RESEARCH BULLETIN OF KAOHSIUNG DISTRICT AGRICULTURAL IMPROVEMENT STATION
Volume 6, Number 2 June, 1995

Studies on Host Range of Phytophthora capsici and Its Length of Survival in Soil.

Y. C. Chen1 and W. H. Hsieh2

Abstract

　Phytophthora blight of solanaceous plants caused by Phytophthora capsici is one of the most destructive diseases in Taiwan. It mainly occurred on sweet pepper, hot pepper, tomato and eggplant in Nantow, Yuanlin, Changhwa, Tainan and Pingtung areas during the spring and summer rainy seasons. Thirty-eight isolates of P. capsici were isolated from 15 counties and all isolates belong to A1 mating type. Solanum nigrum is the first to be found as a host plant of P. capsici. The viable P. capsici can be detected 5,7 and 1 month after the natural field soil inoculated with hyphae, zoosporangia and zoospore, respectively. In addition, the organism remained detectable after diseased plant buried in natural field soil for 6 months.

Key words: Phytophthora blight, Solanaceous, Host

1 Assistant Phytopathologist, Kaohsiung District Agricultual Improvement Station, Pingtung , Taiwan 90002, R.O.C.

2 Professor of Dept. of Plant Pathology , Natioal Chung-Hsing
University, Taichung, Taiwan, R.O.C.

表 1. Phytophthora capsici 菌株之特性
Table 1. Characteristics and origin of Phytophthora capsici isolated from
solanaceous diseased plants
───────────────────────────────────────
Characteristics of sporangia
孢 囊 特 性
────────────────────
Isolates Date Location Host Length Broadth L/B Pedicle length
菌 株 採 集 採集地點 寄 主 長 度 寬 度 長寬 孢囊柄長度
日 期 (μm) (μm) 比值 (μm)
───────────────────────────────────────
APC01 79 04 臺中烏日 甜椒莖基 28-61 20-47 1.3 14-103
APC02 80 02 南投竹山 〃 27-66 23-51 1.3 12-148
APC03 80 07 〃 〃 35-70 23-50 1.4 35-140
APC04 80 07 〃 〃 27-66 23-55 1.2 20-156
APC05 80 07 〃 甜椒枝條 31-62 23-51 1.2 39-144
APC06 80 07 〃 甜椒果實 27-62 20-55 1.1 16-125
APC07 80 07 〃 〃 27-66 23-51 1.3 31-148
APC08 80 08 〃 甜椒莖基 31-62 23-51 1.2 39-156
APC09 80 08 〃 〃 23-66 20-47 1.4 31-117
APC10 80 12 屏東里港 〃 31-59 20-43 1.4 16-98
BPC01 79 08 彰化溪湖 辣椒枝條 31-62 20-43 1.5 20-177
BPC02 79 08 〃 辣椒莖基 31-62 20-47 1.3 12-103
BPC03 80 06 臺南七股 〃 35-66 23-55 1.2 20-103
BPC04 80 07 臺中新社 〃 23-70 20-47 1.5 31-156
BPC05 80 07 南投魚池 〃 39-70 23-47 1.5 20-156
BPC06 80 07 嘉義鹿草 辣椒枝條 31-66 20-47 1.4 12-117
BPC07 80 07 〃 辣椒莖基 39-66 27-43 1.6 23-160
BPC08 80 07 〃 〃 23-59 20-39 1.5 8-91
BPC09 80 07 彰化溪湖 辣椒枝條 27-66 23-47 1.4 39-98
BPC10 80 08 臺中新社 辣椒莖基 23-62 20-43 1.5 27-176
CPC01 80 07 南頭埔里 角椒莖基 23-66 20-47 1.4 58-103
CPC02 80 07 〃 〃 35-70 23-51 1.4 27-103
CPC03 80 08 〃 角椒枝條 27-62 20-43 1.5 12-98
CPC04 80 08 〃 角椒果實 23-59 20-39 1.5 23-144
DPC01 80 07 雲林林內 茄子果實 35-70 20-47 1.5 23-82
DPC02 80 08 雲林西螺 〃 26-61 22-49 1.3 8-103
DPC03 80 08 雲林莿桐 〃 22-71 18-44 1.6 14-91
DPC04 80 07 雲林林內 〃 23-62 20-43 1.5 12-94
DPC05 80 08 屏東里港 〃 18-53 18-40 1.3 14-81
DPC06 80 08 屏東屏東 〃 28-69 18-40 1.7 14-97
DPC07 80 08 雲林莿桐 〃 16-63 14-44 1.4 10-83
EPC01 76 07 臺北陽明 甜椒莖基 18-70 16-51 1.4 8-101
EPC02 77 07 臺東關山 〃 20-61 20-53 1.2 14-113
EPC03 79 05 臺南善化 辣椒莖基 18-73 18-57 1.3 12-105
EPC04 79 06 南投信義 甜椒莖基 28-63 24-48 1.3 8-91
EPC05 79 08 臺東關山 〃 30-69 20-51 1.4 20-133
EPC09 79 06 南頭信義 番茄葉片 24-73 20-51 1.4 12-93
EPC0B 80 07 南投竹山 龍葵莖基 18-69 18-44 1.6 20-113
─────────────────────────────────────

