Accuracy assessment of Syringa vulgaris L. morphological signs phenotyping with a laser 3D scanner Planteye F500 depending on plant location on the scanned surface

Since the methodological methods of direct genetics are applicable only for monogenic traits, the created breeding material, line or variety must be tested in the field, since the presence of the desired gene in the genome, confirmed by molecular methods, does not always lead to the formation of a trait valuable for selection. Systems based on 3D imaging technologies make it possible to obtain a plant model, as well as information on morphological parameters. However, very little attention is paid to the preparation of protocols for phenoscreening. The purpose of this study was a comparative assessment of the accuracy of determining the morphological characteristics of lilac plants by traditional methods and using machine vision technology, depending on the plant location on the scanned surface. Microclones of lilac ( Syringa vulgaris L.) cv. Microclones are morphologically homogenous and small in size, which allows measurements of sufficiently large sets of samples and makes it easier to compare the research results by their normalization to average values. The measurements were made after the plant complete adaptation and cultivation for 1 month in a greenhouse. With traditional morphometry, in 10 microclones, the height was measured with a measuring ruler, and the leaf area was measured using the contour method. When scanning (PlantEye F500 3D scanner, Phenospex B.V., Netherlands), each of 10 selected plants was placed at five different positions of the scanned surface, and at least five repeated scans were performed in the same position. When using machine vision technology, 3D leaf area, projected leaf area, digital biomass, height, maximum height, leaf tilt, leaf tilt angle, light penetration depth were determined. It has been established that in order to obtain objective and comparable data from using a 3D scanner, it is optimal to place plants in the center of the scanned surface in the same position. The following parameters can be recommended to identify varieties and assess plant growth rate: the leaf area, projected leaf area, height, and leaf inclination angle. For each plant species, it is necessary to preliminarily study particular morphological traits and to compare the obtained data with the scan results in order to introduce correction factors/ This will confirm the information content of the feature set used, thereby increasing the accuracy of machine vision technology data.