Relationship between vascular bundle at panicle neck internode and ripening ability of near-isogenic lines introgressed with genes for increasing spikelet number in rice

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K14453
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39020:Crop production science-related
• Research Institution: Hiroshima University (2021); Nagoya University (2018-2020)
• Principal Investigator: KIKUTA Mayumi 広島大学, 統合生命科学研究科(生), 助教 (20788418)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: イネ / 準同質遺伝子系統 / ケニア

Outline of Final Research Achievements

To improve rice yield in Kenya, we investigated the yield responses of lines of local rice varieties introgressed with the genes for increasing spikelet number (Gn1a and WFP). In the introgression lines, the yield increase due to increased spikelet number was suppressed by decreased filled grain ratio. The lines carrying both genes showed the highest grain number per panicle and higher yields due to additive gene effects. The number and cross-sectional area of vascular bundles at the panicle neck, the transport pathway for water and nutrition to the grain, were increased in the lines introgressed with both genes compared to the parental variety. These results indicate that the rice lines introgressed with genes for increasing spikelet number can increase yield depending on the environmental conditions and the parental variety.

Free Research Field

作物生産科学

Academic Significance and Societal Importance of the Research Achievements

近年，イネ収量に関連する遺伝子が数多く同定され，実際の生産現場に寄与することが期待されている．これまでに報告されている籾数増加遺伝子導入系統では，籾数は増加するものの登熟歩合が大きく低下し，収量増加には繋がっていない．本研究では，ケニアにおいて現地の品種に1穂籾数増加遺伝子（Gn1a および WFP）を導入した準同質遺伝子系統を評価し，収量が増加する系統を見いだした．Gn1aとWFPの両方を導入した系統を利用することでケニアのイネ収量を向上させ，食糧問題解決に貢献することが期待される．