본 연구에서는 작업기의 디스크 헤로우를 이송장치에 부착하여 실내실험을 통해 토양의 물리적 특성(함수율, 단위중량), 작업기의 특성(주행속도, 디스크 헤로우 간의 간격)에 따른 경운 토양의 반전율 등을 분석하고자 하며, 작업시기의 적정 토양의 물리적 상태를 확인하여 농가의 기초자료로 활용하고자 한다. 실험은 4가지 변수를 두고 진행하였다. 함수율, 작업 속도는 3가지 조건으로, 단위 중량은 일반적인 밭 흙 단위 중량 2.3kg/m3을 기준으로 높을 때와 낮을 때로 구분 지었으며, 디스크 헤로우의 간격은 30cm, 40cm로 구분하여 실험을 진행하였다. 이러한 4가지 변수를 두고 실험을 실시할 때 똑같은 조건으로 산포하기 위해 1m x 1m 면적의 프레임을 제작하여 일정하게 3회 석회가루를 산포하고, 경운작업 전․후의 석회가루 분포를 측정하여 반전율을 계산하였다. 반전율은 함수율별 분석 시 25%, 15%, 30% 순으로 측정되었고, 디스크 헤로우의 간격은 30cm 일 때가 더 높게 측정되었으며, 토양의 단위중량은 2.3kg/m3 이상일 때 더 높게 측정되었다.

Brachypodium has been focused as new model plant for grass species. Like small size, small room requirement, and fast growth, Brachypodium shows numerous advantages as a model plant. Brachypodium is a typical grass at the genome level, which also exhibits an overall similarity of gene content and gene families when compared with rice (Oryza sativa) and sorghum (Sorghum bicolor) genomes. Brachypodium is an excellent material for structural and functional genomic studies in grass species. Targeting-Induced Local Lesions IN Genomes (TILLING) is a high-throughput technique and an approach for reverse genetics study. Moreover, it has been wildly utilized to find induced mutation. Bradi3g45515 is orthologue of the cellulose synthase-like HvCslF8 in barley. For TILLING library construction, 384 M2 Brachypodium mutants induced by chronic-gamma irradiation were used. Single nucleotide polymorphysm (SNP) and small deletion in Bradi3g45515 were searched through TILLING analysis. Template DNA for PCR reaction were prepared according to two dimensional pooling (eightfold) strategy. Heteroduplex DNA was digested by SURVEYOR nuclease (TRANSGENOMIC) and the DNA fragment was detected using polyacrylamide gel electrophoresis. Positive signal appeared at polyacrylamide gel from more than 4 lines and their Bradi3g45515 region were sequenced. SNP(s) were identified in 509-2 and 677-3 mutant line. Cellulose content and/or cell wall materials content will be measured using these mutants.

A dietary deficiency of tryptophan can cause pellagra and lead to low levels of serotonin that is associated with depression, aggression, anxiety and overeating in humans. Thus, enhancement of tryptophan content in rice has great potential benefit for human and animal diets. In this study, a total of 1,350 rice mutant population was used to identify single nucleotide polymorphisms (SNPs) in Oryza sativa anthranilate synthase alpha1(OASA1) gene that was associated with negative feedback in tryptophan biosynthesis. For high-throughput TILLING analysis, 5 fluorescence-labeled primer sets were designed to cover exon regions of OASA1 locus and PCR amplifications were analyzed using ABI3130xl DNA sequencer. Through the screening of 1,350 mutant lines, nine mutant lines produced one or two cleaved fragments in the PCR products of OASA1 locus. The full sequencing of nine mutant lines revealed that total 31 SNPs were located in the regions of OASA1. In particular, three mutant lines contained SNPs in coding regions that resulted in an amino acid change. The tryptophan contents of the three mutant lines were 2.2- to 2.3-fold higher than the wild type. These high-tryptophan mutant lines will be used rice breeding programs and contribute directly to enhancing human nutrition.

TILLING (Targeting Induced Local Lesions IN Genomes) is broadly regarded as an excellent methodology for reverse genetics applications. Approximately 15,000 M3 TILLING lines have been developed via the application of gamma-ray irradiation to rice seeds (cv. Donganbyeo), followed by subsequent selections. In an effort to evaluate the genetic diversity of the TILLING population, we have employed the AFLP multiple dominant marker technique. A total of 96 (0.64%) TILLING lines as well as Donganbyeo were selected randomly and their genetic diversity was assessed based on AFLP marker polymorphisms using 5 primer combinations. An average of 100.4 loci in a range of 97 to 106 was detected using these primer combinations, yielding a total of 158 (31.4%) polymorphic loci between Donganbyeo and each of the 96 lines. A broad range of similarity from 80% to 96% with an average of 89.4% between Donganbyeo and each of the 96 lines was also observed, reflecting the genetic diversity of the TILLING population. Approximately 28 polymorphic loci have been cloned and their sequences were BLAST-searched against rice whole genome sequences, resulting in 20 matches to each of the gene bodies including exon, intron, 1 kb upstream and 1 kb downstream regions. Six polymorphic loci evidenced changes in the coding regions of genes as compared to the rice pseudomolecules, 4 loci of which exhibited missense mutations and 2 loci of which exhibited silent mutations. Therefore, the results of our study show that the TILLING rice population should prove to be a useful genetic material pool for functional genomics as well as mutation breeding applications.

TILLING (Targeting Induced local Lesions IN Genomes) is known to be an excellent methodology for reverse genetics approach. About 15,000 M3 TILLING lines have been developed after gamma-ray irradiation to the rice seeds of Donganbye. In order to assess genetic diversity of the TILLING population. we have employed a multiple dominant marker technique, such as AFLP. A total of 96 (0.64%) lines including Dongganbye were randomly selected and their genetic diversity was assessed on the basis of AFLP marker polymorphism by using 5 primer combinations. An average of 100.4 loci with a range of 97 to 106 were detected by using the primer combinations, resulting in 173 (34.6%) polymorphic loci among 96 lines. A broad range of similarities with 80% to 96% was evidenced between Donganbye and each of 96 TILLING lines, reflecting genetic diversity of the TILLING population. About 30 polymorphic loci have been cloned and their sequences have been blasted against rice whole genome sequences. The sequences evidenced highly significant matches to each of genes including exons and introns, upstream sequences and downstream of genes, and intergeneic sequences. Therefore, the TILLING rice population would be valuable genetic sources for rice functional genomics.