our results show there is merit in the use of multiple bi-parental populations as TS when selected using algorithms to maximize relatedness between the training and prediction sets. In a breeding program where relevant past breeding information is not readily available, the phenotyping expenditure can be spread across connected bi-parental populations by phenotyping only a small number of lines from each population. This significantly improves prediction accuracy compared to within-population prediction, especially when the TS for within full-sib prediction is small. Finally, we demonstrate that prediction accuracy in either sparse testing or “test-half-predict-half” can further be improved by optimizing which lines are planted for phenotyping and which lines are to be only genotyped for advancement based on GP.

scholarly journals MYO, a Candidate Gene for Haploid Induction in Maize Causes Male Sterility

Plants ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 773
Author(s):  
Kimberly Vanous ◽  
Thomas Lübberstedt ◽  
Rania Ibrahim ◽  
Ursula K. Frei
Keyword(s):  
Male Sterility ◽  
Gene Isolation ◽  
Haploid Induction ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Positional Candidate ◽  
Haploid Induction Rate ◽  
Induction Rate ◽  
Transgenic Lines ◽  
Strong Candidate

Doubled haploid technology is highly successful in maize breeding programs and is contingent on the ability of maize inducers to efficiently produce haploids. Knowledge of the genes involved in haploid induction is important for not only developing better maize inducers, but also to create inducers in other crops. The main quantitative trait loci involved in maize haploid induction are qhir1 and qhir8. The gene underlying qhir1 has been discovered and validated by independent research groups. Prior to initiation of this study, the gene associated with qhir8 had yet to be recognized. Therefore, this research focused on characterizing positional candidate genes underlying qhir8. Pursuing this goal, a strong candidate for qhir8, GRMZM2G435294 (MYO), was silenced by RNAi. Analysis of crosses with these heterozygous RNAi-transgenic lines for haploid induction rate revealed that the silencing of MYO significantly enhanced haploid induction rate by an average of 0.6% in the presence of qhir1. Recently, GRMZM2G465053 (ZmDMP) was identified by map-based gene isolation and shown to be responsible for qhir8. While our results suggest that MYO may contribute to haploid induction rate, results were inconsistent and only showing minor increases in haploid induction rate compared to ZmDMP. Instead, reciprocal crosses clearly revealed that the silencing of MYO causes male sterility.

scholarly journals QTL Mapping for Gray Leaf Spot Resistance in a Tropical Maize Population

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 304-312 ◽  
Author(s):  
L. Liu ◽  
Y. D. Zhang ◽  
H. Y. Li ◽  
Y. Q. Bi ◽  
L. J. Yu ◽  
...  
Keyword(s):  
Flowering Time ◽  
Leaf Spot ◽  
Genetic Effect ◽  
Gray Leaf Spot ◽  
Chromosome 2 ◽  
Tropical Maize ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Maize Population ◽  
Qtl Effects

A tropical gray leaf spot (GLS)-resistant line, YML 32, was crossed to a temperate GLS-susceptible line, Ye 478, to produce an F2:3 population for the identification of quantitative trait loci (QTL) associated with resistance to GLS. The population was evaluated for GLS disease resistance and flowering time at two locations in Yunnan province. Seven QTL using GLS disease scores and six QTL using flowering time were identified on chromosomes 2, 3, 4, 5, and 8 in the YML 32 × Ye 478 maize population. All QTL, except one identified on chromosome 2 using flowering time, were overlapped with the QTL for GLS disease scores. The results indicated that QTL for flowering time in this population strongly corresponded to QTL for GLS resistance. Among the QTL, qRgls.yaas-8-1/qFt.yaas-8 with the largest genetic effect accounted for 17.9 to 18.1 and 11.0 to 21.42% of variations for GLS disease scores and flowering time, respectively, and these should be very useful for improving resistance to GLS, especially in subtropical maize breeding programs. The QTL effects for resistance to GLS were predominantly additive in nature, with a dominance effect having been found for two QTL on the basis of joint segregation genetic analysis and QTL analysis.

scholarly journals Implications on the introduction of transgenics in Brazilian maize breeding programs

2013 ◽  
Vol 13 (1) ◽  
pp. 9-22 ◽  
Author(s):  
Sidney Netto Parentoni ◽  
Rubens Augusto de Miranda ◽  
João Carlos Garcia
Keyword(s):  
Technology Use ◽  
Critical Analysis ◽  
Driving Force ◽  
Transgenic Technology ◽  
Maize Seed ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Production Sector ◽  
The World ◽  
Seed Market

Transgenic maize was approved in Brazil in 2008/2009. In 2012, it occupied 73% of the country maize growing area. This high adoption rate confirms studies indicating that technology use has been the major driving force in Brazilian agriculture. Maize seed market in the world has been a concentrated sector. Although, when this sector is associated with transgenesis, this concentration increases sharply. In one side, there is the idea that companies can benefit from gains of scale and complementarities to maximize their efficiency in research and development (R&D). On the other side, this concentration may allow the exercise of "market power" by dominant companies. The objective of this study is to analyze the impacts of the adoption of transgenic technology in the arrangements of maize breeding programs and seed production sector in Brazil. A critical analysis of the situation of the breeding programs that do not have this technology is made.

Sign in / Sign up

Export Citation Format

Share Document