Abstract
The genetic mechanism of resistance to mechanical damage in soyabean seeds was investigated so that soyabean breeders may screen for the character. Twelve cultivars of known performance related to mechanical damage were used: resistant - Doko, FT-2, IAS-5 and Parana; moderately resistant - Santa Rosa, IAC-8, FT-10 and Bossier; and susceptible - Davis, Paranagoiana, Savana and IAC-2. Lignin content of the seed coat was determined and its results correlated with the index of resistance to seed mechanical damage obtained by the pendulum test. The coefficient of determination (r2) between these two parameters was 0.90, which was highly significant, meaning that the higher the level of lignin content in the seed coat, the higher the level of resistance to mechanical damage. These results directly implicate lignin content of the seedcoat as the genetic trait that should be used to screen for genotypes that will resist to mechanical damage.