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Native Forb Seed Production in Florida Genetics / 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.
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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
Gen. Diversity – Cultivar/Selection Genotypes of population – mostly ‘A’, some ‘B’ and ‘C’
Gen. Diversity – Cultivar/Selection ‘A’ is susceptible to a biotic or abiotic stress
Gen. Diversity – Natural/No selection Genotypes of population – ‘A’ to ‘M’
Gen. Diversity – Natural/No selection A’ is susceptible to a biotic or abiotic stress
Wildflower Seed Production Floridawildflowers.com
Landscape Fabric System • Minimal weeds • Maximizes yield • Maintains genetic diversity
Seed Harvesting Vacuuming
Coreopsis leavenworthii Prod. Pops.
Leaf type Growth habit Plant survival through winter Days to bloom Flower color Flower size Phenotypic Diversity
DNA Markers and 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 loci Relatively fast • More accurate interpretation of population diversity
PCA Results Phenotypes Production and Natural C. Fla. Populations Genotypes
Production Populations • 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
C. leavenworthii C. tinctoria
C. leavenworthii and C. tinctoria • Can hybridize • C. leavenworthii is narrowly endemic • C. tinctoria is present in much of the US but only 6 Florida counties Escambia, Lake, Highlands, Miami-Dade,Madison and Leon counties • C. tinctoria present in 3 of the same counties as C. leavenworthii Lake, Highlands, Miami-Dade
Morphological Markers C. tinctoria and hybrids have red spot. Hybrid C. tinctoria has trichomes on leaf petiole. Hybrids too?
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 - Importance • Germination and emergence- weed interference- erosion • Sustainability- seed bank reserves
Seed Dormancy • 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
testa cotyledon pericarp endosperm Coreopsis floridana
Coreopsis basalis AR – 59oF, 33% RH AR – 90oF, 33% RH Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH
Coreopsis floridana AR – 59oF, 33% RH AR – 90oF, 33% RH * ** Results for seeds AR 2 wk, stored 24 wk @ 63-66oF, 23% RH *72% for seeds AR 24 wk, and then stored 24 wk **75% for seeds AR 24 wk, and then stored for 24 wk
Coreopsis lanceolata AR – 59oF, 23% RH AR – 90oF, 23% RH Results for seeds AR 24 wk,stored 24 wk @ 63-66oF, 23% RH
Coreopsis leavenworthii AR – 59oF, 33% RH AR – 90oF, 33% RH Results for seeds AR 12 wk,stored 24 wk @ 63-66oF, 23% RH
Seed Dormancy 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 Storage • 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
Labs Specializing in Testing Seed of Native Species Ransom Seed Laboratory, Inc.PO Box 300Carpinteria, CA 93014-0300(805) 684-3427Ransomsl@silcom.comhttp://www.ransomseedlab.com Mid-West Seed Services, Inc.236 32nd AvenueBrookings, South Dakota 57006(877) 692-7611info@mwseed.comhttp://www.mwseed.com
Phenotypic Diversity – Natural Populations • 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 – Production Populations • Extremely uniform • Very similar to a natural pop. from central Fla. • Almost upright • Correlation analysis • Leaf, flower, and origin were highly correlated