초록 ▼

Ⅳ. 연구개발결과
기후변화에 따른 밀 주요 병해 발생 양상을 구명하기 위해서 농가 재배지의 바이러스 및 곰팡이성 병해 발생 양상을 조사하여, 출수기경 잎마름병, 고사 증상이 Alternaria leaf blight로 국내 처음으로 보고하였다. 밀의 주요 문제 병해 피해 양상 및 방제 기술 개발을 위해서 잎집눈무늬병 방제 약제 선발 및 처리시기를 구명하였다.분자마커를 활용한 붉은곰팡이병 저항성 밀 선발효율 향상 연구를 통해 국내 보유 밀 품종의 붉은곰팡이병 관련 마커 선발에 유용한 XSTS3B-52, GWM493 등의 마커를 선

Ⅳ. 연구개발결과
기후변화에 따른 밀 주요 병해 발생 양상을 구명하기 위해서 농가 재배지의 바이러스 및 곰팡이성 병해 발생 양상을 조사하여, 출수기경 잎마름병, 고사 증상이 Alternaria leaf blight로 국내 처음으로 보고하였다. 밀의 주요 문제 병해 피해 양상 및 방제 기술 개발을 위해서 잎집눈무늬병 방제 약제 선발 및 처리시기를 구명하였다.분자마커를 활용한 붉은곰팡이병 저항성 밀 선발효율 향상 연구를 통해 국내 보유 밀 품종의 붉은곰팡이병 관련 마커 선발에 유용한 XSTS3B-52, GWM493 등의 마커를 선별하였고, 인공교배 및 저항성 계통 선발을 통해서 붉은곰팡이병 저항성 계통을 육성하고자 F₄∼F₆ 세대진전과 생산력 검정 시험으로 상정하였다.밀 수발아 저항성 유전자의 발현과 관련한 기작과 구명 및 분자 마커 활용 육종 시스템 개발을 위한 연구에서는 반수체 계통에 대한 수발아 관련 SSR 마커인 Xbarc12와 Xgwm3 마커를 선별하였고, 국내 밀의 수발아 관련 특성을 분석하였다. 국내 밀 품종의 수발아 저항성 평가와 종실 특성이 수발아 저항성에 미치는 영향 분석하여 적립계이면서 천립중이 적은 품종이 수발아 저항성이 강한 것을 알 수 있었고, 농업형질 관련 유전자와 수발아 관련 특성간 상관분석하였다. 수발아 평가를 통한 저항성 계통으로 선발한 반수체 122계통 Germination Index평가를 하였고, 수발아 저항성 백립계 밀 계통 선발을 위한 인공교배와 세대 진전은 계속 육종사업에서 수행하고 있다.

Abstract ▼

This study investigated disease occurrence by abnormal weather and disease outbreak control techniques for three years in the wheat fields.The viruses in the southern wheat plantations were examined for five viruses as SBWMV. SBWMV and BYDV has been identified as a major virus diseases. However, the

