본 연구는 국내 수집 잡초성벼에 존재하는 잎도열병 저항성 관련 유전자를 탐색하고, 이 저항성유전자와 연관된 분자마커를 탐색하는 것이다. 도열병에 감수성인 자포니카 품종인 낙동벼와 도열병에 강한 잡초성벼인 강화앵미11을 교잡하여 120개 RILs를 육성하여, 도열병 균주반응과 잎도열병 밭못자리검정을 통한 저항성 유전자 탐색에 이용하였다. 1. 총 45개 도열병 균주를 이용하여 양친들을 검정한 결과, 잡초성벼 강화앵미11은 25개 균주에 대하여 저항성 반응

조운은 농촌진흥청 국립식량과학원에서 벼 수확기의 분산 및 이른 추석에도 안정적으로 생산할 수 있는 평야지적응 조생종을 육성할 목적으로 1996년 조숙이면서 양질 내병 다수성 계통인 SR14880-173-3-3-2-2-2와 초형이 우수하며 수량성이 높은 단간 조생인 운봉20호를 교배하여 2009년 육성한 평야지적응 극조생 단간 내도열병 고품질 벼 품종으로 주요 특성과 수량성을 요약하면 다음과 같다. 1. 보통기 보비재배에서 출수기는 7월 23일로 오대벼보

평원은 농촌진흥청 국립식량과학원에서 북한 지역에 적응성이 높은 다수성 양질 신품종을 육성할 목적으로 1995년 잠재적 수량성이 있는 북한 벼 품종 삼지연4호와 조숙 단간 내도복 특성의 진부19호를 교배하여 2007년 육성한 조생 단간 내도열병 고품질 품종으로 주요 특성과 수량성을 요약하면 다음과 같다. 1. 보통기 보비재배에서 출수기는 8월5일로 오대벼보다 1일 늦은 조생종이다. 2. 간장은 67 cm이며, 주당수수는 13개, 수당립수는 82개이고, 현

Rice blast resistance is considered one of the most important traits in rice breeding and the disease, caused by Magnaporthe grisea Barr, has brought significant crop losses annually. Moreover, breakdown of resistance normally occurs in two to five years after cultivar release, thus a more durable resistance is needed for better control of this disease. We developed a new variety, Keumo3, which showed strong resistance to leaf blast. It was tested in 2003 to 2007 at fourteen blast nursery sites covering entire rice-growing regions of South Korea. It showed resistance reactions in 12 regions and moderate in 2 regions without showing susceptible reactions. Durability test by sequential planting method indicated that this variety had better resistance. Results showed that Keumo3 was incompatible against 19 blast isolates with the exception of KI101 by artificial inoculation. To understand the genetic control of blast resistance in rice cultivar Keumo3 and facilitate its utilization, recombinant inbred lines (RIL) consisting of 290 F5 lines derived from Akidagomachi/Keumo3 were analyzed and genotyped with Pizt InDel marker zt56591. The recombination value between the marker allele of zt56591 and bioassay data of blast nursery test was 1.1%. These results indicated that MAS can be applied in selecting breeding populations for blast resistance using zt56591 as DNA marker.

Blast resistance of one hundred and thirty-one rice cultivars bred in Korea was tested with thirty Korean isolates and twenty-two Philippines isolates using three screening methods. In the blast nursery conducted in Korea and in the Philippines, average disease index of rice cultivars were 4.6 and 2.2, respectively. Seventy-nine cultivars showed different resistance reaction in Korea and in the Philippines, and 19 cultivars showed the same resistant reaction in two locations. In the seedling test, Korean blast isolates displayed different levels of virulence. 93-093, a Korean isolate, was compatible with 90 cultivars whereas 97-057 showed a compatible reaction with 13 cultivars. Twenty-three cultivars showed high level of resistance against Korean and Philippines isolates but Chucheongbyeo, Heugnambyeo, and Manmibyeo showed susceptible reaction to all blast isolates. Through the sequential planting test in Korea and in the Philippines, Palgongbyeo and Seomjinbyeo displayed durable resistance, and Nagdongbyeo and Gihobyeo showed high level of disease infection over the planting time. These results indicate that blast isolates collected in two countries have different genetic background and number of compatible isolates should be considered in definition the durability of rice cultivar to rice blast.

