Combining Ability and Molecular Genetic Distances in Tropical Maize Lines for Grain Yield and Agronomic Traits

Gichuru, Lilian; Derera, John; Tongoona, Pangirayi; Mwimali, Murenga

doi:10.1080/02571862.2016.1213323

Cited by 5 publications

(3 citation statements)

References 19 publications

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“…In sharp contrast to ndings in the current study, Schrag et al (2010) and Gichuru et al (2017) reported high predictive value of molecular maker genetic distances in heterosis; the observed degree of correlation was associated with the genetic differences and complementary traits of lines used. The ability of genetic distance to predict heterosis in crosses therefore varies with germplasm used (Betran et al, 2003) and probably the set of molecular markers used.…”

Section: Genetic Distancescontrasting

confidence: 99%

Genetic diversity and heterotic orientation of South Africa maize inbred lines towards tropical and temperate testers

et al. 2021

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An e cient hybrid breeding program de nes 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 speci c combining ability (SCA) effects of hybrids were signi cantly different (P<0.05) for grain yield. There was a weak correlation between molecular genetic distances and both grain yield mean and speci c 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 classi ed the inbred lines into 11 clusters that could be simpli ed 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 classi cation of the lines with profound implications for breeding progress.

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Section: Genetic Distancescontrasting

confidence: 99%

Genetic diversity and heterotic orientation of South Africa maize inbred lines towards tropical and temperate testers

et al. 2021

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“…With molecular markers efficiently predicting genetic divergence, there is a general consensus today that such markers can effectively assign individuals to respective heterotic groups (Melchinger et al, 1991;Barbosa et al, 2003) at lower costs (Fernandez et al, 2015;Punya et al, 2018). Heterotic grouping using molecular markers also allows greater number of lines to be evaluated as opposed to traditional methods and are vital in situations where heterotic patterns for developing single cross hybrids are not well established (Gichuru et al, 2016), such as in the current study.…”

Section: Discussionmentioning

confidence: 99%

Genetic characterization and divergence studies of maize (Zea maysL.) lines developed from landraces indigenous to North Eastern Hill Region (NEHR) of India

Naveenkumar

Sen

Vashum

et al. 2020

Plant Genet. Resour.

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The current study focused on characterization of the underlying genetic divergence in inbred lines developed from local landraces of North Eastern Hill Region of India – a designated Asiatic maize diversity centre – following six generations of inbreeding. Substantial genetic differentiation was indicated based on very high to moderate Fst values for 22 of the 38 simple sequence repeat markers studied. STRUCTURE analysis partitioned the subset into two distinct and one admixture subgroup (Populations I, II and III respectively) accompanied by a significant reduction in heterozygosity. Population II was further subdivided into subpopulations Pop-M9 and Pop-T9. Nei's pairwise genetic distance and population Fst values indicated that Populations I and II were more divergent with neighbour joining clustering analysis clearly defining landraces originating from the states of Tripura (Population II) and Sikkim (Population I) as most divergent. Principal coordinates analysis could explain 31.26% of the variation present in the subgroups wherein Population I was more variable. Analysis of molecular variance and Fst coefficients (P < 0.001) indicated 17% population structuring with 55% variation detected for individuals within populations. These results combined with the presence of phenotypic variability in the subgroups for yield traits supported by results of a preliminary partial diallel analysis strongly suggest the existence of distinct heterotic groups. Divergence studies are crucial for exploiting heterosis, and the current study would go a long way to help establish a germplasm base for developing varieties with improved agronomic performance and surer commercial prospects no reports of which are available thus far.

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“…Combining ability estimates have been used to anticipate improvement due to hybridization and selection in maize breeding (Khalil et al, 2010;Issa et al, 2018), but further exploration will be required to dissect the genetic basis of combining ability (Gichuru et al, 2017). With the development of molecular markers (e.g., AFLP, RFLP, SSR), the genetic basis of combining ability effects was estimated by QTL mapping (Liu et al, 2004;Basbag et al, 2007;Shukla and Pandey, 2010;Giraud et al, 2017;Zhou Q. et al, 2017;Seye et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

Genetic Dissection of the General Combining Ability of Yield-Related Traits in Maize

et al. 2020

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Maize yield components including row number, kernel number per row, kernel thickness, kernel width, kernel length, 100-kernel weight, and volume weight affect grain yield directly. Previous studies mainly focused on dissecting the genetic basis of per se performances for yield-related traits, but the genetic basis of general combining ability (GCA) for these traits is still unclear. In the present study, 328 RILs were crossed as males to two testers according to the NCII mating design, resulting in a hybrid panel composed of 656 hybrids. Both the hybrids and parental lines were evaluated in four environments in 2015 and 2016. Correlation analysis showed the performances of GCA effects were significantly correlated to the per se performances of RILs for all yieldrelated traits (0.17 ≤ r ≤ 0.64, P > 0.01). Only 17 of 95 QTL could be detected for both per se performances of RILs and GCA effects for eight yield-related traits. The QTL qKN7-1 and qHKW1-3, which could explain more than 10% of the variation in the GCA effects of KN and HKW, were also detected for per se performances for the traits. The pleiotropic loci qRN3-1 and qRN6, which together explained 14.92% of the observed variation in GCA effects for RN, were associated with the GCA effects of KW and HKW, but not with per se performances for these traits. In contrast, Incw1, which was related to seed weight in maize, was mapped to the region surrounding MK2567 at the qHKW5-2 locus, but no GCA effect was detected. The QTL identified in present study for per se performances and corresponding GCA effects for yield-related traits might be useful for maize hybrid breeding.

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Combining Ability and Molecular Genetic Distances in Tropical Maize Lines for Grain Yield and Agronomic Traits

Cited by 5 publications

References 19 publications

Genetic diversity and heterotic orientation of South Africa maize inbred lines towards tropical and temperate testers

Genetic diversity and heterotic orientation of South Africa maize inbred lines towards tropical and temperate testers

Genetic characterization and divergence studies of maize (Zea maysL.) lines developed from landraces indigenous to North Eastern Hill Region (NEHR) of India

Genetic Dissection of the General Combining Ability of Yield-Related Traits in Maize

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