Intergenic polymorphisms—linkage groups that include closely located, identical, or structurally similar genes—are important in the structure of the plant genome. The absence of a significant connection between them indicates a violation of functional connections. Determinants of plant resistance and a number of traits are associated with polymorphisms of loci in which the corresponding genes are localized. Such “blocks” of hereditary variability are characterized by an increased frequency of spontaneous recessive and dominant mutations. Polymorphism of the determination of a trait is reflected in the variability of the trait, characteristic of genotypes containing an allele blocked for genetic reasons (for example, when the gene is blocked in more than 50% of individuals), and can manifest itself in the form of changes in the average values and variation of the trait in the entire sample. Violation of population heterogeneity is associated with an increase in the variability of somatic and chromosomal rearrangements