Abstract Drought stress reduces seed crop yields in part by causing reproductive sterility associated with increased endogenous ABA. Application of the film antitranspirant, di-1-p-menthene, during reproductive-stage drought has been shown to ameliorate yield loss in wheat but the physiological processes involved are not understood. Using rain shelters to simulate Mediterranean-type terminal drought, we studied the possibility that application of the antitranspirant reduces both endogenous ABA concentration and the subsequent yield loss. Di-1-p-menthene was sprayed on droughted spring wheat plants (cv, Chilham) at 1.0 L/ha in two separate field experiments, at three growth stages between stem elongation and spike emergence in 2018; and at four growth stages between stem elongation and anthesis in 2019, with droughted but unsprayed plants serving as the control. Drought stress increased endogenous ABA but decreased yield. Di-1-p-menthene application reduced endogenous ABA concentration by 33% and 40%; and improved grain yield by 16% and 15% averaged across all growth stages in 2018 and 2019, respectively. The consistent effects of di-1-p-menthene in both years suggests that the mechanism of drought stress amelioration by the film antitranspirant is related to reduced endogenous ABA concentration during key growth stages.

中文翻译：

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在干旱小麦中应用抗蒸腾剂提高产量与降低内源脱落酸浓度有关

摘要 干旱胁迫会导致与内源性 ABA 增加相关的生殖不育，从而降低种子作物的产量。在生殖期干旱期间使用薄膜抗蒸腾剂 di-1-p-menthene 已被证明可以改善小麦的产量损失，但所涉及的生理过程尚不清楚。我们使用避雨棚来模拟地中海型终末干旱，研究了应用抗蒸腾剂降低内源性 ABA 浓度和随后的产量损失的可能性。2018 年，在两个独立的田间试验中，在茎伸长和穗出现之间的三个生长阶段，将 Di-1-p-薄荷烯以 1.0 L/ha 喷洒在干旱的春小麦植物（cv, Chilham）上；并在2019年茎伸长至开花之间的四个生长阶段，以干旱但未喷洒的植物作为对照。干旱胁迫增加了内源ABA但降低了产量。Di-1-p-menthene 的施用使内源性 ABA 浓度降低了 33% 和 40%；2018 年和 2019 年所有生长阶段的粮食产量平均分别提高了 16% 和 15%。这两年di-1-p-薄荷烯的一致作用表明，薄膜抗蒸腾剂改善干旱胁迫的机制与关键生长阶段内源性ABA浓度降低有关。