Optical study of laser biospeckle activity in leaves of Jatropha curcas L.: a non-invasive and indirect assessment of foliar endophyte colonization

Abstract

Currently, the detection of endophytic fungi is determined mostly by invasive methods, including direct isolation of fungal organismsfrom plant tissue in growth media, molecular detection of endophyticfungi DNA from plant material by PCR, or evaluation under microscopy techniques.In this work we explore the potential of laser biospeckle activity (LBSA) to be usedfor the detection of endophytic colonization of leaves of a promising energy crop, Jatropha curcas L. We compared the laser biospeckle activityof endophyte infected and uninfected J. curcas leaves. The differences between blade and veins (including midrib) of the studied leaves was validated and growth parameters of the studied plants were also analyzed using the normalized weigthed generalized differencescoefficient (nWGD). The obtained results showeda relationship between the endophytic burden of leaves and the LBS, suggesting that LSBA is a useful tools to detect endophytic colonization in situ.Also, the increasedwater movements inside leaves promoted by endophytic colonizationcould be explainby the obtained data.