Use of Blue-Green Fluorescence and Thermal Imaging in the Early Detection of Sunflower Infection by the Root Parasitic Weed Orobanche cumana Wallr.

Abstract

Although the impact of Orobanche cumana Wallr. on sunflower ( Helianthus annuus L.) becomes evident with emergence of broomrape shoots aboveground, infection occurs early after sowing, the host physiology being altered during underground parasite stages. Genetic resistance is the most effective control method and one of the main goals of sunflower breeding programmes. Blue-green fluorescence (BGF) and thermal imaging allow non-destructive monitoring of plant diseases, since they are sensitive to physiological disorders in plants. We analyzed the BGF emission by leaves of healthy sunflower plantlets, and we implemented BGF and thermal imaging in the detection of the infection by O. cumana during underground parasite development. Increases in BGF emission were observed in leaf pairs of healthy sunflowers during their development. Lower BGF was consistently detected in parasitized plants throughout leaf expansion and low pigment concentration was detected at final time, supporting the interpretation of a decrease in secondary metabolites upon infection. Parasite-induced stomatal closure and transpiration reduction were suggested by warmer leaves of inoculated sunflowers throughout the experiment. BGF imaging and thermography could be implemented for fast screening of sunflower breeding material. Both techniques are valuable approaches to assess the processes by which O. cumana alters physiology (secondary metabolism and photosynthesis) of sunflower.

Plant phenotyping relevance

BGF画像と熱画像を用いて感染植物の生理状態を非破壊的に検出し、育種材料のスクリーニングへ応用する方法が研究の中心である。

Code and data availability

The article describes BGF and thermal imaging experiments on sunflower infected by Orobanche cumana, but no public phenotype dataset, image repository, analysis code, or supplement with such assets is mentioned. The only URL present (FAOSTAT) is a generic production-statistics reference, not a paper-specific asset.

No evidence-backed public reproduction asset is currently recorded.