Velocity of spread of wheat stripe rust epidemics.
Velocity of spread of wheat stripe rust epidemics.
复制标题
小麦条锈病流行的传播速度。
DOI：
10.1094/phyto-95-0972
复制
发表时间：
2005
期刊：
影响因子：
3.2
通讯作者：
C. Mundt
中科院分区：
文献类型：
--
作者：
C. Cowger;Larae D Wallace;C. Mundt
植物病害流行是以恒定速度传播还是以递增速度传播，一直存在争议。我们在马德拉斯和俄勒冈州的赫米斯顿进行了大规模的小麦条锈病田间试验，以测试这些相互竞争的模型。三个地点-年的数据可供分析。将感病小麦品种与抗条锈小麦品种按1：4或1：1比例混栽于纯林中。地块宽6.1米，长度从73米到171米不等。在每个地块的中心（2001年）或中心（2002年和2003年）的上风处接种1.5 × 1.5 m的病灶。在整个流行期间，每周在每个地块的相同点上，沿着从焦点的上风向和下风向的样带沿着评估疾病严重程度。根据严重度数据计算扩散速度，并分别根据时间和距病灶的距离进行回归。在所有的位置年和治疗，并在所有级别的疾病严重程度，速度始终线性增加的距离，在0.59米/周每米的平均速率，并与时间呈指数关系。此外，在所有流行病中，表观感染率r与空间和时间上的速度增加率之间存在显著的正相关关系。这些研究结果具有重要意义的植物疾病的焦点或部分焦点的字符，特别是在不同的空间尺度ratedreducing疾病管理策略的有效性。
ABSTRACT Controversy has long existed over whether plant disease epidemics spread with constant or with increasing velocity. We conducted largescale field experiments with wheat stripe rust at Madras and Hermiston, Oregon, where natural stripe rust epidemics were rare, to test these competing models. Data from three location-years were available for analysis. A susceptible winter wheat cultivar was planted in pure stand and also in a 1:4 or 1:1 mixture with a cultivar immune to the stripe rust race utilized in the experiments. Plots were 6.1 m wide and varied from 73 to 171 m in length. A 1.5 by 1.5-m focus was inoculated in either the center (2001) or upwind of the center (2002 and 2003) of each plot. Disease severity was evaluated weekly throughout the epidemics in each plot at the same points along a transect running upwind and downwind from the focus. Velocity of spread was calculated from the severity data and regressed separately on time and on distance from the focus. In all location-years and treatments, and at all levels of disease severity, velocity consistently increased linearly with distance, at an average rate of 0.59 m/week per m, and exponentially with time. Further, across epidemics there was a significant positive relationship between the apparent infection rate, r, and the rate of velocity increase in both space and time. These findings have important implications for plant diseases with a focal or partially focal character, and in particular for the effectiveness of ratereducing disease management strategies at different spatial scales.