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. 2017 Jun;130(6):1113-1122.
doi: 10.1007/s00122-017-2873-9. Epub 2017 Mar 18.

Dissection of a major QTL qhir1 conferring maternal haploid induction ability in maize

Sudha K Nair  1 , Willem Molenaar  2 , Albrecht E Melchinger  2 , Prasanna M Boddupalli  3 , Leocadio Martinez  4 , Luis Antonio Lopez  4 , Vijay Chaikam  5
Affiliations

Dissection of a major QTL qhir1 conferring maternal haploid induction ability in maize

Sudha K Nair et al. Theor Appl Genet. 2017 Jun.

Abstract

Among the qhir11 and qhir12 sub-regions of a major QTL qhir1, only qhir11 has significant effect on maternal haploid induction, segregation distortion and kernel abortion. In vivo haploid induction in maize can be triggered in high frequencies by pollination with special genetic stocks called haploid inducers. Several genetic studies with segregating populations from non-inducer x inducer crosses identified a major QTL, qhir1, on chromosome 1.04 contributing to in vivo haploid induction. A recent Genome Wide Association Study using 51 inducers and 1482 non-inducers also identified two sub-regions within the qhir1 QTL region, named qhir11 and qhir12; qhir12 was proposed to be mandatory for haploid induction because the haplotype of qhir11 was also present in some non-inducers and putative candidate genes coding for DNA and amino acid binding proteins were identified in the qhir12 region. To characterize the effects of each sub-region of qhir1 on haploid induction rate, F2 recombinants segregating for one of the sub-regions and fixed for the other were identified in a cross between CML269 (non-inducer) and a tropicalized haploid inducer TAIL8. To quantify the haploid induction effects of qhir11 and qhir12, selfed progenies of recombinants between these sub-regions were genotyped. F3 plants homozygous for qhir11 and/or qhir12 were identified, and crossed to a ligueless tester to determine their haploid induction rates. The study revealed that only the qhir11 sub-region has a significant effect on haploid induction ability, besides causing significant segregation distortion and kernel abortion, traits that are strongly associated with maternal haploid induction. The results presented in this study can guide fine mapping efforts of qhir1 and in developing new inducers efficiently using marker assisted selection.

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Conflict of interest statement

Conflict of interest

The authors declare that they have no conflict of interest.

Figures

Fig. 1
Fig. 1
Strategy used for genetic delineation of qhir1 and analysis of the effects of qhir11 and qhir12 sub-regions on HIR in maize
See this image and copyright information in PMC

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