Hopum is a new japonica rice cultivar developed from the cross between Milyang165 and F1 crossing Milyang165 and Iksan438 at Department of Rice and Winter Cereal Crop, NICS, RDA, in 2006. This cultivar has a short grain shape and about 141 days growth duration from direct seeding to harvesting in the southern plain including Chungcheong province. This cultivar has short culm and spikelet number per panicle is similar to that of Nampyeongbyeo, while filled grain rate is lower than standard variety. This cultivar has medium size of brown rice and shows moderate resistance to leaf blast, to bacterial blight pathogens of K1, K2 and K3 and stripe virus disease but susceptible to major virus diseases and insect pests. The milled kernel of Hopum is translucent with non-glutinous endosperm. Protein and amylose content of Hopum is about 6.5% and 18.7%, respectively. This cultivar has better palatability of cooked rice than Chucheongbyeo harvested in Gyeongki province. Its milling recovery (76.8%) and percentage of perfect-shaped milled rice (94.7%) were higher than Nampyeongbyeo. The milled rice yield of Hopum was 5.83 MT/ha (15% higher than Juan) under wet-direct seeding, 5.66 MT/ha (8% higher than Juan) under dry-direct seeding, and 6.00 MT/ha (8% higher than Nampyeong) under ordinary transplanting cultivation. “opum”would be adaptable for ordinary transplanting and direct seeding in the southern plain including Chungcheong province.

Hwangeumnodeul is a new japonica rice cultivar developed from a cross between Milyang165 and HR15151-B-21-3 at Honam Agricultural Research Institute (HARI), NICS, RDA, in 2007. This cultivar has short grains and about 139 days of growth duration from direct seeding to harvesting in the southern plain areas. Culm length of this cultivar is 78 cm and the number of spikelet per panicle is similar to that of the check cultivar, Nampyeongbyeo, while filled grain rate is lower than the check variety. This cultivar is moderately resistant to leaf blast, bacterial blight pathogens of K1, K2 and K3 and stripe virus but susceptible to major virus diseases and insect pests. Milled kernel of Hwanggeumnodeul is translucent with non-glutinous endosperm. This cultivar has about 5.7% and 18.6% of protein and amylose contents, respectively. Palatability of cooked rice of Hwanggeumnodeul is similar to Nampyeongbyeo. Its milling recovery and head rice were 75.6% and 90.0%, respectively. Hwanggeumnodeul yielded 5.69 and 5.61 MT/ha in milled rice at the under wet-direct and dry-direct seeding conditions, respectively which are 17% and 12% higher than the check variety, Juanbyeo. It yielded 5.86 MT/ha, 8% higher than Nampyeongbyeo at the standard fertilizer level of the ordinary transplanting cultivation. “wanggeumnodeul”would be adaptable for ordinary transplanting as well as direct seeding in the southern plain including Chungcheong province.

“ongjin2”is a new japonica rice cultivar developed from the cross between Milyang165 with short culm and lodging resistance and F1 plant of Iksan438, HR14018-B-1-1 and Iksan435 with high palatability at Honam Agricultural Research Institute (HARI), NICS, RDA in 2005. This cultivar has short grain shape and about 143 days growth duration from direct seeding to harvesting under Korean climate condition. The milled kernels of “ongjin2”is translucent with non-glutinous endosperm. It has about 19.3% of amylose content and better palatability of cooked rice compared with “ampyeongbyeo” This cultivar shows high resistance reaction to the bacterial blight pathogene race from K1 to K3, blast and stripe virus but susceptible to insect pests. “ongjin2”yields about 5.71 and 5.74 MT/ha under the wet direct seeding and the transplanting at standard fertilizer level. “ongjin2”would be adaptable for the southern plain area of Korea.

벼 품종의 직파적응성을 평가하기 위하여 입모율이 높은 ASD1 품종과 비교적 낮은 IR72품종에 대한 종자의 발아기간 중 공기와 질소 충진상태에 따른 sugar와 starch 함량의 변화를 검토하였다. 1. 공기 충진상태와 질소 충진상태에서 직파적응성이 높은 ASD1 품종은 비교적 낮은 IR72 품종보다 발아기간 중 starch 함량이 높았으며 두 품종간 starch 감소 패턴이 상이하였다. 2. 공기 충진상태와 질소 충진상태에서 직파적응성이 높은 ASD1 품종은 비교적 낮은 IR72 품종보다 발아기간 중 sugar 함량이 높았으며 두 품종간 sugar 증가 패턴은 같은 경향이었다. 3. ASD1 품종은 IR72 품종보다 공기와 질소를 계속 충진하거나 주기적으로 주입 또는 질소 충진후 공기를 보충하는 조건 등의 어떠한 충진조건에서도 발아경과에 따른 sugar 함량이 높았다.

“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

Kwanganbyeo is a japonica rice variety developed from the cross between Namyang 7 and SR14779-HB234-31, anelite line derived from the cross between Cheonmabyeo and Aichi 37 at the National Crop Experiment Station, RDA, and washi-tecture and light-dark gre

Junganbyeo is a japonica rice variety derived from a cross of Namyang 72* Hapcheon 1 by the rice breeding team ofNational Crop Experiment Station, RDA, in 1999 and was released in 2000. This is a medium-early variety with growth durationtdark gren leaves.

Rice seedling test was conducted to check the loging tolerance at ripening stage through evaluating the root characters. Thirteen Korean and foreign rice cultivars with direct seeding adaptable or high quality characteristics were grown in a cell pot and under submerged paddy. The root characters and pushing resistance of rice hill were determined at seedling and ripening stage, respectively. The diameter of crown root at the 7th and 8th leaf stages was thicker in lodging tolerance cultivars than those of others and showed significant-positive correlation with both pushing resistance and crown root diameter of mature plants. Also, the tensile strength of crown root at the 7th and 8th leaf stage showed highly positive correlation with the tensile strength of crown root of mature plants. The number of crown root at 7th leaf stage was significant-positively correlated with that of mature plant. The diameter of seminal root was not significantly correlated with the diameter of crown root throughout the whole growth stage. These results indicate that the diameter, tensile strength and number of crown root associated with root lodging tolerance can be detected with the seedling at about 7th or 8th leaf stage, and the seedling test using the cell pot is an useful and practical method to select lodging tolerant cultivars or lines of rice based on root characters, especially diameter of crown root.