Fig. 5

Assessment of plant mechanical barrier in the form of lignin deposition. The image indicates transverse section of chilli stem tissues with lignification in the wall of xylem strands collected from 4 different samples (unprimed, T. asperellum, T. harzianum and T. asperellum + T. harzianum bioprimed seeds) at time intervals 30 and 60 days. Intensity of red-pink color indicates the deposition of lignin. The lignified vascular bundles were seen on primary (protoxylem) and secondary xylem (metaxylem). A-B Microscopic view of transverse section of unprimed (control) plant samples at 30 days intervals. C-D Microscopic view of transverse section of T. asperellum bioprimed plant samples at 30 days. E–F Stem sections were taken from T. harzianum samples at 30 days. G-H Stem sections were taken of T. asperellum + T. harzianum samples at 30 days. I-J T. S of stem sections were taken from unprimed samples at 60 days. K-L Stem sections were taken from T. asperellum samples at 60 days. M–N T. S. of stem sections were taken from T. harzianum samples at 60 days. O-P T. S. of stem sections were taken from T. asperellum + T. harzianum samples at 60 days intervals. All the sections were observed at 4 × and 10 × magnification. Px, primary xylem; Sx, secondary xylem, Pi, pith; Ph, phloem; C, cambium; V, vessel; E, endodermis. Scale bar represents 250 µm