Biocontrol of Amaranthus retroflexus and Rumes crispus by NLP phytotoxine, a selective bioherbicide

Abstract

Non-beneficial and harmful weeds are plants that are unwanted, outside their home farms are growing and have the potential to exceed. This study was done in order to screening fungai and isolating NLP phytotoxine from them for selective biocontrol of <em>Amaranthus retroflexus</em> and <em>Rumes crispus</em> as a dicot, common and chemical herbicide resistance weeds. NLPs are effective just on dicot plants. Contaminated soil and dicotyledons plants were Collected from different regions of Iran. after collecting and culturing them, The effect of Supernatant from fungal cultures, was asseyd by spraying of 5 µl /cm3 of it mid 20 µl tween-20 on leaves of <em>Amaranthus retroflexus,Rumes crispus </em>and wheat as negative control that were cultured in MS media and pots in 3 replications with completely randomized design in laboratory and research green house of baqiatallah university. The effects were assessed according to numbering method. Finally, the <em>QAT₅</em>and<em> G_7-1</em>strains was selected from 9 top strains, because was more destructive than others on <em>Amaranthus retroflexus </em>and<em> Rumes crispus</em> respectively from necrosis to cell death with number 4 according to numbring method and has non-harmful effect on the wheat (<em>Triticum aestivum</em>). SDS-page results showed phytotoxine that was produced by <em>QAT₅</em> strain was a protein and this from G_7-1was non-protein. For better result on SDS-page protein was concentrated using by ammonium sulfat method, but about G_7-1again this outcomewas repeated. The protein purification of <em>QAT₅</em>strain using FPLC showed the presence of a protein with about 24 kDa like other family members of this protein. Considering this fact that these phytotoxines according to the result had similarity features to what founded befor about NLPs, they are recommended as biocontrol factor of these weeds insteade of chemical herbicides.