Heat stress in temperate and tropical maize hybrids: Differences in crop growth, biomass partitioning and reserves use
Heat stress in temperate and tropical maize hybrids: Differences in crop growth, biomass partitioning and reserves use
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DOI：
10.1016/j.fcr.2012.02.009
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发表时间：
2012-03
影响因子：
5.8
通讯作者：
J. R. Edreira;M. E. Otegui
中科院分区：
文献类型：
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作者：
J. R. Edreira;M. E. Otegui
玉米（Zea mays L.）具有热带遗传背景的杂交种是一种有希望的耐热性来源，但它们在高产环境中的表现仍然知之甚少。我们的目标是评估（i）谷物产量的生态生理决定因素的基因型差异;即，作物截获的光的分数（fIPAR），生物量生产的辐射利用效率（芸香），收获指数（HI），和（ii）上述性状的反应短暂的高温。分析了粮食储备对粮食产量的贡献。田间试验包括三个对比玉米杂交种（Te：温带; Tr：热带; TeTr：Te×Tr）在两种温度制度（控制和加热）在白天的时间。我们测试了加热（CA）。33-40°C（穗位）），分为沿着的3个15 d时期（GS1：吐丝前; GS 2：从吐丝开始; GS 3：活跃灌浆期）。热胁迫对叶面积和fIPAR没有影响，但在灌浆期加热通过减少循环持续时间影响光捕获，特别是对于Te杂交种（平均-16.5 d）。加热导致芸香大幅下降，但这一特性在除热后迅速恢复，最终的芽生物量没有受到太大影响（在-3%和-33%之间）。HI显着减少加热和其变化与储备使用的变化（r2=0.61）。在加热小区中，HI的变化比最终地上部生物量的变化（r2 ≥0.59）更好地解释了籽粒产量（r2 ≥0.92）。热量对籽粒产量的影响在开花期（GS 1为-527gm − 2，GS 2为-545gm − 2）大于灌浆期（GS 3为-352gm − 2），Te杂交种（-599gm −2）大于TeTr（-440gm −2）和Tr杂交种（-384gm −2）。吐丝前后加温（GS 1和GS 2），在有效灌浆期积累了明显的储量。相反的趋势被检测到活跃的晶粒形成（GS 3）期间加热的地块。热带遗传背景并没有惩罚产量潜力，并赋予增强的能力，持久的热效应。
Maize (Zea mays L.) hybrids with tropical genetic background are a promising source of heat stress tolerance, but their performance in high yielding environments remains poorly understood. Our objective was to assess (i) genotypic differences in the ecophysiological determinants of grain yield; i.e., fraction of light intercepted by crop (fIPAR), radiation use efficiency for biomass production (RUE), and harvest index (HI), and (ii) the responses of mentioned traits to brief episodes of high temperature. The contribution of stored reserves to grain yield was also analyzed. Field experiments included three contrasting maize hybrids (Te: temperate; Tr: tropical; TeTr: Te×Tr) grown under two temperature regimes (control and heated) during daytime hours. We tested heating (ca. 33–40°C at ear level) along three 15-d periods (GS1: pre-silking; GS2: from silking onwards: GS3: active grain filling). Heat stress had no effect on leaf area and fIPAR, but heating during grain filling affected light capture through reduced cycle duration, especially for the Te hybrid (average of −16.5 d). Heating caused a large reduction in RUE, but this trait had a rapid recovery after heat removal and final shoot biomass was not much affected (between −3% and −33%). HI was markedly reduced by heating and its variation was associated with changes in reserves use (r2=0.61). Grain yield in heated plots was better explained (r2≥0.92) by the variation in HI than by the variation in final shoot biomass (r2≥0.59). Heat effects on grain yield were larger (i) when they occurred around flowering (−527gm−2for GS1and −545gm−2for GS2) than during grain filling (−352gm−2for GS3), and (ii) for the Te hybrid (−599gm−2) than for the TeTr (−440gm−2) and the Tr hybrids (−384gm−2). Heating around silking (GS1and GS2) caused apparent accumulation of reserves during the effective grain-filling period. The opposite trend was detected among plots heated during active grain formation (GS3). The tropical genetic background did not penalize yield potential and conferred an enhanced capacity for enduring heat effects.