capsicum phylogeny and domestication
DESCRIPTION
Capsicum Phylogeny and Domestication. Brian Walsh. Family: Solanaceae Subfamily:Solanoideae Tribe:Capsicinae (since 1999). Estimated 25 species (my count =37) Native to South and Central America Current distribution is global One of the most utilized spice in the world - PowerPoint PPT PresentationTRANSCRIPT
CapsicumPhylogeny and Domestication
Brian Walsh
Family: Solanaceae
Subfamily: Solanoideae
Tribe: Capsicinae (since 1999)•Estimated 25 species (my count =37)
•Native to South and Central America
•Current distribution is global
•One of the most utilized spice in the world
•Part of human diet for 9000 years
•All diploid
•Typically self-fertilize
•Most n=12 (some n=13)
One of the most diversely utilized plants
• Spice• Food• Dye• Medicine• Weapons• Poison• Drinks• Deterrent• Insecticide/Pesticide• Preservative• Snuff
• Rituals• Tribute• Town Names• Punishment
Domestication
•Davenport (1970) proposes all five domesticated species arose from a single ancestor (C. frutescens L.) (Lumper) (based on morphology)
•Heiser (1971) proposes each domesticated species arose from its own unique wild ancestor (Splitter) (hybridization studies)
Pickersgill (1972) agrees with Heiser - different cultivated species show a combination of characters suggesting domestication by different groups of people living in different areas.
•Eshbaugh (1983) argues at least three distinct domesticated lineages based on morphology, plant breeding and enzyme analysis (C. chacoense is plesiomorphic)
View from 1000000 km above 5°18’S 63°55’W
Agricultural Centers of the New World and the theoretical flow of speciation
Based on C. chacoense
Domesticated Characters in Capsicum
• Gigantism of fruit• Altered fruit shape• Fruit color other
than red• Retained on
peduncle a maturity• Variable capsaicin
levels
• small fruit• Fruit round• Red fruit
• Peduncle dehiscence at maturity
• High capsaicin levels
Domesticated Wild
Capsicum annuum
Capsicum annuum complex
C. annuum var. annuum
C. annuum var. avicular
C. frutescens
C. chinense
C. chacoense
Capsicum baccatum group
C. baccatum var. praetermissum
C. baccatum var. pendulum
C. baccatum var. baccatum
Capsicum eximium complex
C. pubescens
C. eximium
C. cardenasii
white flowers
white flowers with yellow spots
purple flowers
Total species=8
Eshbaugh’s breakdown into flower color categories (why?)
Tabasco
C. frutescens
C. baccatum var. praetermissum
Capsicum eximium
Capsicum eximium
C. baccatum var. praetermissum
Capsicum cardenasii
Only species that strictly outcrosses
Flower color classification of Capsicum
•Color categories inaccurate (too many exceptions)
•Only a fraction of total species included
•Doesn’t agree with molecular data
Current phylogenetic questions
• Monophyly of genus
• Resolving species relationships
Capsicum Monophyletic?
