Department of Plant Biology and Soil Sciences, Faculty of Biology, University of Vigo, Vigo, Spain.
Plant Biol (Stuttg). 2013 May;15(3):616-20. doi: 10.1111/j.1438-8677.2012.00720.x.
Reciprocal herkogamy (heterostyly) is an example of extreme relevance of accuracy of the location of the sexual organs within some floral systems. It involves the reciprocal positioning of anthers and stigmas in flowers of different plants within the same population, and the accuracy of this positioning is important to promote out-cross pollination, prevent self-interference, or both. Hence, several indices have been proposed to quantify reciprocity, most of them for populations with two different morphs (distylous). Here, we propose an extension of our index of reciprocity for distylous populations to be applied also to populations with three morphs (tristylous), allowing effective comparisons of reciprocity between tristylous, but also distylous populations. As for the distylous version, the index is based on comparison of the position of every single sexual organ in the sample with each and every organ of the opposite sex, for each of the three possible organ levels. Due to the massive amount of calculations required, a macro was developed that is available as Supplementary Information and at the website of the authors. The index and macro were tested on several hypothetical tristylous and distylous populations with predetermined mean and dispersion of sexual organs at each level, as well as on several actual tristylous and distylous populations. The index proposed is a solid tool for the study of reciprocity in distylous and tristylous populations. Comparisons between distylous and tristylous populations are easily performed and can be readily interpreted. The applicability of the index is facilitated through the software provided.
雌雄异位（异型花柱）是某些花系统中生殖器官位置准确性具有极端重要性的一个例子。它涉及到同一群体中不同植物花朵中花药和柱头的相互定位，而这种定位的准确性对于促进异花授粉、防止自交干扰或两者兼而有之至关重要。因此，已经提出了几种量化异型花柱的指标，其中大多数用于具有两种不同形态（二型花柱）的群体。在这里，我们提出了一个扩展我们的二型花柱种群异型花柱指数的方法，也可以应用于具有三种形态（三型花柱）的种群，从而有效地比较三型花柱和二型花柱种群之间的异型花柱。对于二型花柱版本，该指数基于对样本中每个生殖器官与每个相反性别的每个器官的位置进行比较，对于三个可能的器官水平中的每一个。由于需要大量的计算，因此开发了一个宏，可作为补充信息和作者网站上的资源获取。该指数和宏已在具有预定每个水平的生殖器官均值和离散度的几个假设的三型花柱和二型花柱种群以及几个实际的三型花柱和二型花柱种群上进行了测试。所提出的指数是研究二型花柱和三型花柱种群异型花柱的有效工具。很容易对二型花柱和三型花柱种群进行比较，并可以很容易地解释这些比较。通过提供的软件，该指数的适用性得到了增强。