表 2. Phytophthora capsici 菌株對不同植物幼苗之病原性
Table 2. Pathogenicity tests of Phytophthora capsici on various
plant seedlings
────────────────────────────────
Plant tested Isolates of P.capsici
───────────────
APC03 BPC03 DPC03 EPC0B
────────────────────────────────
蔓陀蘿
Datura stramoniun L. -a - - -
龍葵
Solanum nigrum L. +b + + +
酸漿
Physalis pubescens L. + - - -
秘魯酸漿
Nicandra physaloides (L.)Gaertn. - - - -
昭和草
Erechthits valerianifolia. - - - -
馬齒莧
Portulaca oleracea. - - - -
紫花霍香薊
Ageratum congzoides L. - - - -
綠藜
Chenopodium murale. - - - -
心葉母草
Vandellia cordifolia - - - -
多花水莧
Ammannia multiflora Roxb. - - - -
────────────────────────────────
a. Stem rot symptom appeared on the tested Plants.
b. No symptom was observed.

表 3. P. capsici 游走孢子囊在土壤中之存活時間
Table 3. Survival of zoosporangia of P. capsici in soil
───────────────────────────
Months after treatmenta NSb SS
───────────────────────────
1 +c +
2 + +
3 + +
4 + +
5 + +
6 + +
7 + +
8 - -
───────────────────────────
a. 100 ml of zoosporangial suspengial suspension of P.
capsici at concentration of 5x104 zoosporangia/ml
were added into 1Kg soil.Isolation of P. capsici was
made by using egg-plant tissue bait once a month
after treatment.
b. NS:Non-sterilized soil.
SS:Sterilized soil (autoclaved at 121℃ for 30min.)
c. +: P. capsici was detected.
-: No P. capsici was detected.

表4 P. capsici 游走孢子在土壤中之存活時間
Table 4. Survival of zoospores of P. capsici in soil
──────────────────────
Months after treatmenta NSb SS
──────────────────────
1 +c +
2 - +
3 - -
4 - -
5 - -
6 - -
7 - -
8 - -
──────────────────────
a. 100 ml of zoospore suspension of P. capsici
at concentration of 5 x 104zoospores/ml were
added into 1Kg soil.Isolation of P. capsici
was made by using egg-plant tissue bait once
a month after treatment.
b. NS:Non-sterilized soil.
SS:Sterilized soil (autoclaved at 121 ℃ for
30min.)
c. + :P. capsici was detected.

表5 P. capsici 菌絲在土壤中之存活時間
Table 5. Survival of hyphae of P. capsici in soil
─────────────────────────
Months after treatmenta NbS SS
─────────────────────────
1 +c +
2 + +
3 + +
4 + +
5 + +
6 - +
7 - +
8 - -
─────────────────────────
a. 20g mycelia of P. capsici were added into 1Kg
soil.Isolation of P. capsici was made by using
egg-plant tissue bait once a month after
treatment.
b. NS:Non-sterilized soil.
SS:Sterilized soil (autoclaved at 121 ℃ for
30min.)
c. + :P. capsici was detected.
- :No P. capsici was detected.

表6 Phytophthora capsici在埋入土壤中之病株殘
體存活
Table 6. Survival of Phytophthora capsici in
residual diseased plant
───────────────────────
Months after treatmenta NSb SS
───────────────────────
1 +c +
2 + +
3 + +
4 + +
5 + +
6 + +
7 - -
8 - -
──────────────────────
a. Diseased plant stems buries in the pot
containing 1Kg soil.Isolation of P. capsici was
made by using egg-plant tissue bait once a
month after treatment.
b. NS:Non-sterilized soil.
SS:Sterilized soil (autoclaved at 121 ℃ for
30min.)
c. + :P. capsici was detected.
- :No P. capsici was detected.