穆心愿 夏来坤 谷利敏 张凤启 张君 丁勇 齐建双 唐保军 赵发欣 邢健伟

摘要：【目的】明确花期不同程度干旱胁迫对夏玉米花后干物质运转的影响机制，為夏玉米抗旱栽培提供理论依据。【方法】于2018—2019年在人工控水条件下，以干旱敏感型品种伟科702（WK702）和耐旱型品种郑单958（ZD958）为供试材料，于玉米花期设4个干旱胁迫处理，分别为CK（对照，全生育期正常灌水）、T1（花前干旱胁迫）、T2（花后干旱胁迫）和T3（花期连续干旱胁迫），探究花期不同程度干旱胁迫对玉米植株形态、叶面积指数、花后干物质积累分配及运转和籽粒产量的影响。【结果】花前干旱胁迫能抑制株高、穗位高、茎粗和叶面积的生长，而花后干旱胁迫的影响较小，但生育后期叶面积指数下降幅度较大。花期干旱胁迫不仅显著降低夏玉米花后干物质积累量（P<0.05，下同），还抑制茎叶等营养器官干物质向籽粒的运转，降低干物质运转量、运转率及其对籽粒产量的贡献率，使成熟期干物质在籽粒中的分配比例减少。花前干旱胁迫对夏玉米穗长、穗粗、穗粒数和百粒重等穗部性状的影响大于花后干旱胁迫。花期干旱胁迫导致夏玉米籽粒产量显著下降，其中花期连续干旱胁迫籽粒产量降幅最大，花前干旱胁迫籽粒产量降幅大于花后干旱胁迫;ZD958在T1、T2和T3处理下的籽粒产量分别比对照下降20.1%、15.6%和35.9%，WK702分别比对照降低32.3%、19.3%和51.3%。【结论】花期干旱胁迫在不同程度上影响夏玉米的植株形态、有效光合面积、花后干物质积累与运转等，导致夏玉米产量显著降低，对干旱敏感型品种WK702花后干物质积累与运转的抑制高于耐旱型品种ZD958。

关键词： 花期干旱胁迫;夏玉米;干物质积累、分配与运转;产量

中图分类号： S513.01                             文献标志码： A 文章编号：2095-1191（2021）04-0931-11

Effects of drought stress during flowering on post-flowering dry matter accumulation and transfer and yield of

different maize cultivars

MU Xin-yuan， XIA Lai-kun*， GU Li-min， ZHANG Feng-qi， ZHANG Jun， DING Yong，

QI Jian-shuang， TANG Bao-jun， ZHAO Fa-xin， XING Jian-wei

（Cereal Institute， Henan Academy of Agricultural Sciences/Henan Provincial Key Laboratory of Maize Biology，Zhengzhou  450002， China）

Abstract：【Objective】To analyze the influence mechanism of drought stress during flowering on post-flowering dry matter accumulation and transfer and yield of summer maize， and provide reference for summer maize drought resistant cultivation. 【Method】Conducted a field study under a rain exclusion shelter from 2018 to 2019，investigated the effects of drought stress during flowering stages on plant morphology，leaf area index，dry matter accumulation and distribution after flowering and grain yield of maize. Two maize cultivars（ZD958，a drought-tolerant cultivar，and WK702，a drought-sensitive cultivar） were subjected to four drought stress treatments respectively，including CK（control， well watered during the whole growth period），T1（drought stress before flowering），T2（drought stress after flowering），and T3（drought stress during flowering）. 【Result】The results showed that drought stress before flowering inhibited the growth of plant height，ear height，stem diameter and leaf area，while drought stress after flowering had less effect on plant height，ear height，stem diameter and leaf area，but had greater effect on the decline of leaf area index in later growth period. Drought stress during flowering not only significantly reduced the dry matter accumulation（P<0.05， the same below），but also inhibited the transport of dry matter from vegetative organs such as stems and leaves to grains，reduced the transport amount and transportrate of dry matter from vegetative organs as well as their contribution rate to grain yield，thus reducing the proportion of dry matter distribution in grains at the maturity stage. The effect of drought stress before flowering on ear length，ear dia-meter，grain number per ear and 100-grain weight in summer maize was greater than that of drought stress after flowering. Drought stress during flowering significantly reduced grain yield of summer maize. Decline in grain yield was the largest under drought stress during flowering， the decline in grain yield under drought stress before flowering  was larger than drought stress after flowering . Compared with the control，the grain yield of T1，T2 and T3 in drought-tolerant cultivar ZD958 were 20.1%，15.6% and 35.9%，respectively，while were 32.3%，19.3% and 51.3% in drought-sensitive cultivar WK702，respectively. 【Conclusion】Drought stress during flowering affects plant morphology，effective photosynthetic area， dry matter accumulation and transport of summer maize after flowering to various extents，which causes significant decrease of maize yield.  The inhibition of dry matter accumulation and transport after flowering in drought-sensitive cultivar WK702 is significantly higher than that in drought-resistant cultivar ZD958.

Key words： drought stress during flowering; summer maize; dry matter accumulation，distribution and transfer;yield

Foundation item： National Key Research and Development Program of China（2017YFD0301101）; Henan Natural Science Foundation（182300410072）; Project of Corn Industry Technology System Construction in Henan（S2015-02-04）

0 引言

【研究意義】旱灾是我国农业主要的自然灾害，具有发生频率高、范围广、强度大及季节性强等特点。黄淮海是我国夏玉米主产区之一，由于年降雨量少且时空分布不均衡，玉米生长季常发生不同程度的干旱灾害，制约着该地区玉米单产的持续提升（吴霞等，2019;Liu et al.，2020a）。花期是玉米的水分临界期，此时干旱胁迫严重影响玉米的吐丝和散粉，降低结实率而造成减产（李英等，2017）。因此，研究花期干旱胁迫对夏玉米干物质生产特别是花后干物质运转的影响机制，对丰富玉米抗旱栽培理论及指导黄淮海地区夏玉米减灾稳产具有重要意义。……