Molecular mechanisms of phenotypic plasticity for abnormal growth in interspecific hybrids of wheat

2019 Fiscal Year Final Research Report

• Project/Area Number: 16H04862
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Science in genetics and breeding
• Research Institution: Kobe University
• Principal Investigator: Takumi Shigeo 神戸大学, 農学研究科, 教授 (50249166)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 生殖隔離 / 種間雑種 / 異質倍数性進化 / ゲノム / トランスクリプトーム

Outline of Final Research Achievements

Breeding use of agriculturally important genes in crop relatives is essential, but wild relative species is not necessarily utilized effectively. Grass clump dwarfism (Gcd) has been frequently observed in interspecific hybrids of wheat relatives. Gcd appears only under normal temperature conditions, whereas hybrid necrosis develops under the low temperature conditions in many hybrids between cultivated tetraploid wheat and Aegilops tauschii. On the other hand, no difference of the Gcd development is observed among the growth temperature conditions in the hybrids between cultivated tetraploid wheat and Aegilops umbellulata. In this study, molecular mechanisms for the temperature-dependent plasticity to develop Gcd were predicted based on the comparative transcriptome analyses. Isolation of the two hybrid abnormality genes Net2 and Gcd1 for Gcd was progressed, and two candidates for Net2 were identified.

Free Research Field

植物遺伝育種学

Academic Significance and Societal Importance of the Research Achievements

異質倍数性進化は近年注目されつつあり、人為倍数体を基にした研究も萌芽期にあると言える。コムギでもパンコムギで異質倍数性進化に伴うクロマチン修飾の変動などに迫る研究例が出てきているが、コムギ近縁種まで含めた属全体の種間雑種の研究は、古典遺伝学的な研究以外に例がない。この属の種間雑種に見られる特徴的な雑種矮性から、その発症機構についてもこれまでの病害抵抗性関連遺伝子だけでない要因を見出せる可能性が高い。また、雑種不全の原因遺伝子に密接連鎖した分子マーカーを開発して、雑種不全を避けつつタルホコムギやAegilops umbellulataの有用遺伝子をパンコムギ育種に幅広く利用できるようになる。