조생종 벼 품종인 오대, 운광과 HR28021-AC16 계통에 대한 벼흰잎마름병 저항성 유전자분석과 K1과 K3a 균계를 접종한 후에 수량 및 품질 관련 형질들의 변이에 대하여 분석하였다. 오대는 저항성 유전자를 보유하지 않는 것으로 나타났고, 운광은 Xa3 유전자를, HR28021-AC16은 Xa21 유전자를가지는 것으로 확인되었다. 오대는 K1과 K3a 균계 모두에 이병성을 보였고, 운광은 K1에는 저항성을 K3a에는 이병성을보였다. HR28021-AC16은 K1 균계에는 이병성을 나타냈고K3a 균계에는 저항성 반응을 보였다. 균계접종에 의한 이병성 정도와 2차 감염 정도로 볼 때, K3a 균계가 K1 균계에 비해 병원성이 강한 것으로 나타났다. K1과 K3a 균계 접종에따른 생산력검정시험에서 균계 처리와 반응에 의해 변이가발생한 형질들 중에 등숙률, 정현비율, 현미수량과 완전미도정수율은 서로 간에 정의 상관관계를 나타냈으며, 이들 형질들과 현미 및 백미 단백질 함량은 부의 상관관계를 나타냈다.사미는 등숙률 및 완전미도정수율과 부의 상관관계를 나타냈다. 주성분분석에서 주성분 1을 기준으로 등숙률, 정현비율,현미수량 및 완전미도정수율과 사미, 현미 및 백미 단백질 함량이 다른 방향성을 나타냈고, 주성분 2를 기준으로는 등숙률과 사미가 다른 방향성을 나타냈다. Xa21 유전자를 가지고있는 HR28021-AC16은 K3a에는 저항성 반응을 보였으나K1 균계 접종구에서는 등숙률, 정현비율, 현미수량 및 완전미도정수율은 감소하였고 사미는 증가하는 등 이병성 반응을나타냈다. Xa21 유전자는 최근 큰 피해를 주는 K3a 균계에대해 강한 저항성을 보이나, 우리나라 우점 균계인 K1에 이병성을 보이기 때문에 K1 균계에 저항성인 다른 유전자와의집적을 통한 활용이 안정적인 저항성 증진에 효과적인 것으로 나타났다.

Phosphorus (P) is an important structural component and plays critical roles in the process of energy transfer and signal transduction. Effect of low P on carbohydrate metabolism was investigated at the transcription level via transcriptome analysis using the rice 60K oligonucleotide DNA microarrays. Two-week-old rice seedlings were grown under a low (32 μM) or high (320 μM) P condition for two weeks and leaves from the seedlings were used for transcriptome analysis. Expression of genes involved in carbohydrate metabolic pathways (eg. glycolysis, sucrose degradation and starch synthesis and degradation) was most significantly affected under low P. Under low P, most genes involved in glycolysis were intensively down-regulated, genes of starch biosynthesis and degradation pathway were up- or down-regulated, and many genes involved in sucrose biosynthesis were intensively up-regulated. In leaves under low P, glucose and pyruvate levels decreased, but sucrose and starch levels increased. These results suggest that carbohydrate metabolism is adjusted primarily through comprehensive transcriptional modulation of genes involved in the carbohydrate metabolic super-pathway.

Resveratrol (3,5,4'-trihydroxystilbene) is a naturally occurring antioxidant found in grapes, grape products such as wine, and some other botanical sources, like peanuts. In grapes, resveratrol occurs both as free resveratrol and piceid, which is 3-β-mono-D-glucoside of resveratrol. In recent years, research on resveratrol has discovered several beneficial biological effects of this compound to human health. These include anticancer activity, cardioprotection, antioxidant activity, inhibition of platelet aggregation, and antiinflammatory activity. So, we conducted this study to develop transgenic rice plants an enhanced phytochemicals associated with reduced cancer risk by overexpression of a peanut RS gene and selected 2 lines, 'Iksan 515' and 'Iksan 526', according to agronomic traits of rice plant and resveratrol contents in rice grain. Resveratrol content of Iksan 515 was increased by 2.3 times until 5 days after seedling and decreased at 7 days after seedling. Expression level of RS gene according to seedling days by Real-time PCR increased until 5 days, but decreased by half at 7 days. Now, we are planning to analyze medicinal function of these high resveratrol rices and development of cultivation technology to increase resveratrol content. Therefore, transgenic rices producing high resveratrol can be used to develop new rices with a cancer chemopreventive role in human medicine.

“unbora”is a new japonica rice cultivar developed from a cross between Iksan433 resistant to bacterial blight and Miyadamamochi, a waxy line. at Honam Agricultural Research Institute, NICS, RDA, in 2006. This cultivar is a short grain shape and about 118 days of growth duration from transplanting “unbora”to harvesting under Korean climatic conditions. The milled rice are snow white and glutinuous. This cultivar shows high resistant reactions to the bacterial blight pathogen race K1～K3 and blast respectively. The milled rice yield of “unbora”is about 5.34 MT/ha under the standard fertilizer level of the ordinary transplanting cultivation. “unbora”would be adaptable for in the middle plain, north middle-mountin plain and Honam plain, and Youngnam plain areas of Korea.

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.

Phosphorus (P) is a macronutrient playing important roles in many plant processes. Significant interest has been devoted to search and utilize genotypic variations in P use efficiency in rice but with little effort to understand its physiological and biochemical bases. In this study, we examined responses to P deprivation of some primary and secondary traits in 3-week-old seedlings of the three genotypes, Sobi-byeo (japonica), Dasan-byeo (japonica ~times indica) and Palawan (indica). In general, percent weight due to root was increased up to 26%, but amounts of root protein and proteins secreted from roots were decreased by 11 to 19% and 31 to 51 %, respectively, by 3 to 21 days of P deprivation in the three genotypes. Interestingly, however, responses of Palawan to short-term P deprivation were contrasting to those of Dasan-byeo and Sobi-byeo in seedling weight and contents of shoot protein, chlorophyll and anthocyanin. Seedling weight was not decreased, but shoot protein content was decreased in P-deprived seedlings of Palawan. Contents of chlorophyll in leaves and anthocynin in roots were increased in Dasan-byeo and Sobi-byeo, but decreased in Palawan. The results suggest that responses of protein and pigment synthesis to P deficiency are different in modem and traditional varieties and the difference may at least in part be due to the selection for high yield under highly fertilized conditions.