Crop Evolution II

Question 1

What is shattering?

Answer 1

Natural shedding of seeds.

Question 2

What is tillering?

Answer 2

Production of side shoots.

Question 3

What has maize evolved from?

Answer 3

Teosinte

Question 4

How has maize evolved and what are the benefits?

Answer 4

• Larger ears
• Reduced shattering and tillering
  ^ both led to increased yield and easier to farm
• Reduced fruit casing - Easier to eat

Question 5

What led to naked kernels in maize?

Answer 5

Amino acid substitution in tga1.

Question 6

What are the diploid progenitors of wheat?

Answer 6

• Einkorn (AA): Hulled wheat, very resistant
• Durum (AABB): Free threshing, very hard grains
• Emmer (AABB): Hulled, hard grain
• Bread (AABBDD): Free threshing, soft grain, increased grain size, delayed senescence, reduced tillering

Question 7

What is free threshing?

Answer 7

The seeds separate cleanly from the chaff during the threshing process.

Question 8

What is different about dwarf Arabidopsis?

Answer 8

Makes too much gibberellic acid

Question 9

What is different about dwarf rice and peas?

Answer 9

Insensitive to GA

Question 10

What is different about dwarf wheat?

Answer 10

Does not make enough gibberellic acid

Question 11

How has rice evolved to become a domesticated plant?

Answer 11

• Reduced shattering: by mutation in abscisic layer
• Reduced awn length: deletion in LABA1, makes processing easier

Question 12

What do rice awns do?

Answer 12

Aid seed dispersal and protection.