A Biosystematic Study on Echinochloa oryzoides (Ard.) Fritsch

Abstract

Echinochloa oryzoides (Ard.) Fritsch is distributed in Australia and southern Europe to eastern Asia. The habitat is confined to the rice fields, and has the erect plant architecture. E. oryzoides can be recognized as a lowland rice mimic. The chromosome number is n=27. Artificial hybrids of E. oryzoides with the two varieties of E. crus-galli (n=27) were easily produced. It was elucidated that E. oryzoides is closely related to E. crus-galli, having the same genomic constitution in common. Cytologically and morphologically E. oryzoides might be. relegated to a variety of E. crus-galli.