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.