Agronomic performance of transgenic and isogenic corn hybrids in the state of Mato Grosso do Sul1

Wesley Souza Prado,Manoel Carlos Gonçalves,André Carlesso,William Leonello Estevão,Arthur Kenji Mendes Maeda,Livia Maria Chamma Davide

doi:10.1590/0034-737x201663060008

Abstract

ABSTRACT Theoretically, isogenic hybrids should not present any differences in their genetic makeup due to recombinant DNA technology. However, these materials may behave differently in relation to adaptability and stability. This study aimed at evaluating the agronomic performance of transgenic corn and their isogenic hybrids in two locations in Mato Grosso do Sul, Brazil. Three isogenic simple hybrids and two transgenic varieties of each hybrid were evaluated. The first and second corn crop of 2013/14 were simultaneously analyzed in Dourados and Caarapó, two locations in the State of Mato Grosso do Sul, totaling four environments x season conditions that were evaluated.. A randomized complete block design with three replicates per location was used, and the treatments were arranged in a 3 × 3 factorial design (three genetically modified and three conventional hybrids), with three replicates per site. Characteristics such as plant height, ear height, male flowers, female flowers, and grain yield were evaluated. The parameters adaptability and stability were estimated using the Eberhart and Russell model. In all environments, transgenic hybrids showed higher average grain yield. Considering the environments, AG 7000, a conventional isogenic hybrid, obtained the highest average grain yield. The most stable and productive hybrids were DKB 390 VT PRO and AG 7000 YG, both transgenic. All assessed hybrids exhibited greater average plant height, ear height, and grain yield in Caarapó during the second corn crop, demonstrating that the environment at that site and time was more favorable.

Highlights

Corn (Zea mays L.) is one of the oldest domesticated plants and is the most produced grain in the world accounting for 38% of all grain produced, followed by wheat (29%) and rice (21%) (Conab, 2014)
Isogenic hybrids should not present any differences in their genetic makeup due to the recombinant DNA technology used to create them
It is worth noting that when location was assessed, the second corn crop in Caarapó experienced superior conditions for the development of genotypes, both for the transgenic and isogenic hybrids

Summary

Introduction

Corn (Zea mays L.) is one of the oldest domesticated plants and is the most produced grain in the world accounting for 38% of all grain produced, followed by wheat (29%) and rice (21%) (Conab, 2014). Corn is the second largest transgenic crop grown in Brazil, occupying about 12.5 million hectares considering both summer and winter corn crops (Celeres, 2014). According to Embrapa (2013), 253 transgenic and 214 conventional corn cultivars were made available to farmers during the corn crop of 2013/14. Transgenic cultivars currently available are the result of five genetic modification events to control caterpillars, some of which include YieldGard® MON 810 and MON 89034 YieldGard VT PRO®. Transgenics derive from conventional cultivars by classical breeding methods and are known as isogenic hybrids. In this manner, theoretically, isogenic hybrids should not present any differences in their genetic makeup due to the recombinant DNA technology used to create them. Transgenics may interfere with the adaptability and stability of these materials

Objectives

Methods

Results