Barley breeding program of RDA (Rural Development Administration) has been develop to new hulled barley variety that has been used for malt and beer material. Through this program, we developed new two-rowed covered barley, Imaeg, with disease resistant, lodging tolerant and good malt quality for beer and Korean traditional drink ‘Sikhye’ in 2013. Imaeg showed resistant to Barley yellow mosaic virus (BaYMV), lodging tolerant and early maturing. The regional yield trials were conducted for Imaeg as a breeding line ‘Iksan166’ during three years at four different regions. And then it was registered to Plant protection right, No. 5681 in 2015 after field experiment by KSVS (Korea Seed & Variety Service). Imaeg has I of vernalization and shorter stem length as 77cm than 7cm to control variety Hopum. Yield potential of Imaeg about 4.8ton/ha that higher about 3% in paddy field condition than control, however, it has no significant difference. In quality examination for beer usage, Imaeg has higher 1,000 grain weight (45.6g) and higher assortment ratio (93.6%) than those of Hopum as 42.6g and 90.4% respectively. In malt quality, Imaeg showed higher soluble protein, Kolbach index and diastatic power than those of Hopum significantly. In addition, Imaeg has better ‘Sikhye’ malt quality significantly in lightness of grain (58.4 L value) and growth rate (216.8%) than those of Hopum as 54.3 (L value) and 177.5% respectively. Imaeg would be suitable for cultivation at the area above -4°C of daily minimum temperature in January in Korean peninsula.

Barley yellow mosaic virus (BaYMV) is transmitted by a root-inhabiting Polymyxa graminis (P. graminis) and thus the disease is called “soil-borne”. In this study, the presence of P. graminis was confirmed by PCR test based on specific sequences of P. graminis type Ⅰ (P. graminis f. sp. temperata) Internal Transcribed Spacer (ITS). P. graminis was detected in the BaYMV infected soil and root of barley plants. The monitoring of P. graminis was conducted in March 2015 in 8 korean provinces. It was detected in the soil of all collected regions. This is the first report on a P. graminis a survey of Korea.

백호'는 흰가루병 및 보리호위축병 저항성 품종을 육성하기 위하여 'Azuma Golden'과 'Nishinochikara'를 인공교배 하여 육성하였다. 익산 137호로 명명되어 지역적응 시험을 수행한 후 2008년 농촌진흥청 농작물 직무육성 신품종 선정 위원회에서 흰가루병 및 보리호위축병 저항성 맥주보리 신품종 '백호'로 명명되었다. '백호'의 출수기 및 성숙기는 4월 21일과 5월 28일로 대비인 '호품' 보리에 비해 약 2-3일 늦었다. 또한 간장은

Barley Yellow Mosaic Virus (BaYMV) caused significant reduction in barley yield and is difficult to control due to alive parasitic soil-borne fungus, Palmyra gamines that transmits the, virus. Previous studies have indicated that a virus-free soil could be infested by using virus-contaminated farming machineneries and implements. For the further confirmation of this finding, different proportions of BaYMV-infested soil were mixed into virus free soil. Three barley varieties (Hordum vulgarae, cv "Olbori", "Baegdong" and "Sacheon 6") were sown in pots treated with different rate of P. graminis-infested soil ranging from 0% to 100% in October 20, 2001. Results showed that BaYMV infection increased as the rate of infested soil increased. Initial symptoms were observed in a pots treated with 10% infested soil in all the 3 varieties of barley. "Olbori" had about 5% infection in 20% infested soil and about 10% infection in 40% or 50% infested soil and about 20% infection in 60% infested soil. In "Baegdong", the trend of BYMV occurrence was similar with "Olbori" but the time of severe infection was earlier than "Olbori". BaYMV infection in "Sacheon 6" was even earlier than "Baegdong" with much more severe symptoms than "Baegdong". The growth rate of barley was affected by about 19-22% when grown in 20% infested soil. As the rate of BaYMV infested soil increased the heading date was delayed but the maturing date was early in "Olbori" and "Sacheon 6". Also, reduction rate of culm length in 3 varieties increased with increase of infested soil content. However, "Olbori" showed the highest reduction. "Sacheon 6", have been characterized with long spike length, however was significantly reduced as the infested soil increased. On the other hand, spike length of "Olbori" was not significantly affected despite of increased of infested soil. The reduction rate of 1000 kernel weight was higher in large kernel size cultivar "Sacheon 6" and "Olbori" than small kernel size "Baegdong" as increase of BaYMV-infested soil content.

