Lectures 1-4

Question 1

Three cereals that provide over 50% of our calories

Answer 1

wheat, rice and maize

Question 2

Give examples of cereal grains

Answer 2

wheat, rice, maize, barley, sorghum, millet

Question 3

Give examples of Root crops

Answer 3

potato, sweet potato, yam, cassava

Question 4

Give examples of Pulse crops

Answer 4

bean, pea, chickpea, cowpea, lentil, mung

Question 5

Give examples of Sugar crops

Answer 5

sugarcane, sugar beet

Question 6

Give examples of Fruit crops

Answer 6

banana, plantain, citrus, apple, berries

Question 7

Give examples of Vegetables

Answer 7

tomato, cabbage, onion, carrot, cucumber

Question 8

2014 World Production by Crop Type Ranking

Answer 8

1. Cereals
2. Vegetables
3. Roots
4. Fruits
5. Oilcrops
6. Citrus
7. Pulse Crops
8. Fibre Crops

Question 9

Where do most of the prairie crops originate? Why would they be grown here?

Answer 9

Fertile crescent. Dryland adaptation? Similar geography? Cultural and culinary characteristics of the European settlers.

Question 10

Why do acreages of different crops differ in the different provinces?

Answer 10

Available land, summer fallow; adaptability of crop; climate, geography; frost free units (days to maturity); heat units (length of growing season); soil type, irrigation; land use competition, value of crop.

Question 11

Why do yields vary in the different provinces?

Answer 11

All relate to moisture availability, soil type, irrigation; land use competition, varieties (winter vs. spring). In general yields also vary because of the value of the crop.

Question 12

Yields are in bushels - What do they mean?

Answer 12

Density of grain (Hulless vs. Hulled); Seed size, shape (packing); Indication of quality.

Question 13

What is a bushel weight?

Answer 13

A bushel weight is a set size/volume.

Question 14

What is the fertile crescent?

Answer 14

A region in the middle east where agriculture was first settled and people begun to domesticate crops.

Question 15

Define the plant domestication process and given examples.

Answer 15

The act of bringing wild species into cultivation and selecting for desirable traits.

1. Select against shattering
2. Select against husks (hulls)
3. Select against lodging (strong straw)
4. Select against dormancy
5. Select for size (yield), taste & use

Question 16

Name the Precursor of maize, how it was known, and when it happened.

Answer 16

Teosinte 5,000 years ago: “Food of the Gods” or “Food of Humanity”

Question 17

Which technology gave rise to plant domestication?

Answer 17

Genetic mutation.

Question 18

What are the main differences between Harlan’s and Vavilov’s theories of the origins of crop species?

Answer 18

Vavilov identified eight primary areas of diversity and origin of cultivated plants: Mexico / Central America;
South America; Mediterranean; Middle East; Ethiopia;
Central Asia; India / Indochina; and China. Whereas Harlan amended Vavilov’s work and theorized three regions in which domestication of plants originated, and that for each, there is a definable center of origin and a more disperse non-centre, each of which interacts with the other. He preferred the term “centre of diversity” over “centre of origin”

Question 19

Define Chromosome

Answer 19

Highly organized bodies carrying genes in the nucleus of the cell

Question 20

Define Genome

Answer 20

One set of chromosomes

Question 21

Define Polyploidy

Answer 21

Extra sets of chromosomes may be found in plants (> 1 genome)

Question 22

Define Level of ploidy

Answer 22

Greatly increases the amount of genetic variability

Question 23

Describe the two aspects of Vavilov’s Law of Homologous Series.

Answer 23

Variation found in one plant will also be found in plants of other species and genera, and Definite cycles of variability occur among whole families and common traits develop

Question 24

Draw the Polyploidy scheme.

Answer 24

Embryo	Gamete
Haploid (x)		  2n		  n
Diploid (2x)	     	  2n		  n
Tetraploid (4x)	  2n		  n
Hexaploid (6x)	  2n		  n	
Octoploid (8x)	  2n		  n

Question 25

What is the genetic difference between common wheat and durum wheat?

Answer 25

Triticum aestivum (common wheat) is a hexaploid (6x), and consists of three sub-genomes (A, B, and D) Triticum durum (durum wheat) is a tetraploid (4x), and consists of only the A and B genomes

Question 26

Theory of wheat evolution.

Answer 26

A genome: T. urartu B genome: Related to Ae. speltoides D genome: Ae. Tauschii

Question 27

Evolution of oats (Avena sativa L.)

