Young Hak Jung

Comparative proteomic study between tuberous roots of light orange- and purple-fleshed sweetpotato cultivars

This study compares the differences in proteomes expressed in tuberous roots of a light orange-fleshed sweetpotato (Ipomoea batatas (L.) Lam. cultivar Yulmi) and a purple-fleshed sweetpotato cultivar (Shinjami). More than 370 protein spots were reproducibly detected by two-dimensional gel electrophoresis, in which 35 spots were up-regulated (Yulmi vs. Shinjami) or uniquely expressed (only Yulmi or Shinjami) in either of the two cultivars. Of these 35 protein spots, 23 were expressed in Yulmi and 12 were expressed in Shinjami. These protein spots were analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and electrospray ionization tandem mass spectrometry. Fifteen proteins in Yulmi and eight proteins in Shinjami were identified from the up-regulated (Yulmi vs. Shinjami) or uniquely expressed (only Yulmi or Shinjami) proteins, respectively. In Yulmi, α-amylase and isomerase precursor-like protein were uniquely expressed or up-regulated and activities of α-amylase, monodehydroascorbate reductase, and dehydroascorbate reductase were higher than in Shinjami. In Shinjami, peroxidase precursor and aldo-keto reductase were uniquely expressed or up-regulated and peroxidase and aldo-keto reductase activities were higher than in Yulmi. PSG-RGH7 uniquely expressed only in Shinjami and the cultivar was evaluated more resistant than Yulmi against the root-knot nematode, Meloidogyne incognita (Kofold and White, 1919) Chitwood 1949 on the basis of shoot and root growth. Egg mass formation was 14.9-fold less in Shinjami than in Yulmi. These results provide important clues that can provide a foundation for sweetpotato proteomics and lead to the characterization of the physiological function of differentially expressed proteins.

Field evaluation on the synergistic attractiveness of 2-(1-undecyloxy)-1-ethanol and ipsenol to Monochamus saltuarius

To develop an optimal attractant for Monochamus saltuarius (Gebler) (Coleoptera: Cerambycidae), the synergistic effects of a few potential attractants (ethanol and α‐pinene as host‐plant volatiles, and ipsenol and ipsdienol as bark beetle pheromones) were tested in a pine forest combined with 2‐(1‐undecyloxy)‐1‐ethanol (monochamol), the aggregation pheromone of Monochamus species, for two consecutive years, 2014 and 2015. Total number of catches was 65 and 33 in 2014 and 2015, respectively. Ethanol or ethanol + monochamol (a base blend) were not attractive to M. saltuarius with no difference from the control. Addition of α‐pinene and ipsdienol to the base blend did not significantly increase catches. However, ipsenol was significantly synergistic to the base blend in attracting M. saltuarius in 2014, and the blend (ipsenol + base blend) attracted meaningfully higher numbers of M. saltuarius in 2015. Our study illustrates the potential for monochamol and ipsenol baits for monitoring and trapping of M. saltuarius in the field.

A Survey on Diseases and Insect Pests in Sweet Persimmon Export Complexes and Fruit for Export in Korea

Between 2010 and 2012, diseases and insect pests of sweet persimmon were surveyed at sweet persimmon export complexes and non-export orchards in Suncheon, Jeonnam Province; Jinju, Changwon (Dongeup and Bukmyeon), and Gimhae, Gyeongnam Province; and Ulzu, Ulsan. The following diseases were found in the sweet persimmon orchards: angular leaf spot (Cercospora kaki), anthracnose (Colletotrichum gloeosporioides and Colletotrichum acutatum), circular leaf spot (Mycosphaerella nawae), powdery mildew (Phyllactinia kakicola), and gray mold (Botrytis cinerea). Circular leaf spot was the most frequent and serious disease, and C. gloeosporioides and C. acutatum were found on fruits. Thirty-three insect pest species that belonged to 32 genera of 20 families in 5 orders were found in the sweet persimmon orchards; the two-spotted spider mite, Tetranychus urticae, was also found in the surveyed orchards. Apolygus spinolae, Pseudaulacaspis cockerelli, and Adoxophyes orana were widely found in the surveyed orchards; Spodoptera litura and Homona magnanima were also recorded. Damage by insect pests was low, and the quarantine insect pests peach pyralid moth (Dichocrocis punctiferalis) and persimmon fruit moth (Stathmopoda masinissa) were rarely or not found in the sweet persimmon export complexes. In addition, other quarantine insect pests, such as persimmon false spider mite (Tenuipalpus zhizhilashviliae) and Japanese mealybug (Planococcus kraunhiae), were not detected. These quarantine insect pests were also not found in the sorting places, storage houses, and fruits for export; however, scale insects and two-spotted spider mites were found at a low rate. Although anthracnose (C. acutatum) infested fruit was found in the storage houses, only one in Jinju and Gimhae.