It was practiced that crop rotation between barley and soybean to reduce the Barley yellow mosaic virus(BaYMV) in barley and investigated barley growth and yield. The diseased degree of barley by BaYMV reduced in one or two years fallow of barley with the soybean cultivated continuously in summer season. In the same practices, barley growth such as plant height and tiller number was better than another crop rotation plots. In yield components of barley, culm length and number of head was different among the treat plots. One or two years fallow of barley plots was better results than others. The yield of barley also showed significant difference in above one or two year fallow of barley. These plots showed higher yield from 24% to 32% than continuously cultivated barley and soybean plot. In comparison to conventional practice barley and rice, these rotation system presented higher barley yield from 3% to 13%. These crop rotations affect the density of the BaYMV vector, Polymyxa graminis. In these results, crop rotation with one or two years fallow of barley in viral infested paddy fields could reduce the BaYMV disease incidence and fungal vector density in soil.

A stable method for strain distinction using viral RNA 1 structures analyses was developed and compared with the combined RT-PCR and RAPD methods. Seven out of 61 random primers were found to be polymorphic based on RAPD analysis resulting on the differentiation of the 33 BaYMV isolates into four distinct groups according to geographical districts. The first and largest group includes 13 isolate and consists mainly of two-rowed malting barley in Haenam area. The second group had ten collections from inland in west southern. The third group had seven isolates from west southern coastal region, where mainly six-rowed naked barley is cultivated. The last fourth group included three isolates from Gyungnam region in east southern area. Conclusively, RNA 1 analysis proved to be stable and efficient method for strain distinction for Korean BaYMV isolates. Further, results of pathogenicity and RNA 1 structure analyses revealed four groups BaYMV strains and were distributed all over Korea, represented by Naju, Haenam-okcheon, Iksan and Milyang.

보리호위축병 피해지역에 대한 수량감소의 예측을 위하여, 보리호위축병(BaYMV)에 대한 저항성 품종과 이병성 품종간 수량구성요소, 수량 및 증질 변이를 건전구와 이병구에서 비교 조사하였다. 1. 보리호위축병의 이병주는 BaYMV에 감염된 것으로 나타났으며, 이병정도는 감수성 품종인 백동에서 9, 저항성 품종인 내한쌀보리에서 1정도 발병하였다. 2. 감수성 품종인 백동은 천립중을 제외한 간장, 수당립수, m2 당 수수 등의 수량구성요소가 유의하게 감소하였으며, 수량은 대조구의 20%수준으로 현저히 감소하였다. 3. 보리호위축병 감염구에서 종자의 발아율은 감수성 품종과 저항성 품종간에 차이가 없었으나, 정립률은 감수성 품종인 백동에서 설립중이 유의하게 증가하였으며, 대조구에 비하여 정립률과 조단백질 함량 모두 유의한 차이를 보였다. 4. 보리호위축병은 간장, 수량, 정립률, 수수, 천립중, 1수립수 등의 피해와 부의 상관을, 조단백질 함량과는 정의 상관을 보여 보리호위축병에 이병이 되면 수량 및 품질에 크게 피해를 주는 것으로 나타났다.