Field resistance is defined as the resistance that allows effective control of a parasite under natural field condition and is durable when exposed to new races of that parasite. To identify the genes for field resistance against rice blast, quantitative trait loci (QTLs) conferring field resistance in japonica rice cultivars were detected and mapped using SSR markers. QTL analysis was carried out in 190 RILs population from the cross between Suweon365 (moderately resistance) and Chucheong (highly susceptible). Fourteen QTLs for nine blast races inoculated were detected on chromosomes 1, 2, 4, 5, 6, 7, 11 and 12. They explained from 6.4 to 39.7% of total phenotypic variation. Eight QTLs for blast nursery screening in 4 regions for three years were detected on chromosomes 1, 2, 4, 5, 11 and 12. The phenotypic variation was explained by each QTL ranged from 5.9 to 38.0%. Three BC2F5 backcrossed progeny lines were developed to transfer the QTLs into the susceptible cultivar Chucheong as a recurrent parent. A NIL4 containing two QTLs Qbl6.2 and Qbl7 for blast races showed the reaction 6 to 7 in blast nursery in 2007 and 2008, respectively. Two lines NIL143 and NIL93 containing Qbl11.2 and Qbl12.1 for QTLs related with field resistance, respectively, were 3 to 4 reactions in blast nursery.

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.

Magnaporthe oryzae is a causal pathogen of the rice blast, the most destructive disease of rice worldwide. This ascomycete fungus has been intensively studied as a model organism in plant-pathogen interactions. Recently, the genome sequence of M. oryzae 70-15 was published by International Rice Blast Consortium. This led us to investigate comparative and functional analysis of this pathogen at genome-wide level. As a first step, sequencing project of M. oryzae Korean strain KJ201 was launched to face practical interests on diversity of plant pathogens. We constructed a fosmid library with a copy number controllable pCC1 vector. Over 13,000 end reads from 6637 fosmid clones were generated and anchored on genome sequence of the strain 70-15. Currently, 9,793 end reads, in which 2.684, clones with both ends and 1,757 clones with on end matched, are aligned to the sequence of strain 70-15. In the next step, shotgun sequencing of fosmid clones was conducted for fine scale comparative analysis of chromosome 7 that is well defined in genome sequencing of 70-15. Totally 119 fosmid clones were pooled in region and analyzed. For reasonable intra-species comparison in genome of M. oryzae, two strains, KJ201 and Guy11, were chosen for whole genome shotgun sequencing analysis with GS454 FLX system. About 8X genome coverage sequences were obtained for each strain and being merged for comparative analysis. Genome information of other strains is being also available from China and Japanese research groups and could be joined together for extended comparative analysis and the results give more detail in genome diversity in species level.

Blast resistance of 18 rice cultivars which recommended as a high quality rice cultivars evaluated by blast nursery test, seedling test, and field screening and sequential planting methods. Sangmibyeo, Hwayeongbyeo, and Dongjin 1 were showed high resistance reaction to leaf blast at the blast nursery continuously, while Chucheongbyeo showed highest disease severity. All of the early maturing cultivars, Odaebyeo, Junghwabyeo, and Sangmibyeo, showed the lowest compatibility against 25 blast isolates. Saechucheongbyeo, a multiline variety of Chucheongbyeo genetic background showed 45.8%, half compatibility of 82.6% in Chucheongbyeo against 25 isolates screened. Diseased leaf areas (DLA, %) of cultivars were very low level at all test sites in the field test. Three cultivars, Sangmibyeo, Ilmibyeo, and Junghwabyeo didn’t show any leaf blast lesions across the test sites. The most variable incidences of panicle blast were observed on Odaebyeo which was 42.4%, 0.4%. and 0.0% at Jaecheon, Naju, and Chuncheon, respectively. In the sequential planting method, four rice cultivars, Nampyeongbyeo, Sindongjinbyeo, Hwayeongbyeo, and Junambyeo showed less than 40% disease leaf area (DLA) from 1st planting to 7th planting, so those cultivars were considered as a durable resistant rice cultivar against rice blast diseases.