scholarly journals Development of Quality Protein Maize (QPM) Inbred Lines and Genetic Diversity Assessed with ISSR Markers in a Maize Breeding Program

2012 ◽  
Vol 2 (4) ◽  
pp. 626-640 ◽  
Author(s):  
K. Nkongolo
BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Sirlene Viana de Faria ◽  
Leandro Tonello Zuffo ◽  
Wemerson Mendonça Rezende ◽  
Diego Gonçalves Caixeta ◽  
Hélcio Duarte Pereira ◽  
...  

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.


2010 ◽  
Vol 120 (7) ◽  
pp. 1289-1299 ◽  
Author(s):  
Delphine Van Inghelandt ◽  
Albrecht E. Melchinger ◽  
Claude Lebreton ◽  
Benjamin Stich

2021 ◽  
pp. 1-8
Author(s):  
J. E. Iboyi ◽  
A. Abe ◽  
V. O. Adetimirin

Abstract Knowledge of the genetic diversity and relationships among maize inbred lines can facilitate germplasm management and plant breeding programmes. The study investigated the level of genetic diversity among S6 lines developed from a tropical-adapted shrunken-2 (sh-2) maize population and their relationship with normal endosperm tropical inbred lines of known heterotic groups. Ninety-one sh-2 maize inbred lines (UI1-UI91) developed in the University of Ibadan super-sweet Maize Breeding Programme were genotyped at 30 simple sequence repeat (SSR) loci, alongside five normal endosperm maize inbred lines viz. TZi3, TZi4, TZi10, TZi12 and TZi15, four of which belong to two heterotic groups. Twenty-three SSR markers were polymorphic and detected a total of 61 alleles, with a range of 2–7 and an average of 2.65 alleles per locus. The polymorphic information content ranged from 0.12 in bnlg1937 to 0.77 in phi126, with an average of 0.36. The gene diversity (He) averaged 0.43. Cluster analysis resulted in five groups consisting of 16, 36, 17, 23 and 3 inbred lines, with one sh-2 line ungrouped. TZi 12 and TZi 15, both of which are of the same heterotic group, clustered with TZi 3 of another heterotic group. Considerable genetic diversity exists among the 96 inbred lines. Only two of the five normal endosperm lines shared clusters with the sh-2 lines. The clustering of the normal endosperm inbred lines is not related to their established heterotic patterns. Inbred lines in two clusters offer the possibility of guiding the exploitation of heterosis among the sh-2 lines.


Author(s):  
Ana COPá‚NDEAN

The genetic value of maize inbred lines is determined by the source of germplasm that they are extracted from, the selection methods used during the successive inbreeding generations, as well as by the combination capacity expressed in the obtained heterosis. In the field of applied genetics, quantifying genetic distance can be considered a tool for predicting heterosis, which serves to the prognostication of hybridization formulas with the best possible performance. The priority objectives that need to be studied in the assessment of genetic diversity are numerous and need to be discussed systematically. Considering the importance and timeliness of research knowledge on phenotypic diversity and genetic inbred lines, our analysis methods pursued the following objectives: evaluating genetic diversity; controlling, conservation, utilizing and maintaining the existing germplasm on a rigorous scientific basis. The biological material used in the conducted research was represented by: 5 inbred lines, considered to be indicators of the heterotic groups, and 12 lines, new creations of the maize breeding team at ARDS Turda. Analysis of additive effects corresponding to quantitative characters is one of the most effective ways to determine the amelioration value of donor sources of favourable genetic material for complementarily perfecting the initial material during recurring selection works. The calculation of additive and non-additive genic effects, allowed the prediction of genetic performance in simple and trilinear hybrids, with maximum chances of confirmation by the competition experiments, for homologation.


2014 ◽  
Vol 59 (2) ◽  
pp. 101-116
Author(s):  
Omolaran Bello ◽  
Odunayo Olawuyi ◽  
Sunday Ige ◽  
Jimoh Mahamood ◽  
Micheal Afolabi ◽  
...  

