Manpung is a new japonica rice cultivar developed from three-way cross between Nakdongbyeo, Iri390 and Milyang111 by the rice breeding team of National Honam Agricultural Experiment Station (NHAES), RDA in 2000. This cultivar has a short grain shape and a

Inweolbyeo is a japonica rice (Oryza sativa L.) variety developed by Unbong Substation, National Honam Agricultural Experiment Station, RDA in 1998. It was selected from progenies from a cross between Fukei 127 and Unbongbyeo by pedigree breeding method.

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).