Root Rots-Dicots

Question 1

Where does Infection Court occur?

Answer 1

Main and lateral roots, a point in which lateral root reachers main root.

• ***Exudates to the roots, nutrients released in the soil
• ** Infection Courts, where root cells expand rapidly

Question 2

What happens during an infection? Root Rot

Answer 2

1. Infection Cushion: fungus in contact with the area of elongation, a layer of mycelium on tissue of root.
2. Infection Peg: Gets in the root system, and a plug of mycelium.
3. Enzymes and Toxins get in, and plant response is SUBERIN and LIGNIN.

Question 3

What is an infection cushion?

Answer 3

Fungus in contact with the area of elongation, the root, and a layer of mycelium on the tissue of the root.

Question 4

What is an infection peg?

Answer 4

Infection gets in to the root system, and a plug of mycelium is formed.

Question 5

Phytophthora spp.

Answer 5

DICOT. Most destructive to trees.

Overwintering as clamydiospores, oospores, sporangia, and infected tissue of woody perennials.

Question 6

Controls for Phytophthora

Answer 6

Well drained soils, plant resistance, fungicides (metalaxyl), raised beds, gypsum to improve macrospores int he soil.

Question 7

Armillaria Butt Rot

Answer 7

Attacks crowns of treets, ex… honey mushroom (basidiocarp).
RHIZOMORPH-Produces a thick band of mycelium transports nutrients from a plant to attack another tree.

Question 8

Rhizomorph

Answer 8

Has exploratory hyphae, and a thick band of mycelium transports nutrients from a plant to attack another tree.

Question 9

Armillaria Control

Answer 9

Remove stumps, delay replanting (5 years)

HUMUNGUS FUNGUS

Question 10

Rhizoctonia/Armillaria

Answer 10

Anastamosis groups (AG)
Vegetative Compatibility groups (VCG)

Question 11

Rhizoctonia solani- multinucleate

Answer 11

Multikaryotic, diff. anastamosis groups.