생육 후기 한발 스트레스가 밀의 지상부 생육, 뿌리 발달 및 수량에 미치는 영향

초록

This study evaluated how drought intensity during the reproductive stage affects shoot physiological responses, root development, and grain yield of wheat. A field experiment was conducted at the Gyeongsang National University experimental farm in Daegok-myeon, Jinju, Korea, from October 2024 to June 2025, using the Korean landrace wheat cultivar ‘Anzunbaengimil’. Drought was imposed during the reproductive stage using a rainout shelter with three treatments: control (open field), moderate drought (−0.5 ± 0.2 MPa), and severe drought (−1.2 ± 0.2 MPa). At grain filling, plant height decreased by 8.8% and 5.7% under moderate and severe drought, respectively, compared with the control, while leaf area index did not differ significantly among treatments. Moderate and severe drought reduced flag leaf photosynthesis rate by 33.0% and 31.3% and stomatal conductance by 40.0% and 43.3% relative to the control at grain filling. Under drought stress, root length per tiller tended to increase at heading, suggesting greater root elongation to obtain soil water. Severe drought significantly reduced grain yield and harvest index by 24.3% and 42.9%, respectively, relative to the control. Overall, wheat with spring drought tended to increase root elongation but decrease shoot biomass and photosynthesis rate, leading to yield loss, and the degree of effects depended on the intensity of drought.

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