Search

The cellular functions of Ku70 in repair of DNA double-stranded breaks and telomere regulation have been described in a wide range of organisms. In this study, we identified the rice (Oryza sativa) Ku70 homolog (OsKu70) from the rice genome database. OsKu70 transcript was detected constitutively in every tissue and developmental stage examined and also in undifferentiated callus cells in rice. Yeast two-hybrid and in vitro pull-down experiments revealed that OsKu70 physically interacts with OsKu80. We obtained loss-of-function osku70 T-DNA knockout mutant lines and constructed transgenic rice plants that overexpress the OsKu70 gene in the sense (35S:OsKu70) or antisense (35S:anti-OsKu70) orientation. The homozygous G2 osku70 mutant lines were more sensitive than wild-type plants to a DNA-damaging agent (0.01%-0.05% methyl-methane sulfonate), consistent with the notion that OsKu70 participates in the DNA repair mechanism. Terminal restriction fragment analysis revealed that telomeres in homozygous G2 osku70 mutants were markedly longer (10-20 kb) than those in wild-type plants (5-10 kb), whereas telomere length in heterozygous G2 osku70 mutant and T2 OsKu70-overexpressing transgenic (35S: OsKu70) rice resembled that of the wild-type plant. h-i contrast to what was observed in Arabidopsis (Arabidopsis thaliana) atku70 mutants, homozygous G2 osku70 rice plants displayed severe developmental defects in both vegetative and reproductive organs under normal growth conditions, resulting in sterile flowers. Analysis of meiotic progression in pollen mother cells demonstrated that up to 11.1% (seven of 63) of G2 mutant anaphase cells displayed one or more chromosomal fusions. These results suggest that OsKu70 is required for the maintenance of chromosome stability and normal developmental growth in rice plants. [ABSTRACT FROM AUTHOR]

"Cheongan" is a new japonica rice variety developed from a cross between SR15225-B-22-1-2-1 and Iksan431 in summer season, 1997 by National Institute of Crop Science, RDA. The line SR15225-B-22-1-2-1 has good canopy architecture and multi-disease and insect resistance, and Iksan431 has translucent milled rice and good eating-quality. Heading date of Cheongan is August 13 in central lowland and mid-mountainous areas. "Cheongan" having culm length of 84 cm shows relatively semi-erect pubescent leaf blade and rigid culm, tolerance to lodging with and good canopy architecture. This variety has 14 tillers per hill and 126 spikelets per panicle. It shows tolerance to heading delay and spikelet sterility comparable to Hwaseongbyeo when exposed to cold stress. Leaf senescence of Cheongan progresses slowly during the ripening stage and the viviparous germination ratio was 59 %, similar to that of Hwaseongbyo. "Cheongan" shows moderately resistance to blast disease, but susceptible to stripe virus and brown planthopper. The milled rice of "Cheongan" exhibits translucent, clear non -glutinous endosperm and medium short grain. It shows similar amylose content of 18.7%, gelatinization temperature, and similar palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.54 MT/ha at ordinary season culture in local adaptability test for three years. Especially, "Cheongan" has better milling properties of higher 98.4% and 73.9% in the percentage of head rice in milled rice and milling recovery of head rice, respectively, than those of Hwaseongbyeo. "Cheongan" could be adaptable to the central and mid-southern plain area, and mid-western coastal area of Korea. [ABSTRACT FROM AUTHOR]

"Sangok", is a new japonica rice variety (Oryza sativa L.), which is a midium maturing ecotype developed by the rice breeding team of National Yeongnam Agricultural Experiment Station (NYAES) in 2003. This variety was derived from the cross of Milyang 101/YR8697Acp97 (in 1988/1989 winter) and selected by combination of the bulk and pedigree breeding. The pedigree of Sangokbyeo, designated as Milyang 182 in 2000, was YR12950-B-B-B-19-2-4-2-2. It has about 79cm stature in culm length and is medium maturing. This variety is resistant to bacterial blight (K1, K2, and K3), stripe virus and moderately resistant to leaf blast disease. Milled rice kernels of "Sangok" is translucent, clear in chalkness and good at eating quality in the panel test. The yield potential of "Sangok" in milled rice is about 5.16MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to the southern plain of Korea below the Chungnam province by latitude from ordinary transplanting to transplanting after barley harvest. [ABSTRACT FROM AUTHOR]

A new rice variety 'Jungmo1009ho' is a japonica rice (Oryza sativa L.) with lodging tolerance and resistance to rice stripe virus (RSV) and blight bacterial disease (BLB) and good eating quality. It is developed by the rice breeding team of Yeongdeog Substation, National Institute Crop Science, RDA in 2009. This variety was derived from a cross between 'Iksan443' with good grain quality and 'Milyang165' with lodging tolerance conducted in 1999 summer season. A promising line, YR22207- 5-3-1-3, selected by pedigree breeding method was designated as 'Yeongdeog48' in 2006. After the local adaptability test was carried out at nine locations from 2007 to 2009, 'Yeongdeog48' was released as the name of 'Jungmo1009ho' in 2009. 'Jungmo1009ho' is very short culm length as 61cm and medium-late growth duration. This variety is resistant to races, K1, K2, and K3 of bacterial blight and stripe virus and moderately resistant to leaf blast disease with durable resistance, and also has tolerance to unfavorable environment such as cold and dried wind. 'Jungmo1009ho' has translucent and clear milled rice kernel without white core and belly rice, and good eating quality as a result of panel test. The yield potential of 'Jungmo1009ho' in milled rice is about 5.47 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to east-south coastal cold salty wind and south mid-mountainous area. [ABSTRACT FROM AUTHOR]

