Germination and seedling growth under anaerobic conditions in Echinochloa crus-galli (barnyard grass).
Seeds of two varieties of E. crus-galli germinate and grow for prolonged periods in a totally oxygen-free environment. E. crus-galli germinates as well as rice (Oryza sativa) under a total nitrogen atmosphere and produces as large a seedling in spite of its much smaller seed size. Like rice, the seedlings of E. crus-galli are unpigmented, the primary leaves do not emerge from the coleoptile and no root growth occurs without oxygen. Mitochondrial profiles from the primary leaf of seedlings grown continuously in nitrogen are very similar to those grown aerobically. The size and shape of the mitochondria are similar and the cristae are numerous and normal in appearance. Ultrastructure and 14C labeling studies showed that anaerobically-grown seedlings are highly active metabolically, which may explain the ability of E. crus-galli var. oryzicola to germinate and emerge from flooded rice fields.