Toothpick test: a methodology for the detection of RR soybean plants

Fabiana Mota Da Silva,Otávia Tiago Villela,Antonio Orlando Di Mauro,Sandra Helena Unêda-Trevisoli,Dilermando Perecin

doi:10.5935/1806-6690.20150024

Fabiana Mota Da Silva, Otávia Tiago Villela + Show 3 more

Open Access

https://doi.org/10.5935/1806-6690.20150024

Copy DOI

Abstract

Due to the large increase in the area cultivated with genetically modified soybean in Brazil, it has become necessary to determine methods that are fast and efficient for detecting these cultivars. The aim of this work was to test the efficiency of the toothpick method in the detection of RR soybean plants, as well as to distinguish between cultivars, for sensitivity caused by herbicide. Ten transgenic soybean cultivars, resistant to the active ingredient glyphosate, and ten conventional soybean cultivars were used. Toothpicks soaked in glyphosate were applied to all the plants at stage V6 and evaluations were made at 2, 4, 6, 8 and 10 days after application (DAA). The effects of the glyphosate on the cultivars, and the symptoms of phytotoxicity caused in the transgenic plants were evaluated by means of grading scales. The toothpick test is effective in identifying RR soybean cultivars and also in separating them into groups by sensitivity to the symptoms caused by the glyphosate.

Highlights

Brazil is the second largest producer of soybeans, with a production of about 90 million tonnes (COMPANHIA NACIONAL DE ABASTECIMENTO, 2014)
The aim of this study was to test the efficiency of the toothpick method in the detection of soybean cultivars which are tolerant to glyphosate, as well as to differentiate the cultivars as to sensitivity caused by the herbicide
The experiment was conducted in the agricultural year of 2012, in a completely randomised design (CRD), where the treatments consisted of ten conventional soybean cultivars (FD 39, CD 217, CD 205, IAC Foscarim, FT Crystalina, BRS 183, BRS Sambaíba, BRS Conquista, BRS Tucunaré and BRS Renasença) and ten Roundup Ready (RR) soybean cultivars (BMX Potência, TMG 4001, NA 6411, BRS Juliana, P 98Y70, CD 242, TMG 315, SYN 9078, M 8336 and M 7908), with 10 replications

Summary

Introduction

Brazil is the second largest producer of soybeans, with a production of about 90 million tonnes (COMPANHIA NACIONAL DE ABASTECIMENTO, 2014). Merrill.) covers an area of 27 million hectares, of which 91.1% (24.60 million hectares) is given over to growing genetically modified soybean (CÉLERES, 2013). A characteristic of Roundup Ready (RR) soybean is a tolerance to the active ingredient glyphosate. Glyphosate is a herbicide which acts by inhibiting the enzyme 5-enolpyruvylshikimate-3phosphate synthase (EPSPS), obstructing the formation of amino acids essential for protein synthesis (QUERCI et al, 2010). In RR soybean, glyphosate tolerance is acquired by recombination with the CP4-EPSPS gene, derived from the Agrobacterium bacteria (PADGETTE et al, 1995)

Objectives

Methods

Results