Lecture 4

Question 1

Crown of a tiller does not elongate. T or F?

Answer 1

True

Question 2

Under stress….which tillers die first?

Answer 2

Youngest

Question 3

What does the Root Cap do?

Answer 3

protects root meristem from abrasive effects of soil particles as growth proceeds through the soil.

Question 4

upward movement of substances (from root to base of plant) -xylem

Answer 4

Basipetal transport

Question 5

downward movement of photoassimilates from leaves to roots (from base of plant to roots) - phloem

Answer 5

Acropetal transport

Question 6

What do Root Hairs do?

Answer 6

increase surface area of roots to absorb water and nutrients

Question 7

The amount of shoot growth is directly related to the amount of _______ ?

Answer 7

Root Growth

Question 8

Root growth is dependent of what?

Answer 8

the Photosynthetic capability of the plant

Question 9

What is the Inflorescence?

Answer 9

The flowering portion of the grass shoot that includes the spikelets and the supporting axis or branch system.

Question 10

What is the stem called that bears the inflorescence?

Answer 10

Flowering Culm

Question 11

Formation of the grass inflorescence occurs in 4 distinct stages. What are they? 1 - 4….

Answer 11

1. Maturation of the plant
2. Induction of the flowering stimulus
3. Initiation of the stem apex
4. Development of the flowers

Question 12

in the second stage of grass inflorescence…Induction of the Flowering stimulus. What major change is going on in the plant? What causes that change?

Answer 12

apical meristem changes from vegetative to reproductive.

1. Vernalization - plant is exposed to cold temperatures
2. Photoperiod Induction - “length of day”

Question 13

Cool season grasses have a Vernalization requirement as the First prerequisite for flowering. What is the most effective temperature range?

Answer 13

32 - 50 degrees F.

Question 14

Vernalization Requirements for Perennial Ryegrass:

Answer 14

• –Low Requirement—
• Short period, a few weeks with Temperature 45 - 50 degrees
• Only need ONE vernalized tiller for WHOLE plant to flower

Question 15

Vernalization Requirements for Creeping Bentgrass:

Answer 15

—High Requirement—
-Longer period or 2 - 3 weeks with temperatures at 40 degrees.
Only the tillers that are vernalized will flower

Question 16

Where does the Photoperiod induction take place?

Answer 16

In the leaves

Question 17

In the Third stage of grass inflorescence production, Initiation of the Stem Apex…..What is the major change that is going on?

Answer 17

Transformation of the stem apex from a vegetative to a flowering axis.

Question 18

Define: Lodicules

Answer 18

function to open the grass flower for pollination

Question 19

the Male reproductive structure of the flower is called what? How many are there? and what do they consist of?

Answer 19

It’s called a Stamen and there are three on each flower They have pollen bearing anthers and their filaments. (see diagram in notes)

Question 20

What is the Female reproductive structure of the flower called? what does it consist of?

Answer 20

The female portion is called Pistil and it consists of a single ovary and usually two feathery stigmas and styles.

Question 21

During egg pertilization…describe that the 2 different sperm do…

Answer 21

one fertilizes the the egg (embryo) and one fertilizes the polar nuclei (endosperm)