RÉSUMÉ

Spondia tuberose seeds are enclosed by the walls of a rigid, woody, lignified endocarp. Plasma treatment of such seeds is extremely difficult due to the necessary distance for the plasma species to penetrate until reaching the seed. Several studies have been published describing the success of the plasma treatment in increasing the wettability of seed coats; however, no investigation has also been carried out in situations in which the barrier is not just the integument, but also other anatomical complexities of the seed, such as the walls of the endocarp. In this study, the S. tuberose seed, which is enclosed by an impermeable endocarp, was treated by atmospheric plasma to verify whether the plasma is effective in penetrating to the seed, modifying its germinative properties. Significant changes were observed in the absorption of water leaching substances, germination, and seedling vigor due to plasma treatment. These results show that the plasma, through a mechanism that needs to be better investigated, alter the physical and physiological responses of the seed.