102 Microorganisms as plant pathogens > Lecture 3 > Flashcards

Lecture 3 Flashcards

Aim: To understand the impact and importance of viral plant pathogens - 3x viruses: Tulip breaking virus GVLRaV-3 Papaya ringspot virus - fungus: South American Leaf Blight S.A.L.B (67 cards)

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1
Q

What is tulipomania

A
  • in Netherlands
  • early 1600s
  • unusual variegated color patterns of flowers, especially on tulips, were highly coveted
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2
Q

At the height of trading tulips (1634-1637) how much did a single, rare tulip bulb cots

A

4500 guilders ($2500 USD) plus a horse and a carriage

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3
Q

Why did the Tulip crash occur in 1632

A
  • due to transmissible virus via tuber grafts

called Tulip breaking virus (which caused the unique colors in the tulips)

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4
Q

How is the Tulip breaking virus spread

A

aphid transmitted virus

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5
Q

What genus does the Tulip breaking virus belong to

A

Potyvirus

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6
Q

What is the Leafroll disease (virus)

A
  • one of the most important diseases infecting vineyards throughout the world
  • GVLRav-3
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7
Q

What are the symptoms of Leafroll disease (GVLRav-3)

A
  • leaves change color (mottled red)
  • reduced yield
  • reduced fruit quality
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8
Q

How does leafroll disease affect the NZ wine industry (GVLRaV-3)

A

eg. Sauvignon blanc vines potential $58000 NZD per hectare
- infected vines also show reduced yield and fruit quality with lower sugar and acid levels which affects the flavor of the wine

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9
Q

How was it initially thought that GVLRaV-3 was spread

A
  • infected cuttings
  • scion buds
  • rootstock
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10
Q

What have we discovered that spreads the GVLRaV-3 disease

A

spreads within vineyards by mealy bugs

- genus Pseudococcus

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11
Q

How is GVLRaV-3 controlled

A
  • cannot be eliminated from plants in the field
  • propagation wood should be collected from vines that are free of leafroll (tested by ELISA or PCR)
  • control of mealy bugs to limit spread
  • vines are inspected for symptoms late in the growing season and infected vines removed
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12
Q

What is the Papaya ringspot virus (PRSV) caused by

A
  • virus disease
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13
Q

true or false; Papaya ringspot virus is the most serious papaya disease

A

true

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14
Q

What was the crop that Hawaii exported to mainland US and Japan

A
  • papaya
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15
Q

When was the production of Papaya eliminated in Oahu because of the virus

A

1940s-1950s

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16
Q

Where was papaya production relocated

A
  • Big Island, Hilo in the 1960s (but virus found again)
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17
Q

What are the transgenic papaya made up of

A
  • two hawaiian cultivars were transformed with the coat protein gene of PRSV
  • research 1980s
  • GM cultivars are now used commercially
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18
Q

What were the two cultivars that PRSV resistant papaya was transformed with

A

SunUp
Rainbow
- Denis Gonsalves
-University of Hawaii

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19
Q

How is PRSV transmitted

A

aphids, mechanical transmission

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20
Q

What did the mayans use rubber for

A

ball games and religious artifacts

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21
Q

Which country began to import rubber and when

A

Portugal

1700s

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22
Q

What is Microcyclus -S.A.L.B

A

fungus

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23
Q

Where do best quality latex come from

A

hevea spp

H. brasiliensis

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24
Q

What hindered the rubber production in South America

A

Ascomycete fungus

Microcyclus (Dothidella ulei)

