The mutants of sugary-2 (su-2), floury (flo), shrunken-1 (shr-1), and dull-1 (du-1) were crossed to waxy (wx) to
produce F2 seeds. Chi-square analysis on the segregating ratio of the F2 seeds revealed that flo, su-2, and shr-1 were independently transmitted with wx, while wx was epistatic over du-1. The floury and sugary-2 were crossed to Hwasunchalbyeo, a waxy variety, and then the F4 of floury-waxy and sugary-2-waxy seeds were developed, respectively. As the parents phenotypes of sugary-2 and floury, the grains of these two lines showed lower hardness and grain weight than normal grain of Hwacheongbyeo. For alkali digestive value (AVD), the sugary-2-waxy showed lower ADV than Hwacheongbyeo. For the gel consistency of grain flours, the floury was medium like Hwacheongbyeo, while those of the sugary-2, floury-waxy, and sugary-2-waxy were soft like Hwasunchalbyeo. The amylose contents in the grains of the sugary-2 and floury were decreased to ~15% whereas that of Hwacheongbyeo was 19.1%. All the lines showing waxy endosperm (Hwasunchalbyeo, floury-waxy, and sugary-2-waxy) showed less than 4% amylose contents. Interestingly, the free sugar content in the brown rice was increased to 9.27% in the sugary-2-waxy, showing transgressive segregation phenomenon where the free sugar contents in its parents, sugary-2 and Hwasunchalbyeo, were 5.98% and 3.98% respectively. Also, the floury-waxy showed transgressive segregation phenomenon, containing 6.15% of free sugar content in the grains
Late blight caused by Phytophthora infestans is historically a serious epidemic disease in potato and tomato
cultivations. Accession L3708 (Solanum pimpinellifolium), a new source for late blight resistance was identified in AVRDC, and carries the resistance gene, Ph-3, incompatible to P. infestans race 3. The AFLP markers linked to Ph-3 were previously developed from the L3708 accession (Chunwongse et al. 2002). To facilitate tomato breeding with the Ph-3 gene, an attempt was made to convert AFLP markers to sequence-characterized amplified region (SCAR) markers. Among 6 AFLP markers, only one AFLP marker, L87, was successfully converted to SCAR marker. The resistance-specific 230 bp AFLP fragment was cloned and sequenced, and the PCR primer amplifying a 123 bp fragment was designed. This SCAR marker could discriminate resistant and susceptible individuals with high stringency. The developed SCAR marker could be used for the marker assisted-selection in tomato breeding programs.
Total phenolic content, total anthocyanin content and antioxidant activity were analyzed from rice samples collected in Korea, Japan and China. The results showed that the total phenolic content and free-radical scavenging activity differed
significantly in these rice lines. The correlation between content and activity was subsequently investigated. The results showed that in black rice, anthocyanin was the major phenolic component and that both phenolic content and anthocyanin content were closely correlated with free-radical scavenging activity. Reverse Phase High Performance Liquid Chromatography (RP-HPLC) data showed that cyanidin-3-O-glucoside and peonidin-3-O-glucoside composed about 90% of the total anthocyanin content in black rice and in red rice. In the red rice extract, the total phenolic content produced a high correlation coefficient with antioxidant activity but correlated very poorly with the total anthocyanin content. The OD458 and the OD500 values which represent the proanthocyanidin content of the rice extract, produced high correlation coefficients with antioxidant activity and total phenolic content. These results suggest that the OD458 and the OD500 values can be used to evaluate the quality of red rice. In addition, based on the data obtained, a competitive accumulation model of anthocyanin and proanthocyanidin in black and red rice was proposed.
The characteristics of rice starch by sampling six rice cultivars for making rice bread were examined. Six rice varieties exhibited different level of amylose content and the ratio of chain length distribution within the amylopectin cluster. Especially, examination by colorimetric measurement of starch-I2 complex showed the maximum absorption wavelength was the highest in Goamibyeo. The X-ray diffraction patterns of starch granules showed the traditional "A" type, except in Goami 2 and Goami 3 and there was difference in crystalline of rice starch. There were significant difference in the changes of swelling power of rice starches through temperature. We could also found that the six rice cultivars had different levels of the hydrolysis rate by 5% glucoamylase. These results could suggest that properties of rice starch impact on the level of loaf formation and specific gravity of rice bread after baking.
