Cassava brown streak disease and the sustainability of a clean seed system.
Cassava brown streak disease and the sustainability of a clean seed system.
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DOI：
10.1111/ppa.12453
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发表时间：
2016-02
期刊：
影响因子：
2.7
通讯作者：
van den Bosch F
中科院分区：
文献类型：
--
作者：
McQuaid CF;Sseruwagi P;Pariyo A;van den Bosch F
减少作物疾病的一种方法是将无病种植材料从繁殖地点传播给种植者。这项研究评估了这种方法对木薯褐条病的有效性和可持续性，木薯褐条病是对整个东非木薯作物的威胁。使用数学模型，在单田繁殖位点确定不同环境和控制条件对病原体传播的影响。大量病媒种群和周边地区的疾病造成的高疾病压力，加上不良的欺诈行为，导致疾病抑制工作不成功。然而，如果这些因素能够克服，田地可能会产生足够清洁的材料用于重新种植。评估低压系统在多次收获中的可持续性，发现管理良好的田地可以保持较低的疾病水平，尽管产生足够的插条可能具有挑战性。重新种植上一次收获的土地不会导致种植材料退化，只会减少数量，并且不一定需要进口新的清洁材料。建议仅在疾病压力和媒介种群密度较低的地区建立繁殖场所，并强调田间管理培训的重要性。应鼓励表现出强烈叶部症状的品种，因为这些品种可以有效地进行欺诈，从而对疾病产生负面选择并减少其传播。最后，提高植物繁殖率（即从每株植物获得的插条数量）的努力对场地的可持续性具有重大影响，因为这是成功的主要限制因素。
One method of reducing disease in crops is the dissemination of disease‐free planting material from a multiplication site to growers. This study assesses the validity and sustainability of this method for cassava brown streak disease, a threat to cassava crops across East Africa. Using mathematical modelling, the effects of different environmental and control conditions on pathogen spread were determined in a single‐field multiplication site. High disease pressure, through large vector populations and disease in the surrounding area, combined with poor roguing practice, resulted in unsuccessful disease suppression. However, fields may produce sufficiently clean material for replanting if these factors can be overcome. Assessing the sustainability of a low‐pressure system over multiple harvests, well‐managed fields were found to maintain low disease levels, although producing sufficient cuttings may prove challenging. Replanting fields from the previous harvest does not lead to degeneration of planting material, only cutting numbers, and the importation of new clean material is not necessarily required. It is recommended that multiplication sites are only established in areas of low disease pressure and vector population density, and the importance of training in field management is emphasized. Cultivars displaying strong foliar symptoms are to be encouraged, as these allow for effective roguing, resulting in negative selection against the disease and reducing its spread. Finally, efforts to increase plant multiplication rates, the number of cuttings that can be obtained from each plant, have a significant impact on the sustainability of sites, as this represents the primary limiting factor to success.