A new Japonica variety, 'Keunnun' was induced from the mutants of N-methyl-N-nitrosourea (MNU) treatment on fertilized egg cell of Ilpumbyeo by a rice breeding team of National Institute of Crop Science, RDA, in 2005. This variety has about 136 days of growth duration from transplanting to harvesting and a midium-maturty with heading date of August 17 in central plain area of Korea. It has resistance to lodging with strong culm and good semi-elect plant type. The number of panicles/hill of 'Keunnun' is more than that of Hwaseongbyeo. 'Keunnun' has a giant-embryo and richer GABA content than that of Ilpumbyeo after 2 days' germination in sprouting brown rice. It is susceptible to leaf blast, bacterial blight, virus disease and insect pests. The yield performance of this variety is about 4.52 MT/ha in milled rice in local adaptability test for three years from 2003 to 2005. 'Keunnun' is one of cultivars adaptable to central and southern plain area of Korea. [ABSTRACT FROM AUTHOR]

Cheonga is a new japonica rice cultivar developed from a cross between Kinuhikari, Japanese japonica cultivar of good quality and clear external appearance of brown rice and Yangjuseonbal, a japonica line of good quality and ripened grain (or leaf) color, which was collected in the farmer's field by the rice breeding team of National Institute of Crop Science, RDA. Cheonga has about 126 days duration from seeding to heading in central lowland and mid-mountainous areas South Korea. It is about 87 cm in culm length and tolerant to lodging. It has relatively semi-erect pubescent leaf blade and slightly tough culm with good canopy architecture. This cultivar has 14 tillers per hill and 106 spikelets per panicle. It shows a little sensitivity to premature heading in the transplanting of 50 days' old seedling. It shows similar tolerance to both heading delay and spikelet sterility due to cold stress compared with Hwaseongbyeo. This cultivar shows slow leaf senescence and low viviparous germination during the ripening stage. This variety shows susceptibility to the diseases and insect of leaf blast, bacterial blight (K1, K2, K3). stripe virus, and brown planthopper. Milled rice of Cheonga has medium short grain with translucent and clear non-glutinous endosperm. It shows similar amylose content (19.6%), and gelatinization temperature compared with Hwaseongbyeo, but good palatability of cooked rice. The milled rice yield performance of this cultivar is about 5.56 MT/ha by ordinary culture in local adaptability test for three years. This cultivar may be highly adaptable to the central plain area, middle-Southern plain and middle-western coastal areas of South Korea. [ABSTRACT FROM AUTHOR]

'Heugseol', a new black pericarp and processing soft rice (Oryza sativa L.) cultivar, was developed by the rice breeding team of National Institute of Crop Science, R.D.A., Suwon, Korea during the period from 1996 to 2007 and released in 2008. It was derived from a cross between 'Seolgaengbyeo' and 'Heugjinjubyeo'. This cultivar has about 13 tillers per hill and more spikelet numbers per panicle than that of 'Heugjinjubyeo'. This new variety has grain shattering resistance and is susceptible for bacterial leaf blight and stripe virus. This variety has opaque endosperm, soft texture of cooked brown rice and low protein content. This variety provides better brewing ability and panel score test of brewing alcohol than 'Heugjinjubyeo'. The brown rice yield of 'Heugseol' is 419 kg/10a in the local adaptability test for three years. 'Heugseol' is adaptable to central plain area of Korea. [ABSTRACT FROM AUTHOR]

A new rice variety 'Jinbo' is a japonica rice (Oryza sativa L.) with good eating quality, lodging tolerance, and resistance to rice stripe virus (RSV) and bacterial blight disease (BB). It was developed by the rice breeding team of Yeongdeog Substation, National Institute of Crop Science (NICS), RDA in 2009. This variety was derived from a cross between 'Yeongdeog26' with good grain quality and wind tolerance and 'Koshihikari' with good eating quality in 1998 summer season. A promising line, YR21324-56-1-1, selected by pedigree breeding method, was designated as the name of 'Yeongdeog45' in 2005. After the local adaptability test was carried out at nine locations from 2006 to 2008, 'Yeongdeog45' was released as the name of 'Jinbo' in 2009. 'Jinbo' has short culm length as 74 cm and medium maturating growth duration. This variety is resistant to K1, K2 and K3 races of bacterial blight and stripe virus and moderately resistant to leaf blast disease with durable resistance, and also it has tolerance to unfavorable environments such as cold and dried wind. 'Jinbo' has translucent and clear milled rice kernel without white core and white belly rice, and good eating quality as a result of panel test. The yield potential of 'Jinbo' in milled rice is about 5.65 MT/ha at ordinary fertilizer level in local adaptability test. This cultivar would be adaptable to middle plain, mid-west costal area, east-south coastal area, and south mid-mountainous area. [ABSTRACT FROM AUTHOR]

"Jongnambyeo", a new japonica rice cultivar(Oryza sativa L.), is a mid-late maturing ecotype developed by the rice breeding team of National Yeongnam Agricultural Experiment Station(NYAES) in 2001 and released in 2002. This variety originated from the cross of Milyang96/YR12734-B-B-22-2(in 1991/1992 winter) and was selected by means of a mixed method of bulk and pedigree breeding. The pedigree of Junambyeo, Milyang 169 designated in 1999, was YR15161-B-B-B-57-2-3. It has about 79cm in culm length and tolerant to lodging. And this variety is resistant to bacterial leaf blight(K1), stripe virus and moderately resistant to leaf blast disease. Milled rice kernels of "Jongnambyeo" is translucent with non-glutinous endosperm and clear in chalkness and good at eating quality in pannel test. The yield potential of "Jongambyeo" in milled rice is about 5.60MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to the Yeongnam plain and southern coastal of Korea. [ABSTRACT FROM AUTHOR]