Starchy Plants

Question 1

Why do we eat/ use different plant parts?

Answer 1

Nutritional value
Easy to store
Propagation and trade 
May grow well in dry environments 
Less maintenance

Question 2

Monocultures

Answer 2

Asexual propagation = lack of crop diversity threatens food security

Question 3

Edible plant roots

Answer 3

Most of the roots plants has high in nutrients, water content, not much starch.

Only cassava, sweet potato, true yam have starchy roots.

Question 4

Several stable / Food Crops

Answer 4

Major raw material for industrial starch
Most widespread energy store in plants 
Linear polymer glucose units
Most common CHO in human diet 
Store in several plant organs

Question 5

Euphorbiaceae (Milkweed family)

Answer 5

Manihot esculenta
(Cassava, Manihot, Yucca, Tapioca)

Intercropped with vegetables

Good crop to plants on poor soils: drought resistant

Third most important source of calories

Question 6

Origin of Euphorbiaceae

Answer 6

South America Native (Peru at 4,000)

Africa - via slave trade

Marginal Lands

Storability

Question 7

The Cassava Belt

Answer 7

Low Latitudes 30N & S

Question 8

Cassava’s Caloric and Nutrition Ratios

Ethnomedicial Uses

Answer 8

Root: Diarrhea, malaria

Leaves: Hypertension, headache

Question 9

Ipomoea batatas (Sweet potato, “yam - not true yam”)

Answer 9

Convolvulaceae - only family crop

Central America to Soup America Anders at 8000 to 10000 BC, cultivated species - hybridization

Vine plants. Roots have two parts: Storage roots to make the sweet potato, pencil roots to absorb water

Question 10

C. Columbus (1492) –> Europe

Answer 10

Tropical and Subtropical - China and India - primary producers / consumers

Second vegetable crop after potato

Sweet Potato has the most edible energy and edible protein compared to cassava > potato >yam

Question 11

Sweet Potato

Answer 11

Tetra and Hexaploidy lines, > 40 cultivars: food and fed types

Vegetative propagation => shrink the genetic diversity

Question 12

Germplasm Collection

Answer 12

In situ vs. Ex situ

Question 13

Disocorea opposita

True WIld Yam

Answer 13

Vine, climbing, very vigour plants
South Africa
Starchy Tubers

Question 14

Pacyrrhus erosus (Jicama, Yambean) - Fabaceae

Answer 14

Mexico, Vine 4-5 m

High in carbohydrates - dietary fiber, less starch - mostly water (86-90%)

Question 15

Potato Origin

Answer 15

Archaeological Datawild potato 13000 years ago, cultivated potato 7000 years ago
Spanish adopted from Incas

European potato originated from a Chilean stock early in 1800s

Question 16

The Inca potato drink

Answer 16

Fermented potato drink: Chicha

Question 17

Other inca uses of potato

Answer 17

Raw Slices; healing broken bones
Carried to prevent rheumatism
Eaten with other food prevents indigestion

Question 18

Traditional vs Modern Method

Answer 18

Temperate countries and tropical uplands: 1st potato patches in N America established in 1719
Propagated by Seed Potato “eyes” facing up or sprouts facing up
Male sterility; not make seeds

Question 19

Problem Potato Blight

Answer 19

Potatoes affected by Phytophthora infestans

Affected by tubers, contaminated the soils by spores, mycellia

England Ireland (1800s)

Question 20

Introduced to Europe (potatoes)

Answer 20

Dependence on Potato
1500s
Risk of genetic uniformity monoculture
selection for disease resistance

Question 21

Irish Famine Disaster

Answer 21

1845-1849
Great Famine
Crop dependence from supplementary to based food to stable monoculture to loss of diversity

Environment + the pathogen development + susceptible non-disease resistant cultivars = Disease

Population drop ca 25 %

Disease emigration => 1.15 m death