Identification of AG germination energy genes in dihaploid androgenic rice plants

Rice plays a huge role in the nutrition of the world population In Russia, as in Europe and America, rice is mainly sown by direct seeding, while in Asian countries, seedling technology is used. Direct seeding is followed by flooding of the field, which can lead to a low percentage of seedlings and death of young plants. On the other hand, flooding of rice fields helps in the fight against weeds and rodents. Despite the fact that rice is a hydrophyte plant, water can lead to hypoxia or even anoxia, contributing to the suppression of young shoots. In general, most rice varieties at the early stages of development under water stress have low survival, so it is necessary to screen 8 genotypes and select breeding material capable of withstanding stressful conditions. One of the factors of tolerance to water stress conditions is the germination energy AG (anaerobic germination), which is a complex trait controlled by several genes mapped on different chromosomes. Foreign scientists have identified varieties with the AG germination energy genes (Khao Hlan On, Mazhan Red and others). In our country, there are currently few varieties with genes for resistance to anaerobic conditions. Currently, a small number of local varieties and populations have been studied for tolerance to anaerobic conditions using QTL, so it is necessary to expand the study of a large number of samples to select resistant genotypes. Therefore, the purpose of the study was to screen dihaploid androgenic rice plants for the presence of AG1, AG2 germination energy genes and to select promising genotypes of particular interest for breeding work. The source material was 25 regenerated plants obtained by in vitro anther culture from four hybrids whose parental lines were donors of germination energy (Khao Hlan On), resistance to deep-water flooding (Inbara-3, IR-64) and Russian varieties (Contact, Magnat, Novator). Molecular genetic analysis was performed using molecular markers AG1 (qAG–9–2) and AG2 (qAG–7–1). In total, the AG1 gene was identified in 17 rice lines, the AG2 gene in 11 lines, and both genes in 9 rice lines (4641/1, 4641/2, 4641/3, 4641/4, 4641/6, 4641/8, 4641/9, 4641/10, 5010/4). Laboratory experiment on dihaploid lines resistance to anaerobic stress revealed samples with high germination energy. Promising dihaploid androgenic rice plants were selected as source material for breeding.

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