| Summary: | 碩士 === 國立臺灣大學 === 昆蟲學研究所 === 100 === Calla lilies (Zantedeschia spp.) are ornamental plants in the family Araceae and native to southern Africa. They were introduced into Taiwan for producing cut flowers and pot plants from New Zealand in 1990s. Their colorful bulbous flowers have won the affection of consumers. Nevertheless, bacterial soft rot and viral diseases are the major limiting factors for calla lily cultivation. Konjak mosaic virus (KoMV), belonging to genus Potyvirus, is one of the main virus causing epidemics in the calla lily-producing areas. The symptoms of KoMV-infected calla lilies are mosaic, green islands, vein chlorosis and distortion on leaves; short peduncle and discolored spots on flowers. This virus decreases the marketable value of calla lily. The first objective of this research was to study the transmission ecology of KoMV in calla lily by aphid vectors. The second objective was to develop a simple, rapid, inexpensive and sensitive sample preparation method for the detection of plant virus infection in mucilaginous plants by reverse transcription-polymerase chain reaction (RT-PCR). Six aphid species were examined for their abilities to transmit KoMV, and Myzus persicae and Aphis gossypii were able to transmit the virus in laboratory conditions. M. persicae and A. gossypii transmit KoMV with an acquisition access period of 10 min and an inoculation access period of 24 hours, which corresponds with the features of non-persistent transmission manner. There are many biotic and abiotic factors affecting the transmission of plant viruses by insect vectors. There was no significant difference in KoMV transmission efficiency by M. persicae and A. gossypii among developmental stages and morphs. The temperature during virus acquisition and inoculation has no effect on the transmission of KoMV by these two aphid species. For developing a rapid virus detection method of calla lily-infecting viruses, crude RNA extraction with the YG buffer following with RT-PCR assay not only successfully detected the infection of four potyviruses in calla lily but also was suitable for detecting KoMV and Dasheen mosaic virus in calla lily and other mucilaginous plants. Furthermore, this new developed protocol was demonstrated to be more sensitive than enzyme-linked immunosorbent assay (ELISA) and TRIzol RNA extraction following with RT-PCR assay. The knowledge of transmission ecology and the development of rapid and sensitive virus detection assay would be valuable for developing disease control strategies for KoMV in calla lily.
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