passages.id: split_4_test_481_passage
passages.type: progene_text
passages.text: Endogenous , 14 kb double - stranded RNAs ( dsRNAs ) have been found in two ecospecies of cultivated rice ( temperate japonica rice and tropical japonica rice , Oryza sativa L. ) and in wild rice ( O. rufipogon , an ancestor of O. sativa ) .