Plant breeding requires the collection of genetically diverse genetic resources. Studies on the characteristics of Platycodon grandiflorum resources have not been carried out so far. The present study was carried out to discriminate P. grandiflorum based on morphological characteristics and genetic diversity using simple sequence repeat (SSR) markers. Methods and Results :We collected 11 P. grandiflorum cultivars: Maries II, Hakone double white, Hakone double blue, Fuji white, Fuji pink, Fuji blue, Astra white, Astra pink, Astra blue, Astra semi-double blue and Jangbaek. Analyses of the morphological characteristics of the collection were conducted for aerial parts (flower, stem and leaf) and underground parts (root). Next, the genetic diversity of all P. grandiflorum resources was analyzed using SSR markers employing the DNA fragment analysis method. We determined that the 11 P. grandiflorum cultivars analyzed could be classified by plant length, leaf number and root characteristic. Based on the genetic diversity analysis, these cultivars were classified into four distinct groups. Conclusions : These findings could be used for further research on cultivar development using molecular breeding techniques and for conservation of the genetic diversity of P. grandiflorum. Moreover, the markers could be used for genetic mapping of the plant and marker-assisted selection for crop breeding.

Red-ripe ‘Betatiny’ jujube-shaped cherry tomato fruits via stem maintenance or stem removal were stored at 20℃ for 12 days. Their quality and microbial safety parameters like their respiration rate, weight loss, soluble solids content (SSC), titratable acidity (TA), firmness, hue value, aerobic microflora, coliform, yeast and mold count, and decay were evaluated during their storage. The jujube-shaped cherry tomato fruits whose stems were removed lost less weight than the fruits whose stems were maintained during their 12 days of storage. The stem removal lowered the respiration more significantly than the stem maintenance, and the formation of novel tissues at the stem scar that resulted from the stem removal was observed morphologically. The SSC, TA and hue value of the skin color decreased after eight storage days, but showed no difference between the stem maintenance and removal. The stem had higher microbial counts like aerobic microflora, coliform, and yeast and mold counts. The stem maintenance showed a short shelf-life because molds grew on the attached stem after five storage days. The shelf-life of the jujube-shaped cherry tomato fruits whose stems were removed was about eight days, but that of the fruits whose stems were maintained and that were stored at 20℃ was only about six days.

With the rapid growth of fresh-cut produce market, the South Korean fresh-cut industry is facing the challenge of ensuring food safety. As the estimation of the microbial numbers in fresh-cut produce processing lines (tools, and equipment) using the conventional microbiological techniques takes days, so there is a need for faster and easier monitoring methods. This study was conducted to investigate the use of ATP bioluminescence assay to measure the degree of microbial contamination from three actual fresh-cut processing lines. The samples collected from frech-cut vegetables, and fresh-cut fruits processing plants were tested for the estimation of the bacterial number, using the ATP bioluminescence and microbiological methods. The result of former was transferred to log RLU/100 cm2, and that of the latter was transferred to log CFU/100 cm2. A positive linear correlation between the ATP bioluminescence assay value and aerobic-plate count was found for fresh-cut processing lines, with a correlation coefficient of 0.8772 (n=50). The results of this study indicate that ATP bioluminescence assay can be used to monitor microbial contamination in fresh-cut produce processing plants, and can help improve the hygiene therein.