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

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.

摘要：从理论层面而言，通过重组DNA技术（recombinant DNA technology）获得的同基因杂交种（isogenic hybrids）本不应存在遗传组成层面的差异，但此类材料在适应性与稳定性方面却可能表现出不同的性状表现。本研究旨在评估巴西马托格罗索州南部两个试验点中转基因玉米及其同基因杂交种的农艺表现。本次试验共评估了3个同基因单交种，以及每个杂交种对应的2个转基因品种。于2013/2014年度的第一季和第二季玉米种植季，在马托格罗索州南部的杜拉多斯（Dourados）和卡拉波（Caarapó）两个试验点同步开展试验，共计4个环境×季候组合供评估。试验采用完全随机区组设计（randomized complete block design），每个试验点设置3次重复，处理采用3×3因子排列（3个转基因杂交种与3个常规同基因杂交种），每个试点设置3次重复。试验测定的性状包括株高、穗位高、雄花期、雌花期以及籽粒产量。本研究采用埃伯哈特-拉塞尔模型（Eberhart and Russell model）估算适应性与稳定性参数。在所有试验环境中，转基因杂交种的平均籽粒产量均更高。分试验环境来看，常规同基因杂交种AG 7000获得了最高的平均籽粒产量。稳定性与产量表现最优的杂交种为转基因品种DKB 390 VT PRO与AG 7000 YG。所有供试杂交种在卡拉波（Caarapó）的第二季玉米种植季均表现出更高的平均株高、穗位高与籽粒产量，表明该试点此时的环境条件更为适宜。