''Phytophthora capsici'' is an

oomycete Oomycota forms a distinct phylogenetic lineage of fungus-like eukaryotic microorganisms, called oomycetes (). They are filamentous and heterotrophic, and can reproduce both sexually and asexually. Sexual reproduction of an oospore is the resul ...

plant pathogen Plant pathology (also phytopathology) is the scientific study of diseases in plants caused by pathogens (infectious organisms) and environmental conditions (physiological factors). Organisms that cause infectious disease include fungi, oomyc ...

that causes blight and fruit rot of

peppers Pepper or peppers may refer to: Food and spice * Piperaceae or the pepper family, a large family of flowering plant ** Black pepper * ''Capsicum'' or pepper, a genus of flowering plants in the nightshade family Solanaceae ** Bell pepper ** Chili ...

and other important

commercial crop A cash crop or profit crop is an agricultural crop which is grown to sell for profit. It is typically purchased by parties separate from a farm. The term is used to differentiate marketed crops from staple crop (or "subsistence crop") in subsisten ...

s. It was first described by L. Leonian at the New Mexico State University Agricultural Experiment Station in Las Cruces in 1922 on a crop of

chili pepper Chili peppers (also chile, chile pepper, chilli pepper, or chilli), from Nahuatl '' chīlli'' (), are varieties of the berry-fruit of plants from the genus ''Capsicum'', which are members of the nightshade family Solanaceae, cultivated for ...

s. In 1967, a study by M. M. Satour and E. E. Butler found 45 species of cultivated plants and weeds susceptible to ''P. capsici '' In Greek, ''Phytophthora capsici'' means "plant destroyer of capsicums". ''P. capsici'' has a wide range of hosts including members of the families

Solanaceae The Solanaceae , or nightshades, are a family of flowering plants that ranges from annual and perennial herbs to vines, lianas, epiphytes, shrubs, and trees, and includes a number of agricultural crops, medicinal plants, spices, weeds, and orn ...

and

Cucurbitaceae The Cucurbitaceae, also called cucurbits or the gourd family, are a plant family consisting of about 965 species in around 95 genera, of which the most important to humans are: *''Cucurbita'' – squash, pumpkin, zucchini, some gourds *''Lagena ...

as well as

Fabaceae The Fabaceae or Leguminosae,International Code of Nomenc ...

Hosts

Under field conditions, ''P. capsici'' has been found to affect a wide range of hosts in the families Cucurbitaceae, Fabaceae, and Solanaceae, including:

cantaloupe The cantaloupe, rockmelon (Australia and New Zealand, although cantaloupe is used in some states of Australia), sweet melon, or spanspek (Southern Africa) is a melon that is a variety of the muskmelon species (''Cucumis melo'') from the fami ...

cucumber Cucumber (''Cucumis sativus'') is a widely-cultivated Vine#Horticultural climbing plants, creeping vine plant in the Cucurbitaceae family that bears usually cylindrical Fruit, fruits, which are used as culinary vegetables.

watermelon Watermelon (''Citrullus lanatus'') is a flowering plant species of the Cucurbitaceae family and the name of its edible fruit. A scrambling and trailing vine-like plant, it is a highly cultivated fruit worldwide, with more than 1,000 varieti ...

bell pepper The bell pepper (also known as paprika, sweet pepper, pepper, or capsicum ) is the fruit of plants in the Grossum Group of the species ''Capsicum annuum''. Cultivars of the plant produce fruits in different colors, including red, yellow, orange ...

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

snap bean Green beans are young, unripe fruits of various cultivars of the common bean (''Phaseolus vulgaris''), although immature or young pods of the runner bean (''Phaseolus coccineus''), yardlong bean ( ''Vigna unguiculata'' subsp. ''sesquipedalis' ...

s, and

lima bean A lima bean (''Phaseolus lunatus''), also commonly known as the butter bean, sieva bean, double bean, Madagascar bean, or wax bean is a legume grown for its edible seeds or beans. Origin and uses ''Phaseolus lunatus'' is found in Meso- and Sou ...

s.Lamour, K.H. and Hausbeck, M.K. vegetable.msue.msu.edu/resources/phytophthora.htm Phytophthora Root, Crown, and Fruit Rot of Vine Crops Although

bean A bean is the seed of several plants in the family Fabaceae, which are used as vegetables for human or animal food. They can be cooked in many different ways, including boiling, frying, and baking, and are used in many traditional dishes th ...

s, lima beans, and

soybean The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses. Traditional unfermented food uses of soybeans include soy milk, from which tofu an ...

s were previously thought to be immune to ''P. capsici'', in 2000 and 2001, "''Phytophthora capsici'' was isolated from five commercial cultivars of lima bean in

Delaware Delaware ( ) is a state in the Mid-Atlantic region of the United States, bordering Maryland to its south and west; Pennsylvania to its north; and New Jersey and the Atlantic Ocean to its east. The state takes its name from the adjacent Del ...

