Dasheen mosaic virus (DsMV), Turnip mosaic virus (TuMV), Konjac mosaic virus (KoMV) and Zantedeschia mild mosaic virus (ZaMMV) are important potyviruses previously identified in calla lily plants in Taiwan. In order to save time and cost of virus detection, a multiplex RT-PCR assay was developed for these calla potyviruses. Specific primers for each virus were designed based on the sequences of 3′ terminal region of respective viruses. To prevent false negative results, a primer pair specific to plant mitochondrial nad5 mRNA was used to produce a 185-bp fragment as an internal control of RT-PCR. The specificities of primers were confirmed by means of simplex and multiplex PCR assays. Optimal primer concentration ratio was identified by multiplex PCR assay. Total RNAs purified from virus-infected plants were used directly or mixed in different combinations, and then tested by multiplex RT-PCR. The result indicated that the expected RT-PCR products could be specifically amplified and identified on the basis of their molecular sizes. The detection sensitivity of multiplex RT-PCR was 25-625 times higher than that of indirect-ELISA (I-ELISA) depending on the virus. When applied to field surveys, multiplex RT-PCR could detect more single as well as mixed infection samples than I-ELISA. Accordingly, our multiplex RT-PCR assay provides a simple, rapid and reliable method for multiple potyvirus detection in calla lily.

The occasional rains that occur during dry seasons often stir up the bottom sediment of reservoirs, which leads to high turbidity and electrical conductivity in raw waters received by water utility companies. A newly developed real-time precision multi-layer sensor (RPMS) system was used to monitor a high-speed flocculation flat-bottomed sludge blanket clarifier (HFSBC) pond in real time to solve the water quality problems caused by drought and flood conditions. The RPMS is capable of monitoring the thickness of a sludge blanket; if the coagulation and sedimentation processes of the HFSBC are not working well, the sludge blanket will be thin and have a low sludge concentration. Conversely, if the HFSBC is working properly, the sludge blanket will have a thick and highly concentrated layer of sludge. Any heavy metals that are not removed by water treatment processes will enter the water supply network, which will result in poor water quality for end users. Against the backdrop of intensifying climate change, the enhancement of automated monitoring systems and adaptation processes will be an important part of efforts to minimize and resolve acute changes in water quality.