Abstract Cassava mosaic disease is caused by cassava mosaic begomoviruses (CMBs) and can result in crop losses up to 100% in cassava (Manihot esculenta) in Tanzania. We investigated the efficacy of chemotherapy and thermotherapy for elimination of East African cassava mosaic virus (EACMV) of Tanzanian cassava. In vitro plantlets from EACMV‐infected plants obtained from coastal Tanzania were established in the greenhouse. Leaves were sampled from the plants and tested to confirm the presence of EACMV. Plantlets of plants positive for EACMV were initiated in Murashige and Skoog (MS) medium. On the second subculture, they were subjected into chemical treatment in the medium containing salicylic acid (0, 10, 20, 30 and 40 mg/L) and ribavirin (0, 5, 10, 15 and 20 mg/L). In the second experiment, EACMV‐infected plantlets were subjected to temperatures between 35 and 40°C with 28°C as the control. After 42 days of growth, DNA was extracted from plant leaves and PCR amplification was performed using EACMV specific primers. It was found that plant survival decreased with increasing levels of both salicylic acid and ribavirin concentrations. In general, plants treated with salicylic acid exhibited a lower plant survival % than those treated with ribavirin. However, the percentage of virus‐free plants increased with an increase in the concentration of both ribavirin and salicylic acid. The most effective concentrations were 20 mg/L of ribavirin and 30 mg/L of salicylic acid; these resulted in 85.0% and 88.9% virus‐free plantlets, respectively. With regard to thermotherapy, 35°C resulted in 79.5% virus‐free plantlets compared to 69.5% at 40°C. Based on virus elimination, ribavirin at 20 mg/L, salicylic acid 30 mg/L and thermotherapy at 35°C are recommended for production of EACMV free cassava plantlets from infected cassava landraces.

中文翻译：

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化疗和热疗消除坦桑尼亚木薯地方品种东非木薯花叶病毒的效果

摘要 木薯花叶病是由木薯花叶病毒 (CMB) 引起的，可导致坦桑尼亚木薯 (Manihot esculenta) 作物损失高达 100%。我们研究了化疗和热疗消除坦桑尼亚木薯东非木薯花叶病毒（EACMV）的功效。在温室中培育从坦桑尼亚沿海获得的 EACMV 感染植物的试管苗。从植物的叶子中取样并进行测试以确认 EACMV 的存在。EACMV 阳性植物的幼苗在 Murashige 和 Skoog (MS) 培养基中培养。在第二次继代培养时，将它们在含有水杨酸（0、10、20、30和40mg/L）和利巴韦林（0、5、10、15和20mg/L）的培养基中进行化学处理。在第二个实验中，将感染 EACMV 的幼苗置于 35 至 40°C 的温度下，并以 28°C 作为对照。生长 42 天后，从植物叶子中提取 DNA，并使用 EACMV 特异性引物进行 PCR 扩增。研究发现，随着水杨酸和利巴韦林浓度水平的增加，植物存活率下降。一般来说，用水杨酸处理的植物表现出比用利巴韦林处理的植物更低的植物存活率。然而，随着利巴韦林和水杨酸浓度的增加，无病毒植物的百分比增加。最有效的浓度是利巴韦林20mg/L和水杨酸30mg/L；分别产生了 85.0% 和 88.9% 的无病毒植株。就热疗而言，35°C 的植株脱毒率高达 79.5%，而 40°C 的脱毒率则为 69.5%。基于病毒消除，建议使用 20 mg/L 利巴韦林、30 mg/L 水杨酸和 35°C 热疗，从受感染的木薯地方品种中生产不含 EACMV 的木薯苗。