Modified from Bohs & Olmstead 1997
A B C
A A C
A B C
=
Monophyletic
A A C
=
Not Monophyletic
Walsh 2001
(chloroplast atpB-rbcL spacer data)
Walsh 2001
(chloroplast atpB-rbcL spacer data)
n=12/13
Walsh 2001
combined atpB-rbcL spacer and waxy data
Walsh 2001
(chloroplast atpB-rbcL spacer data)
Capsicum monophyly
• Intact for the time being
• Odd C. ciliatum seems to be the weak link
(n=13)
Mascone’s missing treeMascone 2003
Flow cytometry and Feulgen densitometry
1C-value of DNA = an equation for calculating genome size in absolute units
Genome size in Mbp
Capsicum anuum complex
C. annuum var. annuum
C. annuum var. avicular
C. frutescens
C. chinense
C. chacoense
white flowers
United by similar DNA amount and little heterochromatin
Visualization of Mascone’s results
C. annuum var. annuum
C. frutescens
C. chinense
C. chacoense
1C G
3.35 3273
3.38 3312
3.40 3332
3.42 3352
Capsicum baccatum group
C. baccatum var. praetermissum
C. baccatum var. pendulum
C. baccatum var. baccatum
white flowers with yellow spots
Similar DNA amounts – not surprising
C. baccatum var. umbilicatum New variety described in 1998
Domesticated status unknown
C. baccatum var. pendulum
C. baccatum var. baccatum
C. baccatum var. umbilicatum
Interpreted from data – not explicitly stated
C. annuum var. annuum
C. frutescens
C. chinense
C. chacoense
1C G
3.35 3273
3.38 3312
3.40 3332
3.42 3352
3.69 3621
3.71 3636
3.76 3636
Capsicum eximium complex
C. pubescens
C. eximium
C. cardenasii
purple flowers
C. eximium has DNA content intermediate between C. baccatum and C. pubescens, but genome size supports close relationship to C. pubescens as well as isozyme and cross studies
C. parvifolium synonym with C. cardenasii? (but description is off – tree?)
C. parvifolium only compared to C. campylopodium
C. campylopodium groups with C. pubescens – large genome size, and large amounts of heterochromatin forming complex patterns (tone implies trepidation)
points out distantly related and nothing more
C. baccatum var. pendulum
C. baccatum var. baccatum
C. baccatum var. umbilicatum
C. pubescens
C. eximium
C. parvifolium/cardenasii
C. campylopodium
?
?
C. annuum var. annuum
C. frutescens
C. chinense
C. chacoense
1C G
3.35 3273
3.38 3312
3.40 3332
3.42 3352
3.69 3621
3.71 3636
3.76 3636
4.06 3979
4.47 4381
5.14 5032
5.77 5655
However, Mascone claims his data supports his hypothesis
• Increase in DNA amount is evolutionary advancement
• C. chacoense most plesiomorphic (ancestral)• C. campylopodium most advanced• n=13 in more recently evolved
C. baccatum var. pendulum
C. baccatum var. baccatum
C. baccatum var. umbilicatum
C. pubescens
C. eximium
C. parvifolium/cardenasii
C. campylopodium
?
Mascone tree rooted
Least DNA
Most DNA x=13
C. annuum var. annuum
C. frutescens
C. chinense
C. chacoense
C. baccatum var. pendulum
C. baccatum var. baccatum
C. baccatum var. umbilicatum
C. pubescens
C. eximium
C. parvifolium/cardenasii
C. campylopodium
?
Mascone
Least DNA
Most DNA x=13
C. annuum var. annuum
C. frutescens
C. chinense
C. chacoense
?
ancestral
molecular
X=13 species• C. ciliatum• C. buforum• C. campylopodium• C. cornutum• C. schottianum• C. villosum• C. pereirae *• C. friburguense *• 3 unnamed Capsicum
Capsicum flexuosum
n = 13
n = 12
•Capsicum needs more research
•Appears to be an x=12/x=13 split in distant past
•research hindered by incomplete sampling
•Difficult to study domestication when phylogeny unresolved
•6 new species identified in last 8 years
Conclusion
Naga Morich
Following Photos unused in presentation
Cherrapeño
Bolivian rainbow
Cherry Pepper
Chilaca Fluorescent
Fredrik from Amalfi
Jalapeño - Biker Billy
Lemon black pepper
Little nubian
O'odham Indian Piquin
Peter Pepper Pimenta-Doce
Poblano Suryamukhi
Tepin Variegata
Naga Jolokia / Tezpur
C. Frutescens
Tabasco PI451762
Antillerna (Paris)
C. chinense
C02466
Capsicum galapagoense
PI560944 - Putapario
C. chacoense
C. Pubescens
praetermissum
Capsicum eximium
C. ciliatum
Capsicum Cardenasii
C. tovarii