The genetic resources of cereal crops in terms of resistance to aphids are reviewed. Phytosanitary destabilization led to a significant increase in the harmfulness of this group of insects. The breeding of resistant plant genotypes is a radical, the cheapest, and environmentally safe way of pest control. The genetic homogeneity of crops hastens the adaptive microevolution of harmful organisms. Both major and minor aphid resistance genes of cereal plants interact with insects differentially. Therefore, rational breeding envisages the expansion of the genetic diversity of cultivated varieties. The possibilities of replenishing the stock of effective resistance genes by studying the collection of cultivated cereals, introgression, and creating mutant forms are considered. The interaction of insects with plants is subject to the gene-for-gene relationship. Plant resistance genes are characterized by close linkage and multiple allelism. The realizing plant genotype depends on the phytophage biotype. Information about the mechanisms of constitutional and induced plant resistance is discussed. Resistance genes differ in terms of stability of expression. The duration of the period when varieties remain resistant is not related either to its phenotypic manifestation or to the number of resistance genes. One explanation for the phenomenon of durable resistance is the association of the virulence mutation with pest viability.

The phenomenon of cytoplasmic male sterility (CMS), consisting in the inability to produce functional pollen due to mutations in mitochondrial genome, has been described in more than 150 plant species. With the discovery of nuclear fertility restorer (Rf) genes capable of suppressing the CMS phenotype, it became possible to use the CMS-Rf genetic systems as the basis for practical utilization of heterosis effect in various crops. Seed production of sunflower hybrids all over the world is based on the extensive use of the PET1 CMS combined with the Rf1 gene. At the same time, data on Rf1 localization, sequence, and molecular basis for the CMS PET1 type restoration of fertility remain unknown. Searching for candidate genes of the Rf1 gene has great fundamental and practical value. Therefore, in this study, association mapping of fertility restorer gene for CMS PET1 in sunflower was performed. The genome-wide association study (GWAS) results made it possible to isolate a segment 7.72 Mb in length on chromosome 13, in which 21 candidates for Rf1 fertility restorer gene were identified, including 20 pentatricopeptide repeat (PPR)family genes and one Probable aldehyde dehydrogenase gene. The results will serve as a basis for further study of the genetic nature and molecular mechanisms of pollen fertility restoration in sunflower, as well as for further intensification of sunflower breeding.

America is the center of origin of the annual sunflower

Powdery mildew (causal agent Blumeria graminis) is a widespread and harmful fungi disease of cereal crops especially in the regions with humid climate. The pathogen is differentially interacting with plant host genotypes. Growing cereal crop varieties protected with different resistance genes is the most rational, costly and ecologically safe way of combating powdery mildew. The supply of effective genes can be increased due to studies of crop genetic resources collection, introgression of resistance from wild relatives, and also at the expense of mutant forms created with the use of traditional (induced mutagenesis) and biotechnological methods including genome editing. This causes the increasing interest to searching and identifying resistance genes, elucidation of their structural and functional organization, and analysis of molecular mechanisms of the character development. The review summarizes modern information on the identified genes of powdery mildew resistance of the main cereal crops wheat, barley and oat. The list of wheat and barley genes identified at the molecular level is presented. It includes genes encoding NLR and CNL proteins (Pm2, Pm3, TaMla2, TaMla3 genes of wheat, rye Pm8 gene, barley Mla gene), receptor-like proteins (barley Mlo gene), transport proteins and receptor-like kinases (Lr34, Lr67, Pm21 of wheat).