Harmful Microorganism
Chapter Name : Microorganisms: Friend And Foe |
Sub Topic Code : 103_08_02_02_03 |
Topic Name : Harmful Microorganism |
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Sub Topic Name : Disease -Causing Microorganism In Plants |
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Introduction
Plant pathology = Plant diseases caused by pathogens and environmental conditions.
Pre-Requisites:
Pathogens = Fungi, Bacteria, Virus, Viroids, Nematodes, Protozoa, Parasitic plants.
Activity:
Plants near you house showing symptoms mentioned above, Fruits and vegetables are washed before cooking them to make sure pathogens are washed out.
Real Life Question:
How does white patches appear on leaves and how does pollution cause diseases in plants?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Bacteria | Most bacteria that are associated with plants are actually saprotrophic. Most plant pathogenic bacteria are rod-shaped (bacilli) |
| Pathogens | Fungi such as Ascomycetes and the Basidiomycetes. Fusarium spp. (causal agents of Fusarium wilt disease) Thielaviopsis spp. (causal agents of: canker rot, black root rot) Phakospora pachyrhizi (causal agent of soybean rust) Puccinia spp. (causal agents of severe rusts of virtually all cereal grains and cultivated grasses) |
| Virus and viroids | There are many types of plant virus, and some are even asymptomatic. Under normal circumstances, plant viruses cause only a loss of crop yield.Most plant viruses have small, single-stranded RNA genomes.Plant viruses must be transmitted from plant to plant by a vector. |
| Nematodes | Nematodes are small, multicellular wormlike creatures. Many live freely in the soil, but there are some species that parasitize plant roots. They are a problem in tropical and subtropical regions of the world, where they may infect crops. |
| Protozoa | There are a few examples of plant diseases caused by protozoa. They are transmitted as zoospores that are very durable, and may be able to survive in a resting state in the soil for many years. They have also been shown to transmit plant viruses. |
| Parasitic plants | Parasitic plants such as mistletoe and dodder. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| White patches and yellowing of leaves and spots on fruits | These indicate the plant has been infected by pathogens. |
Places to visit :
Gardens, Parks, Farms, trees and shrubs grown near your house
Practical examples around us
| Examples | Explainations |
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What you learn in Theory:
Different pathogens affecting plants.
What you learn in Practice:
Symptoms caused by pathogens can be observed and identified on leaves, fruits and vegetables.