Heat Stress during Late Vegetative Growth of Maize: Effects on Phenology and Assessment of Optimum Temperature
Heat Stress during Late Vegetative Growth of Maize: Effects on Phenology and Assessment of Optimum Temperature
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DOI：
10.2135/cropsci2009.07.0400
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发表时间：
2010-07-01
期刊：
影响因子：
2.3
通讯作者：
Otegui, M. E.
中科院分区：
文献类型：
--
作者：
Cicchino, M.;Edreira, J. I. Rattalino;Otegui, M. E.
物候的预测是基于热时（TT）计算，这需要正确定义基础温度（T-B）和最佳温度（T-O）。这些特征的大多数信息来自于使用大范围平均气温（T-X）的受控环境，包括T-X > T-O和T-X < T-B。这些条件在野外环境中很少发现。我们评估了在玉米（Zea mays L）后期营养生长期间白天温度高于T-O对发育的影响，并建立了一个基于每小时（TTh，在摄氏度h）而不是每天（TTd）的TT计算模型用于T-O估计。田间试验包括两个温度制度（T-C：控制; T-H：加热）之间的V-11和T-C抽雄。我们记录了穗位温度、开花和吐丝日期。我们计算了处理期间（TTh 1）和V-11和吐丝之间（TTh 2）的发育率（DR），TTh高于8 ℃，这是一个基于TTh差异商的应激指数T-H和T-C之间的（Δ TTh）（SI = Δ T-h2/Δ TTh 1），而T-O热胁迫导致开花事件延迟，和DR的下降。估计的T-B高于（12.7摄氏度）通常用于计算。估计的T-O在预期范围内（36 ℃> To > 30 ℃），与T-B无关。胁迫温度促进延迟吐丝，确定为至少2.14摄氏度时，TTh增加每度以上的T-O。估计T-O不同生长季节（P = 0.04），这表明可能的变化，由于气候的影响。
Prediction of phenology is based on thermal time (TT) computation, which requires the correct definition of base (T-B) and optimum (T-O) temperatures Most information on these traits came from controlled environments using a wide range of mean air temperatures (T-X), including T-X > T-O and T-X < T-B. These conditions are rarely found in field environments. We assessed the effect on development of day-time temperatures above T-O during late-vegetative growth of maize (Zea mays L), and established a model based on TT computation on a per hour (TTh, in degrees C h) rather than per day basis (TTd) for T-O estimation. Field experiments included two temperature regimes (T-C: control; T-H: heated) between V-11 and tasseling of T-C. We registered temperature at ear level, and dates of anthesis and silking. We computed developmental rates (DR), TTh above 8 degrees C during treatment period (TTh1) and between V-11 and silking (TTh2), a stress index based on the quotient of differences in TTh (Delta TTh) between T-H and T-C (SI = Delta T-h2/Delta TTh1), and T-O Heat stress caused a delay in flowering events, and a decline in DRs. Estimated T-B was higher (12.7 degrees C) than normally used in computations. Estimated T-O was within the expected range (36 degrees C > To > 30 degrees C), independently of T-B. Stressful temperatures promoted a delayed in silking, identified as an increase of at least 2.14 degrees C h in TTh for each degree above T-O. Estimated T-O differed between growing seasons (P = 0.04), suggesting possible variation due to climatic effects.