Soybean seed coat structures: relationship to weathering resistance and infection by the fungus Phomopsis phaseoli

The fungus Phomopsis phaseoli (Desmaz.) Sacc. (syn. P. sojae Lehman) incites a serious disease of soybean [Glycine max (L.) Merr.] seeds. This study was conducted to determine if an impermeable seed coat reduces infection by this fungus. Seeds of four soybean cultivars found in blotter tests to be infected by P. phaseoli in very low amounts (0-5%) and seeds of four other cultivars with high amounts of infection by this fungus (65-83%) were studied under scanning electron microscopy. Seed coats of cultivars with low P. phaseoli infection were found to lack pores, whereas those with high infection had multiple pores