Analysis of the phenotypic factor resulting in differences in onion bulb weight without changing the length of the growth period

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14851
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39030:Horticultural science-related
• Research Institution: National Agriculture and Food Research Organization
• Principal Investigator: Sekine Daisuke 国立研究開発法人農業・食品産業技術総合研究機構, 野菜花き研究部門, 主任研究員 (80823236)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: タマネギ / DNAマーカー / 生育速度 / 葉面積

Outline of Final Research Achievements

Onion bulb weight is known to be correlated with the length of the growth period. However, we previously revealed that the different genotypes of a particular genomic region caused a significant difference in bulb weight without changing the length of the growth period. Because the bulb is a sink part of the onion, the different genotypes would also influence the source part such as leaf area. We compared the leaf phenotypes in sibling lines which were developed from the same heterozygous plant. Field evaluation revealed that leaf growth speed was significantly different between the sibling lines. This difference was observed in the seeding stage and enhanced after transplantation in the field. In contrast, such differences were not observed when the sibling lines were grown in a growth chamber. These results suggests that a causal gene on a certain genomic region would respond to field environmental conditions, such as temperature and day length.

Free Research Field

園芸育種

Academic Significance and Societal Importance of the Research Achievements

タマネギの品種育成における新たな視点を切り開いた。これまで、タマネギでは収穫時期（早晩性）とりん茎重は強く相関した形質とされており、各々を別々に改良することは難しいと考えられていた。本研究では、（１）同じ早晩性の系統であっても地上部の生育速度に違いがあり、その結果としてりん茎重に顕著な差を生じること（２）この生育速度の違いは遺伝的な要因で制御されていることを明らかにした。早晩性とりん茎重を切り離して、改良することができることを明確に示した。