Strawberry pear (pitahaya, pitaya) [Hylocereus undatus (Haw.) Britt. and Rose] postharvest fruit rot was found at an agricultural products store in Itoman city, Okinawa Prefecture in 2006. The symptoms included depressed, water-soaked lesions with olive to black powdery spots coalescing into a soft rot. The causal fungus was identified as Bipolaris cactivora (Petrak) Alcorn. This is the first report of strawberry pear fruit rot caused by B. cactivora.Keywords Pitaya Á Fruit rot Á Bipolaris cactivora Á Water-soaked lesions Á Black powdery spot Strawberry pear [pitahaya, pitaya; Hylocereus undatus (Haw.) Britt. and Rose] is a perennial succulent plant in the family Cactaceae. In Okinawa Prefecture, strawberry pear has emerged in recent years as a cash crop with high commercial value. A fungal disease clearly different from anthracnose (Taba et al. 2006) was observed on strawberry pear fruits at an agricultural products store in Itoman city in November 2005. The purpose of this study was to identify the fungus causing this disease and to confirm its pathogenicity. SymptomsBrown spots were initially observed on fruit (Fig. 1a). Water-soaked to depressed water-soaked developed lesions. Olive to black powdery spots then formed in the center of expanding, coalescing lesions (Fig. 1b), ultimately resulting in a soft rot of the fruit. Isolation and identification of the pathogenLesions were cut into ca. 5 mm 3 pieces, immersed in 70% ethanol for 30 s and in 2% hypochlorous acid solution for 1.5 min., washed with sterile distilled water, and air-dried on a clean bench. Surface-sterilized lesion tissues were then placed on PDA (potato dextrose agar) plates and incubated at 25°C. Hyphal tips were aseptically transferred to fresh PDA. Five monoconidial isolates (PBW-1, PBW-2, PBW-3, PBR-1 and PBR-2) were obtained from the PDA cultures. Colonies on PDA consisted of a pale-olive to black aerial mycelium (Fig. 1c). Conidiophores were pale to light brown, caespitose, straight or flexuous, and often swollen at the apex and at the base (Fig. 1d), and were 72.6-238.4 · 4.1-9.7 [length (L) · width (W), average 181.9 · 7.8] lm. Cespitose conidiophores were also present on the diseased fruit (Fig. 1e). Conidia (porospores) with a basal hilum were straight, ellipsoidal, fusiform or obclavate, 2-4 septa, pale light brown to brown (Fig. 1f), and were 35.3-45.5 · 8.5-10.9 (ave. 42.8 · 9.7) lm. The mycelium was often narrow and sclerotized (Fig. 1d).

An outbreak of black mottle and dieback on basil (Ocimum basilicum L.; Lamiaceae) was recorded in a greenhouse in Okinawa Prefecture, Japan during 2004. The causal agent was identified as Alternaria alternata (Fr.) Keissler based on morphological characters and growth temperature. This report is the first of Alternaria leaf spot of basil caused by A. alternata.

Synthetic riboswitches that can regulate gene expression by a small molecule recognized by an RNA aptamer in mammalian cells have various potential applications in biotechnology and medicine. However, the variety of small molecules and their cognate aptamers that have been demonstrated to function in mammalian cells is limited. The currently available aptamer-ligand pairs also require high small molecule concentrations to enable gene regulation, making them less desirable for industrial and biomedical applications. We conducted in vitro selection of RNA aptamers against a small molecule ASP7967 whose structure is closely related to ASP2905, a known inhibitor of potassium voltagegated channel sub-family H member 3 (KCNH3). One of the aptamers selected (AC17−4) was found to be functional in HEK293 cells, and it was used to design aptazyme-based riboswitches that can activate gene expression (>10-fold) in the presence of ASP2905 or ASP7967 at as low as 5 μM in the culture medium. An aptazyme-based riboswitch was successfully used to regulate human erythropoietin expression in mice injected with an adeno-associated virus (AAV8) vector using orally administered ASP7967. Furthermore, by combining aptazyme-based and exon-skipping riboswitch mechanisms, an ON/OFF ratio approaching 300 was achieved with a low basal expression level in cultured cells.

Indian mulberry (Morinda citrifolia L.) caused by Colletotrichum gloeosporioides. Jpn. J. Phytopathol. 75: 35-37.An outbreak of anthracnose on Indian mulberry (Morinda citrifolia L.) was recorded in Okinawa Prefecture in 2006. Abundant conidial masses formed on the surface of brown spots or zonate brown spots on leaves. A Colletotrichum species was isolated from the diseased leaves and stems, and typical symptoms were reproduced after inoculation of either wounded or intact leaves. The causal agent was identified as Colletotrichum gloeosporioides based on morphological characters and growth temperature.