QTL Mapping for Haploid Inducibility Using Genotyping by Sequencing in Maize.

Area of Science:

• Plant breeding
• Genetics
• Maize genetics

Background:

• Doubled haploid (DH) technology is crucial for maize breeding, utilizing in vivo haploid induction (HI).
• The inducibility (IND) of different maize germplasm varies, with underlying molecular mechanisms remaining largely unknown.
• Understanding IND is essential for optimizing DH technology in elite maize inbred lines.

Purpose of the Study:

• To investigate the phenotypic variation for IND in a maize mapping population.
• To identify quantitative trait loci (QTL) associated with IND in temperate maize inbred lines.
• To explore potential QTL x location interactions affecting IND.

Main Methods:

• Developed a mapping population from a biparental cross of elite maize inbred lines (A427 and CR1Ht).
• Evaluated 247 F2:3 families across three distinct locations.
• Employed Inclusive Composite Interval Mapping (ICIM) to detect QTL for IND.

Main Results:

• Identified four QTL associated with IND, collectively explaining 37.4% of the phenotypic variance.
• No single QTL exhibited stable effects across all tested locations.
• Detected significant QTL x location interactions, indicating environmental influence on IND.

Conclusions:

• Minor QTL with environmental sensitivity appear to control IND in maize.
• Further research is needed to elucidate the genetic architecture of IND and its environmental interactions.
• Optimizing HI efficiency in maize breeding programs requires considering genotype-by-environment interactions.