SEED-GERMINATION BEHAVIOR OF BAPTISIA-TINCTORIA (L) R-BR

Seeds of wild grown Baptisia tinctoria plants reveal a low germination rate. Investigations were made to elucidate the factors responsible f or seed dormancy of Baptisia. The seeds differ in colour and size. In seeds with intact seed coat a correlation between seed colour, hardnes s of the testa and germination rate was found. Seed size did not influ ence imbibition and germination. Microscopic studies describe the test a structure of Baptisia and indicate the importance of the palisade la yer for water restrict ion. Common scarification procedures were appli ed to break the hardseededness. In addition to the hardseededness germ ination inhibiting substances are located in the seed coat. They are d elivered to the exterior when imbibition occurs and also delay seed ge rmination and seedling development of Lepidium sativum L. and Lolium p erenne L. The presence of phenolic substances in the testa was proved. Their possible influence on germination inhibition and the role of ha rdseededness and inhibitory substances in the natural habitat are disc ussed.