Plant Pathogens and Immunity Flashcards
1
Q
coconut cadang-cadang viroid
A
- 247nucelotides sense/antisense circularRNA
- rolling circle
- coconut and African oil palm
- pollen vector
- 1927
- 0.5km/year
- 30 million coconut deaths in the Philippines
- no treatment
2
Q
papaya ringspot virus
A
- sense ssRNA potyvirus
- the papaya and cucurbins (such as cucumber and watermelon)
- 1950s: 94% loss
- RNAi transgenic breeding
3
Q
olive tree quick dieback, Xyello fastias
A
- aerobic Gram negative bacteria
- 500 woody and herbaceous hosts, some of which are grapevines, olive trees and citrus trees of more than 500 years old
- 2015
- xylem feeding insects
- some trees are asymptomatic
4
Q
Magnaporthe oryzae
A
- rice
- 10-35% losses
- fungicide use and resistance breeding
- appressorium punching pores into epithelia via hyphal injection
5
Q
Dutch elm disease
A
- Ulmus minor
- 1970, it has caused close to 100% wilting and branch collapse
- bark beetle
- immunopathological xylem blocking
- vector eradication, good sanitation and resistance breeding
6
Q
Ash dieback, Hymenoscyphus fraxineus
A
- Fraxineus ornus
- 1972 in poland, 2012 in the UK
- when infected, young trees die quickly, and older trees more slowly
- sexual stage on the leaf debris.
7
Q
black sigatoka, Mycosphaerella firensis
A
- banana crops
- 1972, causing 50% losses
- natural evolutionary resistance, sanitation and heavy fungicide use, which takes up 5-50% of the selling cost.
8
Q
Fusorium oxysporum
A
- tomatoes, melons, bananas and palm
- horizontal chromosomal exchange once per host
- previously caused an epidemic of coffee wilt disease
- heavy fungicide usage and resistance breeding
- xylematic immunopathology
9
Q
wheat stem rust Puccinia graminis
A
- infect stem tissue
- treated with fungicides and with resistance breeding, such as in the Green Revolution by Normal Borlaug
- Uganda-99 strain
10
Q
downey grape mildew
A
- Vitis viticola
- close to 100% crop losses
- “fungi”-cides, good sanitation and resistance breeding.
11
Q
potato late blight, Phytophthora infestans
A
- “crop destroyer”
- potatoes, tomatoes, and Solanaceae
- P. infestans was the cause of the 1845-1851 An Gorta Mor (Irish Potato famine), which caused one million to die of starvation, and another million to emigrate to the US
- good hygiene, resistance breeding and “fungi”cide biweekly application.
12
Q
sudden oak/larch death
A
- oak, larch, rhododendron, beech, chestnut and birch
- horizontal gene transfer from larch in 2009, Phytophthora ramorum is spreading across the UK
- resistance breeding and removal
13
Q
Erysiphe gram inis on wheat
A
“green islands” extend host lifespan
14
Q
Puccinia Monoica on Arabis
A
zoophilous pseudo flowers
15
Q
Gibberella fujikorei on rice
A
foolish seedlings spread spores by wind
