|0.15| °C in defined time windows, and that RH affected the shape of these thermal fingerprints. We demonstrated that IRT can also be used to assess the viability of the lichens Lobaria pulmonaria, Pseudevernia furfuracea and Peltigera leucophlebia. No clear relationship between aerobic metabolism and the shape of thermal fingerprints was found. Conclusions Infrared thermography appears to be a promising method for the diagnosis of viability of desiccation-tolerant tissues at early stages of water uptake. For seeds, it is possible to diagnose viability within the first hours of rehydration, after which time they can still be re-dried and stored until further use. We envisage our work as a baseline study for the use of IR imaging techniques to investigate physiological heterogeneity of desiccation tolerant life forms such as lichens, which can be used for biomonitoring, and for sorting live and dead seeds, which is potentially useful for the seed trade."/>
Skip to main content
Fig. 4 | Plant Methods

Fig. 4

From: Non-invasive diagnosis of viability in seeds and lichens by infrared thermography under controlled environmental conditions

Fig. 4

Thermal fingerprints of the fungal tissue in the lower cortex of L. pulmonaria discs (Experiment 3). Unlike in Fig. 3, the thallus discs were placed upside down to measure rT of the fungal layer. a Viability staining of "live" and "dead" thallus discs stained with 1% nitroblue tetrazolium (NBT). As actively respiring cells convert NBT to a dark precipitate, only "live" discs show dark staining. b Maximal photochemical efficiency (Fv/Fm) of "live" (green symbols) and "dead" (red symbols) thallus discs at the end of imbibition. Bars labelled with different letters indicate significant differences between treatments (P < 0.05; Kolmogorov–Smirnov test). Bars are means ± SE of (n = 14 lichen discs). c Moisture content (MC) of "live" (green) and "dead" (red) thallus discs during imbibition. Symbols are means ± SE (n = 14 discs). Asterisks indicate significant differences between treatments ("live", "dead") at P < 0.05 (Mann–Whitney U test) at each time-point. d Thermal fingerprints of "live" and "dead" thallus discs, showing median values of relative temperature (rT) during imbibition. Data are medians of n = 14 discs. e Differences between the fingerprints of "live" and "dead" thallus discs (ΔTlive–dead). Green horizontal bars at the bottom of the panel indicate the time windows in which the rT values of "live" and "dead" thallus discs differed significantly (P < 0.05, Two Sample t-test). Open blue horizontal bars indicate the time periods of hydration by water vapour and closed blue bars indicate imbibition in liquid water from below

Back to article page