Evaluation of the stability of quantitative traits of winter oilseed rape (Brassica napus L.) by AMMI analysis

Agronomical traits of crop plants exhibit quantitative variation that is controlled by multiple genes and is dependent on environmental conditions. The main objective of this study was to decipher the genotype-by-environment interaction (GEI) for six yield-related traits of 25 winter oilseed rape (WOSR) genotypes using the additive main effects and multiplicative interaction (AMMI) model. The genotypes chosen included canola cultivars, our newly developed WOSR breeding lines, yellow-seeded, semi-resynthesized and mutant genotypes, together with ogu-INRA F1 hybrids and their parental lines. These were tested in field trials at two locations over three growing seasons. Field experiments were conducted in a randomized block design with four replicates. We recorded the beginning of flowering, seed yield (SY) and SY components, the number of siliques per plant, the length of siliques, the number of seeds per silique, and the weight of 1000 seeds. The average SY in six environments varied from 16.55 to 41.64 dt<middle dot>ha(-1). The AMMI analysis showed significant effects of both G and E, as well as GEI, for the above traits. In this study, we observed that the climate condition, especially precipitation in addition to the soil type were the most influential factors on the SY and SY-trait value. Seed yield was positively correlated with: the number of siliques per plant, the length of siliques, the number of seeds per silique and the weight of 1000 seeds. We also found that our new ogu-INRA F1 hybrids, as well as cultivars Monolit, Mendel, Starter and Sherlock, showed stability for the analyzed traits.