Data distribution and asymmetry in leaf blade Prunus padus L.

Abstract

To test the level of developmental stability of plants, an indicator of the asymmetry of their leaf blades is often used. The resulting systematic additive and multiplicative errors depend on the nature of the distribution sample data. On the example of bird cherry (Prunus padus L.) leaf blades, two types of distribution of sample data are demonstrated – normal and exponential. Statistical analyzes were performed in STATISTICA 10 (Stat.Ink). The exponential form of the distribution did not allow obtaining the mean value of the sample. The normalizing transformation of the sample contributed to obtaining the mean value and finding the relative level of the developmental stability of the population. In the Murmansk population (Apatity), a high variability of leaf blades was revealed, but, despite a significant asymmetry obtained in the normalizing difference formula, it did not have a statistically significant fluctuating asymmetry (FA). The sample from the Vladimir population (Vladimir) with the highest level of FA (0.018±0.004) was characterized by high values of kurtosis, skew and variance which was confirmed in a two-way analysis of variance (p <<0.05). In the Moscow population (Elektrostal) a high level of asymmetry was also obtained in the normalizing formula, but was not confirmed in a 2-way ANOVA. Thus, only the population from Vladimir showed a deviation in developmental stability in both methods. The authors recommend paying attention to the nature of the distribution of the difference between the left and right trait values, and using a two-way analysis of variance for the final determination of the FA value.