High level of genetic diversity among Steinernema monticolum in Korea revealed by single-enzyme amplified fragment length polymorphism.

Steinernema monticolum was first described from a mountainous forest at sites of Sancheong, Gyeongnam province in Korea. Since S. monticolum is one of the most commonly isolated entomopathogenic nematodes from Korea, it is desirable to investigate the diversity of this species. Single-enzyme amplified fragment length polymorphism (SE-AFLP) analyses were used to differentiate 32 S. monticolum populations. Our results revealed a high level of genetic diversity within S. monticolum at the population level. On the geographic scale, SE-AFLP analysis revealed that there was no correlation between the genetic similarity of populations of this species and their geographical proximity.

Occurrence and damage of Japanese gall-forming thrips, Ponticulothrips diospyrosi Haga et Okajima (Thysanoptera: Thripidae) in persimmon orchards.

Occurrence of Japanese gall-forming thrips, Ponticulothrips diospyrosi was surveyed from 143 orchards at 11 cities or counties in 6 provinces, Korea from 2008 to 2009. Occurrence of P. diospyrosi was not observed from Jeju (4 persimmon orchards) in Jeju-do and Wanju (12 persimmon orchards) in Jeollabuk-do. However, P. diospyrosi occurred newly in the orchards in Sanchung, Gyeongsangnam-do and in Gangreung, Gangwon-do. Rate of damaged orchards by P. diospyrosi in Gumi, Mungyeong, Sangju and Euseong in Gyeongsangbuk-do (73.3%) was higher than that of in Gyeongsangnam-do or Youngdong areas in Chungcheongbuk-do. A maximum rate of damaged trees by P. diospyrosi was 23.5% in Gumi, while the damage was lower in Sancheong and Jinju representing 0.2 and 1.6%, respectively. Rate of damaged leaves by P. diospyrosi was the highest in Sangju (0.12%). P. diospyrosi occurred between and and between to . Persimmon orchards close to mountain were more damaged by P. diospyrosi. Edge parts of persimmon orchards were more damaged by P. diospyrosi than inner parts, especially in orchards close to mountain. Also, the middle and lower parts of tree canopy were more damaged by P. diospyrosi than the upper parts of canopy.

Evaluation of Entomopathogenic Nematodes against Armyworm, Pseudaletia separata on Tall Fescue, Festuca arundinacea

The armyworm, Pseudaletia separata was occurred suddenly in a golf club in Namhae, Gyeongnam province in 2013. Thus, pathogenicity of seven species of entomopathogenic nematodes (Steinernema carpocapsae GSN1 strain, S. glaseri Dongrae strain, S. longicaudum Nonsan strain, S. monticolum Jiri strain and S. siamkayai, Heterorhabditis sp. Gyeongsan strain, and H. bacteriophora Hamyang strain) was evaluated against armyworm on tall fescue in pot and golf course to control this pest environmentally friendly. The pathogenicity against P. separata larvae was significantly different depending on nematode species. The corrected mortality of fifth instar of P. separata was 100% in the treatment with S. carpocapsae GSN1 in 7 days in tall fescue pot. However, there was not different in the mortality of fifth instar of P. separata (80 to 100%) at the rate of 385 to 6,160 infective juveniles (Ijs) (=2.5×102 to 4×105 Ijs/m2) of S. carpocapsae GSN1 strain in each pot. Corrected mortality of P. separata was 65 and 60% at the rate of 105 Ijs/m2 of S. carpocapsae GSN1 and S. longicaudum Nonsan strain, respectively in the tall fescue of golf course.