Yin Xinyou
Crop and Weed Ecology Group, Department of Plant Sciences, Wageningen University, PO Box 430, 6700 AK Wageningen, The Netherlands.
Ann Bot. 2008 Mar;101(4):603-11. doi: 10.1093/aob/mcm319. Epub 2008 Jan 17.
The responsiveness of plant ontogeny to temperature may change with plant age. These changes may best be identified by experiments in which individual plants are transferred in a time series from low temperature (LT) to high temperature (HT), and vice versa. Any change in the value of the slope for a plot of the duration taken to complete a developmental phase against time of transfer (either LT to HT or HT to LT) will indicate a change in the temperature responsiveness of development, and the time at which this change occurs. The analysis of this type of reciprocal-transfer experiment is usually performed by regression for each of the visually identified linear sub-phases, separately for the data for LT-to-HT and for HT-to-LT transfers. Here, a mathematical approach is presented using a single curve-fitting procedure.
Both LT-to-HT and HT-to-LT transfers are combined in a single curve-fitting procedure. This new, combined approach is illustrated using a published data set for three rice (Oryza sativa) cultivars, where the pre-flowering duration is divided into three sub-phases, and temperature responsiveness is generally stronger during the second than the first and third sub-phases.
This new model approach provides an objective method, relative to the separate analyses, for assigning data points to a particular sub-phase. Plausible parameter values can be obtained from capturing the whole data of both sets of transfers, which otherwise could not be obtained from the separate-analysis method. Furthermore, the length of sub-phases identified from the LT-to-HT transfers is consistent, in terms of its response to temperature, with that identified from the HT-to-LT transfers. Re-analysis of the published rice data using the new approach reveals that in addition to temperature sensitivity, the optimum temperature of pre-flowering development may vary with plant age. The new approach gives rise to a generalized model for the analysis of reciprocal transfer experiments to quantify age-dependent changes of response of plants (and potentially insects) to any environmental variables that have a significant impact on their development.
植物个体发育对温度的响应可能随植株年龄而变化。通过将单株植物按时间序列从低温（LT）转移至高温（HT），反之亦然的实验，或许能最好地识别这些变化。对于绘制完成一个发育阶段所需持续时间相对于转移时间（从LT到HT或从HT到LT）的曲线而言，斜率值的任何变化都将表明发育对温度的响应发生了变化，以及这种变化发生的时间。这类互逆转移实验的分析通常是针对每个视觉识别出的线性子阶段进行回归分析，LT到HT和HT到LT转移的数据分别进行。在此，提出一种使用单一曲线拟合程序的数学方法。
将LT到HT和HT到LT的转移合并在一个单一曲线拟合程序中。使用已发表的三个水稻（Oryza sativa）品种的数据集来说明这种新的组合方法，其中开花前持续时间分为三个子阶段，并且在第二个子阶段温度响应通常比第一和第三个子阶段更强。
相对于单独分析，这种新的模型方法提供了一种将数据点分配到特定子阶段的客观方法。通过捕获两组转移的全部数据可以获得合理的参数值，否则无法从单独分析方法中获得。此外，从LT到HT转移识别出的子阶段长度，在对温度的响应方面，与从HT到LT转移识别出的子阶段长度一致。使用新方法对已发表的水稻数据进行重新分析表明，除了温度敏感性外，开花前发育的最适温度可能随植株年龄而变化。这种新方法产生了一个用于分析互逆转移实验的通用模型，以量化植物（以及可能的昆虫）对任何对其发育有重大影响的环境变量的响应的年龄依赖性变化。
