cassava
not annotated - annotated - LINNAEUS only
20923689
Simultaneous virus-specific detection of the two cassava brown streak-associated viruses by RT-PCR reveals wide distribution in East Africa, mixed infections, and infections in Manihot glaziovii.
The expanding cassava brown streak disease (CBSD) epidemic in East Africa is caused by two ipomoviruses (genus Ipomovirus; Potyviridae), namely, Cassava brown streak virus (CBSV), and Ugandan cassava brown streak virus (UCBSV) that was described recently. A reverse transcription polymerase chain reaction (RT-PCR) based diagnostic method was developed in this study for simultaneous virus-specific detection of the two viruses. Results showed that CBSV and UCBSV are distributed widely in the highlands (> 1000 m above the sea level) of the Lake Victoria zone in Uganda and Tanzania and also in the Indian Ocean costal lowlands of Tanzania. Isolates of UCBSV from the Lake Victoria zone were placed to two phylogenetic clusters in accordance with their origin in Uganda or Tanzania, respectively. Mixed infections with CBSV and UCBSV were detected in many cassava plants in the areas surveyed. CBSV was also detected in the perennial species Manihot glaziovii (DNA-barcoded in this study) in Tanzania, which revealed the first virus reservoir other than cassava. The method for detection of CBSV and UCBSV described in this study has important applications for plant quarantine, resistance breeding of cassava, and studies on epidemiology and control of CBSD in East Africa.
21526935
Assessment of attractiveness of cassava as a roosting plant for the melon fly, Bactrocera cucurbitae, and the Oriental fruit fly, B. dorsalis.
Application of bait spray to crop borders is a standard approach for suppression of melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) populations and may also be of value for suppression of oriental fruit fly, B. dorsalis (Hendel) populations. Establishment of preferred roosting hosts as crop borders may help to improve suppression of both fruit fly species by providing sites for bait spray applications. In an area-wide B. cucurbitae suppression trial, the question was raised as to whether cassava, Manihot esculenta Crantz (Euphorbiales: Euphorbiaceae), could be used as a B. cucurbitae roosting host. M. esculenta was of interest as a roosting host because, in contrast to many other identified preferred roosting hosts, it would also be a crop potentially increasing the productivity of the crop production system overall. As a short-lived and shrubby perennial, M. esculenta potentially constitutes a crop with more persistent roosting foliage than an annual crop such as corn, Zea mays L. (Cyperales: Poaceae), that has often been planted as a roosting host for B. cucurbitae control. Using protein-baited traps set amidst potted plants placed adjacent to a papaya Carica papaya L. (Violales: Caricaceae) orchard known to have established populations of B. cucurbitae and B. dorsalis, the effectiveness of M. esculenta as a roosting host was assessed by comparing its attractiveness to that of castor bean, Ricinus communis L (Malpighiales: Euphorbiaceae), previously identified as one of the most attractive roosting hosts for B. cucurbitae, and to corn, a crop which has been planted as a roosting host for help in B. cucurbitae control. The results showed that use of M. esculenta as a roosting host is comparable to use of R. communis by both B. cucurbitae and B. dorsalis. These results provide encouragement to incorporate M. esculenta on a farm as a trap crop (i.e. site for bait spray application). This has the advantage of having the trap crop be a crop on its own (as opposed to castor bean) and, among prospective crops that could be used as a trap crop, has foliage more persistent than an annual trap crop such as corn.