Three methods testing the asymmetry of the leaf blades of the small-leaved lime

Abstract

Three methods were used to determine the fluctuating asymmetry (FA) of leaf blades and the developmental stability of smallleaved linden (Tilia cordata Mill): the normalizing difference method, the sample normalization method, and the two-factor analysis method (FA10). The collection of leaf blades took place along the latitudinal zonality gradient from north to south in five cities from Murmansk (68°58′ N) to Mozhaisk (55°30′ N), including the cities of Apatity, Petrozavodsk and Saint Petersburg. In all analyses, the highest FA value was obtained in the population of Petrozavodsk, the lowest in the population of Mozhaisk. In other cities, the FA indices differed, except for the populations in Apatity and Petrozavodsk with FA10 indices, respectively, 0.02 (p=0.02) and 0.03 (p=0.01). In the northernmost population (Murmansk), no decrease in developmental stability was noted. The stability of the development of Tilia cordata was more strongly influenced by the climatic and geographical conditions of the area and the technogenic state of the environment than by the geographic latitude. The authors note that a non-parametric sample distribution is advisable to use the two-factor analysis of variance, since normality difference and normalization lead to a non-equivalent deviation of the results. Bonferroni’s adjustments for measurement error were convenient for accurately distributing FA values at significance level.