Abstract Rice plays a huge role in the nutrition of the world’s population. Similarly to Europe and America, rice is mainly sown in Russia by direct seeding; in Asian countries, seedling technology is used. On the one hand, direct seeding is followed by flooding of the field, which may lead to a low germination rate 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 may cause hypoxia or even anoxia in plants, suppressing the sprouts. In general, most rice varieties have low survival rates under water stress at the early stages of development, so screening is necessary for identifying the genotypes and for selecting the breeding material capable of withstanding stressful conditions. The germination energy AG (anaerobic germination) is one of the factors of rice plant tolerance to water stress conditions; it is a complex trait controlled by several genes, mapped on different chromosomes. Several rice varieties carrying the genes for germination energy AG (Khao Hlan On, Mazhan Red, etc.) have been described earlier by a number of authors. In Russia, there are currently few rice varieties carrying the genes of resistance to anaerobic conditions. Using QTL (quantitative trait locus), a small number of Russian varieties and populations have been studied for their tolerance to aerobic conditions, so it is necessary to expand the study to a large number of samples to select resistant genotypes. The study aims to screen dihaploid androgenic rice plants for the presence of germination energy genes AG1 and AG2 and to select promising genotypes of particular interest for further breeding. In total, 25 regenerated plants were obtained by the in vitro anther culture method from four hybrids, whose parental lines were donors of germination energy (Khao Hlan On), resistance to deep-water flooding (Inbara-3 and IR-64), and highly productive Russian varieties (Kontakt, Magnat, and Novator). Molecular genetic analysis was carried out using molecular markers AG1 (qAG-9-2) and AG2 (qAG-7-1). The AG1 gene was found in 17 rice lines, the AG2 gene in 11 lines, and both genes in nine rice lines (4641/1, 4641/2, 4641/3, 4641/4, 4641/6, 4641/8, 4641/9, 4641/10, and 5010/4). A laboratory experiment on resistance of dihaploid lines to anaerobic stress showed those with high germination energy. Promising dihaploid androgenic rice plants were selected as a source material for further breeding.

Identification of AG Germination Energy Genes in Dihaploid Androgenic Rice Plants

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发表日期：

2025年6月1日

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N. G. Chertkova,
P. I. Kostylev,
A. V. Usatov,
N. V. Kalinina

摘要

Abstract

Rice plays a huge role in the nutrition of the world’s population. Similarly to Europe and America, rice is mainly sown in Russia by direct seeding; in Asian countries, seedling technology is used. On the one hand, direct seeding is followed by flooding of the field, which may lead to a low germination rate 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 may cause hypoxia or even anoxia in plants, suppressing the sprouts. In general, most rice varieties have low survival rates under water stress at the early stages of development, so screening is necessary for identifying the genotypes and for selecting the breeding material capable of withstanding stressful conditions. The germination energy AG (anaerobic germination) is one of the factors of rice plant tolerance to water stress conditions; it is a complex trait controlled by several genes, mapped on different chromosomes. Several rice varieties carrying the genes for germination energy AG (Khao Hlan On, Mazhan Red, etc.) have been described earlier by a number of authors. In Russia, there are currently few rice varieties carrying the genes of resistance to anaerobic conditions. Using QTL (quantitative trait locus), a small number of Russian varieties and populations have been studied for their tolerance to aerobic conditions, so it is necessary to expand the study to a large number of samples to select resistant genotypes. The study aims to screen dihaploid androgenic rice plants for the presence of germination energy genes AG1 and AG2 and to select promising genotypes of particular interest for further breeding. In total, 25 regenerated plants were obtained by the in vitro anther culture method from four hybrids, whose parental lines were donors of germination energy (Khao Hlan On), resistance to deep-water flooding (Inbara-3 and IR-64), and highly productive Russian varieties (Kontakt, Magnat, and Novator). Molecular genetic analysis was carried out using molecular markers AG1 (qAG-9-2) and AG2 (qAG-7-1). The AG1 gene was found in 17 rice lines, the AG2 gene in 11 lines, and both genes in nine rice lines (4641/1, 4641/2, 4641/3, 4641/4, 4641/6, 4641/8, 4641/9, 4641/10, and 5010/4). A laboratory experiment on resistance of dihaploid lines to anaerobic stress showed those with high germination energy. Promising dihaploid androgenic rice plants were selected as a source material for further breeding.