Olericulture Hort 320 Lesson 3, Domestication, Classification

Olericulture – Hort 320

Lesson 3, Domestication, Classification

Jeremy S. Cowan WSU Spokane County Extension

222 N. Havana St.

Spokane, WA 99202

Phone: 509-477-2145 Fax: 509-477-2087

Email: jeremy.cowan@wsu.edu

Origin, Evolution

• Nikolai Ivanovich Vavilov

Most of the varietal wealth in our crop plants was

concentrated in eight great centers of diversity:

China, Hindustan, Central Asia, Asia Minor, the

Mediterranean region, Abyssinia, Central

America, west-central S. America

Fig. 2.1 Centers of Origin

Origin, Evolution

• Nikolai Ivanovich Vavilov

Centers of origin of species coincide with the areas

where the greatest diversity exists in the species.

Video time:

http://www.youtube.com/watch?v=WQz5lb72XbE

Origin, Evolution

• Nikolai Ivanovich Vavilov

Secondary centers of origin (centers of diversity) may

be found far removed from the primary center of origin.

These may be associated with domestication

and human movement

Centers of Origin

Determination of centers:

1. Botanical evidence

2. Archeological evidence

3. Historical evidence

4. Linguistic evidence

(Items 2-4 most likely to determine center of domestication (secondary centers of origin)

Centers of Origin

Features:

Geographical location of species

origin

Site of maximum adaptation

Site of maximum diversity

Presence of related species

Usually associated with site of

domestication

Centers of Origin

Centers of Origin

Vavilov’s Centers of Diversity (origin)

lettuce, turnip

cucumber

cantaloupe

cabbage

watermelon

manioc

potato

pumpkin, tomato

corn, bean

carrot celery lettuce

onion

pepper

beet

sweet potato

okra eggplant

Centers of Origin

Centers of Origin – Major Crops

Lettuce – Europe and Asia

Cabbage – Europe

Beet – Europe

Carrot – Europe and Asia

Onion – Asia

Potato – South America

Sweet Potato – South America

Bean – South America

Centers of Origin – Major Crops

Pea – Europe and Asia

Tomato – Central America

Pepper – Central and South

America

Cucumber – Asia and Africa

Cantaloupe – Asia

Watermelon – Africa

Squash – Central and North

America

Sweet Corn – Mexico

Edible species

20,000

Species used

for food

3,000

Species cultivated

200

Major crop

species - 25

Crop Species Domestication

Began 8-10,000 years ago

Process

Foraging and unintentional selection

Early cultivation

Domestication

Intensified and large scale production

Foraging

Impact of foraging and plant management

Selection of best food types – seed distribution

Selection of best adapted types in habitat region

Unintentional altering of habitat to promote growth of certain plants (i.e. burning)

Early Cultivation

Began as man approached food production

systematically

Started as unintentional habitat alteration to favor desired

species

Led to more intense cultivation; form depended on

geographical constraints

Early Cultivation

Vegetatively propagated plants:

Re-growth from remnants

No dormancy

Discarded propagules in refuse piles

Favored in tropical regions:

Early Cultivation

Seed propagated plants:

Collected seeds may fall, germinate

(after rain) around settlements

Eventually seed were actively stored

and systematically planted

Favored in mountainous or temperate regions:

Early Cultivation

Impact of early cultivation on crop

species

Deliberate care of preferred plants

Preferential survival of edible crop

plants

Distribution to new areas of habitat

Increased population of humans and

thus populations of crop species

Domestication

Domestication

Domestication

Video Time:

https://www.youtube.com/watch?v=6odEvT-YHxE

Domestication

Characteristics of wild species:

Edible parts small, fibrous, bitter

Numerous seeds, rapidly dispersed

Poor or non-uniform seed emergence

Often contain toxic compounds

Domestication

Changes in maize

Domestication

North American marsh elder

Domestication

Changes in plants as a result of selection:

Gigantism

- often a result of changes in PLOIDY

Where PLOIDY reflects the number of chromosomes in a

SOMATIC cell (somatic versus gametic)

