Tolerance of wheat varieties seedlings by glyphosate accelerated degradation

Abstract

Lengths of seedlings aboveground parts of nine wheat varieties grown in greenhouse were reduced by 4-20%. They were tested during April at around 20oC after twice daily treatments with glyphosate based herbicide (0.5 ml in 1l water solution, 0.5 dl on 0.5 m2). When results of permanent artificially and daily lighted trials were compared, four groups of varieties were recognized same as was when near isogenic lines containing different leaf rust resistance genes (Lr NILs) were focused in winter. Growth of variety Pobeda decreased more when seedlings were not permanent lighted which confirmed the common herbicide effect. Tolerance of other varieties was again explained by enzymatic degradation of glyphosate and chlorophyll inhibition by consequential phosphorus acids. Varieties Simonida, Tavita and Rapsodia were similar by reaction to glyphosate as Lr 1 and Lr 21 NILs. NS 40S contained Lr 3a with increased hydrolytic stability compared to Lr 24 but able to cleave external single phosphorus for the difference of Lr 19 or Lr 29. Their final effect was similar to previous stated of Lr 15 NIL during the winter. Varieties Gora and Metka had gene Lr 19, Enigma Lr 29 while Ilina Lr 24. Focusing herbicide residua transfer in seed probability, accounting optimal time for recovering ability of chlorophyll and temporary higher temperatures necessary for Lr genes even parasite free activity the varieties Gora, Metka and Enigma appeared to be possible solution for glyphosate apply near wheat heading in semiarid regions.

Keywords

• glyphosate
• herbicides
• Lr gene
• seedlings
• tolerance
• wheat variety