Osetljivost vrsta Conyza canadensis (L) cronquist i Conyza bonariensis (L) cronquist na glifosat

Changes in leaf anatomy were examined in suspectedly resistant populations of C. canadensis and C. bonariensis after application of 2, 4 and 8 L ha-1 of the product Touch down (500 g a.i. glyphosate L-1). Samples for the analysis (LM, TEM) were collected 3, 7 and 24 h after herbicide application. Changes in chlorophyll and shikimic acid contents were also examined in the populations tested. Changes in the anatomy of leaves were not detected in the investigated populations 3 and 7 h after herbicide application. However, 24 h after application of different herbicide rates, differences were observed in leaf anatomy. Injuries were detected in C. bonariensis population after application of 2 L ha-1, and in C. canadensis population after treatment with the highest glyphosate rate (8 L ha-1). Changes were detected on cell walls, chloroplast lamellae and chloroplasts themselves. Based on chlorophyll and shikimic acid contents, significant statistical differences were detected between the treated and control plants.Praćene su promene u anatomskoj građi listova pretpostavljeno rezistentih populacija C. canadensis i C. bonariensis nakon primene 2, 4 i 8 L ha-1 Touch down (500 g a.m. glifosat L-1). Za analizu anatomske građe listova (LM, TEM) materijal je uzorkovan nakon 3, 7 i 24 h posle primene herbicida. Takođe, praćene su promene u sadržaju hlorofila i šikiminske kiseline kod testiranih populacija. Promene u anatomskoj građi listova nisu konstatovane kod ispitivanih populacija nakon 3 i 7 časova posle primene herbicida. Međutim, 24 časa nakon primene različitih količina uočene su razlike u anatomskoj građi listova. Oštećenja su bila uočljiva kod pop. C. bonariensis nakon primene 2 L ha-1, a kod pop. C. canadensis tek nakon primene najveće količine glifosata (8 L ha-1). Promene su uočene na ćelijskom zidu, lamelama hloroplasta, kao i na samim hloroplastama. Na osnovu sadržaja hlorofila i šikiminske kiseline takođe su utvrđene statistički značajne razlike između tretiranih i kontrolnih biljaka