Changes in Dynamic Leaf Traits in Maize Associated with Year of Hybrid Release
Changes in Dynamic Leaf Traits in Maize Associated with Year of Hybrid Release
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DOI：
10.2135/cropsci2017.04.0256
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发表时间：
2018-03-01
期刊：
影响因子：
2.3
通讯作者：
Lorenz, Aaron J.
中科院分区：
文献类型：
--
作者：
Luetchens, Jon;Lorenz, Aaron J.
随着时间的推移，玉米（Zea mays L.）的遗传改良对谷物产量的增加做出了重大贡献。以前的研究已经研究了与植物生产力增加相关的总体形态性状的变化；然而，与旧的杂交品种相比，新品种的动态性状在整个生长季节是如何独特变化的，人们所知甚少。因此，本研究的目的是监测一组时代杂交种叶片叶绿素浓度和相对含水量的季节变化规律。在整个生长季节收集了34个时代杂交种的非破坏性高光谱反射数据。760/730反射率指数与叶片叶绿素浓度的相关性最好，光化学反射率指数（PRI）与相对含水量的相关性最强。因此，这些营养指标被用来代表这些性状。粮食产量的遗传增益估计为65公斤公顷（-1）年（-1），这与以前报告的估计非常相似。在营养晚期和生殖中期叶绿素浓度以0.06 mg mL(-1) yr（-1）的速率升高。利用760/730指数，除R5和R6外，新杂交种叶绿素浓度在各发育阶段均保持较高水平，其中R1阶段随时间变化最大。较新的杂交品种在V16和R5阶段显示出更高的PRI值，但在所有其他采样日期的杂交品种之间没有观察到差异。本研究结果阐明了受籽粒产量选择影响最大的发育阶段，为进一步研究籽粒产量的生理机制提供了理论依据。
Genetic improvements in maize (Zea mays L.) have contributed significantly to increases in grain yield over time. Previous studies have investigated changes in gross morphological traits associated with increased plant productivity; however, less is known about how dynamic traits uniquely change throughout a growing season in new compared with old hybrids. In light of this, the objective of this study was to monitor seasonal patterns of leaf chlorophyll concentration and relative water content in a set of era hybrids. Nondestructive, hyperspectral reflectance data were gathered on 34 era hybrids throughout the growing season. The 760/730 reflectance index correlated best to leaf chlorophyll concentration, and the photochemical reflectance index (PRI) was most strongly correlated to relative water content. These vegetative indices were therefore used as proxies for these traits. Genetic gain for grain yield was estimated to be 65 kg ha(-1) yr(-1), which is very similar to previously reported estimates. Chlorophyll concentration measured during the late vegetative and midreproductive stages increased at a rate of 0.06 mg mL(-1) yr(-1). Using the 760/730 index, newer hybrids maintained elevated chlorophyll concentrations at every developmental stage sampled except R5 and R6 and displayed the greatest changes through time at the R1 stage. Newer hybrids displayed greater PRI values at the V16 and R5 stages, but differences were not observed between hybrid eras for all other sampling dates. Results from this study illuminate the developmental stages most influenced by selection for grain yield and could inform future studies aimed at dissecting the physiology of grain yield.