AUTHOR=Khammona Kanogporn , Dermail Abil , Suriharn Khundej , Lübberstedt Thomas , Wanchana Samart , Thunnom Burin , Poncheewin Wasin , Toojinda Theerayut , Ruanjaichon Vinitchan , Arikit Siwaret 

TITLE=Accelerating haploid induction rate and haploid validation through marker-assisted selection for qhir1 and qhir8 in maize

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1337463

DOI=10.3389/fpls.2024.1337463

ISSN=1664-462X

ABSTRACT=<p>Doubled haploid (DH) technology becomes more routinely applied in maize hybrid breeding. However, some issues in haploid induction and identification persist, requiring resolution to optimize DH production. Our objective was to implement simultaneous marker-assisted selection (MAS) for <italic>qhir1</italic> (<italic>MTL/ZmPLA1/NLD</italic>) and <italic>qhir8</italic> (<italic>ZmDMP</italic>) using TaqMan assay in F<sub>2</sub> generation of four BHI306-derived tropical × temperate inducer families. We also aimed to assess their haploid induction rate (HIR) in the F<sub>3</sub> generation as a phenotypic response to MAS. We highlighted remarkable increases in HIR of each inducer family. Genotypes carrying <italic>qhir1</italic> and <italic>qhir8</italic> exhibited 1 – 3-fold higher haploid frequency than those carrying only <italic>qhir1</italic>. Additionally, the <italic>qhir1</italic> marker was employed for verifying putative haploid seedlings at 7 days after planting. Flow cytometric analysis served as the gold standard test to assess the accuracy of the <italic>R1-nj</italic> and the <italic>qhir1</italic> marker. The <italic>qhir1</italic> marker showed high accuracy and may be integrated in multiple haploid identifications at early seedling stage succeeding pre-haploid sorting via <italic>R1-nj</italic> marker.</p>