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Native ForbSeed Production in FloridaGenetics / Seed Dormancy
Dave Czarnecki II, Zhanao Deng, Jeffrey G. Norcini*, Sarah Smith, Fred Gmitter, and M. Nageswara Rao
Plant Material
What matters?
Sustainability• Seed / plant origin (ecotype)• ↑ Genetic diversity : ↑ sustainability
A A A A A A B A B A A A A A A A
A A A A A A A A A A A A A A A A
A B A C A A A A A A C B A A A A
A A A A A A A A A A A A A A B A
A A A A B A A A A A A A A A A A
A A A A A A A A A A A A A A A A
A A A A A C A A B A A A A A C A
A B A A A A A A A A A A A A A A
A A A A B A A A A A A B A A A A
A A A A A A A A A A A A A A A A
A A A A A A A A B A A A A A A A
A A A A A A A A A A A A A A A A
A A C A A A B A A A A A A A B A
A A A A A A A A A A A B A A A A
A A A A A A A A A B A A A A A A
A A A A A A A A A A A A A A A C
Gen. Diversity – Cultivar/Selection
Genotypes of population – mostly ‘A’, some ‘B’ and ‘C’
B B
B C C B
B
B
C B C
B
B B
B
C B B
B
B
C
Gen. Diversity – Cultivar/Selection
‘A’ is susceptible to a biotic or abiotic stress
A A H A I C B A B A I L C M H I
D C D M D B L C J B D B D A D C
A B A C A I M D K I A I M B A D
E I E L D F C M L F D F E I E A
M D A D B A D E I L B M A D F E
D A M A F D F G M C F I D L M J
A K D E J C G G B C J C F C D G
K B A I D A A E A A D A M B A J
F J D C B G L M J G B G F J D M
A F J D G C J K E I G A J F J K
M K A G A H M L B H L H L K L L
D D G C D I F G F C D E D D G G
J A C H J J B A K J D J E I C H
G L K A M K K D C K M K G L M D
F M I K D L C B D L D L I M K B
H A D A J I D C A B J D H A D C
Genotypes of population – ‘A’ to ‘M’
Gen. Diversity – Natural/No selection
H I C B B I L C M H I
D C D M D B L C J B D B D D C
B C I M D K I I M B D
E I E L D F C M L F D F E I E
M D D B D E I L B M D F E
D M F D F G M C F I D L M J
K D E J C G G B C J C F C D G
K B I D E D M B J
F J D C B G L M J G B G F J D M
F J D G C J K E I G J F J K
M K G H M L B H L H L K L L
D D G C D I F G F C D E D D G G
J C H J J B K J D J E I C H
G L K M K K D C K M K G L M D
F M I K D L C B D L D L I M K B
H D J I D C B J D H D C
Gen. Diversity – Natural/No selection
A’ is susceptible to a biotic or abiotic stress
http://edis.ifas.ufl.edu/ep297
Wildflower Seed Production
Floridawildflowers.com
• Minimal weeds
• Maximizes yield
• Maintains genetic diversity
Landscape Fabric System
Seed HarvestingVacuuming
Genetics
Coreopsis leavenworthii
Coreopsis leavenworthii
Prod. Pops.
• Leaf type• Growth habit• Plant survival through winter
• Days to bloom• Flower color• Flower size
Phenotypic Diversity
Molecular Diversity – advantages• Insensitive to environmental
changes• Many data points generated
246 plants X 320 loci = 78,720 vs.1,476 (Morphology)
• Screen large number of lociRelatively fast
• More accurate interpretation of population diversity
DNA Markers and Diversity
PCA ResultsPhenotypes
Production and Natural C. Fla.
