종실 돌연변이를 유기하여 미질개선을 위한 육종으로의 적극적인 활용을 목적으로 얻어진 신동진벼 돌연변이 계통의 작물학적 특성과 종실 저장단백질을 변이모본과 비교 분석을 검토하여 얻은 결과를 요약하면 다음과 같다. 1. 종실 변이계통의 작물학적 특성은 변이모본보다 생태특성의 출수기에서는 대부분 조생의 경향을 보였고, 간장 및 수장은 짧은 경향을 나타냈고, 또한 종실특성의 현미 길이, 현미폭 및 천립중에서도 변이모본보다 짧거나 낮은 정도를 나타냈다. 2. SDS-PAGE 분석결과 opaque 군의 SM-22와 giant embryo 군의 SM-34는 글루테린 폴리펩타이드에서 높은 농도를 보였고, floury 군의 SM-23, shrunken 군의 SM-26, sugary 군의 SM-31은 전단백질 농도패턴은 낮게 보이면서 55kDa 이상의 고분자 band에서 다양성을 나타냈다.

Magnesium is important not only for the growth of rice itself, but also as an essential micronutrient component of half of the world population who are supported by rice. Here, we performed genome-wide association study (GWAS) with high-resolution density SNPs to identify natural allelic variation in Mg2+ increase from rice set, which is derived from a total 24,368 rice germplasms. The range of the concentration and distribution of Mg2+ in 295 core accessions of brown rice grain were wide, from 18.17mg/L to 57.11mg/L, with mean 39.71mg/L. In particular, GWAS result shows that the high peak found on chromosomes 3 and 11. The new natural variants identified through haplotyping analysis would be useful to develop new rice varieties with improved storage ability of the valuable mineral through the future molecular breeding.

‘Hyowon 4’, a new medium maturing glutinous rice variety was developed by the rice breeding team of Pusan National University in 2013. This cultivar was derived from a cross between ‘Boseokchal’ and ‘Donna’ with good glutinous property. During F3~F8 generation, breeding lines were selected by a pedigree breeding method. As a result, the promising line (JS23-4-39-14-5-1-1-1) with good glutinous property was advanced and designated as the name of ‘SP 106’ in 2012. This variety headed on Aug. 15, which is 2 days later than ‘Dongjinchal’ in middle plane. The culm length and panicle length of this variety was 82.4 cm and 21.1 cm, respectively. This variety has about 13.9 tillers per a hill and 100 spikelets per a panicle. The ratio of ripened grain is about 92.0% and 1000-grain weight was 20.9 g in brown rice. The yield performance was 5.03 MT/ha in local adaptability test.

Although rice has been cultivated as a major food crop for approximately 5,000 years, the interest of customers in ‘scented rice’ is a recent trend in the Korean market. As a part of developing a germinated scented rice variety, the newly bred scented rice variety ‘Cheonjihyang-1 se’ was germinated for 24 h, and changes in profiles of flavor-related volatiles, lipophilic phytonutrients, and fatty acids were investigated. The profiling of volatile compounds by using a headspace-gas chromatography-mass spectrometry (HS-GC-MS) revealed a total of 56 odor-active flavoring compounds; 52 at the pre-germination stage, 51 at the post-germination stage, and 47 common at both stages. The major flavoring compounds were nonanol and benzene, which constituted 11.5% and 6.6%, respectively, of the total peak area in pre-germinated rice, and 19.4% and 6.5%, respectively, in post-germinated rice. Germination induced an increase in 13 flavoring compounds, including 3,3,5-trimethylheptane and 1-pentadecene, which increased by 763 and 513%, respectively by germination. However, we observed a germination-induced decrease in most of the other flavoring compounds. Especially, the most important scented rice-specific popcorn-flavoring compound, 2-acetyl-1-pyrroline, showed 89% decrease due to germination. Furthermore, the germination of scented rice induced a decrease in the content of various phytonutrients. For example, the total contents of phytosterols, squalene, and tocols decreased from 207.97, 31.74, and 25.32 μg g -1 at pre-germination stage down to 136.66, 25.12, and 17.76 μg g -1 , respectively at post-germination stage. The fatty acid compositions were also affected by germination. The composition of three major fatty acids, linoleic, oleic, and palmitic acids, increased from 36.6, 34.2, and 24.4%, respectively, at the pre-germination stage to 37.9, 36.9, and 20.7%, respectively, at the post-germination stage. All these results suggested significant changes in the flavor-related compounds and phytonutrients of the scented rice variety ‘Cheonjihyang-1 se’ during the process of germination, and subsequently the need for developing a more precise process of germination to enhance the flavor and nutritional quality of the germinated scented rice products.