1. 4개년 조사 기간 중 보리호위축병 발병율은 6.6%-62.5%로 연차간 기상조건에 따라 큰 변이를 나타내었다. 2. 면역혈청학적 검정 결과 보리호위축병의 감염이 확인되었으며, 일부 품종은 BaMMV와의 혼합 감염이 발생하였으나 보리호위축병에 비해 상대적으로 발생이 낮은 경향이었다. 3. 월동전 보리 초기 생육 기간의 기상 조건과 발병율의 변화 조사 결과 평균기온이 바이러스의 감염과 유의성 있는 상관을 나타내었다. 4. 월동기중에는 기상조건과 발병율과는 어떤 요인도 유의성 있는 상관을 나타내지 않았다. 5. 생육재생기 이후의 발병율은 최고기온과 유의성 있는 상관을 나타내어 병징 발현에는 최고기온이 영향을 미치는 것으로 조사되었다.

보리호위축병(BaYMV) 상습 발병지에서 쌀보리인 백동을 공시하여 건전주와 이병주의 농업형질 등을 비교 조사한 결과를 요약하면 다음과 같다. 1. 보리호위축병에 이병된 주는 건전주에 비하여 SPAD 값이 13.7정도 낮은 값을 보였으며, 출수는 10-11일정도 지연이 되었고, 건물중이 75%, 간장은 68%, 수수가 49% 감소하였다. 2. 이병주의 절간장 감소는 이삭을 제외한 상부로부터 제1-6절간에서 나타났으며, 그 중 제3-5절간장에서 감소율이 75-80%로서 가장 켰다. 3. 보리호위축병에 의하여 망장이 17-19%, 입수가 47%, 천립중이 60%, 주당 입중이 78% 감소하였으며, 종실에서는 폭과 두께에서 감소되었고, 종피색의 색도에서는 명도는 낮았으나 적색도는 높게 나타났다.

A rapid and sensitive assay for specific detection and identification of barley yellow mosaic virus(BaYMV) was set up using the reverse transcriptase polymerase chain reaction(RT-PCR). A couple of primers was select to discriminate the viruses. PCR fragments of BaYMV(ca.0.9 kb) were obtained by using the method designed for BaYMV capsid protein. RT-PCR fragments were cloned with vector pT7 Blue and the resulting clones were sequenced. Capsid protein of BaYMV consisted of 297 amino acids and 891 nucleotides. The capsid protein sequence of BaYMV showed that 98% of nucleotides and 99% of amino acids homology.

An isolate of barley yellow mosaic virus(BaYMV-HN) obtained from Haenam, Korea was compared with two BaYMV strains. BaYMV-Ⅱ-1 from Japan and BaYMV-G from Germany. The sequence of the 3'-terminal 3817nucleotides[excluding the poly (A) tail] of RNA 1 of BaYMV-HN was determined to start within a long open reading frame coding for a part of the NIa-VPg polymerase(26 amino acids). NIa-Pro polymerase (343 amino acids), NIb polymerase(528 amino acids) and the entire capsid protein(297 amino acids), which is followed by a noncoding region(NCR) of 235 nucelotides. In the partial ORFs, BaYMV-HN shows higher sequence homology with BaYMV-Ⅱ-1(99.5%) than BaYMV-G(92.7%). The 3' non-coding regions of BaYMV-HN(235nt) shows higher nucleotide sequence homology with BaYMV-G(235nt)(99.6%) than BaYMV-Ⅱ-1(231nt)(97.0%). The 3' NIa-Pro protein sequence of BaYMV-HN shows higher amino acid sequence homology with BaYMV-Ⅱ-1(95.0%) than BaYMV-G(93.6%), but, NIb protein sequence of BaYMV-HN shows same all amino acid sequence. The capsid protein sequence of BaYMV-HN(297aa) shows same with BaYMV-Ⅱ-1, and shows higher nucleotide sequence homology with BaYMV-UK (from United Kingdom)(97.3%) than BaYMV-G(96.9%) and G2(96.9%). Difference of capsid protein amino acid were 0-9 between the Japan, United Kingdom and Germany and were 2-6 between all Korean isolates. Many of the amino acid differences are located in the N-terminal regions of the capsid proteins from 1 to 74 amino acid positions.