The role of biological control in managing parasitic weeds
The role of biological control in managing parasitic weeds
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DOI：
10.1016/j.cropro.2005.12.012
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发表时间：
2007-03-01
期刊：
影响因子：
2.8
通讯作者：
Hershenhorn, J.
中科院分区：
文献类型：
--
作者：
Sauerborn, J.;Mueller-Stoever, D.;Hershenhorn, J.
与普通杂草不同，寄生植物通过从寄主中吸取水、矿物质和光合产物来造成健康成本。宿主来源的物质主要通过稻草状侵入宿主的维管组织。理论上，除非宿主被杀死，否则寄生杂草的资源是无限的。农业生态系统中寄主作物的频繁出现为寄生被子植物提供了有利的繁殖条件，使它们成为竞争物种。由于寄生杂草与其寄主具有相似的营养需求，因此寄生植物造成的损害通常与其生物量成正比。农业上重要的属有菟丝属、菟丝子属、列当属和独脚金属，它们攻击谷物、豆类和蔬菜等主要作物。菟丝子属几乎遍布全世界，而重要经济物种阿莱克特拉（Alectra）和独脚金（Striga）的地理分布集中在非洲，但它们也出现在印度和中国的部分地区。在地中海地区、南欧和东欧以及西亚发现了对农作物有害的列当物种。列当和独脚金都可能随着寄主分布、密度和气候变化而传播。与正常杂草相反，对寄主的大部分损害是在寄生杂草出现在土壤之上之前造成的。因此，控制方法应侧重于减少土壤种子库并干扰寄生虫的早期发育阶段。由于寄生杂草与其寄主之间的密切联系，除草剂控制很困难，因为除草剂不能选择性地区分物种。许多生物体（真菌、细菌、节肢动物）的高度特异性，专门以选定的宿主为食，在我们的例子中是寄生杂草，可以被认为是一个优势，因为这些生物体可以作为其他杂草控制方案失败的生物防治剂。 (c) 2006 Elsevier Ltd. 保留所有权利。
In contrast to normal weeds, parasitic plants inflict fitness costs by withdrawing water, minerals, and photosynthates from the host. Host-derived material is mainly transferred through straw-like intrusions into the host's vascular tissue. Theoretically, resources are unlimited for parasitic weeds unless the host is killed. Frequent occurrence of host crops in agro-ecosystems results in favourable reproduction conditions for parasitic angiosperms, which makes them competitive species. Since parasitic weeds have similar nutritional requirements as their hosts, the damage inflicted by a parasitic plant is often directly proportional to its biomass. Agriculturally important genera are Cuscuta, Alectra, Orobanche, and Striga attacking principal crops like cereals, legumes, and vegetables. Cuscuta species occur nearly worldwide, while the geographical distribution of the economically important species of Alectra and Striga is centred in Africa, but they also occur in parts of India and China. Crop damaging Orobanche species are found in the Mediterranean region, in South and East Europe, and West Asia. Both Orobanche and Striga are likely to spread with host distribution, density, and climatic change.Contrary to normal weeds, most of the damage to the host is done before the parasitic weed emerges above the soil. Therefore, control methods should focus on reducing soil seed bank and interfere with the parasite's early developmental stages. Because of the close interconnection between the parasitic weed and its host, herbicidal control is difficult since herbicides cannot selectively distinguish between the species. The high specificity of many organisms (fungi, bacteria, arthropods), feeding exclusively on selected hosts, in our case parasitic weeds, can be considered an advantage because these organisms may work as biocontrol agents where other weed control options have failed. (c) 2006 Elsevier Ltd. All rights reserved.