''Hyowon 5’, a new aromatic rice variety with high yield was derived from a cross between 'Dasan’ as a high yield source and ‘IR841-1-1-2’ as a donor for aroma. A general pedigree breeding method was applied to develop Hyowon 5. In F8 generation, a promising line, JS14-12-36-8-5-3-1-1-1, was selected and designated as the name of ‘SP 102’ in 2012. This variety headed on Aug. 14 , which is 3 days later than ‘Hwayoung’ in middle plane. The brown rice of this aromatic variety ‘Hyowon 5’ exhibited 51 odor-active volatiles including a pop corn-flavoring 2-acetyl-1-pyrroline which is exclusively detected in aroma rice varieties. The Culm length and panicle length of this variety was 83.2 cm and 26.4 cm, respectively. This variety has about 14.9 tillers per hill and 124.5 spikelet numbers per panicle. The 1000-grain weight was 20.9 g in brown rice. The yield performance of brown rice was 6.27 MT/ha in local adaptability test.

'Hyowon 2’, a new medium-late maturing glutinous rice variety with short clum and lodging tolerance was developed by the rice breeding team of Pusan National University in 2013. This cultivar was derived from a cross between 'Junam’ as a short clum source and ‘Donna’ with a good glutinous properties. During selected by the pedigree breeding method, until F8 generation. As a result, a promising line, JS22-3-24-1-6-2-1-1-1, was advanced and designated as the name of ‘SP 105’ in 2012. This variety headed on Aug. 22 is 9 days later than ‘Dongjinchal’ in middle plane. The Culm length and panicle length of this variety was 65.6 cm and 22.5 cm, respectively. This variety has about 14.4 tillers per hill and 113 spikelet numbers per panicle. The ratio of ripened grain is about 93.0% and 1000-grain weight was 18.4 g in brown rice. This variety has higher α-tocotrienol content compared to that of ‘Hwasunchal’. The yield performance of brown rice was 4.81 MT/ha in local adaptability test.

BADH1 and BADH2 are two homology genes, encoding betaine aldehyde dehydrogenase in rice. In the present study, we scanned BADHs sequences of 295 rice cultivars, and 10 wild rice accessions to determine the polymorphisms, gene functions and domestication of these two genes. A total of 16 alleles for BADH1 and 10 alleles for BADH2 were detected in transcription region of cultivars and wild species. Association study showed that BADH1 has significant correlation with salt tolerance in rice during germination stage, the SNP P11483(T/A)ishighlycorrelatedwithsalttoleranceindex(STI)(P<10-4). While, BADH2 was only responsible for rice fragrance, of which two BADH2 alleles (P23036, P25390) explain 97% of aroma variation in our germplasm. It indicated that there are no overlapping functions between the two homology genes. In addition, a large LD block was detected in BADH2 region, however, no large LD blocks in a 4-Mb region of BADH1. Only BADH2 region shown significant bias Tajima’s D value from the balance. Extended haplotype homozygosity study revealed fragrant accessions had a large LD block that extended around the mutation site (P23036) of BADH2, while both of the BADH1 alleles (SNP P11483(T/A)) did not show large extended LDblock. All these results suggested that BADH2 was identified as a domesticated gene during rice evolution, while BADH1 was not selected by human beings.

