Impact of Verticillium longisporum on Yield and Morphology of Winter Oilseed Rape (Brassica napus) in Relation to Systemic Spread in the Plant
Impact of Verticillium longisporum on Yield and Morphology of Winter Oilseed Rape (Brassica napus) in Relation to Systemic Spread in the Plant
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DOI：
10.1111/j.1439-0434.2008.01429.x
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发表时间：
2008-12-01
影响因子：
1.5
通讯作者：
von Tiedemann, A.
中科院分区：
文献类型：
--
作者：
Dunker, S.;Keunecke, H.;von Tiedemann, A.
采用自然侵染和人工土壤侵染的田间试验方法，研究了长孢黄萎病对油菜单株和整块产量的影响。油菜秸秆在4个不同水平上的接种量与病害发生率（DI）和严重程度（DS）相关。2003年土壤和空气平均温度高于2004年，在相同的接种量水平下，DI和DS高于2004年。人工土壤侵染的最大DI和DS水平分别为54.3%和0.57（评分范围为0 ~ 2），不足以引起整块地的显著减产。相比之下，在生长期（GS） 83 ~ 85移出的单株自然侵染植株的产量显著下降。在DS 5级以上（0 ~ 9级），单株产量损失占20% ~ 80%以上。长孢弧菌在田间植株的系统传播被显著延迟，在植株成熟期之前未发生大量定植。然而，真菌在2003年向茎部的系统传播速度更快，这与田间的视觉疾病评估一致。相反，病原菌在温室内的植物（易感品种‘猎鹰’）中系统传播28天后。用分生孢子悬浮液根浸接种比在土壤中添加微菌核更早、更严重。与田间对照，温室内接种植株发育迟缓严重。与中度敏感品种‘Talent’相比，‘Falcon’表现出更高的DS、更大的根长和茎长缩减以及更快的真菌在植株组织中的传播。气候条件似乎对真菌在田间入侵植物的强烈延迟负有责任。这可以防止植株发育迟缓，减轻病害对产量的总体影响。该研究表明，在DI超过60%的地区，长孢弧菌具有显著的产量危害潜力，并且有加速病原菌在植物中全身传播的条件。
The impact of Verticillium longisporum on single plant and whole plot yield of oilseed rape (OSR) was studied in field experiments with natural infection or artificial soil infestation. Disease incidence (DI) and disease severity (DS) correlated with the amount of inoculum provided at four different levels by addition of infested rapeseed straw to the soil. DI and DS were higher in 2003, a year with higher average soil and air temperatures, than in 2004, at similar levels of added inoculum. Maximum DI and DS levels achieved with artificial soil infestation were 54.3% and 0.57 (rating scale from 0 to 2), respectively, which was insufficient to induce significant yield reduction in whole plots. In contrast, a significant decrease in yield was recorded on single naturally infected plants removed from the field at growth stage (GS) 83 to 85. Yield losses of single plants accounted for 20 to more than 80% at DS levels above 5 (scale 0 to 9). The systemic spread of V. longisporum was significantly delayed in plants in the field with substantial colonization of the shoots not occurring before maturity stages. However, fungal systemic spread into the shoots was faster in 2003, consistent with the visual disease assessment in the field. Conversely, the pathogen systemically spread after 28 days in plants (susceptible cultivar 'Falcon') in the greenhouse. Root dip inoculation with conidia suspension induced earlier and more severe disease symptoms than microsclerotia added to the soil. In contrast to the field, intense stunting was recorded on inoculated plants in the greenhouse. The susceptible cultivar, 'Falcon', showed higher DS, stronger reduction in root and shoot lengths and a faster fungal spread in the plant tissue than the moderate susceptible cultivar, 'Talent'. Climatic conditions appear to be responsible for the strong delay in fungal invasion of plants in the field. This may prevent the plants from stunting and mitigate the overall yield effects of the disease. This study indicates a significant yield damage potential of V. longisporum in areas with DI above 60% and conditions accelerating the systemic pathogen spread in the plants.