In total, 120 ‘Cheonghcheong/Nagdong’ doubled haploid (CNDH) populations was developed by F1 derived from a crossing whitebacked planthopper (WBPH, Sogatella furcifera) resistance ‘Cheongcheong’ and susceptible ‘Nagdong’ lines. The main objective of this research was to determine the rice resistance optimum screening after infesting by WBPH and identify quantitative trait loci (QTLs) associated with rice resistance in order to provide consistent information for marker-assisted selection (MAS) and develop new varieties. The genetic map with average 9.6 centimorgans (cM) between markers was constructed from 120 CNDH populations using 217 SSR markers. In this study, The result of determine rice with WBPH infestation showed that the rice damage and resistance at 7, 14, and 21 days, were 100%, 76%, and 10% resistance lines of 120 CNDH population. Four QTLs were detected on four regions of the chromosomes 1 and chromosome 8, which contained qWBPH1 and qWBPH8 for resistance rice. The markers were found to be contained in identification the genetic markers RM3482, RM1196, RM3709, RM11694, RM11669, RM17699 and RM264 for marker assisted selection. These markers efficiently were shown to be very useful for MAS in breeding populations of crossing lines associated simple sequence repeat (SSR) marker with WBPH resistance in 120 CNDH populations.

The objectives of this study were to investigate the diversity of natural products (DNP7, 9) in responding to Whitebacked planthopper (WBPH) feeding. Resistant rice (cv. Cheongcheong ), susceptible rice (cv. Nagdong) and susceptible control rice (cv. TN1) were used as materials for WBPH infestation in seedling stage. The treatment was conducted by spraying DNP 7 and 9 for 100 ppm to materials before being fed to 2nd and 3rd instar WBPH while control group was not sprayed DNP 7 and 9. The density of WBPH was 7 insect per plant. As a result, WBPH survival rate of 57% was found in the DNP 7 treatment, whereas those in DNP 9 and control were 27% and 71%, respectively. Resistance score of Cheongcheong, Nagdong, and TN1 in DNP 7 treatment were 3.4±0.8, 5.9±1.9, and 6.8±1.6, respectively, while those in DNP 9 treatment were 1.6±0.8, 4.7±1.6, and 7.9 ±1.4, respectively. The plant heights of Cheongcheong, Nagdong, and TN1 in DNP 7 treatment after 3 week infestation were 19.7±3.0, 23.4±7.5, and 15.8±8, respectively while those in DNP 9 treatment were 32.4±4, 26.3±12.7, and 25.9±8.5, respectively. Moreover, chlorophyll content was examined 3 week post infestation. In both DNP 7 and DNP 9 treatment, the chlorophyll levels of Cheongcheong and Nagdong in were higher than that in control. Based on observation and bio-scoring, plant with DNP 9 was strongly resistant to WBPH feeding and the survival rate of WHPB was lower than plant with DNP7.

벼흰잎마름병은 국내에서 가장 주요 병해 중 하나이다. 벼흰잎마름병 저항성유전자 xa5는 국내 흰잎마름병 레이스에 광범위 저항성을 보인다. 2010년 국립식량과학원 기능성작물부에서는 벼흰잎마름병 저항성 유전자 xa5를 가진 벼 신품종 ‘신백’ 육성하였다. ‘신백’은 고품질 복합내병성인 ‘익산469호’를 모본으로 사용하고, 흰잎마름병 저항성유전자 xa5를 가진 계통 HR23966-22-1-2를 부본으로 사용하였다. ‘신백’의 출수기는 보통기 보비재배에서 8월 11일로 ‘남평벼’보다 5일 빠른 중생종이다. 간장은 76 cm로 단간이며 수수가 적고 수당립수가 많으며, 등숙율은 남평벼보다 낮은 편이다. ‘신백’은 흰잎마름병 검정에서 K1, K2, K3및 K3a에 강하였고, 바이러스병인 줄무늬잎마름병에 강하다. 잎도열병은 중정도 저항성이며, 목도열병은 이병율이 낮은 편이다. ‘신백’은 쌀의 심복백이 없으며, 아밀로스함량과 단백질 함량은 ‘남평벼’와 비슷한편이고, 도정특성 및 완전미율은 남평벼보다 약간 낮은 편이다. ‘신백’의 쌀수량은 보통기 보비재배에서 5.75 MT/ha, 이모작 재배에서 5.49 MT/ha, 만식재배에서는 5.18 MT/ha이였다.

‘만미벼’는 작물과학원 영남농업연구소(현 국립식량과학원 기능성작물부)에서 2002년도에 육성한 중만생 저아밀로스 반찹쌀 품종으로 주요특성과 수량성을 요약하면 다음과 같다. 1. 출수기는 남부평야지의 보통기재배에서 8월 16일로 ‘동진벼’ 보다 2일 빠른 중만생종이다. 2. 수당립수는 ‘동진벼’ 보다 18개 많으나, 현미천립중은 19.9 g으로 ‘동진벼’ 보다 가벼운 편이며 등숙비율이 약간 떨어진다. 3. 위조현상에 강하고 성숙기 엽노화가 느린 편이며 내

Lysine is the first essential amino acid for optimal nutrient quality in rice grain. For the narrow genetic diversities of lysine contents in rice, somaclonal variation was the source of mutation in our breeding program. Biochemical selection was conducted using 1 mM S-(2-aminoethyl) cysteine followed by two passages of 5 mM lysine plus threonine in the callus subculture medium. The lysine contents in endosperm of all progenies recovered from the biochemical selection were higher than those of their donor cultivar 'Hwayeongbyeo'. These elevated lysine levels of mutants were successfully transmitted to M4 generation. The lysine contents in endosperm varied 3.85 to 4.80% compare to their donor cultivar 'Hwayeongbyeo' was 3.85%. Three of high-lysine germplasms, Lys-l, Lys-2 and Lys-7 were selected by biochemical selection and rapid screening methods. DNA analysis showed that a new insertion of Tos 17 which mapped to rice chromosome 11 on the high-lysine mutant, Lys-2.