Rice germplasm collections continue to grow in number and size around the world. Since maintaining and screening such massive resources remain as a great challenge, it is important to establish piratical ways to manage them. A core collection, by definition, refers to a subset of entire population but preserves most of the possible genetic diversity, enhancing the efficiency for germplasm utilizations. Here we reports the whole genome resequencing of the 137 Korean rice core set (KRICE_CORE) that represents 25,604 rice germplasms deposited in Korean genebank of Rural Development Administration (RDA). We implemented the Illumna HiSeq 2000 and 2500 platform to produce short reads and then assembled those with 9.8x depth using Nipponbare as a reference. Comparisons of the sequences with the reference genome yield more than 15 million(M) single nucleotide polymorphisms (SNPs) and 1.3M insertion/deletion (INDELs). Phylogenetic and population analyses using 2,046,529 high quality SNPs successfully assigned each rice accessions to the relevant subgroups, suggesting those SNPs comprehensively capture evolutionary signatures accumulated in rice subpopulations. Furthermore, genome-wide association studies (GWAS) for 4 exemplary agronomic traits from the KRIC_CORE manifest the utility of KRICE_CORE, identifying previously defined gene or novel genetic polymorphisms that potentially regulate the important phenotypes. This study provides strong evidences that the size of KRICE_CORE is small but contains such a high genetic and functional diversity across the genome. Thus those resequencing results will be useful for future breeding, functional and evolutionary studies in the post-genomic era.

As one of the most important crop, rice is not only a staple food of half world’s population but a wonderful model plant, which has been leading the evolution and functional genomics study. The next-generation sequencing technology are expediting rice genomic study, by providing a simple but powerful way. In this study, we re-sequenced a core collection of 137 rice accessions from all over the world along with 158 Korean breeding varieties. Finally, 6.3G uniquely mapped reads were obtained, and about 10 million SNPs and ~1.2 million InDels were identified with average sequencing depth of 7.5X. These will help us to maximize our germplasm utilization and assists all the deep research in population dynamics and functional studies. Here, we’d like to show the approaches applied to resequencing data mining and on-going activities.

2-acetyl-1-pyrroline (2AP) was widely known as the principal aroma compound, it development in rice has been reported due to the loss of function of betaine aldehyde dehydrogenase gene (badh2) on chromosome 8. In previous study, a lot of haplotypes have been found of this gene, while only limited haplotypes have been proved as functional mutations. A total of 137 core set accessions, and additional 45 germplasms have been employed in this study. Finally, two new mutations have been found (3bp deletion in exon12 and C/A SNP in exon 10), and 23 haplotypes have been detected, most of them had strong relations with aroma formation. According to the sequence results, five functional markers have been developed, the markers showed a highly efficient in discriminating the special aromatic rice varieties, and displayed perfect co-segregation with the trait of fragrance in F2 population. Those new markers developed in the present study would be useful in molecular breeding of fragrant rice varieties. Based on the haplotypes, the further research is in progress.

‘진상’은 공주대학교에서 2013년도에 육성한 고품질 저아밀로스 품종으로 주요특성과 수량성을 요약하면 다음과 같다. 1.‘진상’은 중서부평야 보통기 보비재배에서 출수기가 8월 11일로 ‘추청’보다 약 11일 빠른 중생종으로, 이삭길이는 19 cm로 ‘추청’과 비슷한 수준이었으나, 간장은 75.2 cm로 ‘추청’보다 짧다. 2.‘진상’의 정현비율은 81.2%로 ‘추청’과 비슷한 수준이며 현미길이와 폭이 각각 4.86 mm, 2.91 mm로 ‘추청’에 비해 약간 길고, 넓은 단원형 품종이다. 현미 천립중은 20.91 g 수준이며, 수량성은 457 kg/10a로 ‘추청’과 비슷하였다. 3.‘진상’은 중간찰벼로서 투명도가 중간 정도의 불투명 배유 특성이고, 알칼리 붕괴도는 6.4 정도이며, 아밀로스함량은 11.9%로 대조품종 19.1%보다 낮고, 도요 식미기로 측정한 밥 윤기치는 대조품종인 ‘추청’보다 높게 나타났다.

Aroma development in rice has been reported due to the lack of function of betaine aldehyde dehydrogenase gene (badh2) on rice chromosome 8. A lot of functional markers have been designed based on the InDels, such as 7bp deletion in exon 2, 803bp deletion in exon 4 and 5, 8bp deletion in exon 7, and 3bp insertion in exon 13. Although there were a lot of functional SNPs, other InDels have not been detected by a PCR-based marker. Here we developed a simple, co-dominant, functional cleaved amplified polymorphic sequence (CAPS) marker for fragrance trait based on 1bp insertion in exon 14. The developed marker showed a high efficiency in discriminating that special aromatic rice variety, and displayed perfect co-segregation with the trait of fragrance in the F2 population. This new marker developed in the present study would be useful in molecular breeding of fragrant rice varieties.