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：理论上，借助重组DNA技术（recombinant DNA technology）培育的等基因杂交种（isogenic hybrids）在遗传构成上不应存在差异。但这类材料在适应性与稳定性方面的表现可能存在差异。本研究旨在评估巴西南马托格罗索州两个试验点中转基因玉米（transgenic corn）及其等基因杂交种的农艺性状表现。本次试验共评估了3个常规等基因单交种，以及对应每个单交种的2个转基因衍生品种。试验于南马托格罗索州的多拉杜斯（Dourados）和卡拉波（Caarapó）两个试验点同步开展，覆盖2013/14年度的春、夏两季玉米种植季，共计4个环境-季别组合供分析评估。试验采用随机完全区组设计（randomized complete block design），每个试验点设置3次重复；处理组采用3×3因子设计，包含3个转基因杂交种与3个常规杂交种，每个试验点均设置3次重复。试验测定的农艺性状包括株高、穗位高、雄花期、雌花期及籽粒产量。适应性与稳定性参数采用埃伯哈特-拉塞尔模型（Eberhart and Russell model）进行估算。在所有试验环境中，转基因杂交种的平均籽粒产量均高于常规等基因杂交种。综合各试验环境来看，常规等基因杂交种AG 7000的平均籽粒产量最高。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试验点的第二季玉米种植季中，均表现出更高的平均株高、穗位高与籽粒产量，表明该试验点此时的种植环境更为适宜。