Morphological characteristics of the leaf blade and the variety of dill morphotypes

Abstract

Relevance. Common dill (Anethum graveolens L.) is an annual plant of the celery family (Apiaceae). It has alternated variously repeatedly pinnatisected simple leaves character- ized by a number of morphological features including color, presence of waxy bloom, size and density of the final segments, size and shape of the leaf blade. Leaves on different nodes of the same plant can be variable. Environment conditions of plant cultivation also affect some morphological characteristics of the leaf (inc. size of the leaf and its final segments). But, under the same conditions each variety of dill possess a certain set of morphological features that determine the variety identity. In recent years, dill varieties with new morphological features of the leaf blade have emerged, and it is important to evaluate and classify the existing morphologic diversity of the plant.Methods. Several methods are currently used to describe morphological features of dill leaves structure: developed by VIR (All-Russian Institute of Plant Genetic Resources), UPOV, the plant approbation manual, description of leafy vegetables in “Cultivated Flora” compendium. There are similarities and differences between the methods in description of characteristics and their grouping according to the extent of the characters. In this study the current methods for description of the morphological features of dill leafs were compared. The described morphological evaluation of the dill varieties was carried out at 2016–2018 in open field in the Research Institute of Vegetable Crop Breeding (LLC), in the “Gavrish-Slobodskoy” Plant Breeding Center (Pavlovskaya Sloboda, Istrinsky district, Moscow region).Results. As a result, it was revealed that the UPOV method more comprehensively describes the morphological characteristics of dill leaf blade. This method can be extended in the following direction: Establish groups according to the length of leaf, using leaf blade length without petiole: small leaf blade – 5-12 cm, medium – 12-25 cm, large – 25- 40 cm; Establish new character: a density of leaf segments (in parts of the 2nd order) and identify the following groups: thin (up to 5 segments), medium density (6-15 segments), and dense (16 or more segments) arrangement of the segments; Establish new character: segment length, grouping it according their actual length: up to 1 cm – short, from 1 to 1.5 cm – medium, and more than 1.5 cm – long leaf segments. According to the evaluated leaf morphological characteristics: size, color, presence of waxy bloom, “leaf patterns”, the dill plants are very diverse. Two dill morphotypes can be distinguished by presence or absence of waxy bloom, 3 morphotypes by the leaf shape (diamond-shaped, elongated, triangular), and 27 morphotypes – by location and size of the final leaf segments.