Partial Characterization and Leaf Bioassay of Toxins of Fusarium udum Butler

Wilt caused by Fusarium udum Butler, is the major constraint to pigeonpea production worldwide, which can cause yield losses up to 100% in susceptible cultivars, These toxic metabolites also known is one of the weapons used by pathogen inducing disease condition in susceptible host plants. Many pathogens are known to produce toxins both in vitro and in vivo and these toxins have been implicated in the symptom development on the host tissues. In the present research, we have isolated and partially characterized the Fusarium udum toxin. The efficacy of the toxins were further tested using detached leaf bioassay. The LCMS analysis of crude and methanolic fraction revealed more than 20 peaks among which seven known mycotoxins were detected on the basis of m/z ratio. The analysis of mycotoxin in present investigation revealed FusrenonX (FX), T2toxin (T2), HT2toxin (HT2), Zearalenon (ZON), Tricothecen-T-2- Diacetoxyscipenol (DAS), .3-Acetyldeoxy-nivalenol (ADON). Detached leaf bioassay results exhibit that necrotic symptoms was increased upon increasing the concentration of the toxin in both crude and menthanolic fraction of the toxins appeared at all the concentration but the severe necrotic lesion was noticed in methanolic fraction of toxins. The maximum lesion of 5.13 mm2 was observed in 200 μl of methanolic fraction of toxin. The identified phytotoxins may prove to be useful tool for screening pigeonpea at earlier stages.