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25
What is the scientific name for Microcyclus ulei (S.A.L.B)
Dothidella ulei
26
What does S.A.L.B stand for
South American Leaf Blight
27
How does S.A.L.B infect the plants
- from initial infection a few days produces enough conidia to infect: - all the young developing leaves on a tree
28
How is S.A.L.B prevented
by planting trees between crops | - in S.America 500M trees survived free from epidemics
29
Who is Charles Goodyear
the man that added sulphur in the process of making rubber (25 years of work) - increased the demand for rubber goods
30
What arrived in the US in 1820
rubber boots (1820)
31
What was rubber used for in the US in 1830s
life preservers, coats, shoes
32
What was the downfall of rubber in the 1830s
it rotted in the summer heat and became brittle when cold
33
Who was H.M Stanley
1876-1877 - explored the Congo Basin - created great interest in Africa
34
How much rubber in the 1860 did US import
300 tons p.a | - (bicycle, cars, rubber tires)
35
Where is rubber obtained from in Africa
Landolphia vines
36
How is rubber collected from Landolphia vines
- pulled down from trees | - notches cut to start latex flow
37
How is reddish power (Latex) collected in Congo
Underground rhizomes - remove bark - pound - release reddish powder
38
What did King Leopold 2 of Belgium asked Stanley to do
to set up trading posts with concessions from local chiefs
39
How did Leopold become the richest man in Europe
from rubber
40
true or false; Plantations are not possible in the Amazon because of S.A.L.B
true
41
How was rubber collected in the Amazon
- collecting from single isolated trees (2kgs/tree p.a)
42
How did the traders trick the S.A indians to slavery
- traders offered cheap trade goods to gather rubber - traders provided food - Indians got further and further into debt and found themselves indentured for life, and living in misery
43
What do you call the traders that became rich from rubber
Rubber Barons
44
true or false; the S.A Indians that ran away were killed if they tried to escape
true
45
true or false; gangs of thugs were sent to tribal villages (S. America) to round up people who were forced into slavery and killed if they tried to escape
true
46
true or false; in Congo, Leopold hired his own private army, and tricked local chiefs into singing treaties handing over their powers
true
47
how many days does every able bodied man have to work in Congo to collect rubber under the supervision of the army
7 days | sunrise to dark
48
How did the workers in Congo die
- exhaustion - starvation - millions died from sleeping sickness, smallpox, etc
49
Who investigated the Congo incident in the 1900s (1903)
Sir Roger Casement
50
true or false; from 1890-1908 the population of Congo dropped from 25M to 10M
true
51
How much did 1 human life equal to (rubber)
4kg of rubber
52
Who is Sir Henry Wickham
- a British Planter | - smuggled H.brasiliensis out of Brazil to Kew Gardens in London
53
Where were the germinated seedlings sent to (germinated in Kew Gardens in London)
Ceylon and Malay Peninsular(1881) and java | - where there was no S.A.L.B
54
What was the significance of what Sir Henry Wickhams act
ended the wild rubber collection and associated slavery and death in the Amazon and Congo
55
What company did Ford try to set up in South America in 1927
Fordlandia - (1834) planted > 8000 acres of rubber trees, but before the last tree was planted the first were already dying from SALB - project failed
56
true or false; allies were dependent of rubber supplies from S.E Asia
true
57
true or false by 1942 Japanese controlled most of the rubber growing areas that usually supplied Europe and USA
true
58
How many people died supplying 20 000 tons of rubber; that the US recruited in Brazil to collect wild rubber
from the 18000 recruited, 17000 died
59
What are the disease caused by viruses in plants (in todays lecture)
Tulip breaking virus GVLRaV-3 (grape industry) aka leafroll disease papaya ring spot virus PRSV
60
What is the fungus discussed in todays lecture
S.A.L.B (South American lead blight) aka: Microcyclus ueli (Dothidella ulei)
61
true or false; Charles Goodyear added sulphur to rubber products, producing the first bicycle and car tyres with increased durability in both heat and cold
true
62
Where was PRSV first discovered and when
Oahu Island | 1940s
63
true or false; Papaya is the second largest food crop in Hawaii; exported to USA and Japan
true
64
What transfers PRSV
aphids
65
What is virus spread reliant on
- pre-infected propagating material (seed, tubers, cuttings, etc.) - vector transmission (insects, nematodes, fungi, humans)
66
What are the common symptoms of virus infection in plants
yellowing mosaics mottles growth distortion
67
true or false; viruses reduce plant vigor and crop yield but most do not kill their plant hosts
true
102 Microorganisms as plant pathogens
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