Restriction landmark genome scanning (RLGS) is a high-speed genome analysis method to detect DNA polymorphism, and is suitable to develop useful DNA markers for cultivar-discrimination of agricultural plants. The mat-rush, Juncus effusus is a vegetatively propagated crop that has been cultivated for over 500 years in Japan as the material of "tatami-omote," a surface of Japanese conventional mats. In recent years, Japanese mat-rush cultivars are grown in foreign countries and reimported to Japan in violation of the Seeds and Seedlings Law, economically damaging domestic production. The largest problem of illegal mat-rush reimportation has been with cv. Hinomidori. We developed a cultivar-discrimination DNA marker of mat-rush using RLGS, and detected the RLGS spot markers that didn't exist specifically in Hinomidori. The spot marker can be used with the RLGS method to identify Hinomidori accurately among cultivars.

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D-erythro-C(14)-Sphingosin (C(14)-Sph) was isolated as the germination accelerating factor in Nomuraea rileyi in our previous study. This activity was expected to support fungal infection by reduction of the infection time between conidial adhesion and invasion into the insect. In this study, we estimated the effect of C(14)-Sph with regard to the infection time. Conidia activated by C(14)-Sph shortened the time to about half, indicating the potential of C(14)-Sph as an adjuvant for fungal pesticide of N. rileyi.

The conidium of the entomopathogenic fungus Nomuraea rileyi has been found to germinate rapidly in the presence of host insect-derived extracts. Thus the extract appears to contain an important factor involved in host recognition by N. rileyi. However, the substance responsible for such unique germination behavior has yet to be identified. Hence we attempted to purify this substance. One thousand g of dried silkworm pupae was subjected to methanol extraction, followed by methanolysis, two different solvent partitions, and three different column chromatographies. A total of 12.4 mg of substance was obtained in the active fraction. The substance obtained exhibited an activity more than 46,000 times higher than that of the methanol extract. The substance was detected as a single peak on Sephadex LH20 column chromatography and as a single band on high-performance thin-layer chromatography. These data indicate that the concentrated fraction contained a high-purity substance.

Browning of plant tissue is generally considered attributable to enzymatic oxidation by polyphenol oxidase (PPO). Electrophoresis followed by activity staining has been used as an effective procedure to visually detect and isolate isozymes; however, it has not been applied for examination of various PPO isozymes in lettuce. Our study demonstrated that different lettuce PPO isozymes could be detected at different pH in active staining, and multiple isozymes were detected only under alkaline conditions. As a result, we concluded that activity staining with approximately pH 8 enabled to detect various PPO isozymes in lettuce. By expression analysis of the PPO isozymes after wounding, PPO isozymes that correlated with time-course of tissue browning were detected. The wound-induced PPO may play a key role in enzymatic browning.

D-erythro-C₁₄-Sphingosine (C₁₄-Sph) accelerated the germination of Nomuraea rileyi in a solution containing peptone, but activity declined to a large degree in water. This suggests the presence of a co-factor in C₁₄-Sph-triggered germination. Since the main role of peptone is to supply nitrogen constituents, we examined the effects of various nitrogen constituents. It was found that Ala and His were highly effective for C₁₄-Sph-triggered germination.

We have developed a genetic marker that can identify a registered variety of mat rush in Japan. A vegetatively propagated plant, mat rush is cultivated and used as the material for the surface layer of tatami mats in Japan. Because it has been difficult to detect DNA polymorphism among mat rush cultivars, we applied restriction landmark genome scanning (RLGS) to discriminate mat rush cultivars. RLGS is a genome analysis technique that can detect many DNA polymorphisms as spots separated by two-dimensional electrophoresis. By cloning the DNA of spots specific to the superior mat rush cultivar 'Hinomidori' detected by RLGS, we developed a sequence-tagged site (STS) marker for polymerase chain reaction (PCR) analyses. This STS marker makes it possible to distinguish 'Hinomidori' specifically from other mat rush cultivars. The strategy of developing the STS marker in this study is applicable to other vegetatively propagated plants that are characterized by difficult DNA polymorphism detection.