Sindongjinbyeo is a new japonica rice cultivar developed from a cross between Hwayeongbyeo and YR13604Acp22 line by the rice breeding team of National Honam Agricultural Experiment Station (NHAES), RDA, in 1999. This cultivar has a large grain and about 1

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

Mihyangbyeo, a new japonica aromatic rice (Oryza sativa L.) was developed by National Honam Agricultural Experiment Station (NHAES), RDA in 1998. It was derived from the three-way cross among Seomjinbyeo of the disease resistance and high yielding lines,

“Hoanbyeo” is a new japonica rice cultivar developed from a cross between Kanto149 and Milyang95 by the rice breeding team of National Honam Agricultural Experiment Station (NHAES), RDA, during 1990 to 1998. This cultivar requires about 121days of growth

“Dongjinchalbyeo” is a new japonica glutinous rice cultivar developed from a cross between Milyang95 and SR11155-4-2/Toyonishiki by the rice breeding team of the National Honam Agricultural Experiment Station (NHAES), RDA, in 1998. This cultivar has a sho

“Sobibyeo” is a new japonica rice cultivar developed from a cross betw een Hwayeongbyeo and YR13604Acp22 line by the rice breeding team of National Honam Agricultural Experiment Station (NHAES), RDA, in 1999. This cultivar has a large grain and about 119

Four different rice varieties, Sindongjinbyeo, Dongjin #1, Saegyehwabyeo, and Iksan 467, were transplanted under three different nitrogen levels and two different seedling numbers per hill to obtain basic information on panicle traits under different cultural conditions and to propose the ideal panicle structure in Japonica rice. Sindongjinbyeo and Iksan 467 were characterized by more primary rachis branches (PRBs) per panicle and more grains on PRB than other cultivars. The two varieties also had fewer secondary rachis branches (SRBs) per PRB and fewer grains on SRB per PRB. These characteristics, consequently, resulted in higher ripened grain rate, contrary to that of Dongjin #1 and Saegyehwabyeo. In the correlation coefficient analysis, PRB number per panicle and grain number on PRB per panicle were positively correlated with ripened grain rate, while SRB number per panicle, number of grains on SRB per panicle, SRB number per PRB, number of grains on SRB per PRB and grain number per panicle were negatively correlated with ripened grain rate. Therefore, the number of grains on PRB per panicle, SRB number per PRB and the number of grains on SRB per PRB were the appropriate criteria for determining and achieving higher ripened grain rate in rice. High ripened grain rate over 90% was obtainable with over 12.5 PRBs per panicle and 63 grains on PRB per panicle, and with under 1.7 SRBs per PRB, 5 grains on SRB per PRB, 130 grains per panicle, and 14 panicles per hill. The study recommended that for over 90% high ripened grain rate, the critical limiting factors should be under 2 SRBs per PRB, 6 grains per PRB, and 130 grains per panicle, irrespective of the PRB number per panicle and the number of grains on PRB.