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
AAAAAABABAAAAAAA AAAAAAAAAAAAAAAA ABACAAAAAACBAAAA AAAAAAAAAAAAAABA AAAABAAAAAAAAAAA AAAAAAAAAAAAAAAA AAAAACAABAAAAACA ABAAAAAAAAAAAAAA AAAABAAAAAABAAAA AAAAAAAAAAAAAAAA AAAAAAAABAAAAAAA AAAAAAAAAAAAAAAA AACAAABAAAAAAABA AAAAAAAAAAABAAAA AAAAAAAAABAAAAAA AAAAAAAAAAAAAAAC Gen. Diversity – Cultivar/Selection Genotypes of population – mostly A, some B and C
B B B C CB 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
AAHAICB AB AILCMHI DCDMDBLCJBDBDADC ABACAIMDKIAIMBAD EIELDFCMLFDFEIEA MDADBADEILBMADFE DAMAFDFGMCFIDLMJ AKDEJCGGBCJCFCDG KBAIDA AEAADAMBAJ FJDCBGLMJGBGFJDM AFJDGCJKEIG AJFJK MKAGAHMLBHLHLKLL DDGCDIFGFCDEDDGG JACHJJB AKJDJEICH GLKAMKKDCKMKGLMD FMIKDLCBDLDLIMKB HADAJIDC ABJDHADC Genotypes of population – A to M Gen. Diversity – Natural/No selection
HICBBILCMHI DCDMDBLCJBDBDDC BCIMDKIIMBD EIELDFCMLFDFEIE MDDBDEILBMDFE DMFDFGMCFIDLMJ KDEJCGGBCJCFCDG KBIDE DMBJ FJDCBGLMJGBGFJDM FJDGCJKEIGJFJK MKGHMLBHLHLKLL DDGCDIFGFCDEDDGG JCHJJBKJDJEICH GLKMKKDCKMKGLMD FMIKDLCBDLDLIMKB HDJIDCBJDHDC A is susceptible to a biotic or abiotic stress
Wildflower Seed Production Floridawildflowers.com
Minimal weeds Maximizes yield Maintains genetic diversity Landscape Fabric System
Seed Harvesting Vacuuming
Genetics
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 loci Relatively fast More accurate interpretation of population diversity DNA Markers and Diversity
PCA Results Phenotypes 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. leavenworthiiC. 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 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 Weed Science 49: Coreopsis after-ripening study or 90 o F - 33% RH, except 23% RH for C. lanceolata Then 24 weeks in commercial, cool storage unit - 23% RH and o F Seed Dormancy
cotyledon pericarp testa endosperm Coreopsis floridana
Coreopsis basalis AR – 59 o F, 33% RH Results for seeds AR 12 wk, stored o F, 23% RH AR – 90 o F, 33% RH
Coreopsis floridana AR – 59 o F, 33% RH Results for seeds AR 2 wk, stored o F, 23% RH AR – 90 o F, 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 **
Coreopsis lanceolata AR – 59 o F, 23% RH Results for seeds AR 24 wk, stored o F, 23% RH AR – 90 o F, 23% RH
Coreopsis leavenworthii AR – 59 o F, 33% RHAR – 90 o F, 33% RH Results for seeds AR 12 wk, stored o F, 23% RH
Coreopsis after-ripening study C. basalis - AR at 59 and 90 o F; viability maintained C. lanceolata - best AR after wk of cool temps. - maybe AR at 90 o F for 24+ wk - viability maintained C. floridana - slight AR but store cold/dry or lose viability C. leavenworthii - 90 o F increases germ but slight loss in viability Seed Dormancy
Cool, dry environment temp. + RH 100 ex.: 35 o F, 40% RH = 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 300 Carpinteria, CA (805) Mid-West Seed Services, Inc nd Avenue Brookings, South Dakota (877)
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