Wheat-rye translocation lines were developed to produce a main crop resistant to biological and physical stress. 'Chaupon' rye contains 2RL chromatin to harbor resistance genes for powdery mildew and leaf rust. In order to identify chromosome 2RL-derived rye proteins and 2RL-perturbed proteins in wheat-rye translocation lines, the gel-based proteomics was employed with 'Coker797' (non-2RL), 'Hamlet' (2RL) and 'near-isogenic line' (stabilized 2RL). The leaf proteome was resolved on 2D-gel, resulting in 216 spots in a final selection. A total of 90 proteins were identified with the identification success rate of 42%. The identified proteins were classified by functional annotation: metabolism (64%), cellular process (5%), translation (2%), regulatory function (1%) and hypothetical (28%). The proteins belonged to metabolism were subdivided into carbohydrate metabolism (36%), energy metabolism (35%), metabolism of lipid, amino acid, other amino acid and biosynthesis of secondary metabolites (each 6%) and others (5%). A total of 53 proteins were differentially expressed, in which β-glucosidase, in particular, originated from the chromosome 2RL of rye, was exclusively appeared in NIL. In addition, small Ras-related GTP binding-protein assigned to wheat was predominantly found in 2RL rye chromatin-possessing NIL. These results suggest that the acquired genetic traits obtained from rye 2RL enhance the resistance to biotic and abiotic stress in wheat-rye translocation lines by altered the proteome expression. In leaf metabolome analysis, 11 predominant metabolites containing trans-aconitate, glutamate, and betaine were identified by 1H-NMR-based metabolite fingerprinting. The overall metabolites pattern of NIH appears to be closer to Coker797 rather than Hamlet. Thus, the metabolic phenotype of NIL was not so much lineated from Hamlet contrast to proteomic phenotyping.
Comparison of the distribution and utilization of free amino acids in buckwheat is required of understanding the amino acid metabolism. The buckwheat sprouts contained the most abundant amino acid Val (40%) followed by Tyr (28%) in common buckwheat (CB), whereas Val was the most predominant amino acid in tatary buckwheat (TB), accounting for 62%. The buckwheat stem and root contained commonly Gln (40~42% in stem; 30~37% in root). Thus, soluble amino nitrogen source is used for Gln in buckwheat. The main difference of amino acid distribution in three tissues between CB and TB was Tyr in sprouts. Low level of Tyr in TB is presumably resulted from the conversion to other phenolic metabolites. The content of essential free amino acids in TB sprout was 53% higher than that in CB. Thus, the TB sprouts are benefit to the human nutrition. The basic study of amino acids gives a clear evidence for different interconversion and metabolism of amino acids in two buckwheat species.
Measurement of amylose content is commonly employed as the predictor of rice quality. Amylose is usually measured by absorbance of the amylose-iodine complex by a variety of ways. However, the effort to standardize the way amylose is measured is still working through the world of rice research. For comparing rice amylose analysis methods in Korea and Japan, major japonica rice-producing countries, rice samples with different amylose contents were selected. The rice samples were harvested, dried and milled at the National Institute of Crop Science, Rural Development Administration in Suwon, Republic of Korea. Amylose contents (AC) were analyzed using Concanavalin A method and modified Juliano methods, as representative methods in Korea and Japan, respectively. The AC of rice starch by Concanavalin A method were ranged 9.4~28.8%, on the other hand, the AC of rice flour by modified Juliano method had a wider range AC, 8.7~41.8%; for example, AC of semi-waxy varieties had lower values and AC of high amylose varieties had higher values in modified Juliano methods, even more than 10%. High correlation coefficients between retrogradation (or gelatinization) and AC using Concanavalin A would indicate that the Concanavalin A method could be more explanatory for evaluating rice quality like gelatinization and retrogradation.