Blast, caused by Pyricularia grisea, is a major constraint on rice production. To widen genetic diversity for disease resistance, the Indian native rice cultivar Aus373 was screened by F2 segregation analyses to investigate the genetic basis of its high resistance. Aus373 was crossed with a series of Japanese differential cultivars (JDCs) and the Chinese susceptible cultivar Lijiangxintuanheigu (LTH). The resistance ratios of subsequent F2 progenies were used to determine the number of blast-resistance loci present as well as allelic relationships with known loci. Resistance of Aus373 was governed by dominant alleles at two loci, one at the Pi-k locus and the second apparently at a new locus linked to an isozyme gene Amp-1 with a recombination fraction of 37·9 ± 3·0% on chromosome 2. This putative new locus and allele were designated Pi16(t).