关键词: 玉米, 单倍体诱导, MTL, CENH3, 双单倍体, 基因组消除

Abstract: Haploid breeding technology can accelerate generation of homozygous doubled haploid（DH）lines through haploid induction followed by chromosome doubling，significantly shortening breeding cycles and improving selection efficiency. In recent years，in vivo haploid induction techniques based on the operation of key endogenous genes have become a research hotspot.Two prominent systems，pollen⁃specific phospholipase A gene MTL（MATRILINEAL）and centromere⁃specific histone H3 gene CENH3，are centered.For the MTL system，its loss⁃of⁃function disrupts phospholipid metabolism in sperm cells，leading to reactive oxygen species（ROS） burst and DNA damage.Finally，the paternal genome is eliminated through a mechanism known as‘post⁃fertilization chromosome elimination’. On the other hand，the CENH3 system involves the modification of CENH3 protein.Common strategies such as N⁃terminal tail modification， point mutations in the histone⁃fold domain， and heterologous complementation are designed to create functionally defective centromeres.These defective centromeres fail in the competition for kinetochore⁃microtubule attachment during zygotic division，leading to their selective elimination.This paper systematically reviewed the molecular mechanism of haploid induction mediated by MTL and CENH3，technical optimization strategies and the application of these technologies in major crops such as maize，rice，and wheat，and compared the differences between the two systems across several key aspects，including induction mechanisms，applicable species，induction efficiency，technical complexity，influence on plant development，and current status of industrial application.Furthermore，the integrated application potential of the above two systems in precision breeding was prospected，aiming to provide a theoretical foundation and technical support for crop genetic improvement.

Key words: Maize, Haploid induction, MTL, CENH3, Doubled haploid, Genome elimination