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.

Dužine nadzemnih delova sejanaca devet sorti pšenice gajenih u staklari bile su redukovane 4-20%. Testirane su pri temperaturama oko 20oC tokom proleća posle dva dnevno uzastopna tretmana herbicidom na bazi glifosata (0,5 ml u 1l vodenog rastvora, 0,5 dl na 0,5 m2). Na osnovu razlika između stalno veštački i dnevno osvetljenog ponavljanja prepoznate su četiri grupe sorti, što je potvrdilo rezultate dobijene kod izogenih linije različitih gena otpornosti prema prouzrokovaču lisne rđe (NIL) testiranih tokom zime. Rast sorte Pobeda bio je usporeniji kada nije bila permanentno osvetljena te je prepoznat uobičajen efekat herbicida. Tolerantnost drugih sorti je bila povezana sa ubrzanom degradacijom glifosata te uticajem posledične fosforne kiseline na inhibiciju hlorofila. Sorte Rapsodija, Simonida i Tavita su po reakciji prema herbicidu bile slične Lr 1 i Lr 21 liniji. Ubrzano žućenje lista NS 40S bilo je zavisno od gena Lr 3a neuticajnog na poslednje fosforne residue nakon otpuštanja kiseonika, dok je sličan efekat hidrolitički najstabilnijeg Lr 15 u NIL isključen na osnovu analiza uticaja na degradaciju glutena. Na osnovu pomenutih kriterijuma, sorte Gora i Metka su sadržale Lr 19, Enigma Lr 29 a Ilina Lr 24. Poštujući pre svega više vremena za eliminaciju originalnih rezidua herbicida blizu klasanja, česte temperature uslove povoljne za aktivnost Lr gena, posledice na rast te brži oporavak hlorofila, za tretman u to doba u semiaridnim regionima, sorte s Lr genima kao Gora, Metka i Enigma su prepoznate kao moguće praktično rešenje. Tretman sorte Ilina je rizičan usled očekivanog izostanka efekta a ostalih usled rezidua.