Answer 27

``` Diploids - Evolution 2N = 14 to Tetraploids - Evolution 2N = 28 to Hexaploids - Evolution 2N = 42 ```

Question 28

Diploid Oats (2N = 14)

Answer 28

Little commercial value, all wild species Avena brevis – “Short oat” Wild in SW Europe Avena wiestil – “Desert oat” Wild in Africa, Egypt, Ethiopia Avena strigosa – “Sand oat” Wild around the Mediterranean Avena nudibrevis - Small seeded, naked China

Question 29

Tetraploid Oats (2N = 28)

Answer 29

Little Commercial value Avena barbata – ”Slender oat” Wild in Mediterranean major range forage in California Avena abyssinica – “Abyssinian oat” Cultivated in Ethiopia

Question 30

Hexaploid Oats (2N = 42)

Answer 30

Important species for cultivation Avena nuda - Naked oat China Avena sterilis - Wild red oat Algeria, N. Africa Avena fatua - Common wild oat Avena sativa - Common white oat spp. diffusa (tree oat) spp. orientalis (slide oat) Avena byzantina - Cultivated red oat Warm climate oat Parent in many Canadian A. sativa species

Question 31

Major difference between covered oat and naked oat.

Answer 31

Covered oat has a thick hull, whereas naked oat has a thin hull.

Question 32

Triticale – Origin and Breeding

Answer 32

Triticale (X Triticosecale Wittmack) Wheat X Rye hybrid First found growing in Scotland in 1875 Potential for new, useful crop for humans 1890 - Partially fertile octoploid triticale was discovered - Spontaneous doubling of chromosomes - Colchicine discovered in 1937 - Facilitated the development of triticale - Octoploids had poor performance and only partial fertility

Question 33

Hexaploid Triticale.

Answer 33

2n = 42 = AABBRR Developed from a cross between tetraploid durum wheat (2n=4x=28) and rye Found to be superior to octoploids Focus shifted to development of hexaploid triticale

Question 34

Genetics of Triticale.

Answer 34

1. Hexaploid wheat x Rye ABD (2n = 42) R ( 2n = 14) Triticosecale octoploid ABDR (2n = 56) 2. Tetraploid wheat x Rye AB (2n = 28) R ( 2n = 14) Triticosecale hexaploid ** ABR (2n = 42)

Question 35

When does the growth stage of plants start?

Answer 35

Starts at germination.

Question 36

What are gibberelins?

Answer 36

Plant hormones and act as Growth regulators. Gibberellins have a number of effects on plant development, including: 1) stimulate rapid stem growth (stimulates cell division and elongation) 2) induce mitotic division in the leaves of some plants 3) increase seed germination rate (breaks dormancy)

Question 37

Explain the two types of germination and give an example of each.

Answer 37

Epigeal: food reserves pushed above soil surface e.g. canola, bean. Hypogeal: food reserves remain below the soil surface e.g. cereals, peas.

Question 38

Requirement for Fertility, weed, disease, insect, and lodging management decisions.

Answer 38

It requires agronomic planning based on the stage of plant growth, rather than calendar dates.

Question 39

Explain the process of cereal germination as discussed in lecture.

Answer 39

1. Imbibition: water fills the seed and embryo produces gibberelin. 2. The water activates secretion of hydrolic and proteolic enzymes from the aleurona layer. 3. Mobilization of starch and protein in the endosperm, and growth of the embryo.

Question 40

What are Seminal roots, Adventitious roots, and Coleoptile?

Answer 40

Seminal roots: First roots out of the radicle Adventitious roots: Form from the seminal Coleoptile: First structure to reach the surface

Question 41

Discuss the different types of meristems and their significance.

Answer 41

Cells in the meristem can develop into all the other tissues and organs that occur in plants. Differentiated plant cells generally cannot divide or produce cells of a different type. ... There are three types of meristematic tissues: apical (at the tips), intercalary (in the middle), and lateral (at the sides).

Question 42

Longitudinal Section of Base at 3-leaf stage.

Answer 42

Tissue differentiates to become different leaves.

Question 43

Types of meristems

Answer 43

``` Apical meristems Elongation Leaves, nodes internodes Roots Inflorescence Intercalary meristems Elongation ```

Question 44

Describe the beginning of Tillering and how it relates to the development of other plant parts.

Answer 44

- Begins at 3-leaf stage - Sequential - Coleoptilar tillers - Prophyll - Direct relationship between tiller development and - crown root development - More roots means more tillers - Phyllocrons

Question 45

Describe the Single ridge stage.

Answer 45

Primordia give rise to axillary buds, the lower half of each future spikelet. Starts floret formation.

Question 46

Describe the Double the ridge stage.

Answer 46

2nd series of primoria; maximum number of spikelets is fixed.

Question 47

Describe the Terminal spikelet formation.

Answer 47

No further florets can be initiated; maximum kernel potential; occurs by late jointing.

Question 48

Stem Extension features.

