Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.
Am J Bot. 2009 Jul;96(7):1313-8. doi: 10.3732/ajb.0800303. Epub 2009 Jun 10.
We propose a new method, the leaf measuring-interval index (LMI), to estimate leaf age in morphological and physiological studies of leaves. When the plastochron, the interval between the initiation of successive leaves, is constant, the well-known leaf plastochron index (LPI) provides a robust measure of leaf age. When the duration of the plastochron is not uniform, however, we show that the LPI can (in simulations) and does (with actual data) turn variation in duration of the plastochron into variance about the regression estimates of leaf growth curves. The method we present in this paper, the LMI, is plastochron independent. This new method is particularly suited, therefore, for studies of plants growing in natural environments rather than in controlled growth facilities where the assumptions of the LPI method can be met.
我们提出了一种新的方法，即叶间隔指数（LMI），用于在叶片形态和生理学研究中估计叶片的年龄。当叶间隔，即相继叶片起始之间的间隔是恒定的，那么著名的叶间隔指数（LPI）就提供了一种可靠的叶片年龄测量方法。然而，当叶间隔的持续时间不均匀时，我们表明 LPI 可以（在模拟中）并且确实（在实际数据中）将叶生长曲线回归估计的方差转化为叶间隔持续时间变化的方差。我们在本文中提出的方法，LMI，与叶间隔无关。因此，这种新方法特别适合在自然环境中生长的植物研究，而不适合在控制生长设施中进行研究，因为 LPI 方法的假设在这些设施中可以得到满足。
