Heterosis x environment interaction in maize: What drives heterosis for grain yield?
Heterosis x environment interaction in maize: What drives heterosis for grain yield?
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DOI：
10.1016/j.fcr.2011.08.001
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发表时间：
2011-12-20
影响因子：
5.8
通讯作者：
Otegui, M. E.
中科院分区：
文献类型：
--
作者：
Munaro, E. M.;Eyherabide, G. H.;Otegui, M. E.
当玉米杂交种和自交系对环境刺激的反应不同时，预计平均杂种优势在一系列环境中会发生变化。然而，杂种优势 x 环境相互作用 (H x E) 的大小和性质尚未得到充分描述。这项工作的目的是确定 (i) 环境变异对植物谷物产量 (PGY) 杂种优势表达和相关生态生理性状的影响，以及 (ii) H x E 对于这些性状杂种优势表达的一般重要性。田间实验包括在阿根廷温带地区的 14 个环境（年份 x 氮 x 水况组合）中生长的一组 6 个自交系和 12 个衍生杂种。测量了 PGY 的主要生理和数量决定因素，并计算了每个性状的中亲杂种优势（MPH）。使用联合回归分析研究基因型x环境相互作用。对于 PGY，杂种对环境的敏感性与平均基因型值之间具有显着但中等的关联，而自交系则没有显示出关联。然而，对于收获指数（HI）而言，杂交种的平均值高于近交系。两个基因型组的回归系数往往略有重叠。环境质量下降会导致PGY杂种优势表达下降，但HI不会。双线性平台模型充分描述了 PGY 杂种优势与环境质量之间的关联，因为检测到了一个阈值，超过该阈值环境平均值的进一步增加不会转化为 PGY 更高的杂种优势。在 PGY MPH 和生理成熟生物量 (Biomass(PM)) MPH 之间发现了类似的响应模式。尽管生物质(PM)具有更大的杂种优势，但当生物质(PM) MPH超过阈值115 g pl(-1)时，无法实现PGY MPH的进一步增加。在有利的环境下，HI MPH 是限制 PGY MPH 的主要因素。 (C) 2011 Elsevier B.V. 保留所有权利。
Variation in mean heterosis over a range of environments is expected when maize hybrids and inbred lines respond differently to environmental stimuli. However, the magnitude and nature of the heterosis x environment interaction (H x E) has not been adequately described. The objectives of this work were to determine (i) the effects of environmental variability on the expression of heterosis for plant grain yield (PGY) and related ecophysiological traits and (ii) to what extent H x E is of general importance for the expression of heterosis for these traits. Field experiments included a set of six inbred lines and twelve derived hybrids grown in 14 environments (year x nitrogen x water regime combinations) in the temperate region of Argentina. Main physiological and quantitative determinants of PGY were measured and mid parent heterosis (MPH) computed for each trait. Genotype x environment interaction was investigated using the joint regression analysis. For PGY, hybrids had a significant but moderate association between sensitivity to the environment and mean genotype value, whereas inbred lines did not show association. For harvest index (HI) hybrids showed greater mean values than inbreds, however. regression coefficients of both genotype groups tended to overlap slightly. A decrease in environmental quality led to a decline in the expression of heterosis for PGY but not for HI. A bilinear with plateau model adequately described the association between heterosis for PGY and environmental quality, because a threshold value was detected beyond which further increases in environment mean did not translate into higher heterosis for PGY. A similar response pattern was found between PGY MPH and biomass at physiological maturity (Biomass(PM)) MPH. Despite the greater heterosis for Biomass(PM), further increases in PGY MPH could not be realized above a threshold value of 115 g pl(-1) for Biomass(PM) MPH. HI MPH was the major factor that set a limit to PGY MPH under favorable environments. (C) 2011 Elsevier B.V. All rights reserved.