Answer 48

- Pseudostem to true stem - Begins once head formation is complete (5-6 leaf stage) - Elevates developing head above ground - Triggered by accumulated temperature and increase in day length

Question 49

Describe the Boot stage characteristics.

Answer 49

- Leaf sheath swells - Continues until emergence of flag leaf - Flowering may take place inside or outside the boot

Question 50

Boot Stage Cleistogamy.

Answer 50

- Flowering occurs before emergence - Act of pollination in the boot E.g. Barley

Question 51

Boot Stage Protandry.

Answer 51

“Maturing the anthers before the stigma” Male parts develop before the female parts Ensures quick pollination E.g. Rye

Question 52

Describe the Types of Flowering and give examples.

Answer 52

Open flowering: occurs shortly after head emergence (e.g. wheat) Closed flowering: occurs prior to head emergence (e.g. spring barley)

Question 53

What can Trigger flowering?

Answer 53

- Vernalization: a) reproductive response to cold temperatures b) switch from vegetative to reproductive phase c) examples winter annuals, winter seeded cereals - Photoperiod: a) reproductive response to day length b) long-day (short-night) c) short-day (long-night)

Question 54

Reproductive Structures

Answer 54

Two floret bracts= outer lemma + inner palea

Question 55

What is Anthesis?

Answer 55

A developmental stage in flowering: - Transition between heading and grain fill - Occurs shortly after heading - Lasts 3 to 5 days - Anthers with pollen are extruding from floret - Depends on open or closed flowering

Question 56

Define: Polination, Cross-polination, and self-polination

Answer 56

Pollination is the transfer of pollens from anthers (stamens) to stigma of the flower. Self pollinated: Transfer of pollen within same flower Transfer of pollen from one flower to another on the same plant Anthers are extruded after pollination Cross pollinated: Transfer of pollen from one individual to another Anthers are extruded before pollination

Question 57

How does grain fill begin, what are its phases and how does it end?

Answer 57

Begins with fertilization Three phases Lag phase Constant rate phase Maximum weight phase Ends with physiological maturity

Question 58

Plant Structure: Kernel

Answer 58

Endosperm + embryo

Question 59

Physiological Maturity:

Answer 59

No further accumulation of dry weight Black layer stage in corn Now waiting for loss of seed moisture for harvest Varies among crops (25-40%)

Question 60

4 facets of phasic development.

Answer 60

1. All the growth and development responses of a plant are influenced by the environment. 2. There are minimum, optimum, and maximum temperatures for different processes in the plant, and these temperature limits may be (and usually are) different for each of the stages of the life cycle. 3. Temperature is one of many environmental factors influencing plant growth. 4. The relationship between the plant and its environment is very complex.

Question 61

Elaborate on the Barrel Theory:

Answer 61

Justus Von Liebig Law of the Minimum. The nutrient with minimum rates will limit the developmennt of the plant to the rate to which that nutrient is at.

Question 62

What determines grain potential and what are its limitations?

Answer 62

Determined by initiation of spike formation (DR) Influenced by: variety, management, stress, environment, partitioning. Limited by: a) Capacity of source (leaves) b) Capacity of sink (grain)

Question 63

Partitioning: Contributions to wheat grain yield from plant parts.

Answer 63

Plant parts closest to ear, contribute most to the ear’s development ``` Percent Ear 30 Flag leaf 30 Flag sheath 15 Flag internode 15 Remainder of plant 10 ```

Question 64

Source (leaves) capacity:

Answer 64

Anything that impacts upon photosynthesis - Management - Crop canopy - Water availability - Inputs (fertility) - Competition (weeds, etc.)

Question 65

Sink (grain) capacity:

Answer 65

1. No. heads / unit area 2. No. grains / head 3. Kernel weight ``` And depends on: Tillering pattern Primordia production (rate and duration) Genetic limits to each of the above Environmental effects on each ```

Question 66

What are the yield components?

Answer 66

Yield is the product of sink(grain) capacity and the availability of assimilate (source) to fill these sinks. Yield / unit area = (heads/area) x (kernels/head) x (wt/kernel) Yield = X x Y x Z

Question 67

Average yield of wheat.

Answer 67

Average yield of wheat - 35 - 37 bu/acre Parkland area - 75 - 100 bu/acre Model predicted yield potential - 337.5 bu/acre Guinness World Records: - 2003 wheat yield of 223 bu/ac Surpassed in 2010 by 232.64 bu/ac  Both in New Zealand

Question 68

Principles for agronomic management.

Answer 68

If you know the main constraint to yield at your site, the site or crop may be managed to reduce the constraint. Agronomic management= 1. seeding dates 2. rates of seeding 3. planting depth 4. row spacing 5. fertility management 6. choice of crop species 7. choice of species variety 8. soil management