Genetic Analysis of Maternal Haploid Inducibility for In Vivo Haploid Induction in Maize

Doubled haploid (DH) technology based on in vivo haploid induction has gradually become the key technology in modern maize breeding. The ability of maternal germplasm to be induced into haploids, inducibility, varies among genotypes. To dissect the genetic basis of maternal haploid inducibility (MHI), an F-2 population derived from inbred lines B73 and Zheng58 was used for single environment QTL analysis and QTL by environment interaction analysis. The mapping population was genotyped by the 48K liquid-phase hybridization probe capture technique and phenotyped in multi-environment trials for MHI. A total of ten QTLs located on chromosome bins 4.05, 4.09, 5.05/5.06, 6.07, 7.00, 7.01, 7.02, 7.03, 9.02, and 10.06 were identified for MHI. The PVE value of each QTL ranged from 4.79% to 10.01%. The QTL qMHI5 is a stable QTL identified in JSH, HN, and across environments with the highest PVE value of 10.01%. Three QTLs, qMHI4-1, qMHI5, and qMHI 9-1, were detected by both methods. Three genes, Zm00001d017366, Zm00001d017420, and Zm00001d017432, involved in seed development were the most likely candidate genes. This study provides valuable information for the genetic basis of MHI.