biology

Plasmopara obducens

Plasmopara obducens is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Plasmopara obducens rather than just read about it. In short: Plasmopara obducens is a species of oomycete that causes Impatiens downy mildew. It was first described on Impatiens noli-tangere in Germany in 1877.

Key takeaways

Plasmopara obducens belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Plasmopara obducens to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Plasmopara obducens from memory before moving on to harder problems.

Reference excerpt

Plasmopara obducens is a species of oomycete that causes Impatiens downy mildew. It was first described on Impatiens noli-tangere in Germany in 1877. Plasmopara obducens is known from native species of Impatiens since the 1800s, but outbreaks on cultivated varieties of Impatiens walleriana started in 2003 in the United Kingdom and in 2004 in the United States. The outbreak spread worldwide by 2016.

Morphology Sporangiophores are an average of 373 (260-484) micrometers with the first branch appearing at 197 (120-271) micrometers. Sporangia are 16 (13-18) micrometers by 13 (11-16) micrometers. Resting spores are globose with a diameter of 28 micrometers

Disease symptoms Initially, leaves are stippled or yellowed. Infected leaves curl downward. A white down is often present on the underside of the leaves; buds and stems may also develop a down. Eventually, the leaves fall off the plant leaving just stems. In about a week, the plants are dead.

Taxonomy J. Schröter originally placed the species in the genus Peronospora but later moved it to the genus Plasmopara. Some authors believe the outbreaks on I. walleriana and I. balsamina are not caused by P. obducens but two new species P. destructor and P. velutina.

References

External links Disease threatens garden impatiens; Surprising scientists and horticulturalists, once-mild downy mildew disease has struck the popular blooms in 33 states March 20, 2013 Vol.183 #8 Science News

Worked examples

Example 1 — a first encounter with Plasmopara obducens

Start with the simplest possible case. Write down what Plasmopara obducens claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Plasmopara obducens before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Plasmopara obducens ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Plasmopara obducens

In research: Plasmopara obducens appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Plasmopara obducens in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Plasmopara obducens is common in secondary-school and first-year university syllabi. It links to neighbouring topics Oomycete plant pathogens and diseases, Oomycete species, Oomycete stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Plasmopara obducens outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Plasmopara obducens in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Plasmopara obducens means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Plasmopara obducens out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Plasmopara obducens in simple terms?

Plasmopara obducens is a species of oomycete that causes Impatiens downy mildew. It was first described on Impatiens noli-tangere in Germany in 1877.

Why does Plasmopara obducens matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Plasmopara obducens?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Plasmopara obducens.