Epidemiology of Phytophthora capsici on bell pepper
Epidemiology of Phytophthora capsici on bell pepper
复制标题
甜椒辣椒疫霉的流行病学
DOI：
10.1017/s0021859600032391
复制
发表时间：
1983
期刊：
影响因子：
--
通讯作者：
R. Schlub
中科院分区：
文献类型：
--
作者：
R. Schlub
辣椒(Capsicum annuum L.)温室移栽成活率从对照的100%下降到田间土壤的84±6、55±8和18±6%，每克土壤分别含有1个、5个和25个辣椒疫霉繁殖株。在15℃和31℃下用孢子囊悬浮液接种离体叶，需要24小时才能达到50%的侵染率。在27℃下培养4h，有60%的叶片被侵染。当相对湿度为47%或以下，或温度为-12℃或40℃时，孢子囊和菌丝在叶组织中都不能存活一周。当相对湿度从100%降至87%时，接种的茎段(长2 cm)在25℃下贮藏1周，孢子囊的回收率从1455个减少到30个。辣椒疫霉在田间接种后2天不能从接种叶组织中分离到病原菌，但埋藏14天后很容易分离到病原菌。在一块试验田中，病害的分布遵循田间的排水模式。飞溅的雨水和径流似乎是传播的主要方式。症状出现前3、4、5、6天的总降雨量与发病率呈正相关(r=0.53，P<；0.01)。
SUMMARY The number of pepper seedlings (Capsicum annuum L.) surviving transplanting in a glasshouse decreased from 100% in the control to 84 ± 6,55 ± 8, and 18 ± 6% in field soil containing 1, 5 and 25 propagules of Phytophthora capsici Leonian per gram soil, respectively. When detached leaves were inoculated with a sporangial suspension at 15 and 31 °C, an incubation period of 24 h was required before an infection level of 50% was reached. Incubation at 27 °C for 4 h resulted in 60% of the leaves infected. Neither sporangia nor mycelia survived a week in leaf tissue if the relative humidity was 47% or less or if the temperature was -12 or 40 °C. Recovery of sporangia from inoculated stem pieces (2 cm long) stored for 1 week at 25 °C was reduced from 1455 to 30 sporangia per stem piece when the relative humidity was reduced from 100 to 87%. P. capsici could not be isolated from inoculated leaf tissue 2 days after being placed on the soil surface in a field, but was easily isolated after 14 days if buried. The distribution of disease within a test field followed the field's drainage pattern. Splashing rain and run-off water appear to be the main means of spread. Combined rainfall for days 3, 4, 5 and 6 prior to symptom development correlated with disease incidence (r = 0·53, P < 0·01).