Evaluation of shape and asymmetry in rye leaf

Abstract

The variability of bilateral structures is associated with the stability of development; the populations attribute which characterizes homeostasis of plant development at the epigenetic level. A violation in the functioning of regulatory proteins creates a deviation from the norm in fluctuating asymmetry, as a measure of ontogenetic noise. To test the variability of the shape and asymmetry of winter rye leaf plates depending on the dose of mineral fertilizer, we used the Generalized Procrustes analysis and the thin splines method. A small dose (N90P90K90) caused the apical growth and the fluctuating asymmetry of the leaf plate, indicating a reduced development stability of the population (p <0.0001), the “side” factor was statistically insignificant. The interaction side × individual was statistically significant at both doses of fertilizer. The bending energy of the thin spline was higher (p = 0.001) in population with an increased dose of fertilizer (N90P90K90) and high directional asymmetry (“side”; p <0.0001). The authors consider that a high dose of fertilizer contributed to the synthesis of cells in the medial part of the leaf blade and caused asymmetry in a mix of fluctuating and directional asymmetry. Thus, an increased dose of mineral fertilizer enhanced the growth of the lateral part of the leaf blade and led to directional asymmetry, which reduced the asymmetric variability and increased the variability of the shape in the leaf blade.

Spatial Variability of Small-leaved Linden (Tilia cordata Mill.) Leaf Blade

“…As previous studies have shown, the photographing error is extremely small, therefore, the image was acquired once, and the labeling with subsequent processing was carried out twice. The procedure for applying true landmarks of the first type was carried out with the splitting of the entire contour into equal segments, and is described in detail in previous works [20][21].…”