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A new intermediate parent 'Wonye 30002' (Allium cepa L.) was developed by Bioenergy Crop Research Center, NICS in 2009. As a male sterile line, 'Wonye 30002' can be used to hybrid seed production by crossing with pollen parent. The first cross was conducted between male sterile plants of 402AC203 and M1 in 2002. The male sterile line 'Wonye 30002' has circular bulb and bulb weight is 283 g. As early maturing type, lodging date is May 6. Plant height and pseudostem diameter are 43 cm and 15.5 mm, respectively. In seed harvesting characteristics, number of flower stalks and the length are 43 cm and 110 cm, respectively. The flowering date of 'Wonye 30002' is around May 24 and is completely male sterile. 'Wonye 30002' is a promising male sterile line for hybrid bulb onion seed production. [ABSTRACT FROM AUTHOR]

A new intermediate parent 'Wonye 30001' (Allium cepa L.) was developed by Bioenergy Crop Research Center, NICS in 2009. As a male sterile line, 'Wonye 30001' could be used for hybrid seed production by crossing with pollen parent. The first cross was conducted in 2000. Male sterile plants were selected from 'Ginque' breeding lines and fertile plants were selected from YG-1-1. The male sterile line 'Wonye 30001' has circular bulb and bulb weight of 260 g. As mid-late maturing type, lodging date is around May 20. Plant height and stem diameter are 57 cm and 15.9 mm, respectively. In seed harvesting characteristics, number of flower stalks and the length are 6 and 135cm, respectively. Flowering date of 'Wonye' is May 23 and is completely male sterile. 'Wonye 30001' is a promising male sterile line for hybrid bulb onion seed production. [ABSTRACT FROM AUTHOR]

Two novel inactive alleles of Dihydroflavonol 4-reductase-A ( DFR-A) were identified in yellow onion ( Allium cepa L.) cultivars and breeding lines from Korea and Japan. Unlike the previously reported inactive yellow DFR-A allele, designated as DFR-A TRN , in which the 3′ portion of the coding sequences was deleted, an allele containing a premature stop codon, DFR-A PS , was isolated from the majority of cultivars. Co-segregation of DFR-A PS and color phenotypes in the F2 population from a cross between yellow and red parents showed that inactivation of DFR-A was responsible for lack of anthocyanin in these yellow onions. In addition, RT-PCR analysis of F2 population showed that the transcription level of the DFR-A PS allele was significantly reduced owing to non-sense-mediated mRNA decay. A 20-bp deletion of a simple sequence repeat in the promoter region of the DFR-A PS allele was used to develop a simple PCR-based molecular marker for selection of the DFR-A PS allele. All genotypes of 138 F2 individuals were clearly distinguished by this molecular marker. In addition to the DFR-A PS allele, another DFR-A allele, DFR-A DEL , was identified in some cultivars. In case of the DFR-A DEL allele, no PCR products were amplified throughout DFR-A sequences including promoter regions, suggesting deletion of the entire DFR-A gene. Co-segregation of the absence of DFR-A and color phenotypes was confirmed in another F2 population. Furthermore, RT-PCR results showed that no DFR-A transcript was detected in any yellow F2 individuals. [ABSTRACT FROM AUTHOR]

The bulb storability of eight red and ten yellow onion (Allium cepa L.) cultivars grown primarily in Korea was evaluated. During storage, sprouting occurred earlier in red cultivars than in yellow cultivars. In addition, the ratio of sprouted to unsprouted bulbs increased more rapidly in red cultivars than in yellow cultivars. However, not all yellow cultivars had strong storabilities. Bulb storability of three yellow cultivars was as poor as that of red cultivars, suggesting only a slight possibility of a pleiotropic effect of color and bulb storability. Meanwhile, F3 lines of a red cultivar selected based on stronger storabilities showed intermediate storabilities between those of the red and yellow cultivars, implying that strong storability could be obtained by successive selection. In contrast, F1 hybrids from crosses between yellow and red breeding lines showed poor storability compared with the yellow cultivars, indicating that poor storability may be dominant over strong storability. The relationships between color and other traits that potentially affect storability, such as fresh and dry weight, water content, and firmness of bulbs, were evaluated. No significant differences in these traits were observed between the two colors, although the water content of yellow cultivars and the dry weight of red cultivars were slightly higher than their counterparts. Correlation analyses between bulb storability and other traits, including weight, water content, and firmness, also showed no significant correlations. In this study, no correlations were identified between bulb color, storability, and other traits. However, based on these results, red cultivars with stronger storabilities could be developed through successive selection of bulbs with stronger storabilities. [ABSTRACT FROM AUTHOR]

Heating effect on total phenol, flavonoids, antioxidant activity, and sugar content of six onion varieties has been quantitatively investigated to explore the effect of different temperatures. The onion varieties comprised one red-skinned variety, two white-skinned varieties, and three yellow-skinned varieties. The heating temperature was scanned at 80°C, 100°C, 120°C, and 150°C for 30 minutes each, and quantitative analysis was performed relative to the powdered onion at ambient temperature. Quercetin, glucosides and sugar content were analyzed using high-performance liquid chromatography. The total phenolic and antioxidant content increased in all six varieties. The total flavonoid levels showed a considerable change. On heating the onion samples at 120°C for 30 minutes, the red-skinned variety showed the highest level of total phenolic content [13712.67 ± 1034.85 µg of gallic acid equivalent/g dry weight (µg GAE/g DW)] and total flavonoids [3456.00 ± 185.82 µg of quercetin equivalents/g dry weight (µg Q/g DW)], whereas the content of total phenolics and total flavonoids were 13611.83 ± 341.61 µg GAE/gDW and 3482.87 ± 117.17 µg Q/g DW, respectively, for the yellow-skinned (Sunpower) variety. Quercetin and its glucoside contents increased up to 120°C and then decreased at 150°C, whereas the sugar content continuously decreased with heating. All cultivars showed the same pattern in the heating effect, and the predominant flavonoids were destroyed at higher temperatures. Therefore, it is improper to expose onion powder to a temperature higher than 120°C. [ABSTRACT FROM AUTHOR]