Lecture 2 - Setting Objectives

Question 1

why do plant breeders set objectives

Answer 1

to have a direction/a purpose and to serve the industry demands and needs

Question 2

3 basic objectives to most plant breeding programs

Answer 2

1. yield
2. quality
3. pest/disease resistance

Question 3

what is yield heavily influenced by

Answer 3

the environment

Question 4

2 kinds of yield

Answer 4

total plant biomass and economic yield

Question 5

2 kinds of economic yield

Answer 5

grain and biomass

Question 6

what is economic yield

Answer 6

physical features of the plant (i.e. flowers) or extracted/functional compounds

Question 7

what are some examples of a yield penalty

Answer 7

if a crop takes too long to mature, it does not mature if it is high-yielding (won’t be able to harvest)
died due to drought

Question 8

examples of quality in yield

Answer 8

human acceptance
chemical composition
mechanical quality
feed/forage value

Question 9

what are some other objectives of plant breeding

Answer 9

-plant architecture (mechanical harvest and lodging tolerance)
-stability over environment
-herbicide tolerance
-tolerance to abiotic stressors

Question 10

selection can only be effective if….

Answer 10

there is variation in the population and that variation is genetic (heritable) not environmental

Question 11

phenotypic variation

Answer 11

differences in the population that you can see and evaluate

Question 12

environmental variation

Answer 12

variations in characteristics due to responses by the plant to its environment and not due to its genetic make-up

Question 13

genetic (heritable) variation

Answer 13

can be manipulated by the plant breeder in order to produce a superior cultivar

Question 14

how can breeders manipulate genetics to produce a superior cultivar

Answer 14

by crossing to generate genetic recombination that puts new allele combinations together

Question 15

number of allele combinations in a pair of genes (AaxAa)

Answer 15

4

Question 16

number of allele combinations in 2 pair of genes (AaBbxAaBb)

Answer 16

16

Question 17

number of allele combinations in 3 pairs of genes (AaBbCcxAaBbCc)

Answer 17

64

Question 18

number of allele combinations in 4 pairs of genes (AaBbCcDdxAaBbCcDd)

Answer 18

256

Question 19

number of allele combinations in 5 pairs of genes (AaBbCcDdEexAaBbCcDdEe)

Answer 19

1024

Question 20

Fill in the blanks in the chart

Answer 20

n 3n 2n 4n