Screening for resistance to Heterodera sacchari in the two cultivated rice species, Oryza sativa and O-glaberrima

A total of 73 rice accessions belonging to the mio species of cultivated rice, Oryza sativa and O. glaberrima, and one wild species, O. breviligulata, were screened in pot experiments for resistance to.a Congolese population of the cyst nematode Heterodera sacchari. All 43 accessions of O. sativa were susceptible, although they were presumably genetically different as they came from various parts of the world. In contrast, fifteen of the 21 accessions of O. glaberrima and seven of the nine accessions of O. breviligulata were resistant whereas the others were susceptible. All of these 30 accessions originated from Africa, as did the parasite itself. These results were verified with mio other populations of the parasite from Chad and Senegal. These results are analysed and their possible use is discussed. (C) Orstom/Elsevier, Paris.