Quality protein maize (QPM) combining the enhanced levels of lysine and tryptophan with high grain yield and desirable agronomic traits could reduce food insecurity and malnutrition in West and Central Africa. Twenty-two varieties of QPM and two local checks were evaluated for agronomic characteristics and nutritional qualities in the southern Guinea savanna of Nigeria for two years (2009 and 2010). Though crude protein levels are good indicators of quality, amino acid composition analyses, especially lysine and tryptophan that would provide a final proof are in progress. The genotypes comprised five open pollinated varieties (OPVs), nine inbred lines, eight hybrids and two local varieties. Differences among the varieties were significant (P<0.01) for grain yield, days to tasselling as well as plant and ear heights, while year x variety interaction was only significant (P<0.05) for days to tasselling. Most of the QPM inbred lines (CML 437, CML 490 CML 178) and hybrids (Dada-ba, ART98-SW5-OB, ART98-SW4- OB and TZPB-OB) have superior performance for grain yield, other yield attributes and nutritional qualities compared with the OPVs and local checks. These inbreds could be potential sources of favorable alleles useful for future maize breeding, while the hybrids could be evaluated in different environments of Nigeria for comparative advantages in different environments and quality of the grains to be released to farmers.


Genetika ◽  
2007 ◽  
Vol 39 (3) ◽  
pp. 355-363 ◽  
Author(s):  
Jelena Srdic ◽  
Snezana Mladenovic-Drinic ◽  
Zorica Pajic ◽  
Milomir Filipovic

Information about the genetic diversity of inbred lines is essential in planning maize breeding programmes. Utilization of diverse parents in the process of hybridization has the greatest influence on producing high yielding hybrids. The aim of this research was to determine genetic diversity of ten maize inbred lines of different origin on the basis of protein and RAPD markers and to compare these results with pedigree and grain yield heterosis data. Results of genetic distances, based on protein and RAPD markers were similar and in concurrence with the date on the origin of inbreds. Usefulness of protein and RAPD markers for assigning inbreds to heterotic groups was examined by the cluster analysis. Cluster analysis based on protein markers, RAPD and heterosis showed clear grouping of lines into two main heterotic groups. Only few deviations were noticed, and those among inbreds not belonging to those heterotic groups. According to the observed results it could be concluded that grouping of inbred lines based on molecular markers, generally agrees with their pedigrees and that clusters are representatives of heterotic groups. Very high and highly significant estimate of rank correlation coefficient between RAPD and heterosis (0,876**) also confirmed that.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0252506
Author(s):  
Pearl Abu ◽  
Baffour Badu-Apraku ◽  
Beatrice E. Ifie ◽  
Pangirayi Tongoona ◽  
Leander D. Melomey ◽  
...  

Information on the genetic diversity, population structure, and trait associations of germplasm resources is crucial for predicting hybrid performance. The objective of this study was to dissect the genetic diversity and population structure of extra-early yellow and orange quality protein maize (QPM) inbred lines and identify secondary traits for indirect selection for enhanced grain yield under low-soil nitrogen (LN). One hundred and ten inbred lines were assessed under LN (30 kg ha -1) and assayed for tryptophan content. The lines were genotyped using 2500 single nucleotide polymorphism (SNP) markers. Majority (85.4%) of the inbred lines exhibited wide pairwise genetic distances between 0.4801 and 0.600. Genetic distances were wider between yellow and orange endosperm lines and predicted high heterosis in crosses between parents of different endosperm colors. The unweighted pair group method with arithmetic mean (UPGMA) and the admixture model-based population structure method both grouped the lines into five clusters. The clustering was based on endosperm color, pedigree, and selection history but not on LN tolerance or tryptophan content. Genotype by trait biplot analysis revealed association of grain yield with plant height and ear height. TZEEQI 394 and TZEEIORQ 73A had high expressivity for these traits. Indirect selection for high grain yield among the inbred lines could be achieved using plant and ear heights as selection criteria. The wide genetic variability observed in this study suggested that the inbred lines could be important sources of beneficial alleles for LN breeding programs in SSA.


Author(s):  
Ana COPANDEAN

The evaluation of the genetic diversity in maize inbred lines has significant implications on maize breeding, both in the process of creating inbred lines and in the strategy of creating well-performing hybrid formulae, starting from the general concept of parental-form diversity.


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