This study investigated disease occurrence by abnormal weather and disease outbreak control techniques for three years in the wheat fields.The viruses in the southern wheat plantations were examined for five viruses as SBWMV. SBWMV and BYDV has been identified as a major virus diseases. However, the occurrence was varied by depending on the climate and regions. In this investigation, we first identified BaSMV, WSMV and WDV in the Korean wheat fields. In the eaxmination of fungal diseases occurrence, powdery mildew, rust and sharp eyespot were severe incidence in 2012 investigation only. Fusarium head blight showed little occurrence in autumn seeding, while the incidence tend to increase in spring seedng condition.Specially, two disease, Alternaria leaf blight and Stem and spike rot by Fusarium, were identified first which these has been not reported in Korea.To develop control method to these unexpected disease occurred by abnormal weather conditions, first we selected two chemical pesticide, Hexaconazole and Tebuconazole, to sharp eyespot(Rhizoctonia cerealis). These chemicals were more effective pre-treatment before fungal infection in plant test.Also we selected resistant plant materials to SBWMV and Alternaria leaf blight in field examination.Fusarium head blight (FHB), caused by Fusarium graminearum is a major disease problem on wheat and barley in Korea and around the world. We screened for Type II resistance in the greenhouse using single floret inoculation and for Type I resistance in the field using spray inoculation. Sumai 3 was used the FHB resistant check. Three hundred and seventy lines were evaluated for resistance to spread of symptoms within spike (type II). FHB severity was assessed visually 21 days after inoculation on 20 arbitrarily selected spikes per plot. FHB severity was determined as the percentage of symptomatic spikelets from the total of all spikelets observed in these 20 spikes. Based on the field test, we could observe four categories of FHB severity: resistant (R: 0-20%), moderately resistant(MR: 21-40%), moderately susceptible (MS: 41-60%), and susceptible (S: 61-100%). The results showed that forty four lines showed the resistant category on FHB severity between 2.7% and 19.8%. In addition, ten lines showed similar FHB severity compared to Sumai 3.The field screening plots were located in Kimjae-si Joeonbuk Korea and all plots were inoculated twice. The first inoculation was applied at anthesis for wheat and the second inoculation was applied three days after the initial inoculation (dai) for each plot. The inoculum was F. graminearum (GZ3639) prepared at a concentration of 100,000 macroconidai/ml with Tween 20. Mist-irrigation was applied to facilitate FHB development.FHB severity was assessed visually 21 days and determined as the percentage of symptomatic spikelets from the total of all spikelets observed in 20 spikes. Both in the greenhouse and field test, we could observe five categories of FHB severity: resistant (R:0-20%), moderately resistant (MR: 21-40%), moderate (M: 41-60%), moderately susceptible(MS: 61-80%), and susceptible (S: 81-100%). The results showed that seventy seven lines showed the R and MR category on FHB severity. In addition, nine lines showed similar FHB severity compared to Sumai 3.Thirty-two Korean wheat cultivars were evaluated for resistance to spread of symptoms within spike. The 2013 field screening with wheat cultivar was located in Kimjae city Joeonbuk Korea. All plots were inoculated twice. Mist-irrigation was applied to facilitate FHB development. FHB severity was assessed visually 21 days after inoculation on 20 arbitrarily selected spikes per plot. FHB severity was determined as the percentage of symptomatic spikelets from the total of all spikelets. For FHB resistance, the average of FHB severity of Type I exhibited ranging from 21.9% to 77.2% and FHB severity of Type II ranging from 20.8% to 100%. Namhae, Milseong, Geuru, Joen, Anbaek and Sukang were the moderately resistant cultivars while Gobun, Alchan, Dajoong, Eunpa, Shinmichal1 and Uri were the most susceptible cultivars for Type II resistance.We introduced FHB resistant genetic resources for marker test in artificial breeding lines. Among the 89 molecular markers(included XSTS3B-52, XSTS3B-66, XSTS3B-138,Xgwm493, Xgwm533) expressed 200bp, 400bp and so on pattern diversity by PCR. In the marker test results, Xgwm493, XSTS3B-138 molecular markers that were positively significant at the significance level. Using this molecular marker in screening cultivars require complementary parts are difficult to interpret in the middle resistant varieties.There were combination wheat of artificial breeding for FHB resistant(Keumkang/Sumai3, Ning7840/Keumkang and so on). In 2012, 22 lines were selected in F4 generations. In 2013, 16 lines were selected in F₅ generations. In 2014, 23 lines(included '14F6Scab01') were selected in the F₆ generations. We selected '13scabPYT-11' and so on(6 lines) in PYT yield test and '14wAYTs-05' and so on(5 lines) in AYT yield test. The Chinese cultivar Sumai 3 has been used as a major source of resistance in breeding programs, but new source of FHB resistance are desired. One hundred twenty-five selected wheat landraces and cultivars from seven countries varying in FHB resistance levels were evaluated for type II FHB resistance. FHB severities of twenty-eight accessions were lower than resistant control ‘Sumai 3’ (10%). Eighty-eight of the accessions were either resistant or moderately resistant to FHB. Among them,twenty-eight highly resistant accessions mainly originated from China, Japan, Brazil and USA. The results indicated that resistance gene other than ‘Sumai 3’ also provides a relatively high level of FHB resistance in wheat. The new source of resistant accession may enhance FHB resistance in Korean wheat cultivar.FHB, mainly caused by Fusarium graminearum, is a severe disease of wheat and barley around the world. F. graminearum produces trichothecenes mycotoxins such as nivalenol (NIV), deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-ADON), and 15-acetyldeoxynivalenol (15-ADON). Fourty-four