Drought stress is one of the limiting factors for grain filling and yield in wheat. The grain filling and determinants of individual grain weight depend on current assimilation and extent of remobilization of culm reserves to grains. A pot experiment was conducted with eight wheat cultivars at the Pot House to study the grain filling and the contributions of reserves in culm, including the sheath to grain yield under drought stress. Drought stress was enforced by restricting irrigation during the grain-filling period. The plants (tillers) were harvested at anthesis, milk-ripe, and maturity. The changes in dry weights of leaves, culm with sheath, spikes, and grains; and the contribution of culm reserves to grain yield were determined. Results revealed that drought stress considerably decreased the grain filling duration by 15–24% and grain yield by 11–34%. Further, drought-induced early leaf senescence and reduced total dry matter production indicate the minimum contribution of current assimilation to grain yield. The stress reduced the contribution of culm reserves, the water-soluble carbohydrates (WSCs), to the grains. The accumulation of culm WSCs reached peak at milk ripe stage in control, varied from 28.6 to 84 mg culm⁻¹ and that significantly reduced in the range from 14.9 to 40.6 mg culm⁻¹ in stressed plants. The residual culm WSCs in control and stressed plants varied from 1.23 to 8.12 and 1.00 to 3.40 mg g⁻¹ culm dry mass, respectively. BARI Gom 24 exhibited a higher contribution of culm WSCs to grain yield under drought, while the lowest contribution was found in Kanchan. Considering culm reserves WSCs and their remobilization along with other studied traits, BARI Gom 24 showed greater drought tolerance and revealed potential to grow under water deficit conditions in comparison to other cultivars.

中文翻译：

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小麦基因型对干旱胁迫耐受能力的评价：通过秆储备贡献和籽粒灌浆生理学进行剖析

干旱胁迫是小麦灌浆和产量的限制因素之一。籽粒灌浆和个体粒重的决定因素取决于当前的同化和秆储备向籽粒的再动员程度。在盆栽屋对 8 个小麦品种进行盆栽试验，研究干旱胁迫下籽粒灌浆和茎秆储备的贡献，包括鞘对籽粒产量的贡献。干旱胁迫是通过在灌浆期间限制灌溉来加强的。在开花、乳熟和成熟时收获植物（分蘖）。叶片干重的变化，秆具鞘、穗和谷粒；并确定了秆储备对粮食产量的贡献。结果表明，干旱胁迫使籽粒灌浆持续时间显着减少 15-24%，粮食产量减少 11-34%。此外，干旱引起的早期叶片衰老和总干物质产量减少表明当前同化对谷物产量的贡献最小。压力降低了秆储备，即水溶性碳水化合物 (WSC) 对谷物的贡献。对照中茎秆 WSCs 的积累在牛奶成熟阶段达到峰值，从 28.6 毫克到 84 毫克不等。^-1并且在胁迫植物中从 14.9 到 40.6 mg 秆^-1的范围内显着降低。对照植物和受胁迫植物中残留的秆 WSC 分别从 1.23 到 8.12 和 1.00 到 3.40 mg g ^-1秆干重不等。BARI Gom 24 在干旱条件下表现出较高的秆 WSCs 对谷物产量的贡献，而在 Kanchan 中发现的贡献最低。考虑到秆储备 WSC 及其再动员以及其他研究性状，与其他品种相比，BARI Gom 24 表现出更高的耐旱性，并显示出在缺水条件下生长的潜力。