Local upland and lowland rice progenies and some exotic rice germplasms were evaluated with relation to leaf blast resistance. The tests were carried out in field conditions (natural inoculation) in standard nurseries for homogeneous reaction to leaf blast. The plants were evaluated according to the visual symptoms of the disease, and rated from one to seven, according to the degree system adopted in the "Symposium ou the rice blast disease", in 1963. Sixty three upland and thirty lowland rice progenies were scored to leaf blast resistance in the following areas of the State of São Paulo: Itararé, Mococa, Pariquera-Açu, Pindamonhangaba, Pindorama and Ribeirão Preto. Besides, one hundred and two exotic rice germplasms were tested in the game locations plus Campinas, looking for leaf blast resistance sources. Only five upland rice cultivars/progenies (GS-73-164, GS-73-165,. GS-73-94, IAC-25 and GS-73-17) and two lowland rice cultivars (IAC-120 and Pinda F-3-7), although susceptible, performed quite well as related to leaf blast incidence. Twenty seven exotic varieties were indicated as good leaf blast resistance sources in the State of São Paulo.
rice; blast; genetic resistance