isolates of F. graminearum were test for their ability to produce deoxynivalenol and to cause FHB in Korean winter wheat cultivars. F. graminearum was recovered from 44 of 304 samples from wheat grain. The 36 isolates had the NIV genotype while 8 isolates had the DON c hemotype (3-ADON and 15-ADON).There were no significant difference in the mean of FHB severity on the five wheat cultivars between NIV- and DON-producing isolates.FHB is a major disease problem on wheat and barley around the world. F.graminearum produces trichothecenes mycotoxins such as nivalenol (NIV), deoxynivalenol (DON), and zearalenone (ZEA). The objectives of this study were to survey the natural occurrence of FHB and mycotoxins of 32 Korean wheat cultivars grown in 2011-2012 seasons at the National institute of crop science, Iksan, Korea. There was great deal of rainfall and high humidity during flowering time in May 2011. FHB incidence was counted by Fusarium infected spikes per square meter. The samples of 32 wheat cultivar were collected. The grain and flour samples were to analysis for DON and NIV by gas chromatography and ZEA by high performance liquid chromatography. The result showed that the average of FHB incidence(%) per square meter in 2011 and 2012 were 4.2%, 0.5% respectively. There were significant cultivar differences for FHB incidence ranged from 0% to 24% in 2011. All of 32 wheat cultivars contained 9-2088 ng/g for NIV and ten wheat cultivars contained 5.7-8.5 ng/g for ZEA. In addition, DON concentration of Tapdong,Shinmichal1, and Hanbaek were 217, 35 and 683 ng/g respectively. However, the grain and flour sample harvested in 2012 showed that lower FHB incidence and NIV concentration.These results showed that the 32 wheat cultivars harvested in 2011 were heavily contaminated with Fusarium mycotoxins (NIV, DON, ZEA).These results will provide useful information for marker-assisted wheat breeding for improving FHB resistance of Korean wheat varieties.Pre-harvest sprouting (PHS) of Korean wheat cultivars was investigated for five years and allelic variations of functional markers associated with PHS, TaVp-1A, TaSdr-B1 and TaPHS1, were also evaluated to improve PHS resistance in Korean wheat breeding programs. PHS resistance was studied by using mist spray in humid chamber (PHS-MS) over five years. PHS-MS have significantly influenced by year, genotype and the interaction between year and genotype. Resistance of PHS-MS ranged from 1.57% to 84.38%. Red wheat cultivars showed lower PHS-MS (11.39%) than white cultivars(62.24%). There was no significant difference in PHS rate value of Korean wheat cultivars carried different TaVp-1A alleles although five alleles were found in Korean wheat cultivars. The frequency of TaSdr-B1a and TaSdr-B1b allele in Korean wheat cultivars were 79.2% and 20.8%, respectively. That of TaSdr-B1a allele showed lower PHS rate value (16.50%) than that of TaSdr-B1b allele (52.99%). For TaPHS1 allele, it has two types of haplotype I and II in Korean wheat cultivars. There was no significant difference of PHS resistance in Korean wheat cultivars carried between haplotype I (27.19%) and haplotype II (20.45%).PHS resistance, measured by germination index, and grain traits, including grain length, width, thickness, roundness, test weight, and 1,000-kernel weight, were evaluated for four years. The objective of the study was to determine the relationships among PHS and grain traits, and functional markers to improve PHS resistance in Korean wheat breeding programs. Functional markers associated with grain weight, TaSus2-2B, TaGW2-6A, and TaCwi-A1, were also evaluated because grain weight is related to PHS resistance in Korean wheat cultivars. Grain traits, test weight, 1,000-kernel weight, and germination index were influenced significantly by genotype, year and the interaction between year and genotype. Germination index values correlated positively with 1,000-kernel weight (r =0.568, P < 0.01) and grain traits, except grain roundness. White wheat cultivars showed wider length, width, and thickness of grain and 1,000-kernel weight than red wheat cultivars. Wheat cultivars that carried TaSus2-2B with the Hap-L haplotype, showed a higher germination index (0.61) than TaSus2-2B with the Hap-H haplotype (0.18). Wheat cultivars that carried the TaGW2-6A-G haplotype showed higher 1,000-kernel weight(44.62 g) than the TaGW2-6A-A haplotype (39.75 g), although there was no significant difference in germination index between Korean wheat cultivars. Red wheat cultivars that carried the TaCwi-A1a allele showed higher test weights than with the TaCwi-A1b allele and the white wheats that carried the TaCwi-A1a allele exhibited wider length and thickness of grain and higher 1,000-kernel weight than those with the TaCwi-A1b allele.PHS resistance has been associated with grain color and seed dormancy, strongly.Resistance to PHS is a priority of Korea wheat breeding program. We have studied the 122 Doubled Haploid (DH) lines from the cross between Korea cultivars, ‘Keumkang’ and‘Olgeuru’, in order to detect QTLs correlation with PHS resistance and SSR marker. PHS was induced by using misty spray in the humid chamber (PHS-MS) and germination index (GI) was investigated for two years. The variety ‘Keumkang’ has white kernels and higher percentage of PHS rate (30.2%), while ‘Olgeuru’ has red kernels and lower PHS rate (2.8%). There was significant difference in grain color according to the GI. PHS-MS was positively correlated with GI (r = 0.732, P < 0.001). Two molecular markers, Xbarc12 and Xgwm3, were showed correlation with PHS resistance and GI. These markers mapped chromosomes 3A and 3D with Empirical logarithm of the odds (LOD) scores of 4.95 and 4.02. Xbarc12 explained the highest amount of phenotypic variation in GI and PHS, accounting for 11.99% and 27.25%, respectively. Xgwm3 explained 9.10% of phenotypic variation in GI. The PHS-MS and GI in Korean wheat cultivars ranged from 1.37% to 86.75% and from 0.03 to 0.60, respectively. These results will provide useful information for marker-assisted wheat breeding for improving PHS resistance of Korean wheat varieties.