Shrimps infected with WSSV (White Spot Syndrome Virus) generally exhibit white spots in their inner space of carapaces as an acute clinical sign. In an effort to identify the correlation between this acute clinical sign and the condition, the index factors (RNA/DNA concentration and ratio, trypsin activity) were analyzed. A total 580 farmed Fenneropenaeus chinensis and 130 Lithopenaeus vannamei were collected from western and southern fifteen outdoor ponds in Korea. The status of the white spot pathology was divided into four stages (stage 0, stage I, stage II, and stage III), in accordance with the clinical signs as to the size and area of white spots. A significant decrease in RNA concentration and RNA/DNA ratio for multi-infected fleshy prawn (WSSV and vibrio sp.) occurred during the stage III (the whole carapace is covered with a white spot). In particular, RNA/DNA ratio was significantly lower as 1.47±0.04 than other groups. A similar trend was also found in the single infection (WSSV), but the decrease was less than the multi-infection. In the species comparison, both species were vulnerable to the multi-infection, but L. vannamei was more sensitive than F. chinensis (ANOVA, p<0.05): A significant decrease in RNA concentration and RNA/DNA ratio was first found in stage II for the former species, while it was found in stage III for the latter species. Trypsin activity was also showed a similar tendency with nucleic acid variation. Multi-infected shrimp showed drastically decrease of trypsin activity. According to the results, clinical signs of the white spot under carapace have an only physiological effect on shrimp if they covered entirely with white spots.

This experiment was conducted to evaluate feed value and usability of soybean varieties as livestock forage. In this study, three soybean cultivars, OT93-26, Geomjeongsaeol, and Pungwon, were harvested at R5 (beginning seed development)- and R6 (full seed)-reproductive stages for analyzing feed value of soybean. Days to R5 stage harvest of OT93-26 among the three soybean cultivars was 55 days and the shortest while Pungwon took 103 days to reach at R6 stage. The R6-harvested soybeans had higher dry matter (DM) yields and crude protein (CP) content than the R5-harvested. However, both DM and CP were the highest in the R6-harvested Geomjeongsaeol. Contents of neutral detergent fiber (nDF) and acid detergent fiber (ADF) of Pungwon harvested at R5 were the highest whereas the R6-harvested Geomjeongsaeol had the lowest. Digestible dry matter (DDM), dry matter intake (DMI), and relative feed value (RFV) of the R6-harvested Geomjeongsaeol and Pungwon were higher than those of the R5-harvested, but in case of OT93-26, those at R6 stage were low rather than those at R5 stage. However, soybean could be used as alternative forage with high feed value for livestock. Taken together, Geomjeongsaeol could be used for developing new forage soybean varieties with high feed value, and R6 would be the optimum harvesting stage for yield and quality of forage soybean.

This study is to generate SCARs markers for identification of Perilla species. A SCAR is a genomic DNA fragment at a single genetically defined locus that is identified by PCR amplification using a pair of specific oligonucleotide primers. We derived SCARs by sequencing and cloning the both ends of the amplified products of RAPD markers. Sixteen sequence-specific primers were synthesized from eight RAPD markers, which were completely sequenced. We developed the species-specific SCAR markers which could be used successfully in detecting genetic variation in four Perilla species. These markers could be used to verify species-origins of various forms of Perilla germplasms.