The invention belongs to the technical field of genetic engineering and particularly relates to a function and application of an arabidopsis thaliana POL2A gene in reduction division recombination. The application comprises the following steps of using sequence characteristics of coding POL2A protein and the authentication of the new function of the gene in reduction division, i.e. using a fluorescent label site system to analyze the influence of POL2A to reduction division recombination frequency and distribution, and providing a fluorescent label-containing genetic material; providing the function of the gene of analyzing how complete mutation of the gene causes embryo death in reduction division, and providing the technology of a series of cell biology and the like. The important function of POL2A in reduction division recombination is proved in an eukaryote for the first time; the function is used, the modern biotechnology method is used, and the recombination frequency of a generic material in a reduction division process is controlled, so that aggregation of excellent characters is quickened, separation of the excellent characters in a hybrid offspring is delayed, and the aim of propelling and improving breeding study level is fulfilled.