Populations
Genotypes
• Maintained identity even at locations distant from origin
Also, noted that:• High level of diversity within populations• Low level of diversity among populations
Possible to produce highly diverse seed in locations other than the area of origin
Production Populations
C. leavenworthii C. tinctoria
• Can hybridize • C. leavenworthii is narrowly endemic• C. tinctoria is present in much of the US
but only 6 Florida countiesEscambia, Lake, Highlands, Miami-Dade,Madison and Leon counties
• C. tinctoria present in 3 of the same counties as C. leavenworthiiLake, Highlands, Miami-Dade
C. leavenworthii and C. tinctoria
C. tinctoria has trichomes on leaf petiole. Hybrids too?
Morphological Markers
C. tinctoria and hybrids have red spot.
Hybrid
One of the three field blocks for study of natural gene flow from C. tinctoria to C. leavenworthii. Seeds were being collected from one of the 27 pollen trap plots.
Seed Dormancy
• Germination and emergence- weed interference- erosion
• Sustainability- seed bank reserves
Seed Dormancy - Importance
• Seed origin (genetics)• Harvest season (environment)
- temp., light, water, nutrition• Storage conditions
Seed Dormancy
After-ripening to break dormancy
“Afterripening is loss of the dormant state over some period of time through exposure of the seeds to a set of environ-mental conditions after maturation and separation from the parent plant.” Foley, M.E. 2001. Weed Science 49:305-317
Coreopsis after-ripening study• 1-24 weeks @ 59 or 90oF - 33% RH, except 23% RH for C. lanceolata• Then 24 weeks in commercial, cool storage unit - 23% RH and 63-66oF
Seed Dormancy
cotyledon
pericarp
testa
endosperm
Coreopsis floridana
0
20
40
60
80
100FreshARStored
Coreopsis basalis
0
20
40
60
80
100FreshARStored
AR – 59oF, 33% RH
Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH
AR – 90oF, 33% RH
0
20
40
60
80
100FreshARStored
Coreopsis floridana
0
20
40
60
80
100FreshARStored
AR – 59oF, 33% RH
Results for seeds AR 2 wk, stored 24 wk @ 63-66oF, 23% RH
AR – 90oF, 33% RH
*72% for seeds AR 24 wk, and then stored 24 wk
*
**75% for seeds AR 24 wk, and then stored for 24 wk
**
0
20
40
60
80
100InitialFreshStored
Coreopsis lanceolata
0
20
40
60
80
100FreshARStored
AR – 59oF, 23% RH
Results for seeds AR 24 wk,stored 24 wk @ 63-66oF, 23% RH
AR – 90oF, 23% RH
0
20
40
60
80
100FreshARStored
Coreopsis leavenworthii
0
20
40
60
80
100FreshARStored
AR – 59oF, 33% RH AR – 90oF, 33% RH
Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH
Coreopsis after-ripening study• C. basalis - AR at 59 and 90oF; viability maintained• C. lanceolata - best AR after 25-48 wk of cool temps. - maybe AR at 90oF for 24+ wk - viability maintained• C. floridana - slight AR but store cold/dry or lose viability• C. leavenworthii - 90oF increases germ but slight loss in viability
Seed Dormancy
• Cool, dry environment
temp. + RH 100
ex.: 35oF, 40% RH 35+40 = 75 (best is RH < 50%, and total < 75)
*** As temp. ↓ RH ↑ *** (must cool AND dehumidify air)
• Protect against insects and rodents
Seed Storage
Labs Specializing in Testing Seed of Native Species
Ransom Seed Laboratory, Inc.PO Box 300Carpinteria, CA 93014-0300(805) [email protected]://www.ransomseedlab.com
Mid-West Seed Services, Inc.236 32nd AvenueBrookings, South Dakota 57006(877) [email protected]://www.mwseed.com
• Leaf Type• North: most complex• Central: moderately complex• South: most simple
• Growth Habit• North, CP1, and C2: mostly all upright• C3: mostly semi-upright or decumbent• S1: almost entirely semi-upright or decumbent
• Plant Survival• Little differentiation among populations
• Days to Bloom• North: most days to bloom• South: fewest days to bloom
• Flower Color and Size• Possible gradient of size and color from north to south
Phenotypic Diversity – Natural Populations
• Extremely uniform • Very similar to a natural
pop. from central Fla.• Almost upright• Correlation analysis
• Leaf, flower, and origin were highly correlated
Phenotypic Diversity – Production Populations