"Geumanbyeo" is a new japonica rice variety developed by the rice breeding team of National Institute of Crop Science, RDA in 2002, which was derived from a cross between SR11878-14-4-1 of good eating-quality and high yield potential, and Suweon345 of lodging tolerance and resistance to diseases. Geumanbyeo is a medium-maturing variety with heading date of August 12 on ordinary planting in the middle plain area. It has a semi-erect plant type with culm length of 82cm, erect pubescent leaf blade and slightly tough culm with good canopy architecture. Geumanbyeo has a little bit fewer tillers per hill, and more spikelets per panicle than Hwaseongbyeo. It is slightly less tolerant to the cold stress in terms of both heading delay and spikelet fertility than Hwaseongbyeo. This variety shows delayed leaf senescence and considerable tolerance to viviparous germination at ripening stage. It shows moderately resistant to leaf blast and K1 race of bacterial blight, but susceptible to virus diseases and insect pests. The milled rice of Geumanbyeo exhibits translucent, relatively clear non-glutinous endosperm and medium-short grain. It showed lower amylose content of 18.6% and similar gelatinization temperature and better palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this variety is about 5.32 MT/ha at ordinary culture in local adaptability test for three years. Geumanbyeo would be highly adaptable to the central lowland and mid-southern mountainous areas in Korea.

Heading date in rice is a complex trait that is governed by multiple genes and environmental factors, such as day-length, temperature, and soil conditions. The genetic studies using DNA markers have facilitated the genetic dissection of heading date and many quantitative trait loci (QTLs) for heading date have been identified using several mapping population. In a previous study, a new quantitative trait loci (QTLs) for heading date have been identified using several mapping population. In a previous study, a new for heading date was detected near SSR marker RM215 on chromosome 9 using an advanced backcross line, WH29001, developed by introgressing chromosomal segments from an accession of Oryzaminuta (2n=48, BBCC, Acc. No.101141)into the O. sativa subsp. japonica cv. Hwaseongbyeo. The O. minuta allele of QTL contributed to an increase in heading date. To clarify whether dth9 could be dissected genetically, a high-resolution linkage mapping of dth9 was performed using alarge F2 population derived form the cross between one F4 plant which was homozygous for O.minuta in the target region RM5661-RM215 on chromosome9 and Hwaseongbyeo. Days to heading in the F2 population showed continuous variation rang form 102 to 113 days. The dth9 QTL further narrowed down at the interval between the SSR marker RM1553 and RM215 which was approximately 403kb in length based on the physical map of the region. The QTL for heading date(dth9) had not been detected in previous QTL studies between Oryza cultivars, indicating the existence of potentially novel alleles from O. minuta.

In this study, a 141 BC3F4 lines from across between the O. sativa cv. Milyang23 as there current parent, and O. glaberrima as the donor parent was used to identify favorable QTL alleles from O. glaberrima for yield and yield components. To detect the introgressions, 198 microsatellite markers of known chromosomal position were used for the parental survey. Of the 178 markers, 128 (64.6%) showed polymorphism. Among them, 115 SSR markers were used to construct a genetic linkage map with average interval length of 12.7 cM based on the previous rice molecular genetic map. The mean number of O. glaberrima segments in the population was 1.84 ranging from 0 to 7. The average length of the segments was 16.6 cM and ranged from 0.5 to 232.5 cM. This population consisting of 141 lines was used to evaluate for six traits of agronomic importance and genotypes were determined for 141 BC3F5 using SSR markers. A total of 22 QTLs for 6 traits were detected on chromosomes 1, 2, 3, 4, 5, 6, 7 and 9. Phenotypic variance associated with each QTL ranged 9.5% ~ 58.2%. For 26 of the QTLs identified in this study, the O. glaberrima alleles contributed a desirable agronomic effect despite the over all undesirable characteristics of the wild phenotype. Favorable wild alleles were detected for culm length, panicle length, yield, panicles per plant and 1000-grain weight. When compared with previous studies involving interspecific crosses, it can be concluded that O. glaberrima is useful asa source of valuable alleles for rice improvement. There sults will be discussed.

Aluminum (Al) toxicity in plants is one of the major limitations to crop growth on acid soils. The Al-induced change of H+-ATPase expression has been regarded as an important mechanism for Al tolerance in soybean. To investigate whether translational regulation of plasma membrane H+-ATPase is involved in the response to Al stress, we conducted western - blot of this protein. The results show that western - blot of plasma membrane H+-ATPase in the "Sowon" (Al tolernace) significantly increased in translational expression level, while citric acid (50 μM) with Al (50 μM) treatment has not effected. In contrast, Al sensitive cultivar "Poongsannamool" inhibited expression level of plasma membrane H+-ATPase with Al treatment. Two - dimensional gel analysis were performed to determine the protein induction patterns of control and Al (50 μM, 24 h) treated soybean. There are many changes of plasma membrane proteins in both cultivars under Al stress. Especially "Sowon" was significantly enhanced the expression of the plasma membrane H+-ATPase in Al treatment. But protein expression of "Poongsannamool" was less than "Sowon". These results suggest that the regulatory role of plasma membrane H+-ATPase may involved the tolerance mechanism in soybean roots. At the present, transcriptional level of H+-ATPase is under investigation.