Resistance genes to the blast pathogen (Pyricularia grisea Sacc.) were mapped using a recombinant inbred population consisting of 231 lines derived from a cross between the japonica parents, ‘Suwon365’ and Chucheongbyeo. Phenotypic analysis showed that Su

An efficient system of rice microspore culture could contribute to the production of genetically modified rice. The microspores were isolated by mechanical or shed methods. The number of microspores per 100 anthers isolated at uninucleate stage was higher than (or similar to) those at binucleate stage in isolation method with pestle or spatular, but microspore divisions were not easily observed on both stages. On the other hand, pollen division in shed pollen culture was observed more frequently at uninuclear than at binuclear stage. Cold pretreatment at 10~circC for 10 days resulted in the best multicellular division to produce microcalli at 12.5% efficiency in shed microspores. Heat shock at 33~circC for one hour before or after pollen shedding enhanced cell division and callus formation. Out of twelve green regenerants, two were haploids and ten were diploids based on the chromosome analysis of root tips. The size of stoma was 12m m in haploids and 15 ~mu~textrmm in diploids determined by scanning electron microscope (SEM).

Diversity of 80 japonica rice cultivars was evaluated using 65 microsatellite or simple sequence repeat (SSRs) markers. Sixty-five microsatellite markers representing 65 loci in the rice genome detected polymorphisms among the 80 cultivars and revealed 28