Domestication

Terms of Ploidy:

Monoploid – has only a single

complement of a basic chromosome set

of the species

also referred to as the haploid state (gamete cells)

Domestication

Terms of Ploidy:

Diploid – has two complete sets of the basic

chromosome number of the species

Terms of Ploidy:

Diploid – has two complete sets of the basic chromosome number of the species

Triploid

Tetrapoid

Pentaploid

Hexaploid

Domestication

Examples of Ploidy:

Diploid – corn, onion, lettuce, tomato

Triploid – taro, watermelon (seedless)

Tetraploid – cassava, potato,

Pentaploid – sweet potato, potato

Hexaploid – yams, sweet potato

Domestication

Domestication

Changes in seed as a result of selection:

Size

Uniformity of germination

# of seeds per plant

Shattering

Dormancy

Hardness of seed coat

Domestication

Other morphological and physiological changes

resulting from selection:

Loss of survival traits

Loss of photoperiod response (potato)

Emergence of mutant types (brassica)

Absence of toxic substances (tomato)

Domestication – Bean Example

Trait Wild Domesticated

Seed dispersal Present Absent

Pod wall fibers Present Absent

Seed dormancy 70% germination 90% germination

Growth habit Indeterminate Determinate

Number of pods 43.2 7.5

Pod length 5.7 cm 9.3 cm

Seed weight (100) 3.5 g 19.5 g

Days to flower 69 46

Harvest index 0.42 0.62

Flower delay (16 hr) >60 days 0 days

Domestication – Squash

Example of selected diversity in squash

Domestication – Tomato

Example of selected diversity in tomato

Domestication – Cowpea

Example of selected diversity in cowpea

Domestication

Impact of Domestication on crop species

Selection of useful traits within crop species

Elimination of survival traits resulting in dependence on

human culture

Wider distribution and adaptation

Cultivation

Defined as controlled crop production:

Includes:

Tillage

Planting and transplanting

Weed and pest control

Harvest and sometimes storage

Bolivian crop terraces

Result of intensified cultivation

Selection for traits resulting in economic benefit to the producer – directed breeding

Ease of management

Storability

Transportability

Market specific quality traits

Cultivation

Age-old question:

“Why can’t I buy a good tomato any more?”

Is the complaint valid that produce has lost quality as we concentrate on economic production factors?

Cultivation

Cultivation

Classification

Process of lumping numerous crop

species into useful categories

Classification

Classified by:

Adaptation and hardiness

Classification

Classified by environmental adaptation:

Warm-season (very tender)

Cucumber Eggplant

Lima bean Muskmelon

Okra Pepper

Pumpkin Squash

Sweet potato Watermelon

Classification

Classified by environmental adaptation:

Warm-season (tender)

Cowpea

Sweet corn

Tomato

Snap bean

Soy bean

Classification

Classified by environmental adaptation:

Cool-season (semi-hardy)

Beet Carrot

Cauliflower Celery

Swiss chard Lettuce

Parsnip Potato

Classification

Classified by environmental adaptation:

Cool-season (hardy)

Cabbage Broccoli

Brussels sprouts Cauliflower

Onions Leeks

Pea Radish

Garlic Asparagus

Classification

Classified by:

Adaptation and hardiness

Life Cycle

Classified by life cycle:

Annual

Cucumber, tomato, spinach, sweet corn

Biennial

Beet, broccoli, carrot, onion, parsley

Perennial

Asparagus, rhubarb, sweet potato

Classification

Classification

Classified by:

Adaptation and hardiness

Life Cycle

Parts used for food

Classified by edible portion:

Root – beet, carrot, turnip

Bulb – leek, onion, garlic

Stem – asparagus, kohlrabi

Flower – cauliflower, broccoli

Tuber – potato

Classification

Classification

Classified by edible portion:

Fruit – cucumber, tomato, squash

Leaf – cabbage, lettuce, spinach

Petiole – celery

Seed – beans, pumpkin seed

Classification

Classified by:

Adaptation and hardiness

Life Cycle

Parts used for food

Taxonomic grouping

(for Monday)