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

, and

New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...

. It was also recently isolated from commercial snap beans in northern

Michigan Michigan () is a state in the Great Lakes region of the upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the 10th-largest state by population, the 11th-largest by area, and the ...

Symptoms

General Symptoms

General symptoms on the solanaceous crops and cucurbits include seed rot and seedling blight which discolors the roots and causes seedlings to topple over. Preemergence and

postemergence Pesticide application refers to the practical way in which pesticides (including herbicides, fungicides, insecticides, or nematode control agents) are delivered to their ''biological targets'' (''e.g.'' pest organism, crop or other plant). Publ ...

damping-off Damping off (or damping-off) is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions. Symptoms There ar ...

are also possible symptoms that may occur.

Bean

Include water-soaked foliage, stem and pod

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

.Gevens, Amanda J., Roberts, Pamela D., McGovern, R.J.. Kucharek, T.A., Revised July 2008 "Vegetable Diseases Caused by Phytophthora Capsici in Florida" Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Available from: http://plantpath.ifas.ufl.edu/takextpub/FactSheets/sp159.pdf

Pepper

Infection of the pepper commonly starts at the soil line leading to symptoms of dark, water soaked areas on the stem. Dark lesions of the stem may girdle the plant resulting in death. Roots of the pepper plant appear brown and mushy. Leaf spots start out small and become water soaked, and as time progresses may enlarge turn tan and crack. Blighting of new leaves may also take place. The fruit of the pepper is infected through the stem giving way to water soaked areas on the fruit that are overgrown by signs of the pathogen which appear as, "white-gray, cottony,

fungal A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

-like growth" (

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

e). The fruit mummifies and stays attached to the stem.

Eggplant

Solanum melongena Eggplant ( US, Canada), aubergine ( UK, Ireland) or brinjal (Indian subcontinent, Singapore, Malaysia, South Africa) is a plant species in the nightshade family Solanaceae. ''Solanum melongena'' is grown worldwide for its edible fruit. Mos ...

'': Fruit rot is the primary symptom of the eggplant. A dark brown area of the fruit expands into a light tan region. Signs of fungal-like growth may be seen on the lesions.

Tomato

Solanum lycopersicum The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

'': ''P. capsici'' can cause crown infections, leaf spot, and foliar blight in tomato. The plant may eventually topple over from the

crown rot A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

. Fruit rot with patterns of concentric rings is another possible symptom.

Squash

Foliar blight with rapidly expanding water soaked regions and fruit rot are common symptoms on susceptible species of summer and winter squash varieties. These lead to dieback of shoot tips, wilting, shoot rot, and plant death. White fungal growth is also a sign of the pathogen in squash.

Watermelon

Foliar symptoms are less common in watermelon than squash, but the leaves are still susceptible. Fruit rot is more common eventually leading to a total decay of the fruit.

Pumpkin

''P. capsici'' causes pre- and post-emergence

damping off Damping off (or damping-off) is a horticultural disease or condition, caused by several different pathogens that kill or weaken seeds or seedlings before or after they germinate. It is most prevalent in wet and cool conditions. Symptoms There ar ...

of seedlings. It also causes vine blight contributing to developing water soaked lesions on the vine which start off as dark olive-colored and soon turn dark brown. This leads to rapid collapse and death of foliage above the lesions. Similar lesions may appear on the leaves and petioles of the pumpkin. Fruit rot is also a very common symptom.

Cantelope

Similar symptoms to that of the watermelon.

Cucumber

Symptoms of the cucumber are similar to that of other cucurbits, but do not include crown gall as a symptom.

Disease cycle

''P. capsici'' is a

heterothallic Heterothallic species have sexes that reside in different individuals. The term is applied particularly to distinguish heterothallic fungi, which require two compatible partners to produce sexual spores, from homothallic ones, which are capable of ...

oomycete. The sexual types are designated as A1 and A2. ''Phytophthora capsici'' produces both a male and a female type

gametangia A gametangium (plural: gametangia) is an organ or cell in which gametes are produced that is found in many multicellular protists, algae, fungi, and the gametophytes of plants. In contrast to gametogenesis in animals, a gametangium is a haploid st ...

called an

antheridium An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also ...

(male) and an

oogonium An oogonium (plural oogonia) is a small diploid cell which, upon maturation, forms a primordial follicle in a female fetus or the female (haploid or diploid) gametangium of certain thallophytes. In the mammalian fetus Oogonia are formed in larg ...

(female). The antheridium is

amphigynous {{Short pages monitor