Leaf constituents from Zuccagnia punctata: toxicity on seedlings and the endogenous fungal flora of maize grains

JIMÉNEZ, C.M.; SAMPIETRO, D.A.; SGARIGLIA, M.A.; SOBERÓN, J.R. ; VATTUONE M.A.

Tafí del Vale - Tucumán

Congreso; XXXIII Annual Scientific Meeting of Tucuman Biology Society; 2016

Tucuman Biology Society

Leaf tincture (TZP) of Zuccagnia punctata Cav.(Fabaceae) and its constituents 2´,4´-dihydroxychalcone (DC),2´,4´-dihydroxy-3´-methoxychalcone (DMC) and 7-hydroxy-3´,4´-dimetoxyflavone (HF) suppress the growth of Fusarium verticillioides responsible for seedling blight in maize in microdilution assays. In this work, we evaluated the phytotoxicity and the control performance of endogenous fungal flora of the tincture and its contituents on maize grains. Horsetooth grains disinfected with NaClO 0.02% were embebed for 50 min in suspensions of TZP, DC+DMC or HF at concentrations of 20xCIM. The germination of the grains disinfected with NaClO (control), or treated with TZP or its constituents, was evaluated in the rolled towel test for 7 days at 25°C. Then, germination power (PG), and radicle and shoot length were determined. The development of the endogenous fungal flora of the grains was evaluated after 7 days at 30°C in agar-malt-peptone-sucrose medium. The percentages of grains infected with Fusarium and with other fungi were determined. TZP, DC+DMC, HF and control showed a PG=80%. DC+DMC increased by 20% the radicle and shoot length. HF reduced 50% the length of both organs. TZP, DC+DMC and HF increased more than 20% the number of adventitious roots and did not affect the emergence of secondary roots. 97% of the grains treated with these suspensions did not present fungal