THE GENOTYPE-PHENOTYPE RATIO DETERMINED BY GEOMETRIC MORPHOMETRY

Abstract

Phenotypic and genotypic variability are manifested in the shape, size and asymmetry of laminas. To describe the reaction of plants to geographical location, a linear modelling of the shape and asymmetry of laminas of two types of trees was carried out: light-demanding (Bird cherry, Prunus padus) and shade-resistant (small-leaved linden, Tilia cordata Mull). 8 cenopopulations were selected, located from north to south (from Murmansk to Moscow Oblast). In the linden tree, the distance between the bases of the veins were measured, and the bird cherry – the leaf width. Linear signs R (right) L (left) showed no correlation (Spearman's r >0.05) with the index of fluctuating asymmetry |R – L|/(R + L). 100 labels were placed along the sheet contour, and a morphogeometric 2-factor analysis of variance (MorphoJ) was performed. The index of fluctuating asymmetry of FA18 was calculated taking into account the error of threefold labelling, and the p-level taking into account the correction α = 0.05 for the entire range of FA values for seven populations. Directional asymmetry was determined by the criterion F of the "side" factor. The correlation coefficient r was found between the diagonal values of the phenotype and genotype matrices. The obtained values of fluctuating asymmetry, directional asymmetry and phenotype/genotype correlation were multiplied to n =50 taking into account the normal distribution, and linear approximation was performed (R ² = 0.97-0.99). The trend lines were arranged in descending order. The regression coefficients were evaluated according to the F-criterion for the difference in the residuals' variance. The laminas of the small–leaved linden showed a higher fluctuation asymmetry, the leaves of the bird cherry showed a greater directional asymmetry. The phenotype/genotype ratio also was different in the two species (p <0.05). Northern linden populations ( Petrozavodsk and Apatity) showed a higher index compared to the southern populations from Moscow Oblast (Mozhaysk), respectively, FA18 = 0.0002; p = 0.01 and FA18 = 0.0001; p = 0.02. A high proportion of the variability of directional asymmetry as a genotypic manifestation was manifested in bird cherry as a local species. Small-leaved linden as an introduced species showed phenotypic variability, with a high proportion of fluctuating asymmetry. The data obtained indicated a different reaction of the genotype and phenotype of the two species, depending on the geographical location of the cenopopulations.