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

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 diameter, 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.

Abstract

摘要：【目的】明确花期不同程度十旱胁迫对夏玉米花后十物质运转的影响机制, 为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, 以十旱敏感型品种伟科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。