Modification of meiotic recombination frequency to enlarge genetic diversity in the cross breeding of rice

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05981
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39010:Science in plant genetics and breeding-related
• Research Institution: Setsunan University
• Principal Investigator: OKUMOTO YUTAKA 摂南大学, 農学部, 教授 (90152438)
• Co-Investigator(Kenkyū-buntansha): 吉川 貴徳 京都大学, 農学研究科, 助教 (00721606) ; 牛島 智一 摂南大学, 農学部, 講師 (50815058)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: イネ / 減数分裂 / 乗換頻度 / 花粉分析

Outline of Final Research Achievements

Rice plants heterozygous for two different wx mutant allele ( wx hetero plants )were irradiated with ion-beam and M2 wx plants with high segregation ratio of non-glutinous grains were selected. Among selfed progeny of selected M2 plants, we found a mutant line with high segragation ratio of non-waxy pollen grain derived from intragenic recombination between differnt wx mutant allele.
Previously, we found that segragation ration of non-glutinous pollen grain due to intragenic recombination increased under salt-stress condition. We identified the specific genes under salt stress condition by conducting RNA-seq analysis with rice flowers at pollen meiosis stage. Following in situ analysis clalified that expresstion of identifed genes were rice glume tissue specific and they are not expressed in anther.

Free Research Field

植物育種学

Academic Significance and Societal Importance of the Research Achievements

モチ突然変異アレルに関してヘテロ個体（以後、モチヘテロ個体）に重イオンビーム照射を行い、M1個体別M2系統においてウルチ粒分離頻度が高い個体の自殖次代に分離するモチヘテロ個体の花粉分析を行った。この結果、無処理のモチヘテロ個体に対して乗換頻度が最大で5倍となる系統が見出された。この変異系統は乗換頻度の遺伝的制御機構解明の素材として有用であるとともに、イネの交雑育種において交雑後代における遺伝的多様性を大きく広げ有用遺伝子の効率的な組合せ作出に寄与できる。