Physiological Evaluations of Recent Drought-Tolerant Maize Hybrids at Varying Stress Levels
Physiological Evaluations of Recent Drought-Tolerant Maize Hybrids at Varying Stress Levels
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DOI：
10.2134/agronj2013.0066
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发表时间：
2013-07-01
期刊：
影响因子：
2.1
通讯作者：
Vyn, Tony J.
中科院分区：
文献类型：
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作者：
Roth, Jason A.;Ciampitti, Ignacio A.;Vyn, Tony J.
随着全球对粮食、饲料、纤维和燃料的需求增加，玉米 (Zea mays L.) 提高干旱胁迫耐受性提出了巨大的挑战。种子公司正在开发和推广耐旱杂交种，但其生理耐旱机制尚不清楚。研究目的是调查印第安纳州西北部 2 个站点年中不同植物密度 (PD)（两个水平）和施氮量（四个水平）的相似成熟度杂交品种（分为耐旱（非转基因）或常规品种）与产量提高相关的植物性状。生理测量包括多个生长阶段的光合作用（A）、蒸腾作用（E）和叶面积指数，以及花吐丝间隔、潜在籽粒数、籽粒产量（GY）及其组成。 2012年开花前和开花期间的30天期间发生了强烈的高温和干旱胁迫，但2011年则没有。总体而言，成熟度相似的耐旱和非耐旱杂交种在GY或大多数其他性状上没有显着差异，并且杂交种对不同PD和N比率的反应相似。在这两个季节中，GY 受 N 率的影响最大。对 A 和 E 的复合施氮量影响与供水密切相关（即，较高的施氮量在非干旱条件下具有积极影响）。在叶尺度上，A 和 E 的杂交差异并不显着，但一种耐旱杂交种在整个季节的冠层尺度上具有较低的估计累积 A 和 E。在这些单地点试验的非干旱和特定干旱条件下，没有迹象表明指定的耐旱杂种对高拥挤强度和/或低氮胁迫具有更强的耐受性。
Maize (Zea mays L.) improvement in drought-stress tolerance poses a great challenge as the global need for food, feed, fiber, and fuel increases. Seed companies are developing and promoting drought-tolerant hybrids, but their physiological drought-tolerance mechanisms are not well understood. The research objective was to investigate the plant traits related to yield improvement for similar maturity hybrids classified as either drought-tolerant (non-transgenic) or conventional at varying plant density (PD) (two levels) and N rates (four levels) over 2 site-years in northwestern Indiana. Physiological measurements included photosynthesis (A), transpiration (E), and leaf area index at multiple growth stages, as well as anthesis-silking interval, potential kernel number, grain yield (GY) and its components. Intensive heat and drought stress occurred in the 30-d period before and during flowering in 2012, but not in 2011. Overall, similar maturity drought-and non-drought-tolerant hybrids did not markedly differ in GY or most other traits, and hybrid responses to varying PD and N rates were similar. In both seasons, GY was impacted most by N rates. A complex N rate effect on A and E was tightly related to water supply (i.e., higher N had positive impact under non-drought conditions). Hybrid differences in A and E were not significant at the leaf-scale, but one drought-tolerant hybrid had lower estimated cumulative A and E at the season-long canopy scale. Under the non-drought and specific-drought conditions in these single-location trials there was no indication that designated drought-tolerant hybrids were more tolerant to high crowding intensity and/or low N stresses.