The present study describes the bacterial blight of walnut, caused by Xanthomonas arboricola pv. juglandis ( Xaj ) in the northern Gyeongbuk province, Korea. Disease symptoms that appear very similar to anthracnose symptoms were observed in walnut trees in June 2016. Pathogens were isolated from disease infected leaves, fruits, shoots, bud, flower bud of walnut, and cultured onto yeast dextrose carbonate agar plates. Isolated bacteria with bacterial blight symptoms were characterized for their nutrient utilization profiles using Biolog GN2 and Vitek 2. In addition, isolates were subjected to physiological, biochemical, and morphological characterizations. Furthermore, isolates were identified using 16S rDNA sequence analysis, and multi-locus sequence analysis using atpD , dnaK , efp , and rpoD . To confirm pathogenicity, leaves, fruits, and stems of 3-year-old walnut plants were inoculated with bacterial pathogen suspensions as a foliar spray. One week after inoculation, the gray spots on leaves and yellow halos around the spots were developed. Fruits and stems showed browning symptoms. The pathogen Xaj was re-isolated from all symptomatic tissues to fulfill Koch’s postulates, while symptoms were not appeared on control plants. On the other hand, the symptoms were very similar to the symptoms of anthracnose caused by Colletotrichum gloeosporioides . When walnut plants were inoculated with combined pathogens of Xaj and C. gloeosporioides , disease symptoms were greater in comparison with when inoculated alone. Xaj population size was more in the month of April than March due to their dormancy in March, and sensitive to antibiotics such as oxytetracycline and streptomycin, while resistant to copper sulfate.

No abstract

No abstract

A South Korean population from Kongju (n = 350) was screened by isoelectric focusing and immunoblotting procedures to determine the distribution of genetic variations in 3 apolipoprotein genes including APOA-IV, APOE and APOH. Although the known APOA-IV protein polymorphism was not observed, sporadic examples of 2 putative new variants were identified. The frequencies of the APOE*2, APOE*3 and APOE*4 alleles were 0.069, 0.823 and 0.107, respectively. At the APOH structural locus 3 common alleles, APOH*1 (0.010), APOH*2 (0.913) and APOH*3 (0.073) were observed. In addition, a unique APOH allele designated APOH*3 Kongju was identified in this Korean population.

No abstract