On-field optical imaging data for the pre-identification and estimation of leaf deformities

Abstract

Visually nonidentifiable pathological symptoms at an early stage are a major limitation in agricultural plantations. Thickness reduction in palisade parenchyma (PP) and spongy parenchyma (SP) layers is one of the most common symptoms that occur at the early stage of leaf diseases, particularly in apple and persimmon. To visualize variations in PP and SP thickness, we used optical coherence tomography (OCT)-based imaging and analyzed the acquired datasets to determine the threshold parameters for pre-identifying and estimating persimmon and apple leaf abnormalities using an intensity-based depth profiling algorithm. The algorithm identified morphological differences between healthy, apparently-healthy, and infected leaves by applying a threshold in depth profiling to classify them. The qualitative and quantitative results revealed changes and abnormalities in leaf morphology in addition to disease incubation in both apple and persimmon leaves. These can be used to examine how initial symptoms are influenced by disease growth. Thus, these datasets confirm the significance of OCT in identifying disease symptoms nondestructively and providing a benchmark dataset to the agriculture community for future reference.

Optical Coherence Tomography as a Non-Invasive Tool for Plant Material Characterization in Agriculture: A Review

“…The high level of scattering in the epidermal layers suggested that the leaves were infected with Cymbidium Mosaic Virus (CymMV), as confirmed by the enzyme-linked immunosorbent assay (ELISA) test, which is the current gold standard test for detecting virus infection in orchid plants. In our previously published article, a threshold for the pre-identification of palisade parenchyma (PP) and spongy parenchyma (SP) layer anomalies in persimmon and apple-leaf specimens was defined using the depth profile approach, based on OCT cross-sections [ 64 ]. A set of OCT cross-sectional images of apple and persimmon leaves were employed to quantitatively evaluate the inner structure of the leaf specimens, where it was observed that the thickness between the PP and SP layers gradually decreased in apparently healthy leaves and merged in infected apple leaves.…”

“…( i ( a – c )) OCT cross-sectional images of persimmon leaves. ( i ( d – f )) OCT cross-sectional images of apple leaves (figure source [ 64 ]). ( ii ) Depth profiles of healthy, apparently healthy, and infected apple leaves; ( ii ( a , b )), ( ii ( c , d )), and ( ii ( e , f )) show the depth profiles of healthy, apparently healthy, and infected apple leaves, respectively.…”

“…( ii ( a , c , e )) Depth intensity profiles of three regions of interest (ROIs) from a single leaf. ( ii ( b , d , f )) The averaged depth intensity profiles of three ROIs from a single leaf (figure source [ 64 ]).…”

“…( a , d , g ), ( b , e , h ), and ( c , f , i ) A-scan profiles of four ROIs, average depth profiles of four ROIs, and curve-fitted depth profiles of four ROIs of a single persimmon leaf, respectively. UE: upper epidermis, PP: palisade parenchyma, SP: spongy parenchyma (figure source [ 64 ]).…”

A Case Report on Skin Sebum Extraction Using High Lateral Resolution Spectral-Domain Optical Coherence Tomography

“…OCT has also been used in biomedical and clinical investigations in dermatology [25], ophthalmology [26], gastroenterology [27], dentistry [28], otorhinolaryngology [29,30], otology [31], and oncology [32]. Furthermore, OCT is diversely used in multidisciplinary fields, such as industrial evaluation [33], agriculture [34,35], and entomology [36,37]. Non-invasive OCT imaging technology facilitates the investigation of the morphology of sweat ducts [38,39], the qualitative morphological analysis of normal skin [25], and the visualizing of the anatomical structures in biological tissues [40].…”