METHOD FOR BREEDING A SALT-RESISTANT RICE VARIETY Russian patent published in 2022 - IPC A01H1/04 

FIELD: biotechnology.

SUBSTANCE: invention relates to the field of biotechnology, namely, to a method for breeding a salt-resistant rice variety. Method for breeding a salt-resistant rice variety includes the following stages: A) selecting the parent forms with the rice resistance gene and with a high yield, crossing said forms to produce hybrids; B) analysing the hybrids from the second F₂ to the sixth generation F₆ for the presence of Saltol gene by PCR analysis, preserving the dominant homozygotes and heterozygotes; C) subjecting all hybrid forms from the hybrids of the second generation F₂ to the hybrids of the sixth generation F₆ to a strict phenotypic, genotypic, and laboratory selection under stress, accounting for the commercially valuable traits; selecting the best lines for the reproduction of the next generation; D) each year, studying the salt tolerance of all hybrids by a laboratory method: in rolls of filtering paper and polyethylene, in a 1.5% saline solution of NaCl; selecting the best samples with a salt tolerance above 70%; E) in the hybrids of the fourth generation F₄, studying the salt tolerance of seeds of rice hybrids from sowing to ripening in conditions of microfields constituting a soil-filled 300×100 cm container insulated from leaking with plastic film to maintain the stable severe conditions: a 1.5% concentration of salt in the soil; after ripening, conducting biometric analysis of the plants, selecting all surviving hybrids for the reproduction of the next generation in standard rice fields; F) subjecting all seeds of the hybrid forms of the fifth generation F₅ after phenotypic and genotypic selections using PCR analysis to selection on a 1.5% salinification with NaCl by the roll method, putting the best sprouts with an over 50% salt resistance, containing the sought salt resistance gene, to cups with soil, and replanting as seedlings in rice fields; G) for the selection of salinification-resistant forms of rice, the hybrids of the sixth generation F₆ in the period of flowering and seed ripening are extracted from rice fields in the stem extension period and put in boxes with a fixed 1% concentration of NaCl, wherein the plants of the sixth generation F₆, having formed the maximum number of grains in such stressful conditions as salt shock before flowering, are the most resistant to salt-related stress in the period of flowering and seed ripening; H) hybrids of the sixth generation F₆ form lines of maximum purity, ready to be bred and tested in a control nursery and competitive variety testing, and a further state variety testing.

EFFECT: possibility of increasing the yield of rice when cultivating on salinised soils and irrigating with water with a mass fraction of salts up to 1.5%.

1 cl, 6 dwg